Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, Denmark Hill, London, UK.
Prenat Diagn. 2011 Jan;31(1):58-65. doi: 10.1002/pd.2520. Epub 2010 Aug 26.
Firstly, to establish a reference range of birth weight with gestation at delivery; secondly, to identify maternal characteristics that are significantly associated with birth weight; and thirdly, to determine if combinations of maternal characteristics, fetal nuchal translucency thickness (NT), and serum concentrations of free beta-human chorionic gonadotrophin (β-hCG) and pregnancy-associated plasma protein-A (PAPP-A) are significant predictors of small-for-gestational-age (SGA) neonates in the absence of preeclampsia.
Maternal characteristics were recorded; fetal NT, maternal serum free β-hCG and PAPP-A were measured at 11 weeks to 13 weeks 6 days in 33,602 women with singleton pregnancies. Regression analysis was used to determine the association of birth weight with gestation at delivery and to establish a reference range with gestation. Logistic regression analysis was used to determine if maternal factors, fetal NT, free β-hCG, and PAPP-A contribute significantly in predicting SGA in the absence of preeclampsia.
Birth weight increased with maternal weight and height; it was higher in parous than in nulliparous women and in those with a medical history of pre-pregnancy diabetes mellitus, and it was lower in cigarette smokers, in all racial groups other than in Caucasian women, and in those with a medical history of chronic hypertension and in those who previously delivered SGA neonates. In the SGA group compared with the unaffected group, there were lower median delta NT (0.10 vs 0.12 mm), free β-hCG [0.9 vs 1.0 MoM (multiples of median)], and PAPP-A (0.8 vs 1.0 MoM). The prediction of SGA provided by maternal factors was significantly improved by the addition of fetal NT and PAPP-A (34.0 vs 37.0% at a false-positive rate of 10%).
Prediction of the birth of SGA neonates in the absence of preeclampsia can be provided in the first trimester of pregnancy by a combination of maternal characteristics and measurements of parameters used in early screening for aneuploidies.
首先，建立一个与分娩时胎龄相关的出生体重参考范围；其次，确定与出生体重显著相关的产妇特征；最后，确定在没有先兆子痫的情况下，产妇特征、胎儿颈项透明层（NT）厚度、游离人绒毛膜促性腺激素（β-hCG）和妊娠相关血浆蛋白-A（PAPP-A）的血清浓度组合是否是小于胎龄儿（SGA）的显著预测因子。
记录产妇特征；在 33602 例单胎妊娠的 11 周至 13 周 6 天期间，测量胎儿 NT、母体血清游离β-hCG 和 PAPP-A。回归分析用于确定出生体重与分娩时胎龄的关系，并建立与胎龄相关的参考范围。逻辑回归分析用于确定产妇因素、胎儿 NT、游离β-hCG 和 PAPP-A 是否对预测无先兆子痫的 SGA 有显著作用。
出生体重随产妇体重和身高增加而增加；与初产妇相比，经产妇的出生体重更高，有孕前糖尿病病史的产妇的出生体重更高，而吸烟的产妇、除白人以外的所有种族的产妇、有慢性高血压病史的产妇和曾经分娩过 SGA 新生儿的产妇的出生体重较低。与未受影响组相比，SGA 组的中位 NT 差值较低（0.10 对 0.12mm），游离β-hCG[0.9 对 1.0MoM（中位数倍数）]和 PAPP-A[0.8 对 1.0MoM]较低。通过添加胎儿 NT 和 PAPP-A，产妇特征对 SGA 的预测得到显著改善（假阳性率为 10%时，从 34.0%提高到 37.0%）。
在没有先兆子痫的情况下，可以通过产妇特征和早期筛查非整倍体的参数测量相结合，在妊娠早期预测 SGA 新生儿的出生。
