Smoking and Smoking Cessation in the Risk for Fetal Growth Restriction and Low Birth Weight and Additive Effect of Maternal Obesity

Małgorzata Lewandowska; Barbara Więckowska; Lidia Sztorc; Stefan Sajdak

doi:10.3390/jcm9113504

Smoking and Smoking Cessation in the Risk for Fetal Growth Restriction and Low Birth Weight and Additive Effect of Maternal Obesity

J Clin Med. 2020 Oct 29;9(11):3504. doi: 10.3390/jcm9113504.

Authors

Małgorzata Lewandowska^{1

2}, Barbara Więckowska³, Lidia Sztorc^{4

5}, Stefan Sajdak²

Affiliations

¹ Medical Faculty, Lazarski University, 02-662 Warsaw, Poland.
² Division of Gynecological Surgery, University Hospital, 33 Polna Str., 60-535 Poznan, Poland.
³ Department of Computer Science and Statistics, Poznan University of Medical Sciences, 60-806 Poznan, Poland.
⁴ Akademisches Lernkrankenhaus der Charité, Oberhavel Kliniken, Klinik Oranienburg, 16515 Oranienburg, Germany.
⁵ Caritas-Klinik Dominikus, Berlin Reinickendorf, 13467 Berlin, Germany.

Abstract

Many studies have shown that neonates of smoking mothers have a lower birth weight, but several issues remain poorly studied, e.g., the effects of giving up smoking or the combined effects of smoking and maternal obesity. Therefore, we evaluated a prospective cohort of 912 mothers in a single pregnancy, recruited in Poland, in 2015-2016. In the cohort, we recorded 72 (7.9%) newborns with birth weight <10th percentile, 21 (2.3%) fetal growth restriction (FGR) cases, and 60 (6.6%) low birth weight (LBW, <2500 g) newborns. In the cohort, 168 (18.4%) women smoked before pregnancy; the mean number of cigarettes/day was 10.8 (1-30), and the mean number of years of cigarette smoking was 8.5 (1-25). Among smokers, 57 (6.3%) women smoked in the first trimester. Adjusted odds ratio (AOR) of newborn outcomes (with 95% confidence intervals, CI) was calculated in multi-dimensional logistic regressions. Compared to participants who had never smoked, smoking before pregnancy was associated with a higher odds ratio of birth weight <10th percentile (AOR = 1.93, CI: 1.08-3.44, p = 0.027), but the result for LBW (AOR = 2.76, CI: 1.05-7.26, p = 0.039) and FGR (AOR = 1.13, CI: 0.38-3.36, p = 0.822) had the wider confidence interval or was insignificant. Effects of smoking cessation before pregnancy were statistically insignificant for the studied outcomes. Smoking in the first trimester was associated with a higher risk of birth weight <10th percentile (AOR = 4.68, CI: 2.28-9.62, p < 0.001), LBW (AOR = 6.42, CI: 1.84-22.36, p = 0.004), and FGR (AOR = 3.60, CI: 0.96-13.49, p = 0.057). Smoking cessation in the second/third trimester was associated with a higher odds ratio of birth weight <10th percentile (AOR = 4.54, CI: 1.58-13.02, p = 0.005), FGR (AOR = 3.36, CI: 0.6-18.74, p = 0.167), and LBW (AOR = 2.14, CI: 0.62-7.36), p = 0.229), to a similar degree to smoking in the first trimester. The odds ratios were higher in the subgroup of pre-pregnancy body mass index ≥25 kg/m² for the risk of birth weight <10th percentile (AOR = 6.39, CI: 2.01-20.34, p = 0.002) and FGR (AOR = 6.25, CI: 0.86-45.59, p = 0.071). The length of cigarette smoking time was also the risk factor for studied outcomes. Conclusions: Smoking in the first trimester increased the studied risks, and the coexistence of excessive maternal weight increased the effects. Smoking cessation during the second/third trimester did not have a protective effect.

Keywords: birth weight; fetal growth; obesity; paradoxical effect; pregnancy; smoking cessation.