[Diminishing the risk of multiple pregnancies in in vitro fertilization: from selective transfer of two embryos to that of one blastocyst?].
The risk of multiple pregnancy after IVF needs to be drastically reduced. Several policies can be applied including the transfer of a maximum of three embryos to all patients, the fertilization of a maximum of three oocytes or a selective reduction of the number of transferred embryos. The first policy previously applied at the Fertility Clinic at Erasme Hospital until 1996, transferred two good quality embryos to patients with at least three good embryos. If this policy demonstrated that patients with two transferred embryos had similar chances of pregnancies compared to patients with three transferred embryos, it failed to sufficiently decrease the number of multiple pregnancies. The second policy applied since 1997, transferring a maximum of two average or good embryos to all patients aged under 35 years and with less than 3 previous attempts, demonstrated that while preserving the chances of pregnancy for these patients, it decreased by 20% the number of multiple pregnancies and almost eliminated triplets. With the improvement of culture media, it is now possible to culture embryos in vitro for a longer period and therefore transfer embryos with proven viability at a time corresponding more to in vivo physiological conditions. The implantation rates for these embryos, for patients with at least 4 previous attempts can reach 40%. If these results persist, it would be possible to transfer blastocysts to all patients and perhaps move on to the replacement of a single embryo, a policy that will practically eradicate all multiple pregnancies.
Devreker
F
F
Département de Gynécologie-Obstétrique, Hôpital Erasme, U.L.B.
Emiliani
S
S
Revelard
P
P
Govaerts
I
I
Vannin
A S
AS
Englert
Y
Y
D000328:Adult; D001530:Belgium / Q000453:epidemiology; D004624:Embryo Transfer / Q000379:methods* / Q000639:trends*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods* / Q000639:trends*; D006785:Hospitals, University; D006801:Humans; D016134:Organizational Policy; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D011272:Pregnancy, Multiple
Diminuer le risque de grossesse multiple en fecondation in vitro: du transfert selectif de 2 embryons a celui d'un seul blastocyste?