gynecology and obstetrics
Spontaneous Abortion
Introduction
Spontaneous abortionis pregnancy loss before 20 weeks gestation. Diagnosis is by pelvic examination, measurement of beta subunit ofhuman chorionic gonadotropin, and ultrasonography. Treatment may be expectant management or with medication or procedural uterine evacuation. Approximately 10 to 15% of confirmed pregnancies spontaneously abort, and over 80% of spontaneous abortions occur in the first trimester ( General references ). Fetal death and early delivery are classified as follows ( General references , Spontaneous abortion: Pregnancy loss before 20 weeks gestation Fetal death ( Stillbirth ): Fetal death at ≥ 20 weeks Preterm Labor : Delivery of a live fetus between 20 weeks and 36 weeks/6 days The American College of Obstetricians and Gynecologists defines a first-trimester pregnancy loss as a nonviable, intrauterine pregnancy with either an empty gestational sac or a gestational sac containing an embryo or fetus without fetal heart activity within the first 12 6/7 weeks of gestation ( General references ). Terminology for abortion varies based on several factors. Definitions specify the stage of development, embryonic (≤ 10 weeks of gestation) or fetal (≥ 11 weeks). For spontaneous abortion, descriptions are based on the location of the fetus and other products of conception and whether there is cervical dilation (see table). 