Congenital heart defects up preterm birth risk
27 Jan 2021
Researchers discovered that one of the six genes, which affect whether a woman is likely to have a preterm baby, is linked with the metabolism of selenium.Congenital heart defects (CHD) seem to aggravate the risk of preterm birth (PTB), a new study reports.
Drawing from a national birth registry, the researchers identified 1,092,740 births between 1 January 1997 and 31 December 2013. Of these, 71,707 were preterm births. After exclusions, 1,040,474 liveborn singletons remained eligible for analysis, of whom 5,089 had CHD.
In infants with CHD, 13.8 percent of all singleton births were preterm, as opposed to only 4.7 percent in the general population. Spontaneous PTBs were likewise more common among children with CHDs (7.5 percent vs 2.7 percent).
Multivariable Cox proportional hazards regression analysis revealed that the presence of CHD more than doubled the risk of PTB relative to the general population (adjusted hazard ratio [HR], 2.1, 95 percent confidence interval [CI], 1.9–2.4).
Of the CHD subtypes, pulmonary stenosis combined with a septal defect had the strongest impact on PTB risk, increasing its likelihood by more than five times (adjusted HR, 5.2, 95 percent CI, 3.7–7.5). Pulmonary stenosis or atresia, tetralogy of Fallot, and an interrupted aortic arch also had similar effects, but to a lesser degree.
The principal findings were robust to sensitivity analyses, where infants with known congenital syndromes were excluded or when foetal deaths were included. Removing smoking and pre-eclampsia from the statistical models also did not change the obtained estimates, neither did additional adjustments for previous spontaneous PTBs, maternal thyroid disease or asthma, or body mass index.