The interrelation among maternal dietary intake, pregravid weight, amount and pattern of gestational weight gain and cigarette smoking in influencing the balance between fetal growth and maternal postpartum weight retention was in investigated in 1,330 healthy participants in the PEI Nutritional Counselling Program. Among nonsmokers, gestational weight gain was the main predictor of postpartum weight retention and explained 65.3% of its variability, while explaining only 4.7% of infant birth weight variability. Women with higher postpartum weight retention gained more weight during pregnancy and most of the difference between higher and lower weight retention groups occurred in the first 20 weeks. When comparing infant size between smoking and nonsmoking mothers, birth weight increased linearly with maternal weight gain in all weight status groups except in overweight nonsmokers where birth weight reached a plateau at weight gains $>$17 kg. Among smokers, infant length increased at a higher rate with weight gain than nonsmokers. Although higher weight gains seemed to partially mitigate the effect of smoking on the risk of small-for-gestational-age (SGA) infants, such risk remained $>$10% at elevated weight gains among underweight smokers. The effects of smoking in reducing maternal and infant weights were not mediated by lower energy intake, as smokers consumed more energy than nonsmokers after controlling for physical activity and pregravid weight. The independent relative risks of SGA infants due to maternal smoking, pregravid underweight and low weight gain, were 3.23, 1.80 and 1.72 respectively, implying that smoking has the greatest effect on SGA. Based on current smoking prevalence in Canada, the population etiologic fraction of SGA due to the direct effect of smoking is 30.8%; approximately twice that for maternal underweight or low weight gain. Efforts to increase infant birth weight through higher maternal weight gain would require impractically high ene
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.40405 |
| Date | January 1996 |
| Creators | Muscati, Siham K. (Siham Khalili) |
| Contributors | Gray-Donald, Katherine (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (School of Dietetics and Human Nutrition.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001538767, proquestno: NN19754, Theses scanned by UMI/ProQuest. |
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