Hemoglobin F Impacts Physiologic Variables and Perinatal Events

Sunday, 30 October 2011: 11:40 AM

Rebecca Jo Helmreich, PhD, RN, PNNP, WHNP-BC
School of Nursing, Department of Integrative Nursing, University of Texas Health Science Center, Houston, Houston, TX

Learning Objective 1: The learner will be able to discuss the effect of HbF with obesity and gestational weight gain on six physiologic variables

Learning Objective 2: The learner will be able to identify an association between the level of HbF and the frequency of perinatal events in low risk pregnant woman

Objectives: The objectives were 1) to explore the effect of hemoglobin F with obesity and gestational weight gain on heart period, respiratory sinus arrhythmia, oxy-hemoglobin, peripheral oxygenation, hemoglobin A1c , and systolic blood pressure, and 2) to determine if an association exists between the level of HbF and the frequency of perinatal events in low risk pregnant woman with varied body mass index (obese and not-obese).

 Methods: An observational study of 41 pregnant women at three time points: 20, 28, and 36 weeks gestation. Data were organized according to the mean HbF level at 20 weeks gestation, with obesity (obese and non-obese), and gestational weight gain (using the Institute of Medicine’s recommendation for weight gain). Repeated measures data were analyzed by the general linear model (GLM) to test for group differences and changes over time. Odds ratios were computed to compare the frequency of perinatal outcomes.

  Results: There were significant changes in time for HP, RSA, and HbO2. Overall, HbO2 and SBP levels were higher and HP and RSA were lower in the obese women with the lower mean HbF category. Moreover, changes in time of HbO2 were different in obese and non-obese groups. Obese women with the lower mean HbF level had more frequent episodes of diabetes, wound dehiscence and giving birth by cesarean section or assistance with forceps or vacuum extraction.  Non-obese women with lower mean HbF levels had postpartal bleeding

 Conclusion: The findings suggest that the pattern of change of HbF during pregnancy may be different for obese and non-obese women. However, further research is needed before HbF levels can be used as a marker for altered adaptation in pregnancy.