6. Periods during pregnancy.
Many women ask me about having regular periods during their pregnancies. They're concerned because Grandma or a cousin reported having periods every month during their pregnancies, and they wonder if it could happen to them. They swear that these periods during pregnancy really happened. It's false, all the swearing notwithstanding. Shedding a layer of menstrual tissue is not compatible with life. The closest thing we have to this is shedding of decidual tissue (see above). When Grandma swears that it happened, it's certainly the polite thing to listen with an open mind—just be sure to slam it shut by thinking about what's really going on in pregnancy. The cycling of hormones stops because a pregnancy causes the hormone levels to stay high. This is necessary for pregnancy to continue. There are no drops in hormone levels, which is what causes a period, except right before labor. Most likely, Grandma experienced a subchorionic hemorrhage (see above), bleeding intermittently, misinterpreted as cyclic.
Although the above instances describe the causes of bleeding that do not indicate miscarriage, still miscarriage should be ruled out if you have any bleeding at all. And when one considers that the cramping of a threatened miscarriage can feel exactly like the growing pains of a normal uterus, it is fortunate that there are other tools to give you peace of mind.
Blood tests can prove that the pregnancy hormone is increasing as expected, which confirms a healthy pregnancy; ultrasound can demonstrate the physical well-being of a growing baby by showing a healthy heart rate or by ruling out an ectopic (tubal) pregnancy. Although most miscarriages begin with first trimester bleeding, first trimester bleeding isn't always indicative of a miscarriage. Doctors always respect first trimester bleeding until a cause can be determined. Usually it has a good outcome. So although first trimester bleeding can cause a lot of anxiety and worry, your doctor can usually find something unrelated to the pregnancy—and treatable—to blame it on.
Courses of Treatment
Unfortunately, miscarriage can be a time-consuming event, and most couples wish to get it over with once they know for sure this pregnancy won't succeed. But your doctor will want to know such a thing with absolute certainty, because he wouldn't want to intervene against a normal pregnancy. While looking for all of the other innocent reasons to explain away bleeding, blood work and ultrasound are used to find answers as soon as possible.
There's nothing like seeing a normal fetal impression with a good fetal heart motion to reassure you when there are even the most troubling symptoms. Besides documenting the health of the fetus, ultrasound can put another worry to bed—ectopic pregnancy. Seeing the pregnancy within the uterus itself will rule out a pregnancy in a tube or anywhere else, except in the rare occurrence of twins—one in the uterus and one in the tube. And if there is an ongoing concern, like a subchorionic hemorrhage, serial ultrasounds weekly can watch a blood clot shrink away.
Progesterone is maintained at high levels throughout the pregnancy. Although a pregnancy can be in trouble with a low progesterone, most of the time the opposite is true: The progesterone is low because of a faulty pregnancy. There are absolute values that give obstetricians comfort (15-20 ng/ml). If the progesterone were to come back low, this could indicate a problem even if the hCG is reassuring (usually the hCG will not be reassuring with an abnormally low progesterone). Borderline low may warrant progesterone supplementation, but really low values can be assumed to be because of the likelihood of miscarriage.