The influence of assisted reproductive technology on growth discordance in dichorionic twin pregnancies

Objective: We examined the relation between first-trimester crown-rump length (CRL) discordance and birth weight discordance in dichorionic twin pregnancies conceived by assisted reproductive technology ( ART). Methods: We examined 101 nulliparous dichorionic twin pregnancies producing male-male or female-female infants conceived spontaneously (n = 38) or following in vitro fertilization and embryo transfer (n = 63). Results: There were no significant differences in CRL disparity or birth weight discordance between spontaneous and ART-conceived dichorionic twin pregnancies. There was a positive correlation between CRL disparity and birth weight discordance in ART-conceived twin pregnancies (r(2) = 0.22, p = 0.02), while there was no such correlation in spontaneous pregnancies (r(2) = 0.02, p = 0.40). Conclusion: In ART-conceived dichorionic twin pregnancies, CRL disparity may be associated with birth weight discordance. Copyright (c) 2007 S. Karger AG, Basel.