Department of Obstetrics and Gynaecology, University of Campinas (UNICAMP), Campinas, Brazil.
Department of Women and Children's Health, King's College London, London, UK.
BMC Pregnancy Childbirth. 2022 Aug 4;22(1):615. doi: 10.1186/s12884-022-04943-1.
Small-for-gestational-age neonates (SGA) are at increased risk of neonatal morbidity. Nulliparity represents a risk factor for SGA; birthweight charts may perform differently for the detection of SGA among nulliparas. This study aimed at describing the prevalence of SGA in nulliparas according to different birthweight charts and evaluating the diagnostic performance of these charts to maternal and perinatal outcomes.
This is a secondary analysis of a Brazilian cohort of nulliparas named Preterm SAMBA study. Birthweight centiles were calculated using the Intergrowth-21st, WHO-Fetal Growth Charts, Birth in Brazil population chart and GROW-customised chart. The risks of outcomes among SGA neonates and their mothers in comparison to neonates with birthweights between the 40-60 centiles were calculated, according to each chart. ROC curves were used to detect neonatal morbidity in neonates with birth weights below different cutoff centiles for each chart.
A sample of 997 nulliparas was assessed. The rate of SGA infants varied between 7.0-11.6%. All charts showed a significantly lower risk of caesarean sections in women delivering SGA neonates compared to those delivering adequate-for-gestational-age neonates (OR 0.55-0.64, p < .05). The charts had poor performance (AUC 0.492 - 0.522) for the detection of neonatal morbidity related to SGA born at term.
The populational and customised birthweight charts detected different prevalence of small-for-gestational-age neonates and showed similar and poor performance to identify related neonatal adverse outcomes in this population.
小于胎龄儿（SGA）新生儿患新生儿发病率的风险增加。初产妇是 SGA 的一个危险因素；体重图表在初产妇中检测 SGA 的性能可能不同。本研究旨在根据不同的体重图表描述初产妇中 SGA 的患病率，并评估这些图表对母婴围产结局的诊断性能。
这是巴西初产妇早产儿 SAMBA 研究的一项二次分析。使用 Intergrowth-21st、世卫组织胎儿生长图表、巴西出生人口图表和 GROW 定制图表计算体重百分位数。根据每个图表，计算 SGA 新生儿及其母亲与体重在 40-60 百分位数之间的新生儿相比发生结局的风险。使用 ROC 曲线检测每个图表中低于不同截止百分位数的新生儿体重的新生儿发病率。
评估了 997 名初产妇的样本。SGA 婴儿的发生率在 7.0-11.6%之间。所有图表均显示，与分娩适于胎龄儿的产妇相比，分娩 SGA 新生儿的产妇剖宫产的风险显著降低（OR 0.55-0.64，p <.05）。这些图表在检测足月出生的与 SGA 相关的新生儿发病率方面表现不佳（AUC 0.492-0.522）。
人群和定制的体重图表检测到不同的小于胎龄儿发生率，并且在该人群中识别相关的新生儿不良结局的性能相似且不佳。
