Transfer of zona-free embryos improves outcome in poor prognosis patients: a prospective randomized controlled study.
Assisted zona hatching (AZH) has been used in IVF programmes for several years. Recently one group has reported successful pregnancies after transfer of zona-free blastocysts. The aim of our study was to evaluate outcomes after transfer of zona-free day 3 embryos. Two groups of women undergoing intracytoplasmic sperm injection (ICSI) were included in the study. Group A consisted of 52 women under the age of 40 years undergoing their first ICSI attempt. They were alternately randomized to receive zona-free embryos (27 women) and zona-intact embryos (25 women). The second group (group B) included 71 women with a poor prognosis, as defined by age 40 years or more, and/or at least two previous failed IVF/ICSI attempts. They were randomized in a 3:4 ratio (30 zona-free, 41 zona-intact). Acid Tyrode's solution was used to remove the zona pellucida before embryo transfer on day 3 after oocyte collection. The pregnancy rate in group A was not significantly improved when the zona pellucida was removed. However, in the poor prognosis group B, zona removal resulted in a significantly higher pregnancy rate when compared with controls (23 versus 7.3%). We conclude that complete removal of the zona pellucida can improve pregnancy rates in women with poor IVF/ICSI prognosis.
Mansour
R T
RT
The Egyptian IVF-ET Centre, Cairo 11431, Egypt.
Rhodes
C A
CA
Aboulghar
M A
MA
Serour
G I
GI
Kamal
A
A
D000328:Adult; D004624:Embryo Transfer / Q000379:methods*; D004622:Embryo, Mammalian / Q000502:physiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D018873:Pregnancy Rate; D011272:Pregnancy, Multiple; D011446:Prospective Studies; D012996:Solutions; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods*; D016896:Treatment Outcome; D015044:Zona Pellucida
D012996:Solutions