The risk of birth defects after assisted reproduction

Abstract

Purpose Aim of this study was to investigate the association between congenital malformations and type of conception (spontaneous or medically assisted). Methods This is a population based study using data from the regional data base of Lombardy, a Northern Italian Region with a population of about 10 million inhabitants. Included in the study were 277,043 neonates born in Lombardy during the study period 2010-2012. Adjusted and unadjusted odds ratios (OR), and corresponding 95 % confidence intervals (CI), of congenital abnormalities were calculated using unconditional multiple logistic regression. Results A total of 7057 births (2.5 %) were reported after non spontaneous conception. Overall, the frequency of birth defects was 4.4 % among births after spontaneous conception and 6.7 % among births after non spontaneous ones (OR= 1.67, 95%CI=1.5-1.9). The association disappeared after taking into account the confounding effect of maternal age and factors associated with non spontaneous conception. The crude OR of abnormalities was higher than unity for any defect (OR=1.67, 95%CI=1.5-1.9), multiple defects (OR=1.76, 95%CI=1.3-2.3), cardiovascular (OR=2.05, 95%CI=1.8-2.4), musculoskeletal (OR=2.05, 95%CI=1.7-2.5) and metabolic system abnormalities (OR=1.97, 95%CI=1.1-3.5). Almost all these associations, however, disappeared after taking into account potential confounding with the exception of musculoskeletal defects (adjusted OR=1.31, 95%CI=1.1-1.6). In this case also, if adjustment for multiple comparison is taking into account, results did not reach statistical significance. Conclusions The results of this analysis confirm the recently emerging view that the increased frequency of birth defects observed after ART/medically induced ovulation only is largely due to confounders.

Comparison of neonatal outcomes and live-birth defects after progestin-primed ovarian stimulation versus conventional ovarian stimulation for in vitro fertilization

“…Some meta-analyses have suggested that infants, both singletons and multiples, born following ART are at increased risk of perinatal complications and birth defects compared with spontaneous conceptions. [ 39 , 40 ] Meanwhile, the latest available review on the outcome of assisted reproduction concludes that some of the risks to infants born following ART do not arise as a result of the applied techniques or treatments but rather from the underlying health risks of being subfertile. [ 41 , 42 ] Therefore, subfertile couples should improve their health statuses before undergoing ART.…”

Estimating the Risk of Monochorionic Twins in IVF Pregnancies From the Perspective of a Prenatal Diagnosis Unit

“…In other words, if blastocyst transfer, for example, proves to be a risk factor for MZT, the figure emerging from our analysis may change in the near future (data here refer to the period 2007-2011 when the blastocyst strategy was uncommon in our region). Fourth, as controls we referred to a population-based rate as estimated in a recent study of our group in the same geographical area (Parazzini et al, 2015). This choice presents some limitations.…”

The health outcomes of human offspring conceived by assisted reproductive technologies (ART)

“…[42][43][44][45][46][47] However, it is not entirely clear if the contributing factor is the ART procedure, or the underlying infertility itself. One Italian study of >7000 infants born after ART or ovulation induction suggested the increased prevalence of birth defects associated with non-spontaneous conception was largely due to confounding factors such as maternal age, 48 which is associated with poorer oocyte quality, mitochondrial dysfunction, aneuploidy and epigenetic alteration. 49 A large Danish longitudinal study found singletons born of infertile couples who conceived naturally (time to pregnancy >12 months) or after infertility treatment including different types of ART or surgeries had a higher prevalence of congenital malformations compared with singletons born of fertile couples (time to pregnancy ⩽12 months).…”