Access to IVF or in-vitro fertilisation therapy has become more pronounced in recent days owing to its success rates. However, the number of embryos to be transplanted during the process is still a matter of controversy. According to experts from the University of Bristol, implantation of 3 or more embryos should be restrained for women across all ages.
In the study, about 124,148 IVF cycles that resulted in 33,514 live births were inspected. All parameters inclusive of live birth, low birth weight, multiple birth, severe preterm birth and preterm birth were scrutinized among women aged below, above or equal to 40 years.
Professor Debbie Lawlor from the University of Bristol’s and others commented, “Our findings provide some support for the transfer of two embryos in women older than 40 years, because the risks of preterm and low birth weight were lower than those in younger women. In older and younger women, the transfer of two embryos was associated with greatest live birth rates. A clear implication of our study is that transfer of three embryos should no longer be supported in women of any age.”
In the results, 2 or 3 embryo transfer seemed to be associated with greater risk for severe preterm birth and harmful prenatal outcomes. Live birth rate instances appeared to be higher during transfer of 3 embryos than 1 in all the subjects.
Also, transfer of 3 embryos seemed to be linked to lower live birth rate as compared to transferring 2 embryos in younger women. Moreover, the success rates of these women were similar to cases of 2 embryo transfer in older women. Importantly, the chances of severe preterm birth were specifically high during transfer of 3 embryos.
The authors concluded that switching over to IVF at the right age is crucial and is the deciding factor for success of the procedure. A co-operative decision of embryologists and clinicians ought to be considered before stepping onto the transfer process. In case of twin pregnancies or medical contraindications, transfer of more than 1 embryo may not be advisable, say experts.
The study is published in the journal, The Lancet.