Comparative study of perinatal outcome of dichorionic and trichorionic iatrogenic triplets

Objective The purpose of this study was to compare the perinatal outcome of dichorionic and trichorionic triplets who were conceived by assisted reproductive techniques. Study design In this retrospective study, the maternal, neonatal, and chorionicity data were collected from 106 sets of trichorionic triamniotic and 34 sets of dichorionic triamniotic triplet pregnancies who were conceived by assisted reproductive techniques between January 1986 and December 2000. Perinatal and neonatal data were evaluated in relation to chorionicity and intertriplet birth weight discordance. Results The dichorionic triamniotic triplets have an 8-fold higher risk of perinatal death than trichorionic triamniotic gestations (odds ratio, 7.9; 95% CI, 4.4-14.0; P< .001). This is attributed to a higher risk of very low birth weight (P< .01), delivery at <30 weeks of gestation (P< .001), and premature rupture of membrane (P< .001) in dichorionic triamniotic triplets compared with trichorionic triamniotic pregnancies. Twin-twin transfusion syndrome (odds ratio, 11.5; 95% CI, 4.8-27.7; P< .001), delivery at <30 weeks of gestation (odds ratio, 40.5; 95% CI, 16.9-97; P< .01), premature rupture of membrane (odds ratio, 6.7; 95% CI, 3.8-11.9; P< .01), and nulliparity (odds ratio, 3.1; 95% CI, 1.6-6.1; P< .05) had independent effects on perinatal loss rate. Conclusion The dichorionic triplets have an 8 times higher perinatal mortality rate than trichorionic triamniotic pregnancies.