Abortion, Late

There is no agreement in the medical community about the definition of a “late abortion.” The great majority of abortions are performed during the first 13 weeks of pregnancy, and most of the rest occur before the 21st week. For this discussion, therefore, “late” abortion is defined as any abortion performed after the 20th week of pregnancy. Abortions performed at this stage of pregnancy are more difficult and more potentially hazardous than those performed early in pregnancy.

In the first trimester of pregnancy, the embryo is quite small-between the size of a thimble or a finger. In the early second trimester (from 13 to 20 weeks), the fetus is larger, but the uterus is still small enough that a woman may not be aware that she is pregnant. This is especially true for a woman with irregular menses, a woman who thinks she is menopausal, or a young adolescent unfamiliar with the signs and symptoms of pregnancy. By the time the pregnancy has advanced to 21 or 22 weeks, however, it is much more likely that she will be aware of the pregnancy.

Terminating a pregnancy at 21 to 24 weeks is quite different than performing an abortion during the first six to eight weeks of pregnancy. The fetus is much larger in relation to the size of the uterine opening (the cervix) and it is surrounded by amniotic fluid. A critical complication in late abortion is being able to sufficiently open the cervix to permit expulsion or removal of the fetus without damaging the uterus. Another critical issue is preventing the amniotic fluid from entering the woman's circulatory system. If this occurs, it could kill the mother.

The second trimester is when some of the most dangerous, life-threatening conditions can arise during the course of the pregnancy. An example is preeclampsia, which, if untreated, can lead to eclampsia, a fatal combination of high blood pressure, kidney failure, liver failure, bleeding disorder, blindness, seizures, and stroke. Other complications appearing in the second trimester can include pregnancy-induced diabetes and hyperemesis gravidarum, the “uncontrollable vomiting of pregnancy,” which can be fatal. Serious fetal abnormalities or genetic disorders are most likely to be identified and diagnosed in the second trimester. These medical complications or fetal [Page 10]abnormalities account for a large proportion of decisions to have late abortions.