Cerebroplacental ratio in recurrent reduced fetal movements: evidence for worsening fetal hypoxemia

Objective:

To investigate the association between reduced fetal movements (RFM) and the fetal cerebroplacental ratio (CPR).

Methods:

This was a case-control study including singleton pregnancies presenting with RFM at term. The control group consisted of low-risk pregnancies at similar gestation. The fetal biometry, umbilical artery (UA) and middle cerebral artery (MCA), Doppler parameters were recorded. These were converted into centiles and multiples of the median (MoM). Maternal and pregnancy characteristics were obtained from hospital records. Regression analysis was used to identify and adjust for potential confounders.

Results:

The study included 4500 women presenting with RFM and 1527 low-risk controls. The fetuses in the RFM group showed significantly lower MCA pulsatility index (PI) MoM (median 0.95; IQR 0.84–1.09 vs 0.97; 0.86–1.11, p < 0.001) and CPR MoM (median 0.97; IQR 0.83–1.15 vs 0.99; 0.85–1.16, p = 0.018) when compared to controls. The fetuses in the multiple episodes of RFM demonstrated significantly lower CPR MoM (median 0.90; IQR 0.81–1.12 vs 0.96; 0.84–1.08, p = 0.021) compared to those with a single episode of RFM. Logistic regression analysis demonstrated an independent association of maternal age (OR 0.96, 95%CI 0.93–0.99), non-Caucasian ethnicity (OR 0.72; 95% CI 0.53–0.97), estimated fetal weight (OR 1.01; CI 1.00–1.02) and CPR MoM (OR 0.24; 95% CI 0.12–0.47) with the risk of recurrent RFM.

Conclusion:

Pregnancies complicated by recurrent episodes of RFM have significantly decreased CPR MoM and MCA PI MoM when compared to single episodes and controls. This is likely to represent evidence of worsening fetal hypoxaemia in pregnancies presenting with recurrent RFM.