Impact of preterm birth on the developing myocardium of the neonate

Abstract

BackgroundGlobally, ∼10% of infants are born before full term. Preterm birth exposes the heart to the demands of postnatal cardiovascular function before cardiac development is complete. Our aim was to examine, in hearts collected from infants at autopsy, the effects of preterm birth on myocardial structure and on cardiomyocyte development.Methods and resultsHeart tissue was collected at perinatal autopsies of 16 infants who died following preterm birth between 23 and 36 weeks of gestation, and survived for 1-42 days; the hearts of 37 appropriately grown stillborn infants, aged 20-40 weeks of gestation, were used for comparison. Using confocal microscopy and image analysis, cardiomyocyte proliferation, maturation, ploidy, and size were quantified, and interstitial collagen and myocardial capillarization were measured. Preterm birth resulted in a marked reduction in the proliferation of cardiomyocytes relative to age-matched stillborn infant controls (preterm vs. control P<0.0001). In contrast, preterm birth did not affect heart weight, capillarization, interstitial collagen or cardiomyocyte maturation, ploidy, and size.ConclusionsPreterm birth appears to lead to an abrupt reduction in cardiomyocyte cell division. This reduced cardiomyocyte proliferation in preterm infants may adversely impact upon the final number of cardiomyocytes which may reduce cardiac functional reserve, and impair the reparative capacity of the myocardium.

Regulation of cardiomyocyte maturation during critical perinatal window

“…The timely regulation of these changes is critical; for example, in pediatric patients, when the fetal-to-neonatal transition in circulation does not occur (often called 'persistent fetal circulation'), myocardial maturation may become delayed (Hines, 2013). In several studies conducted in both humans and other animals, premature birth was found to be associated with abnormal CM hypertrophy and nucleation and premature cell cycle cessation (Bensley et al 2010(Bensley et al , 2018Aye et al 2017). As a caveat, however, patients in these studies were often treated antenatally and/or postnatally with corticosteroids, which may in turn affect CM maturation (Agnew et al 2017).…”

Echocardiographic analysis of left ventricular function in term and preterm neonates at week 40 of postconceptional life

“…The cardiac cycle was analyzed as 3 flow waves: systolic S' wave, the neonates more vulnerable to circulatory collapse. 7 Preterm neonates often have persistent patent ductus arteriosus (PDA), which increases LV volume overload and leads to enlargement of the LV and left atrium and to mitral valve insufficiency. 8 Moreover, left-to-right flow through persistent PDA, which increases blood flow through pulmonary circulation and causes ductal steal, is associated with systemic hypotension.…”

Maternal peripheral blood platelet‐to‐white blood cell ratio and platelet count as potential diagnostic markers of histological chorioamnionitis‐related spontaneous preterm birth

“…Preterm birth (also named premature birth) is a common obstetrical disorder characterized by premature delivery of the infant at <37 weeks of pregnancy. Based on previous data, the incidence rate of preterm is more than 10% of the total births, and it is also one of the leading causes of pregnancy‐related deaths worldwide (accounts for more than 50% perinatal morbidity and mortality) . Preterm birth can be divided into two subtypes, including physician‐initiated birth and spontaneous preterm birth.…”