Research
Obstetrics
The association between fetal Doppler and admission to neonatal unit at term

https://doi.org/10.1016/j.ajog.2014.10.013Get rights and content

Objective

Fetal cerebroplacental ratio is emerging as a better proxy than birthweight for placental insufficiency and as a marker of fetal compromise at term. The extent to which these fetal Doppler changes are related to neonatal outcomes has not been systematically assessed. The main aim of this study was to evaluate the association between estimated fetal weight percentile, cerebroplacental ratio recorded at 34+0–35+6 weeks’ gestation, and neonatal unit admission at term.

Study Design

This was a retrospective cohort study in a tertiary referral center over an 11 year period from 2002 to 2012. The umbilical artery pulsatility index (PI), middle cerebral artery PI, and cerebroplacental ratio were recorded at 34+0–35+6 weeks. Weight values were converted into percentiles and Doppler parameters into multiples of the median (MoM), adjusting for gestational age. Logistic regression analysis was performed to identify, and adjust for, potential confounders.

Results

We identified 2518 pregnancies in which a scan was performed at 34+0–35+6 weeks and delivery occurred at or beyond 37 weeks. In the 2485 pregnancies included in the analysis, the umbilical artery PI MoM was significantly higher, and the middle cerebral artery PI and cerebroplacental ratio MoM significantly lower in the babies requiring neonatal unit admission (P < .05). However, the estimated fetal weight percentile was not significantly different between those who required neonatal unit admission and those who did not (P = .087). According to multivariate logistic regression, cerebroplacental ratio MoM (odds ratio, 0.39; 95% confidence interval, 0.19–0.79; P = .008) and gestational age at delivery (odds ratio, 0.70; 95% confidence interval, 0.61–0.80; P < .001) were significantly associated with the risk of neonatal unit admission, whereas maternal age and birthweight percentile were not (P = .183 and P = .460, respectively). Irrespective of birthweight or estimated fetal weight percentile, the fetal cerebroplacental ratio appears to be a better predictor of the need for neonatal unit admission (P < .001).

Conclusion

Lower cerebroplacental ratio and gestational age at delivery, but not fetal size, were independently associated with the need for admission to the neonatal unit at term in a high-risk patient group. The extent to which fetal hemodynamic assessment could be used to predict perinatal morbidity and optimize the timing of delivery merits further investigation.

Section snippets

Materials and Methods

This was a retrospective cohort study in a single tertiary referral center over an 11 year period from 2002 to 2012. Cases were identified by searching the ViewPoint database (ViewPoint 5.6.8.428; ViewPoint Bildverarbeitung GmbH, Weßling, Germany) in the Fetal Medicine Unit, St George’s Hospital. The inclusion criteria were singleton morphologically normal fetuses born at term that had previously had an ultrasound scan at 34+0–35+6 weeks’ gestation for a variety of indications such as suspected

Results

We identified 2518 pregnancies with fetal Doppler assessment at 34+0–35+6 weeks, in which the delivery occurred at or beyond 37 weeks’ gestation. We excluded 33 pregnancies (1.3%) because they had aneuploidy, major structural abnormalities, stillbirth, or missing outcome data, leaving 2485 pregnancies included in the analysis. The maternal characteristics, ultrasound, and birth indices in the groups requiring and not requiring admission to the neonatal unit are shown in Table 1. The prevalence

Comment

The findings of this study suggest that neonates that were admitted to the neonatal unit at term had significantly lower CPR at 34-36 weeks, whereas both ultrasound EFW and BW percentiles were not significantly different from those not admitted. A multivariate logistic regression demonstrated that CPR MoM at 34-36 weeks was almost twice as likely as GA at delivery to determine the need for neonatal unit admission. It was also the case that, among the SGA neonates at term, those with a lower CPR

References (27)

  • N.J. Sebire

    Detection of fetal growth restriction at autopsy in non-anomalous stillborn infants

    Ultrasound Obstet Gynecol

    (2014)
  • F. Figueras et al.

    Update on the diagnosis and classification of fetal growth restriction and proposal of a stage-based management protocol

    Fetal Diagn Ther

    (2014)
  • H.P. Robinson et al.

    A critical evaluation of sonar “crown-rump length” measurements

    BJOG

    (1975)
  • Cited by (109)

    • Cerebroplacental ratio and neonatal outcome in low-risk pregnancies with reduced fetal movement: A prospective study

      2022, European Journal of Obstetrics and Gynecology and Reproductive Biology: X
    • Prelabor and intrapartum Doppler ultrasound to predict fetal compromise

      2021, American Journal of Obstetrics and Gynecology MFM
      Citation Excerpt :

      More recent evidence suggests that an abnormally reduced CPR may represent an early index of hitherto undiagnosed placental insufficiency in nonsmall fetuses; in addition, it may be a risk factor for hypoxic complications in this cohort of fetuses considered to be at a low risk of intrapartum complications.77–79 Over the last decade, several groups have demonstrated that AGA fetuses with a low CPR beyond 36 weeks of gestation are at an increased risk of perinatal complications, suggesting that a low CPR represents subclinical, and thus, undetected placental dysfunction, which limits fetal growth potential.77,79–86 In unselected cohorts of women undergoing ultrasound assessment beyond 37 weeks, Morales-Rosellò et al80 and Khalil et al81 reported a higher incidence of obstetrical intervention because of intrapartum fetal distress, neonatal intensive care unit admission, stillbirth, and perinatal mortality at term in AGA fetuses with low CPR.84

    View all citing articles on Scopus

    The authors report no conflict of interest.

    Cite this article as: Khalil AA, Morales-Rosello J, Elsaddig M, et al. The association between fetal Doppler and admission to neonatal unit at term. Am J Obstet Gynecol 2015;213:57.e1-7.

    View full text