The influence of cigarette smoking on antenatal growth, birth size, and the insulin-like growth factor axis.
BACKGROUND
Maternal smoking during pregnancy is associated with a reduction in birth size. Very few studies have collated changes in fetal biometry, neonatal anthropometry, biochemical factors involved in fetal growth, and measures of uterine and umbilical blood flow.


METHODS
We related smoking status in 1650 low-risk, singleton Caucasian pregnancies delivering at term to measures of fetal growth, uterine and umbilical artery blood flow, placental appearance, birth size, and cord concentrations of IGF-I and -II and IGF binding protein (IGFBP)-3.


RESULTS
Mothers who smoked in pregnancy were younger (P < 0.001) and shorter (P = 0.03) and from lower socioeconomic groups (P < 0.001). Mean umbilical artery blood flow at 20 wk gestation was not associated with smoking status but was significantly higher in smokers at 30 wk (P = 0.006). Uterine artery blood flow was unaffected. Smoking was associated with an increase in the percentage of abnormal placentas in a dose-dependent manner and with a 3.1-fold increased risk (odds ratio 3.1, 95% confidence interval 1.3-7.6) of abnormal umbilical artery blood flow (P = 0.009). Smoking was associated with a reduction in fetal femur length (P = 0.005) and abdominal circumference as well as birth weight, length, and head circumference but not skinfold thickness. Cord plasma concentrations of IGF-I and IGFBP-3 were lower in the babies of mothers who had smoked (P = 0.02 and P = 0.01, respectively).


CONCLUSIONS
We concluded that maternal smoking is associated with an altered placental appearance on ultrasonography, increased umbilical artery blood flow resistance, and a reduction in longitudinal and intraabdominal organ growth. Circulating concentrations of IGF-I and IGFBP-3 along with measures of birth size but not markers of body fat are reduced, suggesting smoking results in a reduction in organ size and function.
Pringle
P Jane
PJ
Centre for Human Growth and Maturation at the London Centre for Paediatric Endocrinology and Metabolism, University College London, United Kingdom.
Geary
Michael P P
MP
Rodeck
Charles H
CH
Kingdom
John C P
JC
Kayamba-Kay's
Simon
S
Hindmarsh
Peter C
PC
D000328:Adult; D001724:Birth Weight; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D047109:Fetal Development; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D011247:Pregnancy; D012907:Smoking / Q000503:physiopathology*; D014470:Umbilical Cord / Q000098:blood supply; D014599:Uterus / Q000098:blood supply
D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I