A study carried out in California has shown that there are more obstetrical and perinatal complications in the case of surrogacy by IVF than with natural pregnancy. All of the surrogate mothers taking part in this study had initially conceived at least one child naturally with close monitoring of the pregnancy and birth. This allowed results to be compared without taking the uterine environment factor into account. Twin pregnancies (33% incidence rate with surrogacy, 1% in natural pregnancy) were not included in the results.
Thus the gestational age at delivery is significantly lower in the case of surrogacy compared to natural pregnancy. The incidence of premature births is much higher (10.7% vs. 3.1%) and more children are born with a low birth weight (7.8% vs. 2.4%).
Regarding the mother, there are significantly more obstetrical complications during surrogacy. Increases in gestational diabetes, hypertension, amniocentesis, placenta praevia (poor implantation of the placenta), the need to take antibiotics during labour and the number of births by Caesarean section were recorded in particular.
As earlier studies have already highlighted similar findings with medically assisted reproduction, these data can rule out one of the reasons put forward, namely that ovarian hyperstimulation could affect the uterine environment. These results therefore suggest that medically assisted reproductive procedures have a detrimental effect on the embryo, which will inevitably impact on mother and child.