409: Impact of maternal anxiety on serum catecholamine levels and their role in fetal baseline heart rates during scheduled induction of labor, a prospective study

Abstract

To determine whether there is a relationship between maternal anxiety, maternal serum catecholamine levels, and changes in the fetal baseline heart rates in women undergoing induction of labor. A prospective study was conducted at the University of Kansas Medical Center where we enrolled term pregnant women undergoing induction of labor. Exclusion criteria included diagnosis of preeclampsia, multiple gestations, and known fetal anomalies. After obtaining written informed consent, nursing staff obtained a maternal blood sample when placing the IV. Subjects were provided with a State-Trait Anxiety Inventory self-questionnaire to assess anxiety levels. Additional blood samples were collected from the IV hourly over the course of 3h. Fetal heart rate baselines were recorded every 30 minutes. Maternal serum catecholamines (epinephrine (E) and norepinephrine (NE)) were measured at each time point according to manufacturer protocol. The change in fetal heart rate was plotted against the change in catecholamine levels over time. Forty-three women were enrolled; 39 had enough samples to analyze. The mean fetal heart rate over the 3h declined incrementally from 138.1±8 to 135.6±7 beats per minute (bpm). The mean maternal serum NE decreased from 5.46±3.6 pmol/L to 4.65±2.3 pmol/L over the first 2h but increased to 5.27±3.4 pmol/L at hour 3. Maternal serum E was undetectable and excluded from analysis. The State-Trait Anxiety Inventory questionnaire showed a mean state anxiety score of 34.5±10 and mean trait anxiety score of 29.9±6, consistent with mild anxiety. Serum catecholamine levels do not appear to have a significant impact on baseline fetal heart rate in women experiencing mild levels of anxiety during an induction of labor. None of these women were in active labor during the study period. Future study will examine similar variables in women admitted in early active labor.