<b><i>Objective:</i></b> 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. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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. <b><i>Conclusion:</i></b> Correction of birthweight for maternal characteristics does not alter the proportion of stillbirths that are small for GA.

Objective

Objective: To examine the role of second-trimester uterine artery Doppler in the prediction of stillbirths. Methods: Uterine artery pulsatility index (PI) was measured at 20–24 weeks’ gestation in 65,819 singleton pregnancies. The PI was converted to multiples of median (MoM) and compared in live births and stillbirths. Regression analysis was used to determine the significance of association between log₁₀ uterine artery PI MoM and gestational age (GA) at delivery in cases of stillbirths. Results: There were 306 (0.46%) stillbirths and in 159 (52.0%) of these there was pre-eclampsia (PE), placental abruption and/or birthweight below the 10th percentile (small for gestational age, SGA). In the stillbirths, the uterine artery PI MoM was significantly higher than in live births and was inversely associated with GA at delivery. The uterine artery PI MoM was above the 90th percentile in 80.6% of stillbirths with PE, abruption and/or SGA delivering at <32 weeks’ gestation, in 41.9% at 33–36 weeks and in 34.3% at ≥37 weeks, and the respective percentages for stillbirths without PE, abruption or SGA were 15.8, 25.0 and 12.4%. Conclusion: Second-trimester uterine artery PI is effective in identifying early stillbirths in association with PE, abruption or SGA but not late deaths in the absence of PE, abruption or SGA.