Monozygotic twinning is not associated with zona pellucida micromanipulation procedures but increases with high-order multiple pregnancies.
Between January 1, 1995 and December 31, 2001, 5,310 cycles were performed in the IVF Unit, Sheba Medical Center, Israel, resulting in 1,066 clinical pregnancies. There was no difference in the rate of pregnancies containing monozygotic twins after zona pellucida micromanipulation procedures (0.9%) compared to conventional insemination (1.0%) (6/677 vs. 4/389).
Shai E
SE
Elizur
Jacob
J
Levron
Alon
A
Shrim
Eyal
E
Sivan
Jehoshua
J
Dor
Adrian
A
Shulman
D001755:Blastocyst / Q000166:cytology / Q000648:ultrastructure; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data*; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods / Q000706:statistics & numerical data; D014430:Twins, Monozygotic; D015044:Zona Pellucida / Q000648:ultrastructure*