A Comparison of Pattern of Pregnancy Loss in Women with Infertility Undergoing IVF and Women with Unexplained Recurrent Miscarriages Who Conceive Spontaneously
OBJECTIVE To determine whether women with two or more previous spontaneous abortions of unknown etiology, by conventional testing criteria, have a different rate of subsequent fetal loss than controls after ultrasonic documentation of fetal cardiac activity. METHODS Medical records were reviewed from 185 women with spontaneous abortion of unknown etiology. Of these women, 91.9% were found to have evidence of cellular immunity to trophoblast and were treated with progesterone for immunosuppression. Ultrasound evaluation was obtained at 5-6 weeks' gestation to document fetal cardiac activity. A control group of 63 women was also studied. All women were followed for pregnancy outcome. RESULTS A total of 248 pregnancies were identified from the 185 study patients with multiple spontaneous abortions. Fetal cardiac activity was visualized by ultrasound in 209 pregnancies from 171 study subjects; of these, the outcomes of 208 pregnancies were known. The rate of spontaneous abortion after ultrasound documentation of fetal cardiac activity was 22.7%. Neither maternal age nor number of previous losses was associated with an increased incidence of spontaneous abortion following documentation of fetal cardiac activity. The rate of spontaneous abortion in the control group after documentation of fetal cardiac activity was 3.3%. CONCLUSION These data may help clinicians give couples who have experienced recurrent pregnancy loss a more realistic prognosis for pregnancy success once fetal cardiac activity has been confirmed.