English to Russian Medical Genetics Chromosome disorders

Контекст:
Как бы вы перевели следующее предложение: Persistence of prenatal cardiac structures such as persistent ductus arteriosus (PDA) has also been reported, which again often resolves without the need for surgical intervention?

Из британской брошюры о хромосомных заболеваниях.

Более широкий контекст:
Heart (cardiac) conditions have been described less often in the medical literature than among Unique families. Out of 37 children, a heart condition was mentioned in 18 (49 per cent) in the literature, whereas 86 per cent of Unique families reported a heart condition (Hiraki 2008; Unique).
The most common conditions seen in Unique children were holes between the upper or lower chambers of the heart (ventricular septal defects (VSD) or atrial septal defects (ASD)) which were present at birth. In many children these defects heal (close) naturally without surgery. Persistence of prenatal cardiac structures such as persistent ductus arteriosus (PDA) has also been reported, which again often resolves without the need for surgical intervention. Two Unique children had pulmonary stenosis (a narrowing of the blood vessel leading from the heart) or sub-aortic stenosis (a narrowing of the area below the aortic valve (the valve that allows blood into another blood vessel leading from the heart)). In both pulmonary and sub-aortic stenosis the heart has to work harder to pump blood. Two further Unique children had Fallot’s tetralogy, a complex heart condition (involving both a VSD and pulmonary stenosis) that required surgical correction (Unique). Heart conditions occur irrespective of breakpoints, affecting those with breakpoints in 1q42, 1q43 and 1q44 as well as those with interstitial deletions (Hiraki 2008; Unique).