Cerebroplacental ratio (CPR) and reduced fetal movement: predicting neonatal outcomes

Abstract

Objective

The aim of this study was to evaluate the role of cerebroplacental ratio (CPR) in term pregnancies with reduced fetal movements (RFM) and appropriate for gestational age (AGA)fetuses to predict poor neonatal outcomes.

Methods

A prospective cohort study was performed on 150 singleton pregnancies with gestational age of 37–41 weeks and multiple episodes of RFM (case group) and 150 pregnancies within the same criteria only without RFM (control group). Both groups had appropriate for gestational age (AGA)fetuses. Umbilical artery (UA) and middle cerebral artery (MCA) pulsatility indices (PI) were measured, and MCA to UA ratio (CPR) was calculated. Doppler indices and neonatal outcomes were compared between the two groups. Independent prediction role of CPR MoM was evaluated through a binary logistic regression method.

Results

The RFM group had significantly higher UA- PI MoM (1.01 ± 0.19 versus 0.86 ± 0.05, p < .001), lower MCA MoM (1.28 ± 0.20 versus 1.40 ± 0.13, (p < .001)) and lower CPR MoM (0.98 ± 0.24 versus 1.23 ± 0.12, (p < .001)) compared to the control group. Mean umbilical artery pH was lower in the RFM group and the frequency of neonatal UA cord pH <7.2 was higher in the RFM group. In RFM group, CPR MoM showed a significant linear correlation with birth weight centiles (r = 0.244, p = .003), umbilical artery pH (r = 0.319, p < .001) and Apgar score at minute 1 (r = 0.332, p < .001). CPR MoM exhibited negative correlation with duration of NICU stay (r= −0.187, p = .022). No similar correlation was observed in the control group. In binary logistic regression analysis, CPR MoM was adjusted for the results of NST; and it was concluded that CPR MoM was the only significant predictor of Apgar score minute 1 = <7 (OR: 0.004; 95% CI: 0.0002–0.0673, p < .001), umbilical artery ph <7.2 (OR: 0.019; 95% CI: 0.00005–0.0423, p < .001) and NICU admission (OR: 0.116; 95% CI: 0.018–0.744, p = .023). In multivariate binary logistic regression analysis included parity, history of abortion and ART, AFI, BPP and CPR MoM; the AFI (OR: 0.976; 95% CI: 0.957–0.995, p = .014), BPP (OR: 0.306; 95% CI: 0.172–0.545, p < .001) and CPR MoM (OR: 0.00005 95% CI: 0.000003–0.00061, p < .001) were the significant predictor of RFM. Area under the curve in receiver operating characteristics (ROC) curve was calculated as 0.828 for CPR MoM as a predictor of RFM (SE: 0.024, p < .001), yielding sensitivity and specificity estimates of 80.0% and 65.0%, respectively, using an optimal cutoff level of = < 1.19.

Conclusion

This study concluded that reduced fetal movement was significantly related to low CPR MOM. Also, it showed the independent role of CPR MoM for prediction of lower neonatal umbilical artery pH, lower Apgar score minute 1 and higher rate of NICU admission in AGA term fetuses without considering NST results. Also, AFI, BPP and CPR MoM are significant predictors of RFM.

Keywords:

• Cerebroplacental Ratio (CPR)
• pregnancy
• appropriate for gestational age (AGA)
• fetus
• neonatal outcome
• reduced fetal movement (RFM)
• Doppler velocimetry
• umbilical artery (UA)
• middle cerebral artery (MCA)
• pulsatility indices (PI)
• umbilical artery pH

Acknowledgement

We would like to thank our participants and Shariati Training Hospital staff for their cooperation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study has been supported by Tehran University of Medical Sciences (TUMS), grant no 97-03-30-38644.