The Embryos to Transfer in IVF/ICSI
"last update: 6 August 2024"
- Executive Summary
● It is recommended that clinicians should perform single embryo transfer (strong recommendation).
● Medical SET is indicated for women in whom multiple pregnancy represents an a priori increased risk compared to the overall population such as women with congenital uterine anomalies (e.g. septate uterus), bad obstetric history (e.g. previous premature birth <32 gestational weeks) and severe systemic diseases (e.g. insulin-dependent diabetes).(strong recommendation).
● Elective single embryo transfer should be used in cases with PGTA (strong recommendation) .
● It is recommended to encourage eSET in good-prognosis patients although a maximum of two embryos is allowed after proper counseling. In cases of DET, a written consent explaining the risks of multiple pregnancies should be signed. (conditional recommendation).
➡️Good prognosis patients include:
- First or second IVF attempt whether fresh or frozen ET and excellent embryo quality by morphology. It should be emphasized that DET may have in most studies a higher LBR compared to eSET, but this is at the expense of significantly higher MPR. The higher MPR with DET is a consistent finding whether the embryos are fresh or frozen, cleavage stage or blastocysts, good-quality or mixed (one good & one poor-quality) or two poor-quality embryos.16-21
- Surplus embryos of sufficient quality to warrant cryopreservation, or in cases of FET, the availability of vitrified high-quality day 5 or day 6 blastocysts for transfer.22
- Previously pregnancy/live birth particularly if resulting from IVF. This is associated with an increased chance of LBR and MPR.23,27 Other studies confirmed the association of previous pregnancy with LBR but with no correlation with MPR.27,30
● Females <38 years of age should be strongly encouraged to transfer one embryo especially if they meet the criteria of good prognosis. Emphasis on eSET is highly recommended if the female age is <35 years (strong recommendation).
● Females between 38 and 40 years are allowed to transfer two embryos, however, eSET can still be encouraged especially if they have good prognosis. (strong recommendation).
● Females 41-42 years of age should receive no more than two embryos. (strong recommendation).
● In FET cycles, the decisions should be based on the age of the woman when the embryos were cryopreserved. (strong recommendation).
● Trans-abdominal ultrasound guidance during embryo transfer is recommended as it improves clinical pregnancy rate and live-birth rate. (strong recommendation).
● It is recommended to use a soft embryo transfer catheter as it improves the pregnancy rate in fresh and Frozen cycles. (strong recommendation).
● Anesthesia during embryo transfer does not improve pregnancy rates. Given that there are added risks associated with anesthesia, routine anesthesia is not recommended in IVF-embryo transfer. ( strong recommendation).
● It is recommended to place the catheter tip in the upper or middle (central) area of the uterine cavity, greater than 1 cm from the fundus as this decreases embryo expulsion and optimizes pregnancy rates. (Conditional recommendation).
● It is not recommended to prescribe antibiotics with embryo transfer. (conditional recommendation).
● Bed rest is not recommended after embryo transfer as it does not increase pregnancy rates (Strong recommendation).
● No enough evidence to recommend routine removal of cervical mucous from the cervix before embryo transfer (conditional recommendation).
● There is No specific time to recommend removal of the embryo transfer catheter after embryo transfer. (conditional recommendation).
