Different pregnancies in the same woman may cause different symptoms. It can be very confusing and stressful; in fact, stress over whether or not one is pregnant can cause symptoms of pregnancy! So how do you sort it all out?
The most common sign of pregnancy is missing a period (called “amenorrhea”), especially if the woman has been having regular menses prior to missing her period. This occurs because hormones elaborated by the corpus luteum* maintain the uterine lining for implantation of the embryo. While there are many causes of amenorrhea, in women of child-bearing age pregnancy is one of the most common. It is also possible to be pregnant while continuing to menstruate, although this is very rare.
Fatigue occurs so frequently it can’t be ignored as an early symptom.
Nausea in pregnancy is commonly known as “morning sickness,” despite the fact that it can occur at any time of the day. Most commonly it lasts for a few hours, then recedes. It usually begins at about 4 to 8 weeks gestation (calculated from the first day of the last menstrual period). It is caused by a hormone called human chorionic gonadotropin (hCG, the same hormone measured in pregnancy tests), which usually peaks at about 12 to 14 weeks gestation. Levels of hCG decrease rapidly after their peak, and nausea generally disappears at the beginning of the second trimester. Rarely, nausea can continue throughout the pregnancy.
Breast swelling and tenderness is a result of rapid swelling of the blood vessels called vascular engorgement. There may also be a feeling of tingling and heaviness in the breasts. This usually starts at 4 to 8 weeks gestation and is generally more prevalent in first pregnancies. The swelling usually persists throughout the pregnancy, but the tenderness ordinarily improves after several weeks.
Fatigue is a prominent symptom in early pregnancy. Its cause is unknown, but it occurs so frequently it can’t be ignored as an early symptom. As a rule, this feeling disappears in the second trimester (although other reasons for fatigue may take over by then and cause the symptom to persist). Regular exercise is the best cure for fatigue in pregnancy, paradoxical as it may seem.
Knowing for Sure
It is possible to diagnose pregnancy by physical examination in the physician’s office, but this is done very infrequently in these days of home pregnancy tests. It is very difficult to diagnose by examination alone until 6 to 8 weeks gestation, by which time most women will have found out one way or another.
Definitive testing for pregnancy these days is done by testing for hCG, either in urine or in blood. The newer home pregnancy tests are just about as accurate as laboratory testing, both being correct about 97 to 98 percent of the time. The first-morning urine should be used since the hCG hormone is more concentrated then. A test will be positive when the hCG level is at least 25 mIU, which occurs about 4 to 6 weeks after the first day of the last menstrual period. It is generally advisable to wait about two weeks after missing a period to test since that reduces the number of false positives (thereby reducing the cost of testing).
Once it is determined that the woman is pregnant, she should schedule an appointment for her first prenatal visit. The best time for this is usually between 10 to 12 weeks gestation since that is when we can expect to first hear the heart tones during the examination. There is no significant advantage to being seen earlier unless the woman is having problems. One should try to avoid being seen later than 14 weeks gestation since that causes problems with dating the pregnancy accurately.