背景:出生体重是评估新生儿围产期结局和评估全球宫内环境的最常见和最容易获得的参数。出生太大或太小的婴儿不仅可能会改变产妇的分娩方式,而且还可能面临其他长期疾病,如代谢性疾病和神经发育迟缓。研究表明,单胎妊娠中胎龄大和胎龄小的胎儿的生长状况不同。然而,目前,没有研究关注这些婴儿在双胎怀孕期间的生长轨迹,即使他们胎龄小的风险要高得多。
目的:本研究旨在探讨双胎妊娠中大胎龄和小胎龄婴儿的胎儿生长轨迹,为胎儿生长管理提供策略。
方法:这是2012年至2021年在北京大学第一医院妊娠36周后分娩的所有非复杂双胎妊娠的病例对照研究。每2至4周记录超声数据直至分娩。所有的婴儿被分为大胎龄,小于胎龄,和适合胎龄组。纵向胎儿生长(估计胎儿体重,腹围,等。)使用线性混合模型在3组间进行比较,与其他孕产妇和新生儿围产期结局进行比较。使用接收器工作特征曲线来探索最佳生物特征参数和孕周,以预测小胎龄婴儿。
结果:这里,招募了797名孕妇和1494名婴儿,有59名胎龄小的婴儿,1335例适合胎龄婴儿,和200个胎龄较大的婴儿。小于胎龄儿的平均出生体重为1985.34±28.34g,2662.08±6.60g,适合胎龄婴儿,大胎龄婴儿为3231.24±11.04g。从第26周开始,3组的估计胎儿体重彼此不同,胎龄小的胎儿体重减少了51.946g,胎龄大的胎儿体重比适当的胎龄胎儿多35.233g。这种差异随着妊娠而增加;在39周,小于胎龄胎儿的体重小于707.438g,大于胎龄胎儿的体重大于合适胎龄胎儿的体重614.182g(所有P<.05).小于胎龄组的住院率(89.9%)和黄疸率(40.7%)明显高于适合胎龄组,而大胎龄组的住院率显著低于适宜胎龄组(7.5%和2.5%;均P<0.05)。具有不良结局的小于胎龄婴儿的胎儿体重保持在参考的第10百分位数附近,并在妊娠34周时低于第3百分位数。妊娠30周后估计的胎儿体重在预测小于胎龄婴儿方面具有令人满意的诊断价值。在妊娠30、32、34和36周,曲线下面积分别为0.829,0.840,0.929和0.889.
结论:小于胎龄的生长模式,适合胎龄,和大胎龄双胎从妊娠26周开始出现差异,并在分娩前持续增加;因此,建议从妊娠26周开始对那些携带小胎儿的人进行更密切的监测。
Birthweight is the most common and accessible parameter in assessing neonatal perinatal outcomes and in evaluating the intrauterine environment globally. Infants born too large or too small not only may alter the maternal mode of delivery but also may face other long-term disorders, such as metabolic diseases and neurodevelopmental delay. Studies have revealed different growth profiles of large-for-gestational-age and small-for-gestational-age fetuses in singleton pregnancies. However, currently, no research is focused on the growth trajectories of these infants during twin pregnancies, even though they are at a much higher risk of being small for gestational age.
This study aimed to explore fetal growth trajectories of large-for-gestational-age and small-for-gestational-age infants in twin pregnancies to provide strategies for fetal growth management.
This was a case-control study of all noncomplicated twin pregnancies delivered after 36 weeks of gestation at the Peking University First Hospital between 2012 and 2021. Ultrasound data were recorded every 2 to 4 weeks until delivery. All the infants were divided into large-for-gestational-age, small-for-gestational-age, and appropriate-for-gestational-age groups. Longitudinal fetal growth (estimated fetal weight, abdominal circumference, etc.) was compared among the 3 groups using a linear mixed model, and other maternal and neonatal perinatal outcomes were compared. Receiver operating characteristic curves were used to explore optimal biometric parameters and gestational weeks for predicting small-for-gestational-age infants.
Here, 797 pregnant patients with 1494 infants were recruited, with 59 small-for-gestational-age infants, 1335 appropriate-for-gestational-age infants, and 200 large-for-gestational-age infants. The mean birthweights were 1985.34±28.34 g in small-for-gestational-age infants, 2662.08±6.60 g in appropriate-for-gestational-age infants, and 3231.24±11.04 g in large-for-gestational-age infants. The estimated fetal weight of the 3 groups differed from each other from week 26, with the small-for-gestational-age fetuses weighing 51.946 g less and the large-for-gestational-age fetuses weighing 35.233 g more than the appropriate-for-gestational-age fetuses. This difference increased with gestation; at 39 weeks, the small-for-gestational-age fetuses weighed 707.438 g less and the large-for-gestational-age fetuses weighed 614.182 g more than the appropriate-for-gestational-age fetuses (all P<.05). The small-for-gestational-age group had a significantly higher rate of hospitalization (89.9 %) and jaundice (40.7 %) than the appropriate-for-gestational-age group, whereas the hospitalization rate in the large-for-gestational-age group was significantly lower than the appropriate-for-gestational-age group (7.5% and 2.5%; all P<.05). The fetal weight of the small-for-gestational-age infants with adverse outcomes remained near the 10th percentile of the reference and fell below the 3rd percentile at 34 weeks of gestation. The estimated fetal weight after 30 weeks of gestation had a satisfactory diagnostic value in predicting small-for-gestational-age infants. At 30, 32, 34, and 36 weeks of gestation, the areas under the curve were 0.829, 0.840, 0.929, and 0.889 respectively.
The growth patterns of small-for-gestational-age, appropriate-for-gestational-age, and large-for-gestational-age twin fetuses diverged from 26 weeks of gestation and continued to increase until delivery; therefore, closer monitoring is suggested from 26 weeks of gestation for those carrying small fetuses.