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Gender, smoking during pregnancy and gestational age influence cord leptin concentrations in newborn infants
Simon Kayemba-Kay's1, Michael P P Geary, Jane Pringle
1London Centre for Paediatric Endocrinology and Metabolism at Institute of Child Health, University College London, London W1T 3AA, UK.
Insights
Maternal smoking during pregnancy is linked to lower birth weight and altered fetal growth, potentially mediated by effects on leptin metabolism. This study found maternal smoking and infant gender significantly influence cord serum leptin levels.
Area of Science:
- Perinatal Medicine
- Endocrinology
- Maternal-Fetal Medicine
Background:
- Maternal smoking during pregnancy is associated with adverse infant outcomes including low birth weight (BW), reduced length, and neuro-endocrine dysfunction.
- Limited research has explored the role of leptin in fetal growth restriction linked to maternal smoking and its interaction with factors like infant gender.
Purpose of the Study:
- To investigate the relationship between maternal smoking, infant gender, and cord serum leptin concentrations.
- To examine how these factors influence fetal growth parameters such as birth weight, length, and head circumference.
Main Methods:
- Cord serum leptin concentrations were measured in 1215 infants born to Caucasian mothers.
- Data on birth weight, gestational length, infant gender, and maternal smoking status were collected.
- Multivariate analyses were performed to identify factors influencing cord serum leptin levels.
Main Results:
- Infants born to mothers who smoked had lower birth weight, shorter length, and smaller head circumference compared to non-smokers.
- Cord serum leptin concentrations were significantly higher in female infants than in male infants.
- Maternal smoking, infant gender, birth weight SDS, and gestational length were significant predictors of cord serum leptin concentrations.
Conclusions:
- Maternal smoking appears to restrain fetal growth, potentially through placental vascular effects and alterations in leptin metabolism.
- Further research is needed to elucidate the precise mechanisms by which maternal smoking impacts placental function and fetal adipose tissue development.
Background:
Low birth weight (BW), small head circumference, reduced length, increased preterm births and neuro-endocrine dysfunctions are among known consequences of smoking during pregnancy. Few studies have linked leptin to clinical features of growth restriction associated with maternal smoking and explored interaction with other determinants of size at birth, such as gender.
Methods:
Cord serum leptin concentrations were measured in 1215 term infants born to Caucasian mothers at completion of uneventful pregnancy. Serum concentrations were related to BW, gestational length, gender and maternal smoking and interaction with other determinants of size at birth evaluated.
Results:
Smoking was more frequent in younger (P<0.001) and shorter mothers (P=0.03) from lower socio-economic groups (SEGPs) (P<0.001). Infants born to smokers were lighter (190 g less), shorter and with smaller head circumference. Cord serum leptin concentrations were higher in girls (9.8 s.d. 7.6 ng/ml) than in boys (7.05 s.d. 5.8 ng/ml) (P<0.001). Boys were heavier (BW 3.52 s.d. 0.49 kg) than girls (3.39 s.d. 0.44 kg) (P<0.001), but girls had greater skinfold thickness measurements (sub-scapular and quadriceps skinfold thicknesses 5.5 s.d. 1.6 mm and 7.6 s.d. 1.9 mm respectively; boys 5.3 s.d. 1.6 vs 7.24+/-1.90 mm, P<0.001 respectively). Multivariate analyses showed gender (P<0.001), BW SDS (P<0.001), gestational length (P<0.001) and maternal smoking (P<0.042) as factors that influenced umbilical cord serum leptin concentrations in newborns.
Conclusion:
Maternal smoking restrains foetal growth through placental vascular effects, and likely also via associated effects on leptin metabolism. More studies are needed to determine the influence that maternal smoking may have on placental syncytiotrophoblast and foetal adipose tissue.
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