Let’s also discuss the first, second, and third trimesters of pregnancy. What happens to the developing fetus and mother during each stage? How is nutrition involved in each trimester? First trimester

The first trimester of pregnancy is marked by an invisible — yet amazing — transformation. And it happens quickly. Hormones trigger your body to begin nourishing the baby even before tests and a physical exam can confirm the pregnancy. Knowing what physical and emotional changes to expect during the first trimester can help you face the months ahead with confidence. First trimester pregnancy: Your body Consider common physical changes during the first trimester of pregnancy.
Bouts of nausea Morning sickness, which can strike at any time of the day or night, sometimes begins as early as three weeks after conception. Nausea seems to stem at least in part from rapidly rising levels of estrogen and progesterone, which cause the stomach to empty more slowly. Pregnant women also have a heightened sense of smell, so various odors — such as foods cooking, perfume or cigarette smoke — might cause waves of nausea in early pregnancy.
To help relieve nausea, eat small, frequent meals throughout the day. Choose foods that are low in fat and easy to digest. It's also helpful to drink plenty of fluids. Avoid foods or smells that make your nausea worse. Try drinking ginger ale. For some women, motion sickness bands are helpful. For others, alternative therapies such as acupuncture or hypnosis offer relief. If you're considering an alternative therapy, get the OK from your health care provider first.
Contact your health care provider if the nausea is severe, you're passing only a small amount of urine or it's dark in color, you can't keep down liquids, you feel dizzy or faint when standing up, your heart is racing, or you vomit blood.
Tender, swollen breasts Soon after conception, hormonal changes might make your breasts tender, tingly or sore. Or your breasts might feel fuller and heavier. Wearing a more supportive bra or a sports bra might help.
Increased urination You might find yourself urinating more often than usual, especially at night. Pressure from your enlarging uterus on your bladder might cause you to leak urine when sneezing, coughing or laughing. To help prevent urinary tract infections, urinate whenever you feel the urge. If you're losing sleep due to middle-of-the-night bathroom trips, drink less in the evening — especially fluids containing caffeine, which can make you urinate more. If you're worried about leaking urine, panty liners can offer a sense of security.
Fatigue
Fatigue also ranks high among first trimester symptoms. During early pregnancy, levels of the hormone progesterone soar — which can put you to sleep. At the same time, lower blood sugar levels, lower blood pressure and increased blood production might team up to sap your energy. To combat fatigue, rest as much as you can. Make sure you're getting enough iron and protein. Include physical activity, such as a brisk walk, in your daily routine.
Food aversions or cravings When you're pregnant, you might find yourself turning up your nose at certain foods, such as coffee or fried foods. Food cravings are common, too. Like most other symptoms of pregnancy, these food preferences can be chalked up to hormonal changes — especially in the first trimester, when hormonal changes are the most dramatic.
Dizziness
Pregnancy causes your blood vessels to dilate and your blood pressure to drop, which might leave you lightheaded or dizzy. Stress, fatigue and hunger also may play a role. To prevent mild, occasional dizziness, avoid prolonged standing. Rise slowly after lying or sitting down. If you start to feel dizzy while you're driving, pull over. If you're standing when dizziness hits, sit or lie down.
Seek prompt care if the dizziness is severe and occurs with abdominal pain or vaginal bleeding. This could indicate an ectopic pregnancy — a condition in which the fertilized egg implants itself outside the uterus. To prevent life-threatening complications, the ectopic tissue must be removed.
Heartburn and constipation During first trimester pregnancy, the movements that push swallowed food from your esophagus into your stomach are slower. Your stomach also takes longer to empty. This slowdown gives nutrients more time to be absorbed into your bloodstream and reach your baby. Unfortunately, it can also lead to heartburn and constipation. To prevent heartburn, eat small, frequent meals and avoid fried foods, carbonated drinks, citrus fruits or juices, and spicy foods. To prevent or relieve constipation, include plenty of fiber in your diet and drink lots of fluids. Regular physical activity also helps.
First trimester pregnancy: Your emotions
Pregnancy might leave you feeling delighted, anxious, exhilarated and exhausted — sometimes all at once. Even if you're thrilled about being pregnant, a new baby adds emotional stress to your life. It's natural to worry about your baby's health, your adjustment to motherhood and the financial demands of raising a child. You might wonder how the baby will affect your relationship with your partner or what type of parent you'll be. If you're working, you might worry about your productivity on the job and how to balance the competing demands of family and career.
You might also experience misgivings and bouts of weepiness or mood swings. To cope with these emotions, remind yourself that what you're feeling is normal. Take good care of yourself, and look to your partner and other loved ones for understanding and encouragement. If the mood changes become severe or intense, consult your health care provider for additional support.
Your relationship with your partner
Becoming a mother takes time away from other roles and relationships. You might struggle to retain your psychological identity as a partner and lover — but good communication can help you keep intimacy alive. * Be honest. Let your partner know that you need support and tenderness, sometimes without sexual overtones. Identify the stress points in your relationship before they become problematic. * Be patient. Occasional misunderstandings and conflicts are inevitable. Consider both sides. If your partner dives into work, for example, you may feel hurt and rejected because it appears as a withdrawal from your relationship. Your partner, on the other hand, might simply be trying to provide more security for your family. * Be supportive. Encourage your partner to identify any doubts or worries. Do the same yourself. Discussing your feelings honestly and openly will strengthen your relationship and help you begin preparing a home for your baby.
Appointments with your health care provider
Whether you choose a family physician, obstetrician, nurse-midwife or other pregnancy specialist, your health care provider will treat, educate and reassure you throughout your pregnancy. He or she is there to help you celebrate the miracle of birth.
Your first visit will focus mainly on assessing your overall health, identifying any risk factors and determining your baby's gestational age. Your health care provider will ask detailed questions about your health history. Be honest. The answers you provide will help you and your baby receive the best care. If you're uncomfortable discussing your health history in front of your partner, schedule a private consultation.
Also expect to learn about first trimester screening for chromosomal abnormalities.
After the first visit, you'll probably be asked to schedule checkups every four to six weeks. During these appointments, raise any concerns or fears you might have about pregnancy, childbirth or life with a newborn. Remember, no question is silly or unimportant — and the answers can help you take the best care of yourself and your baby.
Fetal development: The first trimester
Fetal development begins soon after conception. Find out how your baby grows and develops during the first trimester.
By Mayo Clinic staff
You're pregnant. Congratulations! You'll undoubtedly spend the months ahead wondering how your baby is growing and developing. What does your baby look like? How big is he or she? When will you feel the first kick?
Fetal development typically follows a predictable course. Find out what happens during the first trimester by checking out this weekly calendar of events. Keep in mind that measurements are approximate.
Weeks 1 and 2: Getting ready
It might seem strange, but you're not actually pregnant the first week or two of the time allotted to your pregnancy. Yes, you read that correctly!
Conception typically occurs about two weeks after your period begins. To calculate your due date, your health care provider will count ahead 40 weeks from the start of your last period. This means your period is counted as part of your pregnancy — even though you weren't pregnant at the time.
Week 3: Fertilization

CLICK TO ENLARGE | Fertilization and implantation |

The sperm and egg unite in one of your fallopian tubes to form a one-celled entity called a zygote. If more than one egg is released and fertilized, you may have multiple zygotes.
The zygote has 46 chromosomes — 23 from you and 23 from your partner. These chromosomes will help determine your baby's sex, traits such as eye and hair color, and, to some extent, personality and intelligence.
Soon after fertilization, the zygote travels down the fallopian tube toward the uterus. At the same time, it will begin dividing rapidly to form a cluster of cells resembling a tiny raspberry. The inner group of cells will become the embryo. The outer group of cells will become the membranes that nourish and protect it.
Week 4: Implantation
By the time it reaches the uterus, the rapidly dividing ball of cells — now known as a blastocyst — has separated into two sections. The inner group of cells will become the embryo. The outer group of cells will become the membranes that nourish and protect it. On contact, it will burrow into the uterine wall for nourishment. This process is called implantation. The placenta, which will nourish your baby throughout the pregnancy, also begins to form.
Week 5: The embryonic period begins

CLICK TO ENLARGE | Fetal development three weeks after conception |

The fifth week of pregnancy, or the third week after conception, marks the beginning of the embryonic period. This is when the baby's brain, spinal cord, heart and other organs begin to form.
The embryo is now made of three layers. The top layer — the ectoderm — will give rise to your baby's outermost layer of skin, central and peripheral nervous systems, eyes, inner ear, and many connective tissues.
Your baby's heart and a primitive circulatory system will form in the middle layer of cells — the mesoderm. This layer of cells will also serve as the foundation for your baby's bones, muscles, kidneys and much of the reproductive system.
The inner layer of cells — the endoderm — will become a simple tube lined with mucous membranes. Your baby's lungs, intestines and bladder will develop here.
By the end of this week, your baby is likely about the size of the tip of a pen.
Week 6: The neural tube closes

CLICK TO ENLARGE | Fetal development four weeks after conception |

Growth is rapid this week. Just four weeks after conception, the neural tube along your baby's back is closing and your baby's heart is pumping blood.
Basic facial features will begin to appear, including passageways that will make up the inner ear and arches that will contribute to the jaw. Your baby's body begins to take on a C-shaped curvature. Small buds will soon become arms and legs.

Week 7: Baby's head develops

CLICK TO ENLARGE | Fetal development five weeks after conception |

Seven weeks into your pregnancy, or five weeks after conception, your baby's brain and face are rapidly developing. Tiny nostrils become visible, and the eye lenses begin to form. The arm buds that sprouted last week now take on the shape of paddles.
By the end of this week, your baby might be a little bigger than the top of a pencil eraser.
Week 8: Baby's eyes are visible

CLICK TO ENLARGE | Fetal development six weeks after conception |

Eight weeks into your pregnancy, or six weeks after conception, your baby's arms and legs are growing longer, and fingers have begun to form. The shell-shaped parts of your baby's ears also are forming, and your baby's eyes are visible. The upper lip and nose have formed. The trunk of your baby's body is beginning to straighten.
By the end of this week, your baby might be about 1/2 inch (11 to 14 millimeters) long.
Week 9: Baby's toes form

CLICK TO ENLARGE | Fetal development seven weeks after conception |

In the ninth week of pregnancy, or seven weeks after conception, your baby's arms grow, develop bones and bend at the elbows. Toes form, and your baby's eyelids and ears continue developing.
By the end of this week, your baby might be about 3/4 inch (18 to 22 millimeters) long.
Week 10: Baby's neck begins to develop

CLICK TO ENLARGE | Fetal development eight weeks after conception |

By the 10th week of pregnancy, or eight weeks after conception, your baby's head has become more round. The neck begins to develop, and your baby's eyelids begin to close to protect his or her developing eyes.
Week 11: Baby's genitals develop
At the beginning of the 11th week of pregnancy, or the ninth week after conception, your baby's head still makes up about half of its length. However, your baby's body is about to catch up, growing rapidly in the coming weeks.
Your baby is now officially described as a fetus. This week your baby's eyes are widely separated, the eyelids fused and the ears low set. Red blood cells are beginning to form in your baby's liver. By the end of this week, your baby's external genitalia will start developing into a penis or clitoris and labia majora.
By now your baby might measure about 2 inches (50 millimeters) long from crown to rump and weigh almost 1/3 ounce (8 grams).
Week 12: Baby's fingernails develop

CLICK TO ENLARGE | Fetal development 10 weeks after conception |

Twelve weeks into your pregnancy, or 10 weeks after conception, your baby is developing fingernails. Your baby's face now has a human profile.
By now your baby might be about 2 1/2 inches (61 millimeters) long from crown to rump and weigh about 1/2 ounce (14 grams).
Second trimester

Second trimester pregnancy: What to expect
The second trimester of pregnancy is often the most enjoyable. Find out how to relieve common symptoms — and consider ways to prepare for what's ahead.
By Mayo Clinic staff
The second trimester of pregnancy often brings a renewed sense of well-being. The worst of the nausea has usually passed, and your baby isn't big enough to crowd your abdominal organs and make you uncomfortable. Yet dramatic pregnancy symptoms are on the horizon. Here's what to expect.
Second trimester pregnancy: Your body

CLICK TO ENLARGE | Leg cramp stretch during pregnancy |

During the second trimester of pregnancy, you might notice physical changes from head to toe.
Larger breasts
Stimulated by estrogen and progesterone, the milk-producing glands inside your breasts get larger during the second trimester. Additional fat also might accumulate in your breasts. Although some of the initial breast tenderness will likely improve, nipple tenderness might continue throughout the pregnancy. A supportive bra is a must.
Growing belly
As your uterus becomes heavier and expands to make room for the baby, your abdomen expands — sometimes rapidly. Starting in the second trimester, expect to gain 3 to 4 pounds (about 1.4 to 1.8 kilograms) a month until delivery.
Braxton Hicks contractions
Your uterus might start contracting to build strength for the big job ahead. You might feel these warm-ups, called Braxton Hicks contractions, in your lower abdomen and groin. They're usually weak and come and go unpredictably. Contact your health care provider if the contractions become painful or regular. This could be a sign of preterm labor.
Skin changes
As blood circulation to your skin increases, certain areas of your skin might become darker, such as the skin around your nipples, parts of your face and the line that runs from your navel to your pubic bone. Sun exposure can aggravate the issue. When you're outdoors, be sure to use plenty of sunscreen.
Stretch marks
You might notice pink, red or purple streaks along your abdomen, breasts, upper arms, buttocks or thighs during the second trimester of pregnancy. Your stretching skin might also be itchy. Moisturizers can help. Although stretch marks can't be prevented, most stretch marks eventually fade in intensity.
Nasal and gum problems
As pregnancy increases your circulation, more blood flows through your body's mucous membranes. This causes the lining of your nose and airway to swell, which can restrict airflow and lead to snoring, congestion and nosebleeds. Increased blood circulation can also soften your gums, which might cause minor bleeding when you brush or floss your teeth. Switching to a softer toothbrush can help decrease irritation.
Dizziness
Your blood vessels dilate in response to pregnancy hormones. Until your blood volume expands to fill them, your blood pressure will fall and you might experience occasional dizziness. If you're having trouble with dizziness, drink plenty of fluids and rise slowly after lying or sitting down. When you feel dizzy, lie on your left side to restore your blood pressure.
Leg cramps
Leg cramps are common as pregnancy progresses, often striking at night. To help prevent leg cramps during pregnancy, stretch your calf muscles before bed. It also helps to stay physically active and drink plenty of fluids. If a leg cramp strikes, stretch the calf muscle on the affected side. A hot shower, warm bath or ice massage also may help.
Shortness of breath
Your lungs are processing more air than they did before your pregnancy. This allows your blood to carry more oxygen to your placenta and the baby — and might leave you breathing slightly faster and feeling short of breath.
Vaginal discharge
You might notice a thin, white vaginal discharge. This acidic discharge is thought to help suppress the growth of potentially harmful bacteria or yeast. You might want to wear panty liners for comfort. Contact your health care provider if the discharge becomes strong smelling, green or yellowish, or if it's accompanied by redness, itching or irritation. This could indicate a vaginal infection.
Bladder and kidney infections
Hormonal changes slow the flow of urine, and your expanding uterus might get in the way — both factors that increase the risk of bladder and kidney infections. Contact your health care provider if you notice a burning sensation when you urinate, or you have a fever, abdominal pain or backache. Left untreated, urinary infections increase the risk of pregnancy complications.
Second trimester pregnancy: Your emotions
Pregnancy is a psychological journey as well as a biological one. During the second trimester, you might feel less tired and more up to the challenge of preparing a home for your baby. Strike while the iron is hot! Check into childbirth classes. Find a health care provider for your baby. Read about breast-feeding. If you plan to continue working after the baby is born, get familiar with your employer's maternity leave policy and investigate child care options. In some areas, you can't start too soon looking for child care.
As your pregnancy progresses, changes in your body's shape and function might affect your emotions. Some women feel a heightened sexuality during pregnancy. Others feel unattractive — especially as their bellies grow. If you're struggling with your body image, share your concerns with your partner. Express love and affection in ways that help you feel most comfortable.
While anticipation mounts, you might worry about labor, delivery or impending motherhood. Remember that you can't plan or control everything about your pregnancy. Instead, learn as much as you can. Focus on making healthy lifestyle choices that will give your baby the best start.
Appointments with your health care provider
During the second trimester, your prenatal appointments will focus on your baby's growth, confirming your due date and detecting any problems with your health.
Your health care provider will begin by checking your weight and blood pressure. He or she might measure the size of your uterus by checking your fundal height — the distance from the top of the uterus (fundus) to your pubic bone. Pelvic exams are often unnecessary during the second trimester, unless something unusual needs to be explored.
At this stage, the highlight of your prenatal visits might be listening to your baby's heartbeat with a special device called a Doppler. Your health care provider might suggest an ultrasound or other screening tests this trimester. You might also find out your baby's sex — if you choose.
Be sure to mention any signs or symptoms that concern you, even if they seem silly or unimportant. Talking to your health care provider is likely to put your mind at ease.

Fetal development: The second trimester
Fetal development takes on new meaning in the second trimester. Highlights might include finding out your baby's sex and feeling your baby move.
By Mayo Clinic staff
As your pregnancy progresses, your baby might begin to seem more real. You might hear the heartbeat at your prenatal appointments, and your enlarging abdomen might force you to put away your favorite jeans.
While you're adjusting to the changes in your body, fetal development takes on new meaning. Two months ago, your baby was simply a cluster of cells. Now he or she has functioning organs, nerves and muscles. Find out what happens during the second trimester by checking out this weekly calendar of events. Keep in mind that measurements are approximate.
Week 13: Urine forms
Thirteen weeks into your pregnancy, or 11 weeks after conception, your baby's intestines have moved from the umbilical cord to your baby's abdomen. Your baby is also beginning to form urine and discharge it into the amniotic fluid.
Tissue that will become bone is also developing around your baby's head and within his or her arms and legs.
Week 14: Baby's sex becomes apparent
Fourteen weeks into your pregnancy, or 12 weeks after conception, your baby's arms have almost reached the final relative lengths they'll be at birth and your baby's neck has become more defined. Red blood cells are forming in your baby's spleen.
Your baby's sex will become apparent this week or in the coming weeks. For girls, ovarian follicles begin forming. For boys, the prostate appears.
By now your baby might be almost 3 1/2 inches (87 millimeters) long from crown to rump and weigh about 1 1/2 ounces (45 grams).
Week 15: Baby's skeleton develops bones
Fifteen weeks into your pregnancy, or 13 weeks after conception, your baby is growing rapidly. Your baby's skeleton is developing bones, which will become visible on ultrasound images in a few weeks. Your baby's scalp hair pattern also is forming.
Week 16: Baby can make sucking motions

CLICK TO ENLARGE | Fetal development 14 weeks after conception |

Sixteen weeks into your pregnancy, or 14 weeks after conception, your baby's eyes have begun to face forward and slowly move. The ears are close to reaching their final position. Your baby might be able to make sucking motions with his or her mouth.
Although still too slight to be felt, your baby's movements are becoming coordinated and can be detected during ultrasound exams.
By now your baby might be more than 4 1/2 inches (120 millimeters) long from crown to rump.
Week 17: Fat accumulates
Seventeen weeks into your pregnancy, or 15 weeks after conception, fat stores begin to develop under your baby's skin. The fat will provide energy and help keep your baby warm after birth.
Week 18: Baby begins to hear
Eighteen weeks into your pregnancy, or 16 weeks after conception, your baby's ears begin to stand out on the sides of his or her head. Your baby might begin to hear.
By now your baby might be 5 1/2 inches (140 millimeters) long from crown to rump and weigh 7 ounces (200 grams).
Week 19: Baby's uterus forms
Nineteen weeks into your pregnancy, or 17 weeks after conception, a greasy, cheese-like coating called vernix caseosa begins to cover your baby. The vernix caseosa helps protect your baby's delicate skin from abrasions, chapping and hardening that can result from exposure to amniotic fluid.
For girls, the uterus and vagina might begin to form this week.
Week 20: The halfway point
Halfway into your pregnancy, or 18 weeks after conception, you might be able to feel your baby's first movements, also known as quickening.
By now your baby might be about 6 1/3 inches (160 millimeters) long from crown to rump.
Week 21: Baby can swallow

CLICK TO ENLARGE | Fetal development 19 weeks after conception |

Twenty-one weeks into your pregnancy, or 19 weeks after conception, your baby is poised to gain more weight. By this week your baby is becoming more active and might be able to swallow.
Week 22: Baby's hair becomes visible
Twenty-two weeks into your pregnancy, or 20 weeks after conception, your baby is completely covered with a fine, down-like hair called lanugo. The lanugo helps hold the vernix caseosa on the skin. Your baby's eyebrows might be visible.
By now your baby might be 7 1/2 inches (190 millimeters) long from crown to rump and weigh 1 pound (460 grams).
Week 23: Fingerprints and footprints form
Twenty-three weeks into your pregnancy, or 21 weeks after conception, your baby's skin is wrinkled, more translucent than before and pink to red in color.
This week your baby begins to have rapid eye movements. Your baby's tongue will soon develop taste buds. Fingerprints and footprints are forming. For boys, the testes are descending from the abdomen. For girls, the uterus and ovaries are in place — complete with a lifetime supply of eggs.
With intensive medical care, some babies born this week might be able to survive.
Week 24: Real hair grows
Twenty-four weeks into your pregnancy, or 22 weeks after conception, your baby is regularly sleeping and waking. Real hair is growing on his or her head.
By now your baby might be about 8 inches (210 millimeters) long from crown to rump and weigh more than 1 1/3 pounds (630 grams).
Week 25: Baby responds to your voice

CLICK TO ENLARGE | Fetal development 23 weeks after conception |

Twenty-five weeks into your pregnancy, or 23 weeks after conception, your baby's hands and startle reflex are developing. Your baby might be able to respond to familiar sounds, such as your voice, with movement.
Week 26: Baby's fingernails develop
Twenty-six weeks into your pregnancy, or 24 weeks after conception, your baby has fingernails.
Your baby's lungs are beginning to produce surfactant, the substance that allows the air sacs in the lungs to inflate — and keeps them from collapsing and sticking together when they deflate.
By now your baby might be 9 inches (230 millimeters) long from crown to rump and weigh nearly 2 pounds (820 grams).
Week 27: Second trimester ends
This week marks the end of the second trimester. At 27 weeks, or 25 weeks after conception, your baby's lungs and nervous system are continuing to mature — and he or she has likely been growing like a weed. Your baby's crown-to-rump length might have tripled since the 12-week mark.
Prenatal care: Second-trimester visits
Pregnancy and prenatal care go hand in hand. During the second trimester, prenatal care includes routine lab tests and measurements of your baby's growth. You may consider prenatal testing, too.
By Mayo Clinic staff
Prenatal care is an important part of a healthy pregnancy. As your pregnancy progresses, you'll continue to visit your health care provider regularly — probably once a month throughout the second trimester. Here's what to expect at your second-trimester prenatal appointments.
Review the basics
Your health care provider will check your blood pressure and weight at every visit. Mention any signs or symptoms you've been experiencing. Then it's time for your baby to take center stage. Your health care provider may: * Track your baby's growth. By measuring your abdomen from the top of your uterus to your pubic bone, your health care provider can gauge your baby's growth. This measurement in centimeters often equals the number of weeks of pregnancy. * Listen to your baby's heartbeat. At second-trimester visits, you may listen to your baby's heartbeat using a Doppler instrument or occasionally a modified stethoscope. The Doppler instrument detects motion and conveys it as sound, which allows you to "hear" the baby's movement — even though the movement doesn't actually make noise. * Assess fetal movement. Tell your health care provider when you begin noticing flutters or kicks. This usually happens at about 20 weeks — or perhaps earlier if you've been pregnant before.
Expect routine lab tests
Your health care provider may want to test a urine sample for sugar and protein. You may need blood tests to check for low iron levels or gestational diabetes, a type of diabetes that can develop during pregnancy. If you have Rh negative blood, you may be tested for Rh antibodies. These antibodies may be harmful if your baby has Rh positive blood.
Consider prenatal testing
During the second trimester, you may be offered various prenatal screenings or tests: * Blood tests. Blood tests may be done to screen for developmental or chromosomal disorders, such as spina bifida or Down syndrome. * Ultrasound. An ultrasound can help your health care provider evaluate your baby's growth and development. It also gives you an exciting glimpse of your baby. * Diagnostic tests. If the results of a blood test or ultrasound are worrisome or your history suggests high risk, your health care provider may recommend a more invasive diagnostic test, such as amniocentesis.
Keep your health care provider informed
The second trimester often brings a renewed sense of well-being, but there's a lot happening. Tell your health care provider what's on your mind, even if it seems silly or unimportant. Nothing is too trivial when it comes to your health — or your baby's health.
Third trimester
The third trimester of pregnancy can be physically and emotionally challenging. Your baby's size and position might make it hard for you to get comfortable. You might be tired of pregnancy and eager to move on to the next stage. If you've been gearing up for your due date, you might be disappointed if it comes and goes uneventfully.
Try to remain positive as you look forward to the end of your pregnancy. Soon you'll hold your baby in your arms! Here's what to expect in the meantime.
Third trimester pregnancy: Your body
As your baby grows, his or her movements will become more obvious. These exciting sensations are often accompanied by increasing discomfort and other third trimester pregnancy symptoms.
Continued breast growth
By now, you might have an additional 2 pounds (nearly 1 kilogram) of breast tissue. As delivery approaches, your nipples could start leaking colostrum — the yellowish fluid that will nourish your baby during the first few days of life.
Weight gain
By your due date, expect to weigh 25 to 35 pounds (about 11 to 16 kilograms) more than you did before pregnancy. Your baby accounts for some of the weight gain, but so do the placenta, amniotic fluid, larger breasts and uterus, extra fat stores, and increased blood and fluid volume.
Braxton Hicks contractions
These contractions are warm-ups for the real thing. They're usually weak and come and go unpredictably. True labor contractions get longer, stronger and closer together. If you're having contractions that are painful or regular, contact your health care provider.
Backaches
As your baby continues to gain weight, pregnancy hormones relax the joints between the bones in your pelvic area. These changes can be tough on your back. When you sit, choose chairs with good back support. Apply a heating pad or ice pack to the painful area. Ask your partner for a massage. Wear low-heeled — but not flat — shoes with good arch support. If the back pain doesn't go away or is accompanied by other signs and symptoms, contact your health care provider.
Shortness of breath
You might get winded easily as your uterus expands beneath your diaphragm, the muscle just below your lungs. This might improve when the baby settles deeper into your pelvis before delivery. In the meantime, practice good posture and sleep with your upper body propped up on pillows to relieve pressure on your lungs.
Heartburn
During the third trimester, your growing uterus might push your stomach out of its normal position — which can contribute to heartburn. To keep stomach acid where it belongs, eat small meals and drink plenty of fluids between meals. Avoid fried foods, carbonated drinks, citrus fruits or juices, and spicy foods. If these tips don't help, ask your health care provider about antacids.
Swelling
As your growing uterus puts pressure on the veins that return blood from your feet and legs, swollen feet and ankles might become an issue. At the same time, swelling in your legs, arms or hands can place pressure on nerves, causing tingling or numbness. Fluid retention and dilated blood vessels might leave your face and eyelids puffy, especially in the morning. If you have persistent face or eyelid swelling, contact your health care provider.
To reduce swelling, lie down or use a footrest. You might even elevate your feet and legs while you sleep. It can also help to swim or simply stand in a pool.
Spider veins, varicose veins and hemorrhoids
Increased blood circulation might cause small reddish spots that sprout tiny blood vessels on your face, neck or arms, especially if you have fair skin. Blue or reddish lines beneath the surface of the skin (varicose veins) also might appear, particularly in the legs. Varicose veins in your rectum (hemorrhoids) are another possibility.
If you have painful varicose veins, elevate your legs and wear support stockings. To prevent hemorrhoids, avoid constipation. Include plenty of fiber in your diet and drink lots of fluids.
Frequent urination
As your baby moves deeper into your pelvis, you'll feel more pressure on your bladder. You might find yourself urinating more often, even during the night. This extra pressure might also cause you to leak urine — especially when you laugh, cough or sneeze. If you're worried about leaking urine, panty liners can offer a sense of security.
Continue to watch for signs of a urinary tract infection, such as urinating even more than usual, burning during urination, fever, abdominal pain or backache. Left untreated, urinary infections increase the risk of pregnancy complications.
Vaginal discharge
Potentially heavy vaginal discharge is common at the end of pregnancy. If you saturate a panty liner within a few hours or wonder if the discharge is leaking amniotic fluid, contact your health care provider.
Third trimester pregnancy: Your emotions
As anticipation grows, fears about childbirth might become more persistent. How much will it hurt? How long will it last? How will I cope?
If you haven't done so already, consider taking childbirth classes. You'll learn what to expect — and meet other moms-to-be who share your excitement and concerns. Talk with women who've had positive birth experiences, and ask your health care provider about options for pain relief. Tell yourself that you'll simply do the best you can. There's no right or wrong way to have a baby.
The reality of parenthood might begin to sink in as well. You might feel anxious and overwhelmed, especially if this is your first baby. To stay calm, revel in the experience of being pregnant and think about the joy that will come from loving a new human being. Consider: * Writing your thoughts in a journal * Talking to your baby * Taking photos of your pregnant belly to share with your child one day
It's also helpful to plan ahead. If you'll be breast-feeding, gather any supplies you might need, such as a special pillow to use while breast-feeding and a breast pump. If you're expecting a boy — or you don't know your baby's sex — think about what's right for your family regarding circumcision. Consider who'll be your baby's principal health care provider. Make plans for your first few weeks together.
Appointments with your health care provider
During the third trimester, your health care provider might ask you to come in for more frequent checkups — perhaps every other week beginning at week 32 and every week beginning at week 36.
Like previous visits, your health care provider will check your weight and blood pressure and ask about any signs or symptoms you're experiencing. You might need screening tests for various conditions, including: * Gestational diabetes. This is a type of diabetes that sometimes develops during pregnancy. Prompt treatment and healthy lifestyle choices can help you manage your blood sugar level and deliver a healthy baby. * Anemia. Anemia is an abnormally low level of red blood cells or hemoglobin, a protein in red blood cells that contains iron. Severe anemia can slow your baby's growth or trigger preterm labor. To treat anemia, you might need to take iron supplements. * Group B strep. Group B strep is a type of bacteria that can live in your vagina or rectum. It won't make you sick, but it could cause a serious infection for your baby after birth. If you test positive for group B strep, your health care provider will likely recommend antibiotics while you're in labor.
Your health care provider will also check your baby's size and heart rate. Near the end of your pregnancy, vaginal exams can help your health care provider determine your baby's position inside your uterus. He or she might also check your cervix to see whether it's begun to soften or dilate in preparation for birth — although cervical exams aren't a reliable way to predict when labor will begin.
If you have specific desires or preferences for labor and birth — such as laboring in water or avoiding medication — you might want to define your wishes in a birth plan. Review the plan with your health care provider ahead of time to prevent any misunderstandings.
As your due date approaches, keep asking questions. How can I tell the difference between false labor and the real thing? When do I need to go to the hospital? Could I be too late for an epidural? Remember, there's no silly question. Understanding what's happening can help you have the most positive birth experience.
The end of your pregnancy is near! By now, you might be tired of being pregnant — and eager to meet your baby face to face. Your uterus, however, is still a busy place. Understand how fetal development continues as you approach your due date. Here's a weekly calendar of events for the third trimester. Keep in mind that measurements are approximate.
Week 28: Baby's eyes open
Twenty-eight weeks into your pregnancy, or 26 weeks after conception, your baby's eyelids are partially open and eyelashes have formed. Your baby is gaining weight, which is smoothing out many of the wrinkles in his or her skin.
By now your baby might be nearly 10 inches (250 millimeters) long from crown to rump and weigh nearly 2 1/4 pounds (1,000 grams). Otherwise healthy babies born this week have a 90 percent chance of survival without physical or neurological impairment — and the odds improve with each passing week.
Week 29: Baby's bones are fully developed

CLICK TO ENLARGE | Fetal development 27 weeks after conception |

Twenty-nine weeks into your pregnancy, or 27 weeks after conception, your baby's bones are fully developed, but they're still soft and pliable.
Week 30: Baby's eyes are wide open
Thirty weeks into your pregnancy, or 28 weeks after conception, your baby's eyes are wide open a good part of the time. Your baby might have a good head of hair by this week. Red blood cells are now forming in your baby's bone marrow.
By now your baby might be more than 10 1/2 inches (270 millimeters) long from crown to rump and weigh nearly 3 pounds (1,300 grams).
Week 31: Sexual development continues
Thirty-one weeks into your pregnancy, or 29 weeks after conception, your baby's central nervous system has matured to the stage where it can control body temperature.
Week 32: Baby practices breathing
Thirty-two weeks into your pregnancy, or 30 weeks after conception, your baby's toenails are visible.
Although your baby's lungs aren't fully formed, he or she practices breathing. Your baby's body begins absorbing vital minerals, such as iron and calcium from the intestinal tract. The layer of soft, downy hair that has covered your baby's skin for the past few months — known as lanugo — starts to fall off this week.
By now your baby might be 11 inches (280 millimeters) long from crown to rump and weigh 3 3/4 pounds (1,700 grams).
Week 33: Baby detects light

CLICK TO ENLARGE | Fetal development 31 weeks after conception |

Thirty-three weeks into your pregnancy, or 31 weeks after conception, your baby's pupils can constrict, dilate and detect light entering his or her eyes.
Fetal development: The third trimester
Week 34: Baby's fingernails grow
Thirty-four weeks into your pregnancy, or 32 weeks after conception, your baby's fingernails have reached his or her fingertips.
By now your baby might be nearly 12 inches (300 millimeters) long from crown to rump. The pasty white coating that protects your baby's skin — the vernix caseosa — is about to get thicker.
Week 35: Protective coating thickens
Thirty-five weeks into your pregnancy, or 33 weeks after conception, your baby's limbs are becoming chubby. Your baby is gaining weight rapidly — about 1/2 pound (227 grams) a week for the next month.
Week 36: Rapid weight gain begins
Thirty-six weeks into your pregnancy, or 34 weeks after conception, the crowded conditions inside your uterus might make it harder for your baby to give you a punch. However, you'll probably still feel lots of stretches, rolls and wiggles. You might want to check on your baby's movements from time to time (kick count) — especially if you think you've noticed decreased activity. Ask your health care provider how many movements you should detect in a certain number of hours.
Week 37: Baby is full term
Thirty-seven weeks into your pregnancy, or 35 weeks after conception, your baby will be considered full term. Your baby's organs are ready to function on their own. To prepare for birth, your baby might descend into the head-down position.
Week 38: Baby develops a firm grasp
Thirty-eight weeks into your pregnancy, or 36 weeks after conception, your baby is developing a firm grasp.
Your baby's toenails have reached the tips of his or her toes. His or her brain might weigh about 14 ounces (397 grams). After birth, your baby's brain will continue to grow. Your baby has mostly shed all of his or her lanugo.
By now your baby might weigh about 6 1/2 pounds (2,900 grams).
Week 39: Placenta provides antibodies
Thirty-nine weeks into your pregnancy, or 37 weeks after conception, your baby's chest is becoming more prominent. For boys, the testes continue to descend into the scrotum.
The placenta continues to supply your baby with antibodies that will help fight infection after birth. If you breast-feed your baby, your milk will provide additional antibodies.
Week 40: Your due date arrives

CLICK TO ENLARGE | Fetal development 38 weeks after conception |

Forty weeks into your pregnancy, or 38 weeks after conception, your baby might be about 18 to 20 inches long (457 to 508 millimeters) and weigh 6 to 9 pounds (2,720 to 4,080 grams). Remember, however, that healthy babies come in different sizes.
Don't be alarmed if your due date comes and goes without incident. It's just as normal to deliver a baby a week or two late — or early — as it is to deliver on your due date.

Pregnancy diet: Focus on these essential nutrients
A healthy pregnancy diet will promote your baby's growth and development. Understand which nutrients you need most and where to find them.
By Mayo Clinic staff
There's no magic formula for a healthy pregnancy diet. In fact, during pregnancy the basic principles of healthy eating remain the same — get plenty of fruits, vegetables, whole grains and lean protein. However, a few nutrients in a pregnancy diet deserve special attention. Here's what tops the list.
Folate and folic acid — Prevent birth defects
Folate is a B vitamin that helps prevent neural tube defects, serious abnormalities of the brain and spinal cord. Lack of folate in a pregnancy diet may also increase the risk of low birth weight and preterm delivery. The synthetic form of folate found in supplements and fortified foods is known as folic acid.
How much you need: 800 micrograms of folate or folic acid a day before conception and throughout pregnancy.
Good sources: Fortified cereals are great sources of folic acid. Leafy green vegetables, citrus fruits, and dried beans and peas are good sources of naturally occurring folate. Food | Serving size | Folic acid content | Cereal | 3/4 cup (15 to 45 grams) 100 percent fortified ready-to-eat cereal | 100 to 700 micrograms — choose a cereal with at least 400 micrograms | Spinach | 1/2 cup (90 grams) boiled spinach | 131 micrograms | Beans | 1/2 cup (88 grams) boiled Great Northern beans | 90 micrograms | Asparagus | 4 boiled spears (60 grams) | 89 micrograms | Peanuts | 1 ounce (28 grams) dry roasted | 41 micrograms | Oranges | 1 orange (159 grams) | 48 micrograms |
Source: USDA National Nutrient Database for Standard Reference, Release 23
In addition to making healthy food choices, taking a daily prenatal vitamin — ideally starting three months before conception — can help ensure you're getting enough of this essential nutrient.
Calcium — Strengthen bones
You and your baby need calcium for strong bones and teeth. Calcium also helps your circulatory, muscular and nervous systems run normally.
How much you need: 1,000 milligrams a day. Pregnant teenagers need 1,300 milligrams a day.
Good sources: Dairy products are the richest sources of calcium. Many fruit juices and breakfast cereals are fortified with calcium, too. Food | Serving size | Calcium content | Juice | 8 ounces (237 milliliters) calcium-fortified orange juice | 500 milligrams | Milk | 1 cup (237 milliliters) skim milk | 299 milligrams | Yogurt | 6 ounces (170 grams) low-fat fruit yogurt | 258 milligrams | Cheese | 1 ounce (28 grams) part-skim mozzarella cheese | 222 milligrams | Salmon | 3 ounces (85 grams) canned pink salmon with bones | 181 milligrams | Spinach | 1/2 cup (90 grams) boiled spinach | 122 milligrams | Cereal | 1 cup (20 to 60 grams) calcium-fortified ready-to-eat cereal | 3 to 1,000 milligrams |
Source: USDA National Nutrient Database for Standard Reference, Release 23
Vitamin D — Promote bone strength
Vitamin D also helps build your baby's bones and teeth.
How much you need: 600 IU a day.
Good sources: Fatty fish, such as salmon and tuna, are great sources of vitamin D. Other options include fortified milk and orange juice. Food | Serving size | Vitamin D content | Fish | 3 ounces (85 grams) cooked sockeye salmon | 447 IU | Juice | 8 ounces (237 milliliters) calcium- and vitamin D-fortified orange juice | 137 IU | Milk | 1 cup (237 milliliters) skim milk | 115 IU | Asparagus | 4 boiled spears (60 grams) | 89 micrograms | Eggs | 1 large hard-boiled egg (50 grams) | 44 IU |
Source: USDA National Nutrient Database for Standard Reference, Release 23
Protein — Promote growth
Protein is crucial for your baby's growth, especially during the second and third trimesters.
How much you need: 71 grams a day.
Good sources: Lean meat, poultry, fish and eggs are great sources of protein. Other options include dried beans and peas, tofu, dairy products and peanut butter. Food | Serving size | Protein content | Cottage cheese | 1 cup (226 grams) low-fat, 1% milk cottage cheese | 28 grams | Poultry | 1/2 (86 grams) boneless, skinless roasted chicken breast | 26.7 grams | Fish | 3 ounces (85 grams) canned pink salmon with bones | 16.8 grams | Lentils | 1/2 cup (99 grams) boiled lentils | 8.9 grams | Milk | 1 cup (237 milliliters) skim milk | 8.3 grams | Peanut butter | 2 tablespoons (32 grams) smooth, vitamin- and mineral-fortified peanut butter | 8.2 grams | Eggs | 1 large hard-boiled egg (50 grams) | 6.3 grams |
Source: USDA National Nutrient Database for Standard Reference, Release 23
Iron — Prevent anemia
Your body uses iron to make hemoglobin, a protein in the red blood cells that carries oxygen to your tissues. During pregnancy your blood volume expands to accommodate changes in your body and help your baby make his or her entire blood supply — doubling your need for iron.
If you don't get enough iron, you may become fatigued and more susceptible to infections. The risk of preterm delivery and low birth weight also may be higher.
How much you need: 27 milligrams a day.
Good sources: Lean red meat, poultry and fish are good sources of iron. Other options include iron-fortified breakfast cereals, nuts and dried fruit. Food | Serving size | Iron content | Cereal | 3/4 cup (15 to 45 grams) 100 percent iron-fortified ready-to-eat cereal | 18 milligrams | Beans | 1 cup (177 grams) boiled kidney beans | 3.9 milligrams | Spinach | 1/2 cup (90 grams) boiled spinach | 3.2 milligrams | Meat | 3 ounces (85 grams) roasted lean beef tenderloin | 2.6 milligrams | Poultry | 1/2 cup (70 grams) roasted dark turkey | 1.6 milligrams |
Source: USDA National Nutrient Database for Standard Reference, Release 23
Prenatal vitamins typically contain iron. In some cases, your health care provider might recommend a separate iron supplement.
The iron from animal products, such as meat, is most easily absorbed. To enhance the absorption of iron from plant sources and supplements, pair them with a food or drink high in vitamin C — such as orange juice, tomato juice or strawberries. If you take iron supplements with orange juice, avoid the calcium-fortified variety. Although calcium is an essential nutrient during pregnancy, calcium can decrease iron absorption.
Supplements — Ask your health care provider
Even if you eat a healthy diet, you can miss out on key nutrients. Taking a daily prenatal vitamin — ideally starting three months before conception — can help fill any gaps. Your health care provider might recommend special supplements if you follow a strict vegetarian diet or have a chronic health condition. If you're considering taking an herbal supplement during pregnancy, consult your health care provider first.