Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
Fetal Diagn Ther. 2012;32(3):156-65. doi: 10.1159/000338655. Epub 2012 Jul 26.
To establish a normal range of birthweight with gestational age (GA) at delivery and examine the contribution of maternal characteristics in defining growth restriction in stillbirths.
In 69,895 normal singleton pregnancies, regression analysis was used to determine the association of birthweight with GA and maternal characteristics. The proportion of 290 stillbirths classified as small for GA depending on inclusion or exclusion of maternal characteristics was determined.
In normal pregnancies, there was a polynomial association between birthweight and GA. Birthweight increased with maternal weight, height and parity and was lower in Africans and South Asians than in Caucasians. Birthweight for GA was reduced in antepartum stillbirths (n = 243; p < 0.0001) but not in intrapartum stillbirths (n = 47; p = 0.334). There was no significant difference in the proportion of antepartum stillbirths with birthweight below the 10th percentile when birthweight was corrected for GA only compared to correction for GA and maternal characteristics (53.1 vs. 54.3%). The birthweight was below the 10th percentile in 71.8% of antepartum stillbirths at <32 weeks' gestation, in 47.2% at 33-36 weeks and in 31.5% at ≥37 weeks.
Correction of birthweight for maternal characteristics does not alter the proportion of stillbirths that are small for GA.
建立与分娩时胎龄（GA）相关的正常出生体重范围，并研究母性特征对死产中生长受限的定义作用。
在 69895 例正常单胎妊娠中，采用回归分析确定出生体重与 GA 和母性特征的关联。根据纳入或排除母性特征，确定 290 例死产中哪些被归类为 GA 小于胎龄儿。
在正常妊娠中，出生体重与 GA 之间存在多项式关系。出生体重随母亲体重、身高和产次增加而增加，在非洲人和南亚人比在白种人低。产前死产（n=243；p<0.0001）中出生体重与 GA 相关，但在产时死产（n=47；p=0.334）中不相关。仅校正 GA 与 GA 和母性特征校正（53.1%比 54.3%）相比，当仅校正 GA 时，出生体重低于第 10 百分位数的产前死产比例无显著差异。在<32 周的产前死产中，71.8%的出生体重低于第 10 百分位数，在 33-36 周时为 47.2%，在≥37 周时为 31.5%。
校正母性特征对出生体重不会改变 GA 小于胎龄儿的比例。
