A prospective case-control study of risk factors and perinatal outcomes associated with reduced fetal movements

Maternal perception of reduced fetal movements is a frequent reason for referral to maternity services and may signal risk of adverse outcomes, particularly stillbirth.

To identify contemporary maternal and pregnancy-related risk factors for RFM and to examine associations between RFM and perinatal outcomes.

A prospective case-control study in a large urban maternity hospital in Ireland was conducted. Women with singleton pregnancies with RFM at ≥24 weeks' gestation between 1 January and 30 September 2020 (cases) were compared with randomly selected women without RFM during pregnancy (controls) from the same population and timeframe. Associations were assessed using univariate and multivariable logistic regression analyses.

A total of 850 women with RFM were compared with 1743 controls. Women with RFM were younger (mean age [SD] 33.8 [5.04] vs 34.4 [4.93] years; p = 0.004), had a higher body mass index (BMI) (mean [SD] 26.6 [5.76] v 25.89 [5.10]; p < 0.05) and more likely nulliparous (68 % vs 43.8 %; p < 0.001). Multivariable analyses identified anterior placenta (OR 1.24 95 %CI 1.05-1.46; p = 0.01), a prior history of neonatal death (OR 4.65, 95 % CI 1.43-15.15; p = 0.01), and recurrent miscarriage (OR 1.64, 95 % CI 0.99-2.72; p = 0.05) as independent risk factors for RFM. RFM was not associated with stillbirth, preterm birth or neonatal death but was significantly associated with small for gestational age (SGA) infants (OR 1.48, 95 % CI 1.09-2.02). Women with RFM were more likely to undergo induction of labour (aOR 1.44 95 %CI 1.20-1.74) but not emergency caesarean section (aOR 1.20 95 % CI 0.80-1.80), or neonatal intensive care admission.

RFM is influenced by maternal and pregnancy characteristics and is associated with SGA but not severe adverse perinatal outcomes. Careful assessment of women presenting with RFM, targeted growth surveillance, antenatal education and standardised care pathways are essential to optimise maternal and fetal well-being, inform clinical practice, and guide policy in contemporary maternity care.