Cardiac remodelling as a result of pre-term birth: implications for future cardiovascular disease.

Aims: Pre-term birth affects 10-12% of live births and occurs when the myocardium is still developing; therefore, the final structure of the myocardium could be altered. We hypothesized that, in response to pre-term birth, structural remodelling occurs within the myocardium which enables the immature heart muscle to adapt to the haemodynamic transition at birth but results in persistent alterations in its structure. Our objective was to determine how pre-term birth alters the final structure of the myocardium.

Repeated ethanol exposure during late gestation alters the maturation and innate immune status of the ovine fetal lung.

Little is known about the effects of fetal ethanol exposure on lung development. Our aim was to determine the effects of repeated ethanol exposure during late gestation on fetal lung growth, maturation, and inflammatory status. Pregnant ewes were chronically catheterized at 91 days of gestational age (DGA; term approximately 147 days).

The influence of naturally occurring differences in birthweight on ventricular cardiomyocyte number in sheep.

In most species including man, cardiomyocytes cease proliferating soon after birth when they become terminally differentiated. A reduced complement of cardiomyocytes in infancy may adversely impact on the function and adaptive capabilities of the heart in later life. Low birthweight is associated with an increased risk of heart disease in adults, but little is known about its effect on the number of cardiomyocytes.

Does moderate preterm birth lead to altered arterial pressure? Studies in sheep.

1. Low birth weight (LBW) is associated with an increased risk of cardiovascular disease. Preterm birth is a major determinant of LBW and has been shown to result in elevated arterial pressure (AP) in humans, but few studies have investigated the effects of preterm birth in the absence of potentially confounding factors.

Spontaneously occurring differences in fetal weight do not affect blood pressure, the hypothalamic-pituitary-adrenal axis or the renin-angiotensin system in the late-gestation ovine fetus.

Fetal growth restriction (FGR) has been associated with an increased incidence of cardiovascular disease in adult life. Animal models of restricted fetal growth often cause FGR over discrete periods of gestation and hence may not be applicable to individuals with low birthweight but who are not clinically growth-restricted. Our aim was to determine whether spontaneously occurring differences in fetal growth influence the functional development of the hypothalamic-pituitary-adrenal (HPA) axis or the renin-angiotensin system (RAS), both of which are involved in arterial pressure regulation.

The perinatal development of arterial pressure in sheep: effects of low birth weight due to twinning.

The aim of this study is to determine the effect of fetal growth restriction due to twinning on the perinatal development of arterial pressure. Arterial pressure was recorded in fetal sheep (5 singletons, 8 twins) during late gestation and at 8 weeks after birth (11 singletons, 18 twins). In fetuses, there were no differences between singletons and twins in arterial pressure or plasma electrolytes.