We often see twin carriages on the street, twin brothers or identical twins (or not so much) of different ages … in Spain the number of multiple pregnancies has progressively increased in recent years, which is usually associated with the use of assisted reproductive techniques.
There are several evidences that show the importance of opting for a single embryo transfer (SET) and minimize multiple pregnancies, but the current twin pregnancy rate in relation to reproductive treatment is around 20%.
“Aware of this situation and consistent with scientific knowledge, IVI’s current policy involves opting for single embryo transfers whenever possible, and this is reflected in our data. The set has gone from 22% in 2009 to 88% in 2018 in the clinics that IVI has throughout the Spanish territory, which is a 75% reduction in the last decade. The reason why this strategy has been implemented for almost 100% of our treatments is because we know better the mechanisms that regulate endometrial receptivity, techniques such as Timelapse, which allows us to see the evolution of the embryo, or improvements in the embryo selection thanks to pre-implantation genetic diagnosis, to rule out embryos with chromosomal abnormalities. All this complemented by the educational work of both medical professionals and the population so that it is understood that multiple gestation is not an objective to be achieved, but rather a complication to avoid ”, comments the Dr. Agustín Ballesteros, director of IVI Barcelona, Lleida and Girona.
To date, 1 in 80 spontaneous pregnancies is twins, and in the case of women and couples who choose reproductive medicine, the ratio drops to 1 in 4, which makes clear the need to face a reality little advantageous like this.
“According to data from the Spanish Fertility Society (SEF), the transfer of two embryos has decreased from 72% in 2012 to 56% in 2016, while the transfer of a single embryo has increased from 20 to 42%. We are on the right track, however, reproductive efficiency in humans is very low and this circumstance can worsen with increasing maternal age at the time of the first pregnancy. This delay in maternity implies an increase in the demand for assisted reproduction treatments. Women and couples with reproductive problems often choose to ask their specialist for the transfer of more than one embryo, in the belief that this will increase the chances of achieving a full-term pregnancy. However, the results published in different studies indicate that there are no differences in the cumulative pregnancy rate with a single embryo versus the clinical pregnancy rate when two are transferred, both in cycles with own gametes and donor ones, to which they add up the risks that multiple transfers pose to both the mother and her baby, ”says Dr. Ballesteros.
Complications associated with multiple pregnancies
The main complications related to multiple pregnancies that can affect the mother are: higher proportion of cesarean sections, hypertension, premature rupture of membranes, threat of premature delivery or a higher incidence of postpartum hemorrhage.
Regarding the newborn, multiple gestation can be accompanied by prematurity (something very common in this type of pregnancies), congenital defects, delayed intrauterine growth, low birth weight or even perinatal mortality.
The main objective of assisted reproduction treatments is to have healthy live newborns and that these treatments do not pose a risk to the mother.
“On this basis, and despite the fact that the elective transfer of a single embryo is not currently a standard practice in all assisted reproduction centers, the truth is that, in Spain, in 3.5% of cases three embryos are being transferred and in 65%, two embryos. These data are less pronounced in the cases of donation of gametes, although the transfer of two embryos is still the majority. It is therefore necessary, and as we have well commented, to establish policies to reverse this situation ”, concludes Dr. Ballesteros.
Towards effective policies to reduce multiple pregnancies
Did you know that the healthcare cost of multiple pregnancies is double the cost of single pregnancies?
And not only that, but the costs associated with childbirth are 1.7 times more expensive than those of a single pregnancy.
“In fact, we have even considered whether it is necessary to legislate the number of embryos to transfer, as they have done in the Belgian model for public health, in which all treatments where an embryo is transferred are reimbursed. The impact of this policy is translated into 50% of cycles with SET, a decrease in the multiple pregnancy rate from 27% to 11%, a maintenance of success rates and a lower proportion of admission to the pediatric ICU and of treatments for sequelae in newborns. Short-term savings are set at 7 million euros and long-term at 50-70 million euros. However, we believe that it is not necessary to legislate, and it is probably sufficient to promote these practices through a convinced embryologist or gynecologist, together with a good contribution of information to women and couples ”, adds Dr. Ballesteros.
The great scientific advances achieved in the reproductive field outline great opportunities for SET, because with cutting-edge techniques and technology such as those we use, the results achieved lead us towards constant improvement with the best guarantees for mothers and their babies.
We keep investigating!
