Second-trimester cardiovascular biometry in growth-restricted fetuses; a multicenter cohort study.

BACKGROUND: Intrauterine growth restriction is associated with an increased risk of cardiovascular changes neonatally. However, the underlying pathways are poorly understood, and it is not clear whether the dysfunction is already present in the fetus. OBJECTIVE: This study aimed to investigate fetal cardiac dimensions assessed from images at the second trimester anatomy scan from fetuses classified postnatally as small for gestational age and intrauterine growth restricted and compare them with appropriate for gestational age fetuses. STUDY DESIGN: This was a substudy from The Copenhagen Baby Heart Study, a prospective, multicenter cohort study including fetuses from the second trimester of pregnancy in Copenhagen from April 2016 to October 2018. The mothers were recruited at the second trimester anatomy scan that included extended cardiovascular image documentation followed by consecutively measured heart biometry by 2 investigators blinded for the pregnancy outcome. The fetuses were classified postnatally as small for gestational age and intrauterine growth restricted according to the International Society of Ultrasound in Obstetrics and Gynecology 2020 guidelines using birthweight and with a retrospective assessment of Doppler flow. The mean differences in the cardiovascular biometry were adjusted for gestational age at the time of the second trimester scan and the abdominal circumference. The z-scores were calculated, and the comparisons were Bonferroni corrected (significance level of P<.005). Receiver operating characteristic curves were computed after performing backward regression on several maternal characteristics and biomarkers. RESULTS: We included 8278 fetuses, with 625 (7.6%) of them being small for gestational age and 289 (3.5%) being intrauterine growth restricted. Both small for gestational age and intrauterine growth restricted fetuses had smaller heart biometry, including the diameter at the location of the aortic valve (P<.005), the ascending aorta in the 3-vessel view (P<.005), and at the location of the pulmonary valve (P<.005). The intrauterine growth restricted group had significantly smaller hearts with respect to length and width (P<.005) and smaller right and left ventricles (P<.005). After adjusting for the abdominal circumference, the differences in the aortic valve and the pulmonary valve remained significant in the intrauterine growth restricted group. Achievement of an optimal receiver operating characteristic curve included the following parameters: head circumference, abdominal circumference, femur length, gestational age, pregnancy associated plasma protein-A multiples of median, nullipara, spontaneous conception, smoking, body mass index <18.5, heart width, and pulmonary valve with an area under the curve of 0.91 (0.88-0.93) for intrauterine growth restricted cases. CONCLUSION: Intrauterine growth restricted fetuses had smaller prenatal cardiovascular biometry, even when adjusting for abdominal circumference. Our findings support that growth restriction is already associated with altered cardiac growth at an early stage of pregnancy. The heart biometry alone did perform well as a screening test, but combined with other factors, it increased the sensitivity and specificity for intrauterine growth restriction.

Melatonin in Early Nutrition: Long-Term Effects on Cardiovascular System.

Breastfeeding protects against adverse cardiovascular outcomes in the long term. Melatonin is an active molecule that is present in the breast milk produced at night beginning in the first stages of lactation. This indoleamine appears to be a relevant contributor to the benefits of breast milk because it can affect infant health in several ways. The melatonin concentration in breast milk varies in a circadian pattern, making breast milk a chrononutrient. The consumption of melatonin can induce the first circadian stimulation in the infant's body at an age when his/her own circadian machinery is not functioning yet. This molecule is also a powerful antioxidant with the ability to act on infant cells directly as a scavenger and indirectly by lowering oxidant molecule production and enhancing the antioxidant capacity of the body. Melatonin also participates in regulating inflammation. Furthermore, melatonin can participate in shaping the gut microbiota composition, richness, and variation over time, also modulating which molecules are absorbed by the host. In all these ways, melatonin from breast milk influences weight gain in infants, limiting the development of obesity and comorbidities in the long term, and it can help shape the ideal cellular environment for the development of the infant's cardiovascular system.

Neonatal glucocorticoid overexposure alters cardiovascular function in young adult horses in a sex-linked manner.

Prenatal glucocorticoid overexposure has been shown to programme adult cardiovascular function in a range of species, but much less is known about the long-term effects of neonatal glucocorticoid overexposure. In horses, prenatal maturation of the hypothalamus-pituitary-adrenal axis and the normal prepartum surge in fetal cortisol occur late in gestation compared to other precocious species. Cortisol levels continue to rise in the hours after birth of full-term foals and increase further in the subsequent days in premature, dysmature and maladapted foals. Thus, this study examined the adult cardiovascular consequences of neonatal cortisol overexposure induced by adrenocorticotropic hormone administration to full-term male and female pony foals. After catheterisation at 2-3 years of age, basal arterial blood pressures (BP) and heart rate were measured together with the responses to phenylephrine (PE) and sodium nitroprusside (SNP). These data were used to assess cardiac baroreflex sensitivity. Neonatal cortisol overexposure reduced both the pressor and bradycardic responses to PE in the young adult males, but not females. It also enhanced the initial hypotensive response to SNP, slowed recovery of BP after infusion and reduced the gain of the cardiac baroreflex in the females, but not males. Basal diastolic pressure and cardiac baroreflex sensitivity also differed with sex, irrespective of neonatal treatment. The results show that there is a window of susceptibility for glucocorticoid programming during the immediate neonatal period that alters cardiovascular function in young adult horses in a sex-linked manner.

Intrauterine exposure to chronic hypoxia in the rat leads to progressive diastolic function and increased aortic stiffness from early postnatal developmental stages.

AIM: We sought to explore whether fetal hypoxia exposure, an insult of placental insufficiency, is associated with left ventricular dysfunction and increased aortic stiffness at early postnatal ages. METHODS: Pregnant Sprague Dawley rats were exposed to hypoxic conditions (11.5% FiO2 ) from embryonic day E15-21 or normoxic conditions (controls). After delivery, left ventricular function and aortic pulse wave velocity (measure of aortic stiffness) were assessed longitudinally by echocardiography from day 1 through week 8. A mixed ANOVA with repeated measures was performed to compare findings between groups across time. Myocardial hematoxylin and eosin and picro-sirius staining were performed to evaluate myocyte nuclear shape and collagen fiber characteristics, respectively. RESULTS: Systolic function parameters transiently increased following hypoxia exposure primarily at week 2 (p < .008). In contrast, diastolic dysfunction progressed following fetal hypoxia exposure beginning weeks 1-2 with lower early inflow Doppler velocities, and less of an increase in early to late inflow velocity ratios and annular and septal E'/A' tissue velocities compared to controls (p < .008). As further evidence of altered diastolic function, isovolumetric relaxation time was significantly shorter relative to the cardiac cycle following hypoxia exposure from week 1 onward (p < .008). Aortic stiffness was greater following hypoxia from day 1 through week 8 (p < .008, except week 4). Hypoxia exposure was also associated with altered nuclear shape at week 2 and increased collagen fiber thickness at week 4. CONCLUSION: Chronic fetal hypoxia is associated with progressive LV diastolic dysfunction, which corresponds with changes in nuclear shape and collagen fiber thickness, and increased aortic stiffness from early postnatal stages.

Cardiovascular Programming During and After Diabetic Pregnancy: Role of Placental Dysfunction and IUGR.

Intrauterine growth restriction (IUGR) is a condition whereby a fetus is unable to achieve its genetically determined potential size. IUGR is a global health challenge due to high mortality and morbidity amongst affected neonates. It is a multifactorial condition caused by maternal, fetal, placental, and genetic confounders. Babies born of diabetic pregnancies are usually large for gestational age but under certain conditions whereby prolonged uncontrolled hyperglycemia leads to placental dysfunction, the outcome of the pregnancy is an intrauterine growth restricted fetus with clinical features of malnutrition. Placental dysfunction leads to undernutrition and hypoxia, which triggers gene modification in the developing fetus due to fetal adaptation to adverse utero environmental conditions. Thus, in utero gene modification results in future cardiovascular programming in postnatal and adult life. Ongoing research aims to broaden our understanding of the molecular mechanisms and pathological pathways involved in fetal programming due to IUGR. There is a need for the development of effective preventive and therapeutic strategies for the management of growth-restricted infants. Information on the mechanisms involved with in utero epigenetic modification leading to development of cardiovascular disease in adult life will increase our understanding and allow the identification of susceptible individuals as well as the design of targeted prevention strategies. This article aims to systematically review the latest molecular mechanisms involved in the pathogenesis of IUGR in cardiovascular programming. Animal models of IUGR that used nutrient restriction and hypoxia to mimic the clinical conditions in humans of reduced flow of nutrients and oxygen to the fetus will be discussed in terms of cardiac remodeling and epigenetic programming of cardiovascular disease. Experimental evidence of long-term fetal programming due to IUGR will also be included.

In utero programming and early detection of cardiovascular disease in the offspring of mothers with obesity.

The offspring of women with obesity during their pregnancy are exposed to an altered intra-uterine environment. A subsequent influence on the cardiovascular development during fetal life is assumed. In the present thematic review, we report on the current knowledge about this early development of cardiovascular disease from fetal life until adolescence. Based on animal studies, different contributing mechanisms have been hypothesized that still need confirmation in human subjects. Insulin resistance, increased levels of leptin, chronic inflammatory state, perturbation of sympathetic tone and epigenetic modifications contribute to a suboptimal nutrient environment and changed hemodynamics. The ensuing aberrant cardiomyocyte development, impaired endothelial cell relaxation and atherogenic lipid profile put these children at risk for the development of endothelial cell dysfunction. Increasing possibilities for early detection of this preliminary stage of atherosclerotic disease offer new insights into future prevention and treatment strategies. Future research should focus on further unraveling the effect of moderate intense, aerobic exercise. Since it is used to treat the condition in children and adolescents with good results, it might be a contributor to tackling endothelial cell dysfunction at its cradle when applied in early pregnancy.