Effect of spontaneous pregnancy reduction on obstetric outcome.

OBJECTIVE: To determine if obstetric outcome is compromised in pregnancies in which a spontaneous pregnancy reduction (SPR) occurred in the first trimester. STUDY DESIGN: Case-control study. Results: First-trimester SPR was diagnosed in 29 (27.8) of 104 twin pregnancies and 10 (28.6%) of 35 quadruplet pregnancies. Of these 53 patients, 15 were excluded from the analysis. In the remaining 38 women with SPR, vaginal bleeding occurred in 2 (5.3%) as compared to 7 (8.3%) of the controls. Pregnancy-induced hypertension occurred in 4 (10.5%) of SPR pregnancies as compared to 9 (10.7%) of control pregnancies. When compared to respective controls, there were no significant differences in the birth weights or gestational age at delivery of pregnancies spontaneously reduced to singletons (SPR, 38.5 weeks; controls, 38.2 weeks), twins (SPR, 36.2 weeks; controls, 34.4. weeks) or triplets (SPR, 31.0 weeks; controls, 32.0 weeks). CONCLUSION: SPR can be recognized in > 25% of multiple pregnancies diagnosed in the early first trimester. Our data suggests that SPR is not associated with decreased gestational age at delivery, reduced birth weight or increased incidence of pregnancy induced hypertension.