Reproductive Partners Fertility Blog » identical twins

Does IVF increase the chance of identical (monozygotic) twins?

Dr. Arthur Wisot FACOG — Tue, 20 Jul 2010 21:06:50 +0000

It does, at least according to a study in the July 2010 issue of Fertility & Sterility.

The authors surveyed 4976 clinical pregnancies from one large IVF center and found ninety-eight cases of monozygotic twins (MZTs) were diagnosed after first-trimester ultrasound evaluation (2% incidence). In naturally conceived pregnancies the incidence is about 0.25-0.5%.

The incidence in women transfering embryos from …

Monozygotic twinning not increased in blastocyst embryo transfer over cleavage stage transfer

Dr. Arthur Wisot FACOG — Tue, 16 Mar 2010 19:48:38 +0000

One of the discussions we may have with patients prior to a blastocyst transfer is the supposed increased chance of an embryo at the blastocyst stage splitting and becoming an identical twin pregnancy.

In this study in the February 2010 issue of Fertility and Sterility, the authors monitored almost 2000 IVF cycles and found in this group of single-embryo transfers there …