MULTIFETAL REDUCTION INCREASES THE RISK OF PRETERM DELIVERY AND FETALGROWTH RESTRICTION IN TWINS - A CASE-CONTROL STUDY

Objective: To compare pregnancy outcome in twin gestations resulting f rom multifetal reduction to ''primary'' twin pregnancies derived from either spontaneous conception of infertility therapy. Design: Case-con trol study. Setting: University-affiliated tertiary center. Patient(s) : Multifetal pregnancies (quadruplets or more) reduced to twins (group A) compared with twin gestations conceived either spontaneously (grou p B) or through infertility therapy (group C). Intervention(s): Multif etal reduction for group A; perinatal care for groups A, B, and C. Mai n Outcome Measure(s): Comparison of perinatal complications between gr oups including antepartum bleeding, premature membrane rupture, and pr eterm labor. Neonatal outcomes compared including gestational age at d elivery, birth weight, incidence of fetal growth restriction, and twin discordancy. Result(s): A higher incidence of idiopathic preterm labo r was noted in group A cases (14/18) compared with either of the contr ol groups (B: 26/54, or C: 24/54). Ay a consequence, group A had the l owest gestational age at delivery (32.6 +/- 3.9 weeks) compared with g roups B (33.6 +/- 4.4 weeks) and C (36.0 +/- 3.4 weeks). Corresponding birth weights of both first- and second-born twins were significantly lower in group A compared with group C, whereas the birth weight comp arison between groups A and a showed a nonsignificant difference. The proportion of pregnancies in which one or bath twins weighed less than the 10th percentile was greatest in group A pregnancies (A: 5/18 vers us C: 5/54). Discordant birth weight among twin pairs was proportionat ely greater for group A cases at both the 20% and 30% discordance leve ls. Conclusion(s): Twin gestations resulting from multifetal reduction are at increased risk Cor preterm birth, fetal growth restriction, an d discordancy when compared with fertility therapy-derived, nonreduced twins.