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Objective: To identify the incidence of spontaneous preterm birth (SPTB) and indications for delivery in women with twin pregnancy stratified by chorionicity (monochorionic diamniotic and dichorionic diamniotic pregnancy).

Study Design: Multicenter retrospective cohort of all consecutive twin gestations from 2010 to 2017. They were stratified by chorionicity monochorionic diamniotic and dichorionic diamniotic pregnancy: Primary outcome was SPTB < 37 weeks. Secondary outcome was SPTB at <34, 32, and <28 weeks, gestational age at delivery and indications for delivery: maternal and fetal. Analysis: t-test, Fisher’s exact test and multivariable logistic regression.

Results: 510 women with twin pregnancies were identified. 158 (30.9%) were monochorionic diamniotic pregnancies, and 352 (69.0%) were dichorionic pregnancies. The gestational age at delivery was significantly shorter in the monochorionic compared to the dichorionic group of about 2 weeks (MD -2.20 weeks, 95% CI -2.76 to -1.64). Twins with a monochorionic pregnancy had a significantly higher risk of SPTB <37, <34 and <32 weeks. They also have higher incidence of fetal indication for delivery and increased spontaneous onset of labor at any given gestational age. Maternal complications were similar on both types of twin pregnancies

Conclusion: Twins with monochorionic pregnancy had a higher rate of SPTB <37, <34 and <32 weeks and fetal indications for preterm delivery compared with dichorionic pregnancies. This information will assist in counseling patients with twin pregnancy regarding their individual, maternal, fetal and SPTB risk at different gestational ages.

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poster, poster presentation, obstetrics, gynecology, spontaneous preterm delivery, twin pregnancies, chorionicity, preterm birth


Medicine and Health Sciences | Obstetrics and Gynecology

Twin pregnancies and incidence of spontaneous preterm delivery stratified by chorionicity