Abstract
Background. Cigarette smoking during pregnancy is causally related to birthweight, but we do not know whether fetal growth restriction is a continuous process or, if not, at what stage of pregnancy it affects weight gain. Material and methods. A random sample of para 1 and 2 mothers, drawn from the population of pregnant women in Bergen and Trondheim, Norway, and Uppsala, Sweden, were examined by a detailed questionnaire concerning smoking habits, menstrual history and pregnancy dating, and subjected to morphometric sonography of their fetuses in or around week 17. Of the 547 study participants, 31.9% were smokers. Gestational age was primarily determined by the last menstrual period [LMP], except in those with irregular cycles, and in 30 cases (6.6% of those with regular cycles) in whom the biparietal diameter [BPD]-determined age deviated >14 days from the LMP-based date. Results. The analysis did not reveal any statistically significant differences between the fetuses of non-smokers, light smokers (0–9 cigarettes per day) and heavy (10+ cigarettes per day) smokers, regarding BPD, mean abdominal diameter [MAD] femur length [FL], and a ‘body contour index’: [BPD+FL]÷MAD. Conclusion. Tobacco-induced fetal growth restriction probably begins after gestational week 17.
| Abbreviations | ||
| BPD | = | biparietal diameter |
| FL | = | femur length |
| LMP | = | (first day of) last menstrual period |
| MAD | = | mean abdominal diameter |
| SGA study | = | The ‘Successive Small-for-Gestational Age Births, a prospective longitudinal study of fetal growth and perinatal outcome’, sponsored by the National Institute of Child Health and Human Development's (NICHD), National Institutes of Health (NIH), USA |
| ponderal index | = | weight by height of the newborn |
| formula | = | 1000*weight (g)÷height (cm)3 fetal ‘body contour index’: [BPD + FL]÷MAD |
| Abbreviations | ||
| BPD | = | biparietal diameter |
| FL | = | femur length |
| LMP | = | (first day of) last menstrual period |
| MAD | = | mean abdominal diameter |
| SGA study | = | The ‘Successive Small-for-Gestational Age Births, a prospective longitudinal study of fetal growth and perinatal outcome’, sponsored by the National Institute of Child Health and Human Development's (NICHD), National Institutes of Health (NIH), USA |
| ponderal index | = | weight by height of the newborn |
| formula | = | 1000*weight (g)÷height (cm)3 fetal ‘body contour index’: [BPD + FL]÷MAD |