Detection of Adverse Perinatal Outcomes at Term Delivery Using Ultrasound Estimated Percentile Weight at 35 Weeks of Gestation: Comparison of Five Fetal Growth Standards

Abstract

<b><i>Objective:</i></b> To assess the predictive ability of the ultrasound estimated percentile weight (EPW) at 35 weeks of pregnancy to predict adverse perinatal outcomes (APOs) at term delivery according to 5 fetal growth standards, including population, population-customized, and international references. <b><i>Methods:</i></b> This was a retrospective cohort study of 9,585 singleton pregnancies. Maternal clinical characteristics, fetal ultrasound data obtained at 35 weeks and pregnancy and perinatal outcomes were used to calculate EPWs to predict APOs according to: the customized and noncustomized (NC) Miguel Servet University Hospital (MSUH), the customized Figueras, the NC INTERGROWTH-21st, and the NC World Health Organization (WHO) international standards. APOs were defined as the occurrence of cesarean or instrumental delivery for nonreassuring fetal status, 5-min Apgar score < 7, arterial cord blood pH <7.10, or stillbirth. The predictive ability of EPW for APOs was analyzed using the area under the curve (AUC), and sensitivities were calculated for different false-positive rates (FPRs). <b><i>Results:</i></b> For a 10% FPR, detection rates for total APOs ranged between 12.7% with the customized MSUH (AUC 0.52; 95% CI 0.50–0.55) and 14.4% with the NC MSUH standard (AUC 0.55; 95% CI 0.53–0.57) for EPW by ultrasound; and from 22.0% with the customized MSUH standard (AUC 0.60; 95% CI 0.58–0.63) to 27.8% with the NC WHO (AUC 0.65; 95% CI 0.63–0.68) for EPW at delivery. <b><i>Conclusions:</i></b> The predictive capacity of the EPW for APOS is limited and similar, by both ultrasound and at delivery, for the 5 growth standards, without significant differences between customized and NC standards.

Prediction of Large for Gestational Age by Ultrasound at 35 Weeks and Impact of Ultrasound-Delivery Interval: Comparison of 6 Standards

“…On the contrary, when we analyzed LGAs with the APO predictive ability of the 6 standards by percentile weight >90 at the 35th week of gestational age, customized Figueras and MSUH standards showed the greatest diagnostic ability, with statistically significant differences with 3 of the 4 NC models. A previous study did not find any significant difference between customized and NC standards analyzing the predictive ability of EPW to detect APOs; by contrast, using EPW >90, we detected significant differences [9]. The shorter ultrasound-delivery interval is related to better prediction rates with all the standards.…”

“…Since ultrasound assessment allows professionals to monitor intrauterine growth, different fetal growth standards have been based on the EFW to calculate the estimated percentile weight (EPW) using Hadlock et al’s [6, 7] methodology or more recent studies that apply multilevel models. Although studies such as the one conducted by Gardosi et al [8] have claimed that these standards can also be customized to maternal and fetal physiological variables, other studies have questioned the validity of customized standards [9, 10]. Moreover, international population standards have recently been published by EFW [11], including those from the INTERGROWTH-21st project [12, 13] and the World Health Organization (WHO) [14].…”

Reduced fetal growth velocity precedes antepartum fetal death

“…found that the association between birth‐weight percentile and adverse neonatal outcome was similar when customized or non‐customized birth‐weight or fetal growth standards were applied in nulliparous women. Similarly, others observed no improvements in the prediction of neonatal morbidity 58–60 and stillbirth 59,60 by customized fetal growth standards when compared to non‐customized charts. However, we have demonstrated recently that there was a modest benefit in the customized evaluation of fetal growth for prediction of perinatal mortality, yet the choice of the customized and non‐customized standards being compared can also have an effect 58 .…”

Incorporating a New Summary Statistic into the Min–Max Approach: A Min–Max–Median, Min–Max–IQR Combination of Biomarkers for Maximising the Youden Index

“…Small-for-gestational-age (SGA) infants-those with a birth weight below the 10th percentile-have been associated with increased risk of adverse perinatal outcomes [35,36]. Predicting them from the ultrasound percentile at the 35th gestational week as well as other fetal and parental variables may help to avoid these outcomes.…”