Maternal Prepregnancy Body Mass Index and Their Children’s Blood Pressure and Resting Cardiac Autonomic Balance at Age 5 to 6 Years

Abstract

Adverse intrauterine conditions can program hypertension. Because one of the underlying mechanisms is thought to be cardiac autonomic balance, we investigated the association between prepregnancy body mass index (BMI) and blood pressure and indicators of the autonomic balance in the child at age 5 to 6 years. Also investigated was whether these associations were mediated by standardized birth weight and child BMI. Pregnant women (n=3074) participating in the Amsterdam Born Children and their Development study completed a questionnaire at gestational week 14. At age 5 to 6 years, offspring’s sympathetic drive (pre-ejection period), parasympathetic drive (respiratory sinus arrhythmia), and heart rate were measured by electrocardiography and impedance cardiography at rest. Blood pressure was assessed simultaneously. After adjusting for possible maternal/offspring confounders, prepregnancy BMI was positively linearly associated with diastolic blood pressure (β=0.11 mm Hg; 95% confidence interval, 0.05–0.17), systolic blood pressure (β=0.14 mm Hg; 95% confidence interval, 0.07–0.21), but not with heart rate, sympathetic or parasympathetic drive. After adding birth weight and child BMI to the model, the independent effect size of prepregnancy body mass index on systolic blood pressure (β=0.07 mm Hg; 95% confidence interval, 0.00–0.14) and diastolic blood pressure (β=0.07 mm Hg; 95% confidence interval, 0.01–0.13) decreased by ≈50%. Birth weight did not mediate these relationships, but was independently and negatively associated with blood pressure. Child BMI was positively associated with blood pressure and partly mediated the association between prepregnancy BMI and blood pressure. In conclusion, higher prepregnancy BMI is associated with higher blood pressure in the child (aged 5–6 years) but does not seem to be attributable to early alterations in resting cardiac autonomic balance. Child BMI, but not birth weight, mediated the association between prepregnancy BMI and blood pressure.

Childhood Health Consequences of Maternal Obesity during Pregnancy: A Narrative Review

“…Similarly, higher weight gain early on during the pregnancy, but not later, was associated with an increased risk of an adverse childhood cardio-metabolic risk profile [35] . Another Dutch study among 1,459 mothers and their 5-6-year-old children showed that a higher maternal prepregnancy BMI was associated with higher childhood systolic blood pressure and overall metabolic score, as a measure of a metabolic syndrome-like phenotype, but not with childhood sympathetic drive, parasympathetic drive or heart rate [39,41] . A study among 5,154 motheroffspring pairs from the UK showed that higher maternal pre-pregnancy weight and gestational weight gain in the mid-pregnancy period were associated with higher childhood levels of triglycerides, HDL-cholesterol, apolipoprotein A1 and interleukin (IL)-6 at the age of 9 years [10] .…”

Maternal Obesity

“…Maternal overweight and obesity are endemic, and there is strong evidence that the next generations are going to bear the brunt in the form of future risk of not only hypertension, but also many other disease conditions. To limit the impact of this epidemic, we need to make inroads into understanding the consequences for the child, particularly the mechanisms driving the increased risk, and provide evidence-based strategies for future interventions; the study of Gademan et al 9 has started down that path. …”

“…However, as highlighted by Gademan et al 9 in the current issue of Hypertension, maternal obesity in humans is associated with increased risk of being overweight during infancy through to adulthood, and the presence of cardiometabolic disorders such as hypertension. These human data are supported by extensive experimental data in animal models of obesity.…”

“…Such mechanistic programming studies are even rarer in the clinical setting. Driven by evidence in the human fetus' and studies in rats showing maternal obesity program activation of the sympathetic nervous system, Gademan et al 9 investigated whether autonomic function mediated the association between maternal obesity and blood pressure of 5-to 6-year-old children.…”

“…A key feature identified in studies in animal models of programming is that blood pressure and the autonomic nervous system are hyper-reactive. 10,11 Using pre-ejection period, a derivate of sympathetic nervous system activity, and respiratory sinus arrhythmia, a derivate of parasympathetic activity, Gademan et al 9 were unable to detect an association between resting autonomic function and child blood pressure. However, as discussed by the authors, it is difficult to detect, particularly in…”