Is Fetal Cerebroplacental Ratio an Independent Predictor of Intrapartum Fetal Compromise and Neonatal Unit Admission?

Abstract

Topics: Neonatal Morbidity and Mortality, Systems-based Practice I dentifying whether a fetus is at risk for intrapartum hypoxia and other adverse conditions is challenging. Although smaller fetal size is more strongly associated with nonreassuring fetal status, many appropriate weight babies are also at risk for conditions such as cerebral palsy. A recent study suggested that fetal cerebroplacental ratio (CPR) measured within 72 hours of delivery, can successfully identify patients that will require obstetric intervention for intrapartum fetal compromise. The purpose of this study was to determine whether or not the CPR can in fact serve as a reliable indicator of both intrapartum fetal compromise and admission to a neonatal unit.The study was conducted from 2000 to 2013 in a single tertiary referral center and involved a retrospective analysis of prospectively collected data. Within 2 weeks of delivery, information on umbilical artery pulsatility index, middle cerebral artery pulsatility index, and CPR was collected for each case. Birth weights were converted into centiles and Doppler parameters were converted into multiples of the median, with reference ranges used to adjust for gestational age. Possible confounding variables were addressed through the use of logistic regression analysis.A total of 9772 singleton pregnancies were included in the study. Operative delivery in response to presumed fetal compromise occurred in 17.2% of cases, while admission to a neonatal unit occurred in 3.9% of cases. CPRs were lower in cases that required either operative delivery or admission to a neonatal unit (P < 0.01). Logistic regression showed that both CPR and birth weight were independently associated with an increased risk of operative delivery for presumed fetal compromise [adjusted odds ratio (OR), 0.67; 95% confidence interval (CI), 0.52-0.87; P = 0.003 and adjusted OR, 0.994; 95% CI, 0.992-0.997; P < 0.001, respectively). The association with birth weight persisted even when small-for-gestational-age cases were excluded. CPR was shown to be an independent indicator for admission to a neonatal unit at term (adjusted OR, 0.55; 95% CI, 0.33-0.92; P = 0.021), while birth weight was not (adjusted OR, 1.00; 95% CI, 0.99-1.00; P = 0.794).The findings of this study show that there is an association between low fetal CPR measured at term and the need for emergency operative delivery and admission to a neonatal unit. Even after the results were adjusted for potential confounders, this association remained significant. These results emphasize that Doppler assessment is a better indicator of fetal compromise than size alone. The authors recommend that future studies focus on how fetal hemodynamic status could be useful in predicting perinatal morbidity and guiding the best choice of delivery method.

Role of uteroplacental and fetal Doppler in identifying fetal growth restriction at term

“…However, the CPR improves the prediction of adverse pregnancy outcomes when compared to its individual components [49][50][51][52][53]. It has been shown that a suboptimal or low CPR is associated with short-term markers of neonatal outcome such as cord blood acidemia, need for emergency operative delivery and neonatal unit admission [54][55][56][57], as well as stillbirth and neonatal morbidity [48,[57][58][59].…”

“…We recently reported that the CPR is a marker of failure to reach growth potential and adverse pregnancy outcomes, in both AGA and SGA fetuses [55,56], and this has been discussed in a recent review [63]. Most studies that assessed the utility of CPR in identifying at risk fetuses used point estimates and lacked longitudinal data.…”

The usefulness of fetal Doppler evaluation in early versus late onset intrauterine growth restriction. Review of the literature.

“…CPR performed better in identifying fetuses with adverse outcome than the biophysical profile did [28]. Moreover, CPR was a better predictor for the birthweight centile regarding the necessity of admission to the neonatal intensive care unit [44]. These data encourage the recommendation of usage of CPR for risk stratification in L-IUGR fetuses [27].…”

“…If in the third trimester, the obstetrician analyses only the UA PI, these fetuses will be missed and the potential intrapartum and postnatal complications cannot be anticipated [39]. An abnormal CPR and low birthweight centile were identified as significantly and independently associated with emergency caesarean section in both appropriate for gestational age (AGA) and L-IUGR groups [44]. CPR performed better in identifying fetuses with adverse outcome than the biophysical profile did [28].…”

Re: The Montgomery ruling extends patient autonomy

“…3,4 The implication of these findings is that fetuses do not have to be small to be hypoxaemic, and the finding of Murray et al is that not all small fetuses exhibit the long-term neurodevelopmental effects of hypoxaemia. Both of these statements have been long acknowledged as valid, but it is the recent finding of the influence of FCR (or CPR) that alludes to the fact that the mechanism involves prenatal uteroplacental insufficiency and fetal hypoxaemia.…”