Understanding Pregnancy Symptoms

When you become pregnant, the part of your body affected first and the part that undergoes the most significant changes is the uterus. It increases to 20 times its original weight, and 1,000 times its initial capacity. The amount of its muscle, connective and elastic tissue, blood vessels, and nerves increases. Its shape changes from elongated to oval by the second month, to round by midgestation, then back through oval to elongated at term (the end of a normal nine-month pregnancy).

The uterus softens beginning at the sixth week. It changes position as it increases in size, ascending into the abdomen by the fourth month and eventually reaching to the liver. It also becomes more contractile (the tendency to decrease in size), with irregular, painless Braxton Hicks contractions beginning in the first trimester. You may feel these contractions in the last weeks of pregnancy, when they are known as false labor.

Other parts of the reproductive system change along with the uterus. The cervix and vagina have an increased blood supply, which causes a darkening in color apparent by the sixth week. The amount of elastic tissue increases to prepare the way for the stretching that will be required during delivery. Secretions increase, and a mucous plug develops in the cervix. The fallopian tubes, ovaries, and ligaments supporting the uterus all enlarge and elongate. The ovaries, of course, cease to ovulate.

During the fourth month, the uterus grows into the abdomen, causing the abdominal wall to expand to accommodate it. The connective and elastic tissues stretch and straighten, creating thinned areas called striae (stretch marks). While the red of the striae may fade, silver remnants usually remain after delivery. In 50 percent of women, striae develop in the third trimester. Late in pregnancy, the internal pressure from the large uterus may even cause the muscles of the abdominal wall to separate (diastasis).

Your breasts must undergo many changes during pregnancy to produce milk. In the first two months of pregnancy, your breasts may feel sore or full. They enlarge, and veins may become visible. Striae can develop. The nipples also increase in size and usually darken. By midpregnancy, colostrum (a thick, yellowish fluid) can be expressed, but milk is not produced until after delivery.

Blood flow also changes during pregnancy, in order to satisfy your enlarged reproductive organs and feed your baby. Read about changes in the blood during pregnancy next.

Since the baby is fed by your blood supply, and your enlarging reproductive organs require more blood flow, the amount of blood must also increase. Blood volume expands 25 to 40 percent.

To pump an increased amount of blood around the body, your heart must work slightly harder. The heart pumps more blood per beat and beats slightly faster. Heart murmurs attributable to the increased flow through the heart may develop.

The blood vessels are also affected by pregnancy. The enlarging uterus presses on veins in the pelvis, increasing the pressure in the veins that bring blood up from the legs. This increased pressure causes the leg veins to enlarge, producing varicosities (areas of enlargement). The pressure may also cause fluid to leak out of the veins and into the tissues, causing swelling of the feet and ankles. Late in pregnancy, the uterus can also compress a major vein in the abdomen, the vena cava, when you lie on your back; if this occurs, blood is prevented from returning to the heart, and a feeling of faintness may result.

The enlarged uterus also changes your digestive system during pregnancy. This affects your urination and digestion, and contributes to the well-known hunger cravings. Read about changes in the digestive system during pregnancy next.

The enlarging uterus not only pushes forward on the abdominal wall and down on the pelvic veins, but it also pushes up on the bottom of the rib cage and on the diaphragm (the muscle that stretches across the bottom of the chest cavity and assists in breathing). The rib cage widens, and you will likely breathe slightly faster or you may even feel short of breath.

Urination and digestion are also affected during pregnancy. Pressure from the uterus and hormonal changes affect the urinary tract. The uterus presses against the bladder, which may cause you to urinate more frequently. Hormones cause the ureters (the tubes conducting urine from the kidneys to the bladder) to distend (widen) and the flow of the urine in them to slow. The sluggish urine flow predisposes pregnant women to infection. Hormones, along with the increased blood volume, also cause the kidneys to filter more blood.

However, the kidneys may not reabsorb sugar and protein efficiently because of this increased work load, and these substances may spill into the urine. Since the presence of sugar in the urine can also be caused by diabetes and since the presence of protein can be caused by infection, most doctors screen the urine frequently during pregnancy and may do other tests if any abnormality is found.

The changes in digestion associated with pregnancy are well-known. A pregnant woman's cravings for pickles and ice cream have been the premise of many a joke. You may have unusual cravings and also notice changes in your senses of smell and taste, which may cause you to alter your eating habits. During pregnancy, you may produce more saliva, and the saliva is more acidic, which promotes tooth decay. Your gums are more sensitive and may swell and bleed easily.

In the first trimester, you may have morning sickness, characterized by vomiting and a poor appetite. You may also be constipated. One of the pregnancy hormones causes the muscles of the digestive tract to relax; therefore, they pass the food more slowly through the intestines. In addition, the uterus can press on the colon, inhibiting passage of feces.

Similar mechanisms produce heartburn. The muscles at the junction of the esophagus and the stomach relax, and the uterus presses on the stomach from below, causing the stomach contents to flow back into the esophagus. In late pregnancy, a portion of the stomach may even be pushed all the way up into the chest, producing a hiatal hernia.

A number of changes are necessary in the structures supporting the uterus to stabilize it as it grows. The ligaments in the pelvis and abdomen stretch to accommodate the uterus. In late pregnancy, the upper part of the spine bends backward to compensate for the enlarging abdomen. Hormones loosen the joints of the pelvis in preparation for childbirth.

Your metabolism has also increased during pregnancy, urging you to eat more vitamins and minerals for the growing fetus. Amazingly, your physical changes will all return to normal after you give birth. Read about changes in the metabolism during pregnancy in the next section.

Hormonal influences are also responsible for changes in the skin. Pigmentation of the nipples, vulva (the external genital organs), the center of the lower part of the abdomen, and the umbilicus increases. Darkening across the face may appear; this is known as chloasma or melasma, or the mask of pregnancy. Hormones can also cause reddening of the palms and the appearance of small red spots on the skin; these are nests of blood vessels, which are known as spider nevi or telangiectasias. Sweat and oil glands also become more productive during pregnancy.

One of the most important changes during pregnancy is the increase in metabolism, which is necessary to provide nourishment to the fetus. You must eat more to supply adequate protein, carbohydrates, and fat to the fetus and to your own enlarging body. Most women gain about 25 pounds: 3 pounds in the first trimester and 10 to 12 pounds in each of the second and third trimesters. The placenta, fetus, and amniotic fluid and the increased volume of blood and breast and uterine tissue account for 20 pounds of that weight gain. The rest of the weight is fat and extra fluid.

You must also take in more vitamins and minerals for the growing fetus. In general, you need to ingest greater amounts of calcium -- needed for developing bones -- and iron -- used to make new blood cells -- from the fourth month of pregnancy on.

The physical changes during pregnancy are miraculous. And the discomfort during pregnancy that you'll read about next is not to be taken lightly. Amazingly, the physical alterations you undergo reverse after birth: Your body returns to its normal state. For the baby, however, the process of change started nine months before has -- relatively speaking -- just begun.

The sudden and dramatic changes that occur during pregnancy may make you feel that your body is alien to you. Your body looks and feels different. Often, these changes are uncomfortable. Carrying 25 extra pounds around inside your abdominal cavity puts a strain on your legs and hips, not to mention the pressure on other organs.

You may experience pain in the lower part of the abdomen, especially on the right-hand side, beginning at about 20 weeks. This is caused by the stretching of the ligaments that support the uterus. You may also have pain in the upper front part of the thigh, caused by the uterus pressing on a nerve that passes over the rim of the pelvic bone. You can sometimes relieve these pains by lying down.

Pain can also occur in the upper part of the abdomen. This pain is often due to heartburn. To relieve the discomfort, sit upright after meals, eat smaller quantities, and take antacids (with your doctor's permission). However, serious complications of pregnancy, such as gallstones, may also cause upper abdominal pain, so let your doctor know about these pains.

You may experience other sorts of discomfort during pregnancy. Hormonal changes in the first trimester may cause morning sickness, with nausea, vomiting, and loss of appetite. It may help to eat something bland, such as a cracker, before getting out of bed in the morning. Eating small, frequent meals may also ease the sensation. Vomiting that is severe or that continues throughout pregnancy is more serious and requires treatment.

Constipation can be an uncomfortable side effect of pregnancy. It can lead to hemorrhoids, which may result from straining during a bowel movement. Hemorrhoids may also appear because of increased pressure from the uterus on the pelvic veins. Alterations in diet to increase the amounts of fruit and fiber may help, but you may need a laxative and stool softener. You can also use sitz baths, lubricating creams, and suppositories for hemorrhoids, but check with your doctor before using these or any medications.

The uterus also exerts pressure on the veins to the legs, especially in the third trimester. This causes your legs and varicose veins to swell. Wearing shoes may become difficult. Elevate your legs and wear elastic stockings to relieve the pressure.

Late in pregnancy, you may experience pain in your pelvis or feel as if your pelvis is separating. Hormonally induced loosening of the ligaments is responsible for this. The best remedy is to avoid activities that strain these ligaments.

You may also have backaches. These are due to the change in posture required by the enlarging abdomen. A good exercise program (discuss this with your doctor) to strengthen the abdominal and back muscles may help prevent backaches; rest and a heating pad help relieve them when they occur.

The changes of pregnancy can be uncomfortable. But if you're aware of the potential for pain and take appropriate steps to avoid it or relieve it when it occurs, you'll go through the nine months in relative comfort.

ABOUT THE CONSULTANT:

Dr. Elizabeth Eden, M.D. is a practicing obstetrician with her own private practice in New York City. She serves as an attending physician at the Tisch Hospital of the New York University Medical Center, as well as a Clinical Assistant Professor at the New York University School of Medicine.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.