Monoamniotic twinning and zona manipulation: A survey of US IVF centers correlating zona manipulation procedures and high-risk twinning frequency

Purpose: An anonymous survey of NF centers in the United States was employed to calculate frequencies of multiple gestation, monozygotic multiple gestation, and monoamniotic multiple gestation. Rates for zona-manipulated (ICSI, SUZI, zona drilling, mechanical assisted hatching) and non-manipulated pregnancies were compared. Results: From 42 IVF centers in the United States, a total of 143 pregnancies was ascertained from zona-manipulated cycles. A multiple gestation frequency of 16.1% was reported. Five monoamniotic twin gestations were identified: four from manipulated cycles and one from a non-manipulated cycle. All monoamniotic twin gestations resulted in live births, although three showed significant intrauterine growth discordance and one newborn was diagnosed with the VATER malformation sequence. Conclusions: Monoamniotic multiple gestations may be increased in zona-manipulated cycles. The potential obstetric risks and complications of zona manipulation should be discussed with patients.