The role of smoke from cooking indoors over an open flame and parental smoking on the risk of cleft lip and palate: A case- control study in 7 low-resource countries

Abstract

Background Cleft is one of the most common birth defects globally and the lack of access to surgery means millions are living untreated. Smoke exposure from cooking occurs infrequently in developed countries but represents a high-proportion of smoke exposure in less-developed regions. We aimed to study if smoke exposure from cooking is associated with an increased risk in cleft, while accounting for other smoke sources. Methods We conducted a population-sampled case-control study of children with cleft lip and/or palate and healthy newborns from Vietnam, Philippines, Honduras, Nicaragua, Morocco, Congo, and Madagascar. Multivariable regression models were used to assess associations between maternal cooking during pregnancy, parental smoking, and household tobacco smoke with cleft. Results 2137 cases and 2014 controls recruited between 2012-2017 were included. While maternal smoking was uncommon (<1%), 58.3% case and 36.1% control mothers cooked over an open fire inside. Children whose mothers reported cook smoke exposure were 49% (95% confidence interval (CI) = 1.2-1.8) more likely to have a child with a cleft. This was consistent in five of seven countries. No significant associations were found for any other smoke exposure. Conclusions Our finding of maternal cook smoke and cleft in low-resource countries, similar to maternal tobacco smoke in high-resource countries, may reflect a common etiology. This relationship was present across geographically diverse countries with variable socioeconomic statuses and access to care. Exposures specific to low-resource settings must be considered to develop public health strategies that address the populations at increased risk of living with cleft and inform the mechanisms leading to cleft development.

Modifiable Risk Factors of Non-Syndromic Orofacial Clefts: A Systematic Review

“…Maternal exposure to numerous chemicals that are released into the air as a result of the incomplete combustion of tobacco and other organic compounds such as cooking and heating fuels have been shown to cause cracks; these substances include polycyclic aromatic hydrocarbons (PAHs), carbon monoxide (CO) and heavy metals [ 133 ].…”

A plastic and reconstructive surgery landscape assessment of Malawi: a scoping review of Malawian literature

“…The use of open flames for cooking and heating, high density housing situations often with multi-generational occupancy, and lack of residential and industrial construction regulations are all risk factors that contribute to the high incidence of burn injury within Malawi, especially in pediatric and epileptic patients. In addition to preventing burns, providing safe alternatives to open fire cooking may help address other reconstructive issues as one recent study found that pregnant women exposed to cook smoke from open fire had higher risk of birthing children with congenital anomalies [ 55 ]. Suggested solutions in the literature include the use of public awareness campaigns for parents to encourage altered behaviors and instill safe practices around open fire cooking and heating to reduce the incidence of pediatric burns.…”

The International Family Study of Nonsyndromic Orofacial Clefts: Design and Methods

“…This holds true for environmental exposures as well, which may not have been studied due to negligible prevalence in high-resource countries. For example, while maternal smoking may be an important contributor to cleft risk in westernized populations, in low-resource countries where few women smoke, the primary source of exposure to smoke-related agents and therefore attributable risk of NSOFCs, may be from biomass cooking (Mbuyi-Musanzayi et al, 2018; Auslander et al, 2020).…”