Single-embryo transfer: a key strategy to reduce the risk for multiple pregnancy in assisted human reproduction.

In the early days of assisted reproductive technology (ART), the main target was achieving gestation. Success rates were low, and multiple embryo transfers became common practice, with multiple pregnancies being 20 times higher than in natural conception. Multiple pregnancy is associated with a higher risk of complications for the mother and the baby than a singleton pregnancy.

Quadruple pregnancy after post-IVF/ICSI transfer of blastocysts.

Clinical case of a quadruple pregnancy (monochorionic diamniotic and dichorionic diamniotic) after the transfer of two blastocysts generated by intracytoplasmic sperm injection (ICSI). This is the case of a 29-year-old woman patient with transfer of two blastocysts after long cultivation of 6 embryos generated by ICSI and vitrified on day +3. This revealed quadruple clinical pregnancy (monochorionic diamniotic and dichorionic diamniotic) of 56 days of evolution by transvaginal ultrasound.

Comparison of two commercial embryo culture media (SAGE-1 step single medium vs. G1-PLUSTM/G2-PLUSTM sequential media): Influence on in vitro fertilization outcomes and human embryo quality.

Objective: To compare embryo quality, fertilization, implantation, miscarriage and clinical pregnancy rates for embryos cultured in two different commercial culture media until D-2 or D-3.

Methods: In this retrospective study, we analyzed 189 cycles performed in 2016. Metaphase II oocytes were microinjected and allocated into single medium (SAGE 1-STEP, Origio) until transferred, frozen or discarded; or, if sequential media were used, the oocytes were cultured in G1-PLUSTM (Vitrolife) up to D-2 or D-3 and in G2-PLUSTM (Vitrolife) to transfer.