The effect of different maternal positions on reactivity of the nonstress test, maternal blood pressure and heart rate

Abstract

Objective: We aimed to investigate the effects of different maternal positions on reactivity of the Nonstress Test (NST), maternal blood pressure and heart rate. Methods: In this experimental study, 243 pregnants were randomized to the position groups (sitting, semi-Fowler's, semi-Fowler's left lateral) at 34-37 and 38-40 gestational weeks. The questionnaire form inquiring socio-demographic and obstetric characteristics and NST Form were used. For the statistical comparison of the continuous variables, one-way ANOVA, and independent groups t test were used. Results: Though not statistically significant difference existed, NST reactivity at sitting position was higher than the other positions, and it was higher in 38-40 gestational weeks relative to 34-37 gestational weeks (p>0.05). Results of NST reactivity were evaluated at 4 time periods. Time-to-reactivity in relation to position didn't reveal a significant difference. Independent of the position, we found a significant difference in time to reactivity between 0-5 and 0-10 minutes, and between 0-10 and 0-15 minutes (p<0.05), but there was no significant difference in time to reactivity between 0-15 and 0-20 minutes (p>0.05). Fetal heart rate, maternal systolic, diastolic blood pressure levels were similar in all gestational weeks regardless of the position, at baseline and 10 minutes later (p>0.05). Maternal heart rates were significantly different in semifowler left lateral position (p<0.05). Conclusion: As the most comfortable positions for the pregnants NST applications at semi-Fowler's left lateral and sitting positions seem to he more appropriate in order to get higher NTS reactivity results. No significant difference was observed in NTS reactivity between applications at 15 and 20 minutes, so application at 15 minutes may be sufficient for NST evaluation.