Fetal loss after early detection of heart motion in infertility patients. Prognostic factors.

OBJECTIVE

To evaluate the incidence and prognosticators of spontaneous abortion (< 20 weeks' gestation) in an infertile population after early documentation of fetal cardiac activity.

STUDY DESIGN

Retrospective chart review. We examined the incidence of spontaneous abortion in 231 clinical pregnancies with 259 fetuses documented to be viable by transvaginal sonography 28-38 days after ovulation. The population was an unselected group of infertility patients with no history of recurrent pregnancy loss. Maternal age and presence of multiple gestations were analyzed as separate variables by chi 2 testing.

RESULTS

The incidence of spontaneous abortion among all fetuses was 9.6% (95% confidence interval [CI], 6.1-13.2%) and among singleton gestations was 7.7% (95% CI, 4.0-11.3%). Women with multiple gestations were more likely to suffer spontaneous fetal loss as compared to women with singleton gestations (18 vs. 7.6%, P < .05). In addition, women aged 35 and above with singleton pregnancies showed a significantly increased rate of fetal loss (13.4 vs. 4.9%, P < .05) when compared with younger women.

CONCLUSION

Women > or = 35 years old and those with multiple gestations were significantly more likely to suffer late first- or early second-trimester fetal loss even after detection of fetal cardiac activity. These patients should be counseled differently than younger women with singleton pregnancies, and increased monitoring may be indicated.