Pregnancy Loss

Spontaneous abortion is the involuntary loss of a first trimester pregnancy and typically involves cramping and vaginal bleeding. The cramping is a symptom of cervical dilatation that allows for expulsion of the products of conception through the cervix and out through the vagina. Loss is very common with 15 to 20 percent of all known pregnancies ending in spontaneous abortion. Some sources estimate that the burden of unknown pregnancy loss (meaning women who do not yet know they are pregnant) is actually between two and three times higher.

It is important for women experiencing cramping and vaginal bleeding during pregnancy to be seen by a physician right away. She may be experiencing a missed or incomplete abortion where the fetus has died but not all of the uterine contents have been expelled. If this is the case, the woman will need to undergo a procedure known as dilation and curettage to empty the uterus safely. In some situations, it may also be possible to use a medication to dilate the cervix and allow the products of conception to pass without surgical intervention.

Over the course of a pregnancy, the risk of fetal loss decreases but never reaches zero. It is possible to lose a pregnancy in the second and third trimesters, but it is much less common. When the fetus is larger, removal from the uterus is more complicated [Page 1417]and women may either have to be stimulated to dilate their cervix enough to deliver the dead fetus or undergo a dilation and evacuation where the fetus is removed from the uterus manually by a physician. Many women prefer the second option to avoid the psychological trauma of delivering a dead fetus; however, in many resource-deprived settings, this may not be an option.

Pregnancy loss, even repeated pregnancy loss, while devastating for some couples, does not signal the end of childbearing ability.

The most common reason for early term loss is chromosomal anomalies in the developing embryo. In early stages of development, there are numerous rapid cycles of DNA replication and cell division, creating opportunity for error. Or the conceptus may suffer from some intrinsic defect, making it incompatible with life. In other cases, fertilization and cell division may proceed without error, but the embryo is unable to implant successfully into the uterus for continued growth and development.

Recurrent pregnancy loss is defined as three or more consecutive losses before 20 weeks gestation. Reasons include structural defects of the uterus, insufficient pregnancy-supporting hormones, parental genetic anomalies, autoimmune disorders, thrombophilias, and premature cervical dilation. In about 50 percent of cases, no cause can be identified. Many of these causes can be treated, so it is important for women to seek counseling and treatment from a physician.

Pregnancy loss, even repeated pregnancy loss, while devastating for some couples, does not signal the end of childbearing. After one loss, the chance of another is less than 30 percent with between 80 to 90 percent of women going on to have a successful next pregnancy. Even for women with recurrent pregnancy loss, the chances of a future live birth are 55 to 60 percent.

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