Maternal stress responses and anxiety during pregnancy: Effects on fetal heart rate

This study examined the effect of an acute maternal stress response and anx iety on fetal heart rate. Seventeen healthy, 3rd-trimester pregnant women ( mean age = 26 +/- 6 years) were instrumented for continuous electrocardiogr aphy, blood pressure (BP), respiration, and fetal heart rate (HR). Subjects completed the state anxiety subscale of the State Trait Personality Invent ory (STPI), then rested quietly in a semirecumbent position for a 5-min bas eline period, followed by either a 5-min arithmetic or Stroop color-word ta sk. Over the entire 5-min stress period and when averaged across all subjec ts, the stressors led to significant increases in maternal systolic BP and respiratory rate but changes in maternal HR, diastolic BP, and fetal HR wer e not significant. However, when subjects were dichotomized into groups tha t had above or below average anxiety scores [ANX(+) and ANX(-)], both group s had similar respiration rate increases to the stressors, but the BP and f etal heart rate (FHR) responses were significantly different. Women in the ANX(-) group had significantly greater BP responses compared to women in th e ANX(+) group whereas the fetuses of ANX(+) women showed significant HR in creases and the fetuses of ANX(-) women exhibited nonsignificant decreases. These findings suggest that women's acute emotional reactivity during preg nancy can influence fetal HR patterns and that a stress-induced increase in maternal BP is not the primary signal by which a women's stress response i s transduced to her fetus. The results are consistent with the hypothesis t hat maternal psychological variables may shape the neurobehavioral developm ent of the fetus. (C) 2000 John Wiley & Sons, Inc.