Obesity during pregnancy on vagal tone, hemoglobin A1c, oxygenation, and perinatal outcomes

Rebecca Jo Helmreich, The University of Texas School of Nursing at Houston


Purpose: To examine the effect of obesity and gestational weight gain on heart rate variability (HRV), oxygenation (HbO 2 and SpO2), hemoglobin A1c (HbA1c) and the frequency of pregnancy complications in obese (O) and non-obese (NO) women. Design: The study was an observational comparison study with a repeated measures design. Setting: The setting was a low risk prenatal, university clinic located in a large southeastern metropolitan city. Sample: The sample consisted of a volunteer group of 41 pregnant women who were observed at the three time points of 20, 28, and 36 weeks gestation. Analysis: Analysis included general linear modeling with repeated measures to test for group differences with changes over time on vagal response, HbA1c, and oxygenation. Odds ratios were computed to compare the frequency of birth outcomes. Findings: The interaction effect of time between O and NO women on HbO2 was significant. The mean HP, RSA, and HbO2 changed significantly over time within the NO women. The mean HbA 1c increased significantly over time within the O women. Women with excess gestational weight gain had significantly lower heart period than women with weight gain within the IOM recommendations. Obese women were more likely to have Group B streptococcal infections, gestational hypertension, give birth by cesarean or instrument assistance, and have at least one postnatal event. Conclusions: Monitoring HRV, oxygenation, and HbA1c using minimally invasive measures may permit early identification of alterations in autonomic response. Implementation of interventions to promote vagal tone may help to reduce risks for adverse perinatal outcomes related to obesity. Future studies should examine the effect of obesity on the vagal response and perinatal outcomes.

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Recommended Citation

Helmreich, Rebecca Jo, "Obesity during pregnancy on vagal tone, hemoglobin A1c, oxygenation, and perinatal outcomes" (2010). Texas Medical Center Dissertations (via ProQuest). AAI3420489.