Differences in congenital anomalies in unassisted conception vs. in vitro fertilization in dichorionic-diamniotic twin pregnancies.

OBJECTIVE

The aim of this study was to evaluate the incidence of congenital anomalies in dichorionic-diamniotic twins conceived with in vitro fertilization (IVF) vs. unassisted conception pregnancies in a large geographically diverse population.

DESIGN

This is a secondary analysis of data from a retrospective cohort study of twin pregnancies seen at 17 centers between December, 2011-February, 2020.

SUBJECTS: This study included dichorionic-diamniotic twins conceived unassisted, or by in vitro fertilization.

EXPOSURE: The exposure group is dichorionic-diamniotic twins conceived with IVF.

MAIN OUTCOME MEASURE: The primary outcome was presence of a congenital anomaly. Neonates with an abnormal newborn examination were evaluated for having a major or minor congenital anomaly and the major anomalies were further classified by organ system (cardiac, renal/genitourinary, gastrointestinal, and musculoskeletal).

RESULTS

Of the 968 dichorionic-diamniotic twin pregnancies included, 521 (53.8%) were conceived with IVF and 447 (46.2%) were conceived unassisted. Congenital anomalies were found in 70 pregnancies (7.23%). Of those, 37 were found in pregnancies conceived by IVF (52.9%) vs. 33 unassisted conception pregnancies (47.1). There were no significant differences between IVF and unassisted conception pregnancies for major anomalies or minor anomalies.

CONCLUSION

In this large cohort of twin pregnancies, there is no significant difference in the incidence of anomalies for dichorionic-diamniotic twin pregnancies conceived by IVF vs. unassisted conception pregnancies.