Maternal perception of decreased fetal movements is independent of infant size

Fetal movements are often used as a surrogate for fetal wellbeing. Some studies suggest that decreased fetal movements (DFM) are more common in women with small-for-gestational-age (SGA) infants. The aim of this study was to investigate the association between DFM and birthweight centile categories. This was a 5-year cohort study (January 2016 to October 2020) of non-anomalous singleton infants born at 28+0 weeks of gestation or later. The primary outcome for this study was the rate of DFM by birthweight centile categories. Univariate logistic regressions were performed with robust standard errors, and significant maternal predictors at p < 0.20 were included in the initial multivariable models. Variables were eliminated using a backwards elimination method based on p-values, Wald tests, and goodness of fit assessed using the Hosmer-Lemeshow test. 45041 women met the inclusion criteria. Of these, 6689 (14.9%) women presented with DFM. Of the DFM cohort, 80.9% (5410/6689) had only one presentation with DFM, whilst 19.1% (1279/6689) had > 2 presentations. The overall stillbirth rate was similar in women with DFM (0.1%, 7/6689) and without DFM (0.1%, 50/38352). There was no difference in rates of DFM (either single or multiple) versus no DFM and infant birthweight centile categories. Presentation with DFM was also not associated with increased odds of an SGA infant. This lack of association was seen regardless of the number of presentations with DFM. The results of this study suggest that presentation with DFM is not associated with infant size. Clinicians should consider additional risk factors and the overall clinical context in deciding appropriate management. DFM is not necessarily an indication for an immediate or urgent ultrasound scan to assess fetal size.