Comparison of obstetric outcomes in twin pregnancies after in vitro fertilization, ovarian stimulation and spontaneous conception

Objective: To compare the outcomes of liveborn twin gestations conceived after in vitro fertilization (IVF) or ovarian stimulation with spontaneously conceived twin pregnancies. Methods: A review of all twin gestations delivered at Winthrop-University Hospital from 1 January 1999 to 31 December 2000. Women who underwent fetal reduction or had a demise of one twin were excluded. Maternal demographics, antepartum complications, mode of delivery and perinatal outcome were compared. Results: Sixty pregnancies were conceived after IVF, 34 were conceived by ovarian stimulation and 101 were spontaneously conceived. Women in the IVF group were older (p < 0.001), were more often 35 years or older (p < 0.001) and primiparous (p = 0.005). More women in the ovarian stimulation group had a poor obstetric history (p = 0.04). Spontaneous gestations had a higher incidence of monochorionic placentations (p = 0.002). There were no differences in gestational age at delivery, antepartum complications, or mode of delivery. There were fewer low-birth-weight neonates in the IVF group (odds ratio 0.59, 95% confidence interval 0.35-0.98; p = 0.03) than in the spontaneous group, but the difference disappeared when only the dichorionic pregnancies were compared. Other neonatal outcomes studied were the same among groups. Conclusion: Twin gestations conceived following IVF and ovarian stimulation appear to have similar outcomes to spontaneously conceived twin gestations.