Pregnancy is the period from conception to birth. After the egg is fertilized by a sperm and then implanted in the lining of the uterus, it develops into the placenta and embryo, and later into a fetus. Pregnancy usually lasts 40 weeks, beginning from the first day of the woman’s last menstrual period. The condition is divided into three trimesters, each lasting three months.
Pregnancy is a state in which a woman carries a fertilized egg inside her body.
At the end of the first month, the embryo is about 1/3 in long (.85 cm), and its head, trunk, and the beginnings of arms and legs have started to develop. The embryo gets nutrients and eliminates waste through the umbilical cord and placenta. By the end of the first month, the liver and digestive system begin to develop, and the heart starts to beat.
In this month, the heart starts to pump and the nervous system (including the brain and spinal cord) begins to develop. The 1 in (2.5 cm) long fetus has a complete cartilage skeleton, which is replaced by bone cells by month’s end. Arms, legs, and all of the major organs begin to appear. Facial features begin to form.
By now, the fetus has grown to 4 in (10 cm) and weighs a little more than an ounce (28 g). Now the major blood vessels and the roof of the mouth are almost completed. The face starts to take on a more recognizably human appearance. Fingers and toes appear. All the major organs are now beginning to form; the kidneys are now functional, and the four chambers of the heart are complete.
The fetus begins to kick and swallow, although most women still can’t feel the baby move at this point. Now 4 oz (112 g) in weight, the fetus can hear and urinate, and has established sleep-wake cycles. All organs are now fully formed, although they will continue to grow for the next five months. The fetus has skin, eyebrows, and hair.
Now weighing up to 1 lb (454 g) and measuring 8–12 in (20–30 cm), the fetus experiences rapid growth as its internal organs continue to grow. At this point, the mother may feel her baby move, and she can hear the heartbeat with a stethoscope.
Even though its lungs are not fully developed, a fetus born during this month can survive with intensive care. Weighing 1–1.5 lbs (454–681 g), the fetus is red, wrinkly, and covered with fine hair all over its body. The fetus will grow very fast during this month as its organs continue to develop.
There is a better chance that a fetus born during this month will survive. The fetus continues to grow rapidly and may weigh as much as 3 lbs (1.3 kg) by now. Now the fetus can suck its thumb and look around its watery environment with open eyes.
Growth continues but slows down as the baby begins to take up most of the room inside the uterus. Now weighing between 4–5 lbs (1.8–2.3 kg) and measuring 16–18 in (40–45 cm) long, the fetus may at this time prepare for delivery next month by moving into the head-down position.
Adding 0.5 lb (227 g) a week as the due date approaches, the fetus drops lower into the mother’s abdomen and prepares for the onset of labor, which may begin any time between the 37th and 42nd week of gestation. Most healthy babies will weigh 6–9 lbs (2.7–4 kg) at birth, and will be about 20 in (50 cm) long.
Causes and symptoms
Pregnancy is caused by a sperm fertilizing an egg. The first sign of pregnancy is usually a missed menstrual period, although some women bleed in the beginning. A woman’s breasts swell and may become tender as the mammary glands prepare for eventual breastfeeding. Nipples begin to enlarge and the veins over the surface of the breasts become more noticeable.
Nausea and vomiting are very common symptoms that generally occur during the first three months of pregnancy. Since these symptoms are usually worse in the morning, this condition is known as morning sickness.
Many women also feel extremely tired during the early weeks. Frequent urination is common, and there may be a creamy white discharge from the vagina. Some women crave certain foods, and an extreme sensitivity to smell may worsen the nausea. Weight begins to increase.
In the second trimester (13–28 weeks) a woman begins to look noticeably pregnant and the enlarged uterus is easy to feel. The nipples get bigger and darker, the skin of Caucasians may darken, and some women may feel flushed and warm. Appetite may increase.
By the 22nd week, most women have felt the baby move. During the second trimester, nausea and vomiting often fade away, and the pregnant woman often feels much better and more energetic. Heart rate increases as does the volume of blood in the body.
By the third trimester (29–40 weeks), many women begin to experience a range of common symptoms. Stretch marks (striae) may develop on the abdomen, breasts and thighs, and a dark line may appear from the navel to pubic hair. A thin fluid may be expressed from the nipples.
Many women feel hot, sweat easily, and often find it hard to get comfortable. Kicks from an active baby may cause sharp pains, and lower backaches are common. More rest is needed as the woman copes with the added stress of extra weight. Braxton Hicks contractions may get stronger.
At about the 36th week in a first pregnancy (later in repeat pregnancies), the baby’s head drops down low into the pelvis. This shift may relieve pressure on the upper abdomen and the lungs, allowing a woman to breathe more easily. The fetus’ new position, however, places more pressure on the bladder.
The average woman gains 28 lbs (12.7 kg) during pregnancy, 70% of it during the last 20 weeks. An average healthy full-term baby at birth weighs 7.5 lbs (3.4 kg), and the placenta and fluid together weigh another 3 lbs (1.3 kg). The remaining weight that a woman gains during pregnancy is mostly due to water retention and fat stores.
In addition to the typical symptoms of pregnancy, some women experience other problems that may be annoying but usually disappear after delivery. Constipation may develop as a result of food passing more slowly through the intestine. Hemorrhoids and heartburn are fairly common during late pregnancy.
Gums may become more sensitive and bleed more easily; eyes may dry out, making contact lenses feel painful. Pica (a craving to eat substances other than food) may occur. Swollen ankles and varicose veins may be a problem in the second half of pregnancy, and chloasma (light brown spots) may appear on the face.
While the preceding symptoms are considered normal, there are some symptoms that may be signs of a more dangerous underlying problem. A pregnant woman experiencing any of the following should contact her doctor immediately:
- abdominal pain
- rupture of the amniotic sac or leaking of fluid from the vagina
- bleeding from the vagina
- no fetal movement for 24 hours (after the fifth month)
- continuous headaches
- marked sudden swelling of eyelids, hands, or face during the last three months
- dim or blurry vision during the last three months
- persistent vomiting
Many women first discover they are pregnant after a positive home pregnancy test. Pregnancy urine tests check for the presence of human chorionic gonadotropin (hCG), which is produced by a placenta. Home tests can detect pregnancy on the day of the missed menstrual period.
Home pregnancy tests are more than 97% accurate if the result is positive, and about 80% accurate if the result is negative. If the result is negative and there is no menstrual period within another week, the pregnancy test should be repeated.
While home pregnancy tests are very accurate, they are less accurate than a pregnancy test evaluated by a laboratory. For this reason, a woman may want to consider having a second pregnancy test conducted at her doctor’s office to be sure of the accuracy of the result.
Blood tests to determine pregnancy are usually used only when a very early diagnosis of pregnancy is needed. This more expensive test, which also looks for hCG, can produce a result within 9–12 days after conception.
Once pregnancy has been confirmed, there are a range of screening tests that can be done to screen for birth defects, which affect about 3% of unborn children.
Two tests are recommended for all pregnant women: alpha-fetoprotein (AFP) and the triple marker test. Other tests are recommended for women at higher risk for having a child with a birth defect.
These groups include women over age 35 who had another child or a close relative with a birth defect, or who have been exposed to certain drugs or high levels of radiation. Women with any of these risk factors may want to consider amniocentesis, chorionic villus sampling (CVS) or ultrasound. Other prenatal tests
There are a range of other prenatal tests that are routinely performed, including:
- pap test
- gestational diabetes screening test at 24–28 weeks
- tests for sexually transmitted diseases
- blood tests for anemia or blood type
- screening for immunity to various diseases, such as German measles
Alternative medicine offers a variety of treatments for conditions ranging from morning sickness to stretch marks. Before starting any treatment, a pregnant woman should consult with her doctor or practitioner.
Prenatal care is vitally important for the health of the unborn baby. A pregnant woman should eat a balanced, nutritious diet of frequent small meals. Many physicians prescribe pregnancy vitamins, including folic acid and iron supplementation during pregnancy.
Numerous herbs are believed to remedy a range of conditions experienced by pregnant women. Many remedies can be taken as herbal teas, and packaged tea bags are sold at health food stores. The following herbs are recommended for pregnant women:
- Red raspberry leaf tea is regarded as an all-purpose remedy. It’s a good source of iron, it tones the uterus, protects against miscarriage, and prevents infection, cramps, and anemia. Furthermore, red raspberry is believed to aid the birth process by stimulating contractions. The herb also prevents excessive bleeding during labor and afterwards.
- For morning sickness, several forms of ginger provide relief. A cup of ginger tea, ginger capsules, ginger ale, or ginger cookies can ease the queasiness.
- Lemon balm can be taken for nausea; it also helps with digestion.
- Wild yam and burdock root are effective against morning sickness. Wild yam can be taken for pregnancy pain and cramping. The herb is taken to reduce the risk of miscarriage. Burdock root aids with water retention; it also protects against infant jaundice.
- Peppermint can be taken after the first trimester to combat nausea. It helps with digestion, provides stomach relief, and serves as a body strengthener.
- Echinacea boosts the immune system to fight colds, flu, and infection.
- Chamomile provides soothing relaxation and can be used to help with sleep. It also helps with digestive problems and bowel difficulties.
- Yellow dock also thwarts infant jaundice. The herb also helps with iron absorption.
- Bilberry serves as a diuretic for bloating; it also strengthens vein and capillary support.
- Nettles and oat straw are sources of calcium. In addition, nettles and dandelion reportedly prevent high blood pressure and water retention. Nettles contain Vitamin K and help to prevent excessive bleeding. Nettles can also be taken to avoid hemorrhoids and to enhance kidney function.
- Blue cohosh is taken during the last weeks of pregnancy; this remedy is taken to induce labor contractions and ease spasmodic pains.
- Lobelia works to relax the mother during delivery. The herb also aids with delivery of the placenta.
HERBS TO AVOID. Some herbs can cause complications and should not be taken during pregnancy. Uterine contractions can be caused by angelica, lovage, mistletoe, mugwort, tansy, wild ginger, and wormwood. Other herbs to be avoided include cinchona, eucalyptus oil, juniper, ma huang (ephedra), male fern, pennyroyal, poke root, rue, shepherd’s purse, and yarrow.
Aromatherapy involves the use of essential oils as remedies. The application of combined oils to the skin is said to counteract stretch marks. An aromatherapist can recommend specific oil combinations.
Chinese medicine and acupuncture
In addition to giving herbs for infertility problems, traditional Chinese medicine recommends herbal formulas for such problems associated with pregnancy as morning sickness, threatened miscarriage, and postpartum depression.
One well-known formula, recommended to be taken three to six months before attempting conception, is called “The Rock on Tai Mountain Decoction.” The formula is intended to build up both the woman’s qi, or life energy, and her blood. In Chinese medicine it is thought that the mother’s blood nourishes, the qi protects, and the qi in the kidneys holds the fetus.
Chinese practitioners use acupuncture to assist conception by clearing the stagnation of qi in the liver; to prevent miscarriage by conserving qi in the kidney; and to induce labor.
Traditional Chinese medicine recommends abstinence from sex during pregnancy in order to allow the placenta to develop normally and to prevent harm caused by sexual excess to the various organs and substances in the mother’s body. Although the Chinese are not puritanical in the Western sense of that word, they believe that good health requires moderation in all things, including sex.
Although pregnant women should avoid saunas and hot tubs, other forms of hydrotherapy can provide relief. To ease nausea, a warm compress is placed between the chest and abdomen 30 minutes before eating. The compress is a cloth soaked in hot water and wrung out. A foot bath can soothe swollen feet.
Morning sickness can be treated by several homeopathic remedies. If a homeopathic remedy is a decimal potency, it is indicated by an “x” This indicates the number of times that one part of a remedy was diluted in nine parts of a diluent. Distilled water is the preferred diluent.
Ipecacuanha 30x is recommended if the woman feels worse lying down, has diarrhea, and is salivating heavily. If morning sickness is accompanied by queasiness about eating, Colchicum autumnale 6x is recommended.
Nux vomica 6x is the remedy when a woman vomits in the morning, but her condition improves after eating. Phosphorus 6x is taken when a woman vomits after drinking water. For nausea only, Natrum phosporicum 6x may provide relief.
Each remedy is taken every 15 minutes until the feeling of nausea lessens. However, no more than four doses should be taken in one day unless specified by a homeopath.
Flower remedies are liquid concentrates made by soaking flowers in spring water. Also known as flower essences, 38 remedies were developed by homeopathic physician Edward Bach during the 1930s. Walnut, a Bach remedy for difficulty in adjusting to change, may be helpful to pregnant women.
A 39th combination formula, the rescue remedy, is taken to relieve stress. A pregnant woman should, however, check with her doctor before beginning flower therapy. The essence, which contains alcohol, is taken in water and usually sipped.
Relaxation techniques can be used to cope with such conditions as stress or morning sickness. Helpful techniques include meditation , deep breathing, and listening to relaxation tapes. Another useful technique is guided imagery; the person does some deep breathing and then visualizes a positive image or affirmation.
Massaging sore areas of the body during pregnancy can reduce aches and stress. Another form of bodywork is the Alexander technique, developed by actor Frederick Matthias Alexander during the 1800s.
An Alexander technique practitioner can show a woman how to release muscle tension, with emphasis on the neck. The technique focuses on posture and movement. It is said to reduce stress and relieve pain in such areas as the back.
No medication (not even a nonprescription drug) should be taken except under medical supervision, since it could pass from the mother through the placenta to the developing baby. Some drugs have been proven harmful to a fetus, but no drug should be considered completely safe.
Drugs taken during the first three months of a pregnancy may interfere with the normal formation of the baby’s organs, leading to birth defects. Drugs taken later on in pregnancy may slow the baby’s growth rate, or they may damage specific fetal tissue (such as the developing teeth).
To have the best chance of having a healthy baby, a pregnant woman should avoid:
Pregnancy is a natural condition that usually causes little discomfort provided the woman takes care of herself and gets adequate prenatal care. Childbirth education classes for the woman and her partner help prepare the couple for labor and delivery.
There are many ways to avoid pregnancy. A woman has a choice of many methods of contraception that will prevent pregnancy, including (in order of least to most effective):
- spermicide alone
- natural (rhythm) method
- diaphragm or cap alone
- condom alone
- diaphragm with spermicide
- condom with spermicide
- intrauterine device (IUD)
- contraceptive pill
- sterilization (either a man or woman)
- avoiding intercourse