Title	Maternal Smoking Increases The Risk For Craniocynostosis And Oral Clefts
Clinical Question	Does maternal smoking during pregnancy cause Craniocynostosis and Oral Clefts?
Clinical Bottom Line	Maternal smoking during pregnancy leads to a 33% increased risk of Craniocynostosis and 28-34% increased risk of oral clefts.
Best Evidence
PubMed ID Author / Year Patient Group Study type (level of evidence) 21747128 Hackshaw/2011 173,687 malformed cases. 11.7 million control cases Systematic Review Key results The Odds Ratio for craniocynostosis in infants, exposed to maternal smoking during pregnancy, is 1.33 (95% CI 1.03-1.73, P=0.03) with evidence of a dose-response relationship. The Pooled Odds Ratio for Cleft Lip and Cleft Palate is 1.28 (95% CI 1.20-1.36, p<0.00001) with evidence of a dose-response relationship. 15112010 Little/2004 24 Case-control and Cohort studies Meta-anlaysis of case control and cohort studies Key results The Odds Ratio for cleft Lip with or without cleft palate in infants, exposed to maternal smoking during pregnancy, is 1.34 (95% CI 1.25-1.44). The Odds Ratio for Cleft Palate alone is 1.22 (95% CI 1.10-1.35). Both with evidence of a dose-response relationship.
Evidence Search	(pregnancy AND smoking AND (craniosynostosis OR cleft)) OR ("Pregnancy"[Mesh] AND "Smoking"[Mesh] AND ("Craniosynostoses"[Mesh] OR "Cleft Lip"[Mesh] OR "Cleft Palate"[Mesh]))
Comments on The Evidence	The systematic review and meta-analysis are typically the highest levels of evidence however, these consist of case control/cohort studies. Randomized control studies will most likely never be available so these lower level experiments will suffice. The systematic review had a large sample. The meta analysis also used a large number of studies from which to do its analysis. Both studies show evidence that the risk of these defects increased with increasing cigarette consumption.
Applicability	The findings of these studies are highly applicable. Despite the evidence against maternal smoking during pregnancy, a high percentage of women continue to smoke during pregnancy (14-17% in western society). These defects are very expensive and difficult to treat and manage, and the psychological effects are un-measurable. The associated risk is significant enough to push for more advertising against this dangerous practice.
Specialty	(Public Health) (Oral Surgery) (Orthodontics) (Pediatric Dentistry) (Behavioral Science)
Keywords	Maternal Smoking, Craniocynostosis, Oral Clefts, Birth Defects, Tobacco
ID#	2162
Date of submission	10/10/2011
E-mail	pratta@livemail.uthscsa.edu
Author	Allen Pratt, DDS
Co-author(s)
Co-author(s) e-mail
Faculty mentor	Peter T. Gakunga, BDS, MS, PhD
Faculty mentor e-mail	GAKUNGA@uthscsa.edu
Basic Science Rationale (Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?) None available
Comments and Evidence-Based Updates on the CAT (FOR PRACTICING DENTISTS', FACULTY, RESIDENTS and/or STUDENTS COMMENTS ON PUBLISHED CATs) by Thomas Adams and Priscilla Leary (San Antonio, Texas) on 11/28/2017 A Pub-Med search on this topic in November 2017, found a meta-analysis by Xuan et al. 2016(PMID 27727103.) which came to similar conclusions as the original bottom line for this CAT. The conclusions further confirmed a risk between smoking and cleft defects, but couldn't confirm if the risk increased depending on dose.