Placental weight and birthweight: the relations with number of daily cigarettes and smoking cessation in pregnancy. A population study

Abstract

BackgroundWe studied associations of number of daily cigarettes in the first trimester with placental weight and birthweight in women who smoked throughout pregnancy, and in women who stopped smoking after the first trimester.MethodsWe included all women with delivery of a singleton in Norway (n = 698 891) during 1999–2014, by using data from the Medical Birth Registry of Norway. We assessed dose-response associations by applying linear regression with restricted cubic splines.ResultsIn total, 12.6% smoked daily in the first trimester, and 3.7% stopped daily smoking. In women who smoked throughout pregnancy, placental weight and birthweight decreased by number of cigarettes; however, above 11–12 cigarettes we estimated no further decrease (Pnon-linearity < 0.001). Maximum decrease in placental weight in smokers compared with non-smokers was 18.2 g [95% confidence interval (CI): 16.6 to 19.7], and for birthweight the maximum decrease was 261.9 g (95% CI: 256.1 to 267.7). In women who stopped smoking, placental weight was higher than in non-smokers and increased by number of cigarettes to a maximum of 16.2 g (95% CI: 9.9 to 22.6). Birthweight was similar in women who stopped smoking and non-smokers, and we found no change by number of cigarettes (Pnon-linearity < 0.001).ConclusionsIn women who smoked throughout pregnancy, placental weight and birthweight decreased non-linearly by number of cigarettes in the first trimester. In women who stopped smoking, placental weight was higher than in non-smokers and increased linearly by number of cigarettes; birthweight was almost similar to that of non-smokers.

No association between early maternal HbA1c and offspring birthweight among women without pre-existing diabetes in Greenland

“…It cannot be excluded that the high proportion of women with elevated prepregnancy BMI may have blurred the contrast between low or normal BMI compared to high BMI. Similarly, the high proportion of women smoking during pregnancy in this study may also have blurred a possible association, since smoking may increase HbA1c at the same time as it reduces birthweight [29,30].…”

Transcriptomics and Other Omics Approaches to Investigate Effects of Xenobiotics on the Placenta

“…For instance, nicotine acting through nAChR induced endoplasmic reticulum stress in rat pTGC (Wong et al, 2016). Maternal smoking has been linked with changes in gross placental weight and microanatomical structure, especially for the extravillous TB cells (Heidari et al, 2018a,b;Larsen et al, 2018). Metabolism of lipids, namely long-chain polyunsaturated fatty acids and transporters for glucose uptake transporters (SLC2A1 and SLC2A3), amino acids (SLC7A8), and lipid gene expression patterns in the placenta correlate with maternal smoking (Walker et al, 2019;Weinheimer et al, 2020).…”

Maternal folic acid supplementation and more prominent birth weight gain in twin birth compared with singleton birth: a cross-sectional study in northwest China

“…, which was classified according to tertiles of poor, middle and rich (31) . Maternal active smoking was also one of the important predictors of reduced birth weight (32) , which should be considered as a confounder. However, the percentage of active women smokers was extremely low in China (33) , especially among women of child-bearing age (0•3 % for women with singletons and none for women with twins in our study).…”