Birth-weight differences at term are explained by placental dysfunction and not by maternal ethnicity

Ultrasound Obstet Gynecol. 2018 Oct;52(4):488-493. doi: 10.1002/uog.19025. Epub 2018 Aug 23.

Abstract

Objective: To investigate the influence of ethnicity, fetal gender and placental dysfunction on birth weight (BW) in term fetuses of South Asian and Caucasian origin.

Methods: This was a retrospective study of 627 term pregnancies assessed at two public tertiary hospitals in Spain and Sri Lanka. All fetuses underwent biometry and Doppler examinations within 2 weeks of delivery. The influences of fetal gender and ethnicity, gestational age (GA) at delivery, cerebroplacental ratio (CPR) and maternal age, height, weight and parity on BW were evaluated by multivariable regression analysis.

Results: Fetuses born in Sri Lanka were smaller than those born in Spain (mean BW = 3026 ± 449 g vs 3295 ± 444 g; P < 0.001). Multivariable regression analysis demonstrated that GA at delivery, maternal weight, CPR, maternal height and fetal gender (estimates = 0.168, P < 0.001; 0.006, P < 0.001; 0.092, P = 0.003; 0.009, P = 0.002; 0.081, P = 0.01, respectively) were associated significantly with BW. Conversely, no significant association was noted for maternal ethnicity, age or parity (estimates = -0.010, P = 0.831; 0.005, P = 0.127; 0.035, P = 0.086, respectively). The findings were unchanged when the analysis was repeated using INTERGROWTH-21st fetal weight centiles instead of BW (log odds, -0.175, P = 0.170 and 0.321, P < 0.001, respectively for ethnicity and CPR).

Conclusion: Fetal BW variation at term is less dependent on ethnic origin and better explained by placental dysfunction. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Keywords: birth weight; cerebroplacental ratio; ethnicity; fetal Doppler; fetal growth; fetal nutrition.

Publication types

  • Multicenter Study

MeSH terms

  • Adult
  • Cerebrovascular Circulation / physiology
  • Female
  • Fetal Growth Retardation / diagnostic imaging*
  • Fetal Growth Retardation / ethnology
  • Fetus / blood supply*
  • Fetus / diagnostic imaging
  • Humans
  • Infant, Newborn
  • Middle Cerebral Artery / diagnostic imaging*
  • Middle Cerebral Artery / embryology
  • Middle Cerebral Artery / physiopathology
  • Mothers*
  • Placental Insufficiency / diagnostic imaging*
  • Placental Insufficiency / physiopathology
  • Predictive Value of Tests
  • Pregnancy
  • Pregnancy Outcome
  • Pulsatile Flow
  • Retrospective Studies
  • Spain / epidemiology
  • Sri Lanka / epidemiology
  • Ultrasonography, Doppler
  • Ultrasonography, Prenatal
  • Umbilical Arteries / diagnostic imaging*
  • Umbilical Arteries / embryology
  • Umbilical Arteries / physiopathology