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Meta-Analysis
. 2024 Dec 30;19(12):e0312297.
doi: 10.1371/journal.pone.0312297. eCollection 2024.

The invisible enemy: A systematic review and meta-analysis of maternal smokeless tobacco use as a risk factor for low birth weight

Akanksha Mahajan  1 , Bhawna Gupta  2 , Michael Tong  3
Affiliations
Meta-Analysis

The invisible enemy: A systematic review and meta-analysis of maternal smokeless tobacco use as a risk factor for low birth weight

Akanksha Mahajan et al. PLoS One. .

Abstract

Introduction: Smokeless tobacco use is a growing public health concern, with potential adverse implications for foetal outcomes if consumed during pregnancy. Birth weight is an important predictive measure for health outcomes of a child throughout their lifespan. Despite extensive literature, it is unclear whether smokeless tobacco consumption during pregnancy has an adverse effect on birth weight. Hence, this review was conducted to determine whether an association exists between maternal smokeless tobacco consumption during pregnancy and birth weight of infants.

Methods: Systematic literature search was performed in Medline (via PubMed), Embase, Scopus, and CINAHL with no restrictions on language or time until May 2024. All observational studies that examined the relationship between maternal smokeless tobacco use and low birth weight of infants were eligible for inclusion. Methodological quality of included studies was assessed using the Newcastle Ottawa Scale.

Results: Thirty-three studies were eligible for the review, including twenty-eight cohort, three case-control and two cross-sectional studies. A statistically significant association between use of smokeless tobacco and low birth weight was reported in thirteen studies. Eleven studies reported a statistically significant reduction in mean birth weight in maternal smokeless tobacco users. Pooled estimates of eighteen studies with 733,061 participants showed that there was a statistically significant association (OR = 2.25 [1.63, 3.11] P<0.001); between maternal smokeless tobacco use during pregnancy and low birth weight. Subgroup analysis found a significant association between mishri consumption during pregnancy and low birth weight (n = 646 participants, OR = 10.98 [2.03, 59.34], P = 0.005), but not betel nut (n = 8007 participants, OR = 1.02 [0.84, 1.25]), betel quid (n = 483 participants, OR = 1.51 [0.47, 4.89]) or khat (n = 475 participants, OR = 1.41 [0.64-3.09]).

Conclusions: This review presents an association between maternal smokeless tobacco use and low birth weight, and reduction in mean birth weight. It is suggested that cessation and reduction of maternal smokeless tobacco use should receive specific attention within routine prenatal care.

Implications: The results of this study highlight the need for further preventive public health campaigns to create awareness about detrimental effects of smokeless tobacco on foetal outcomes. Patient education in the primary care setting will aid in promoting smokeless tobacco cessation prior to pregnancy.

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Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Flowchart showing process of literature search according to Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines.
Fig 2
Fig 2. Forest plot for effect of maternal smokeless tobacco consumption compared with no tobacco consumption during pregnancy on risk of low birth weight in infants.
Fig 3
Fig 3. Sensitivity analysis for effect of maternal smokeless tobacco consumption compared with no tobacco consumption during pregnancy on risk of low birth weight in infants.
Fig 4
Fig 4. Subgroup analyses of the effect of maternal smokeless tobacco consumption compared with no tobacco consumption during pregnancy on risk of low birth weight in infants.
Fig 5
Fig 5. Funnel plot of all studies included in this meta-analysis.
Fig 6
Fig 6. Funnel plot of studies included in the subgroup analysis based on type of smokeless tobacco consumed during pregnancy.
See this image and copyright information in PMC

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