Objective: We aimed to describe patterns of maternally perceived fetal movement (FM) counts in normal third-trimester pregnancies and present associations between published limits of decreased fetal movement (DFM) and FM patterns in the total population.
Design: Prospective cohort study.
Setting: Norway, in 2005-2007 and 2007-2009.
Population: The total population of women with singleton pregnancies.
Methods: Using a 'count-to-ten' approach, women counted FMs daily from pregnancy week 28 until delivery. Data on maternal characteristics and birth outcomes were obtained from the Medical Birth Registry of Norway and hospital records. We measured the observed mean counting time and used chi-square and Mann-Whitney U-tests to examine differences between normal pregnancies and pregnancies with suboptimal outcomes.
Main outcome measures: Fetal movements in normal pregnancies and in pregnancies ending in a small-for-gestational-age baby, preterm birth or non-elective caesarean section.
Results: A total of 1786 women were included. The mean time to perceive ten movements was approximately 10 minutes in normal pregnancies, with a <2-minute increase in the mean towards term. Fixed limits for DFMs had low predictive values. Overall, the mean counting time in pregnancies with suboptimal outcomes did not differ markedly from normal pregnancies.
Conclusions: This study does not support the notion that FM counts decrease at term in normal pregnancies. A standard approach to FM counting, applying the currently best-founded definition of DFM, was not useful as a screening tool for at-risk pregnancies in this population. Further research is needed to improve measurements of DFM.
Trial registration: ClinicalTrials.gov NCT00513942.
© 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2011 RCOG.