Parental age as a risk factor for isolated congenital malformations in a Polish population

Currently available data on the relationship between the prevalence of isolated congenital malformations and parental age are inconsistent and frequently divergent. We utilised the data from the Polish Registry of Congenital Malformations (PRCM) to accurately assess the interplay between maternal and paternal age in the risk of isolated non-syndromic congenital malformations.
Out of 902 452 livebirths we studied 8683 children aged 0–2 years registered in the PRCM. Logistic regression was used to simultaneously adjust the risk estimates for maternal and paternal age. Our data indicated that paternal and maternal age were independently associated with several congenital malformations. Based on our data, young maternal and paternal ages were independently associated with gastroschisis. In addition, young maternal age, but not young paternal age, carried a higher risk of neural tube defects. Advanced maternal and paternal ages were both independently associated with congenital heart defects. Moreover, there was a positive association between advanced paternal age and hypospadias, cleft palate, and cleft lip (with or without cleft palate).
No significant relationships between parental age and the following congenital malformations were detected: microcephaly, hydrocephaly, oesophageal atresia, atresia or stenosis of small and/or large intestine, ano-rectal atresia or stenosis, renal agenesis or hypoplasia, cystic kidney disease, congenital hydronephrosis, diaphragmatic hernia and omphalocele.     

非综合征性唇腭裂高危因素的条件Logistic回归分析

目的探讨非综合征性唇腭裂（nonsyndromic cleft lip and palate,NSCL/P）发病的主要危险因素；筛选可能存在的保护因素，为临床预防该病的发生提供理论依据。方法采用1：1配对病例对照研究，病例组（n=76）来源于2006年9月至2007年9月在潍坊医学院附属医院、潍坊市人民医院、菏泽市立医院、烟台毓璜顶医院口腔科进行唇腭裂矫正手术的非综合征性唇腭裂患儿；对照组（n=76）来源于同一医疗机构门诊或病房，符合配对条件的非唇腭裂儿童。对病例组和对照组患儿的父母进行42项可能导致发生唇腭裂因素的问卷调查，使用条件Logistic回归，首先对病例资料进行单因素分析，然后对单因素筛选的变量结合非综合征性唇腭裂相关医学专业知识进行多因素分析，筛选主要危险因素及可能存在的保护因素。结果病例组与对照组作对照分析，进入条件Logistic回归模型的变量包括：母亲孕期感染史（P=0．010）、家族唇腭裂遗传史（P=0．009）、母亲孕期饮食是否规律（P=0．007）、胎次（P=0．004）、母亲孕期异常情绪史（P=0．000）、父亲学历（P=0．000）。结论母亲孕期情绪异常、胎次增加、母亲孕期饮食不规律、家族唇腭裂遗传病史、母亲孕期感染史，是非综合征性唇腭裂发病的促进因素；父亲学历是保护因素。     

1988—1992年中国非综合征性唇腭裂发生率的动态变化

目的：了解我国1988－1992年非综合征性唇腭裂发生率的动态变化趋势及流行病学特征。方法：在1988－1992年期间,采用以医院为单位的整群抽样方法,对全国500多所医院孕28周至产后7天的4349例非综合征性唇腭裂病例进行回顾性分析。结果：我国5年非综合征性唇腭裂发生率无显著性差异,城乡发生率也无显著性差异。男性发生率为14．9／万,女性发生率为11．7/万,差异有显著性,非综合征性唇腭裂的性别比为1．3：1。三类非综合征性唇腭裂各自的发生率为：唇裂合并腭裂：7．8／万,单纯性唇裂：3．8／万,单纯性腭裂：1．8/万。结论：我国非综合征性唇腭裂发生率无变化趋势,城乡无差异。男性高于女性,唇裂合并腭裂为最常见类型。     

Maternal reproductive history and the risk of isolated congenital malformations

We examined the relationship between maternal reproductive history and the newborn's risk of isolated congenital malformations in a large case-control cohort from the Polish Registry of Congenital Malformations. Congenital malformations were classified into four categories: isolated congenital heart defects (n=1673), isolated cleft palate (n=255), cleft lip with or without cleft palate (n=448) and renal agenesis (n=103). The case groups were compared with a shared group of 2068 controls recruited in the same time period and geographic area. Multivariable logistic regression was used to assess the risk associated with maternal gravidity and of previous miscarriages after accounting for maternal age and other potential risk factors. In unadjusted analyses, maternal gravidity was significantly associated with increased risk of all four classes of congenital malformations. After adjustment, a significant association persisted for congenital heart defects [odds ratio (OR)=1.22, [95% confidence interval (CI) 1.09, 1.36], P=0.0007] and cleft lip with or without cleft palate (OR=1.21, [95% CI 1.09, 1.36], P=0.0005). A similar trend existed for isolated cleft palate (OR=1.18, [95% CI 1.02, 1.37], P=0.03). There was no appreciable increase in the risk of congenital malformations associated with a maternal history of miscarriages, but a trend for a protective effect on the occurrence of cleft lip with or without cleft palate was observed (OR=0.72, [95% CI 0.52, 0.99], P=0.045). Based on our data, maternal gravidity represents a significant risk factor for congenital heart defects and cleft lip with or without cleft palate in the newborn infant. Our data do not support an increase in risk because of past history of miscarriages.     

Parental occupational pesticide exposure and nonsyndromic orofacial clefts

Nonsyndromic orofacial clefts are common birth defects. Reported risks for orofacial clefts associated with parental occupational pesticide exposure are mixed. To examine the role of parental pesticide exposure in orofacial cleft development in offspring, this study compared population-based case-control data for parental occupational exposures to insecticides, herbicides, and fungicides, alone or in combinations, during maternal (1 month before through 3 months after conception) and paternal (3 months before through 3 months after conception) critical exposure periods between orofacial cleft cases and unaffected controls. Multivariable logistic regression was used to estimate odds ratios, adjusted for relevant covariables, and 95% confidence intervals for any (yes, no) and cumulative (none, low [相似文献   

Maternal dietary intake of vitamin A and risk of orofacial clefts: a population-based case-control study in Norway

A population-based case-control study was carried out in Norway between 1996 and 2001. The aim was to evaluate the association between maternal intake of vitamin A from diet and supplements and risk of having a baby with an orofacial cleft. Data on maternal dietary intake were available from 535 cases (188 with cleft palate only and 347 with cleft lip with or without cleft palate) and 693 controls. The adjusted odds ratio for isolated cleft palate only was 0.47 (95% confidence interval: 0.24, 0.94) when comparing the fourth and first quartiles of maternal intake of total vitamin A. In contrast, there was no appreciable association of total vitamin A with isolated cleft lip with or without cleft palate. An intake of vitamin A above the 95th percentile was associated with a lower estimated risk of all isolated clefts compared with the 40th-60th percentile (adjusted odds ratio = 0.48, 95% confidence interval: 0.20, 1.14). Maternal intake of vitamin A is associated with reduced risk of cleft palate only, and there is no evidence of increased risk of clefts among women in our study with the highest 5% of vitamin A intake.     

A case-control study of nonsyndromic oral clefts in Maryland.

PURPOSE: Isolated, nonsyndromic oral clefts cases (n = 171) and unaffected controls (n = 182) were used to identify both genetic and environmental risk factors. METHODS: Infants born in Maryland between 1992 to 1998 with an isolated, nonsyndromic oral cleft [cleft lip (CL), cleft lip and palate (CLP), or cleft palate (CP)] were recruited and exposure plus family history data were collected. Controls were unaffected infants. DNA was collected from all cases and their parents, plus controls. RESULTS: No statistically significant association was found between any of the following: maternal smoking, vitamin use, urinary tract infection, or recreational drug use in either univariate analysis or after adjusting for maternal age and education. More control mothers reported alcohol use during the critical time period of pregnancy (one month before conception through the first trimester) as compared to case mothers. There was a 10-fold increase in risk to siblings of cases as compared to siblings of controls. Markers at four candidate genes were examined: transforming growth factor alpha (TGF alpha), transforming growth factor beta 3 (TGF beta 3), MSX1, and BCL3. Only MSX1 showed significant differences in allele frequencies between CP cases and controls. MSX1 also showed significant evidence of linkage disequilibrium with a susceptibility gene controlling risk for CP. CONCLUSION: Most environmental risk factors examined here gave little evidence of association with risk to isolated, nonsyndromic oral clefts, although any alcohol consumption seemed protective. MSX1 showed evidence of linkage disequilibrium in both case-control and case-parent trio analysis.     

Smoking and the risk of oral clefts: exploring the impact of study designs

BACKGROUND: Maternal cigarette smoking is a suspected cause of oral clefts, although this association has not been firmly established. We used case-crossover, case-time-control, and bidirectional case-crossover designs to supplement findings from a case-control study of maternal smoking and oral clefts among offspring in a large birth registry. METHODS: Data are from the Swedish Medical Birth Registry. From 1983 through 1997 there were 678 recorded cases of cleft palate and 1175 cases of cleft lip with or without palate. Maternal smoking status was ascertained in early pregnancy. Controls for the case-control study were a random sample of infants born without a cleft; controls for the case-crossover designs were nonmalformed infants born to case mothers. RESULTS: Cleft palate was positively associated with maternal smoking in all study designs, whereas cleft lip with or without cleft palate was associated with smoking only in the case-control design. In the case-control design, the odds ratios for cleft palate were 1.2 (95% confidence interval = 1.0-1.5) for women who smoked 1 to 9 cigarettes per day and 1.4 (1.1-1.8) for women who smoked 10+ cigarettes per day. In the case-time-control analysis, the odds ratio for cleft palate with maternal smoking was 3.2 (1.3-7.4) and in the bidirectional case-crossover design, the odds ratio was 2.2 (1.1-4.1). CONCLUSIONS: An association between smoking and cleft palate was supported by all designs, whereas that between smoking and cleft lip with or without cleft palate was not. Case-only designs are a viable option in birth registries and may yield more information than a case-control design alone.     

Tobacco smoking and oral clefts: a meta-analysis

OBJECTIVE: To examine the association between maternal smoking and non-syndromic orofacial clefts in infants. METHODS: A meta-analysis of the association between maternal smoking during pregnancy was carried out using data from 24 case-control and cohort studies. FINDINGS: Consistent, moderate and statistically significant associations were found between maternal smoking and cleft lip, with or without cleft palate (relative risk 1.34, 95% confidence interval 1.25-1.44) and between maternal smoking and cleft palate (relative risk 1.22, 95% confidence interval 1.10-1.35). There was evidence of a modest dose-response effect for cleft lip with or without cleft palate. CONCLUSION: The evidence of an association between maternal tobacco smoking and orofacial clefts is strong enough to justify its use in anti-smoking campaigns.     

First-trimester maternal alcohol consumption and the risk of infant oral clefts in Norway: a population-based case-control study

Although alcohol is a recognized teratogen, evidence is limited on alcohol intake and oral cleft risk. The authors examined the association between maternal alcohol consumption and oral clefts in a national, population-based case-control study of infants born in 1996-2001 in Norway. Participants were 377 infants with cleft lip with or without cleft palate, 196 with cleft palate only, and 763 controls. Mothers reported first-trimester alcohol consumption in self-administered questionnaires completed within a few months after delivery. Logistic regression was used to calculate odds ratios and 95% confidence intervals, adjusting for confounders. Compared with nondrinkers, women who reported binge-level drinking (>or=5 drinks per sitting) were more likely to have an infant with cleft lip with or without cleft palate (odds ratio = 2.2, 95% confidence interval: 1.1, 4.2) and cleft palate only (odds ratio = 2.6, 95% confidence interval: 1.2, 5.6). Odds ratios were higher among women who binged on three or more occasions: odds ratio = 3.2 for cleft lip with or without cleft palate (95% confidence interval: 1.0, 10.2) and odds ratio = 3.0 for cleft palate only (95% confidence interval: 0.7, 13.0). Maternal binge-level drinking may increase the risk of infant clefts.     

还原叶酸载体基因多态性与先天性心脏病和唇腭裂关联的研究

目的 检验还原叶酸载体基因(RFC1)A80G多态性与先天性心脏病(CHD)和唇腭裂之间的关联,为寻找CHD和唇腭裂危险因素的遗传易感标志物提供流行病学依据。方法 采用RFLP-PCR方法,对67个CHD患儿家庭、82个唇腭裂患儿家庭和100个正常儿童家庭成员的外周血DNA进行RFC1第80位SNP检测,利用核心家庭标本进行以家庭为基础的关联检验(FBAT),并分析了子代RFC1基因型与母亲孕期前后增补叶酸的相互作用。结果 不增补叶酸的母亲生育CHD儿的危险高于增补叶酸的母亲(OR=2 68,95％CI:1 14-6 41),即母亲孕期未增补叶酸与CHD发生危险的关联有统计学意义(x2=6.213,P=0 013);在FBAT检验中,RFC1 G等位基因与CHD发病危险有统计学关联(Z=2 140,P<0 05),表明RFC1 G等位基因可能是CHD发病的遗传易感基因,未发现唇腭裂与RFC1之间的统计学关联。结论 RFC1 G等位基因可能是CHD发生的遗传易感基因之一,子代RFC1基因GG或GA基因型、母亲孕期叶酸缺乏可能增加CHD的发病危险。     

Exploring the effects of methylenetetrahydrofolate reductase gene variants C677T and A1298C on the risk of orofacial clefts in 261 Norwegian case-parent triads

Folic acid and the methylenetetrahydrofolate reductase (MTHFR) gene have both been implicated in the etiology of orofacial clefts. The authors selected 261 case-parent triads (173 cases with cleft lip with or without cleft palate (CL/P) and 88 cases with cleft palate only (CPO)) from a Norwegian population-based study of orofacial clefts (May 1996-1998). A case-parent triad design was used to examine whether MTHFR variants C677T and A1298C, and their haplotypes, are risk factors for orofacial clefts. Among CL/P cases, the child's genotype at C677T or A1298C did not influence the risk. However, children of mothers carrying the C677T variant allele had a lower risk of CL/P. For CPO, children carrying the C677T variant allele had about a twofold increased risk, whereas the mother's genotypes did not contribute to the risk. The haplotype-based transmission/disequilibrium test showed that except for 677T/1298A (p = 0.06), none of the other haplotypes showed evidence of excess transmission to the offspring. The authors also explored interaction of C677T with maternal use of folic acid among children with CPO. Surprisingly, the risk associated with the child's carrying either CT or TT was higher (fourfold) when the mother used folic acid. These findings suggest a possible role of MTHFR and folic acid in the causation of orofacial clefts, but the strength and direction of these effects remain to be clarified.     

Maternal alcohol binge-drinking in the first trimester and the risk of orofacial clefts in offspring: a large population-based pooling study

Using individual participant data from six population-based case–control studies, we conducted pooled analyses to examine maternal alcohol consumption and the risk of clefts among >4600 infants with cleft lip only, cleft lip with cleft palate, or cleft palate only and >10,000 unaffected controls. We examined two first-trimester alcohol measures: average number of drinks/sitting and maximum number of drinks/sitting, with five studies contributing to each analysis. Study-specific odds ratios (ORs) were estimated using logistic regression and pooled to generate adjusted summary ORs. Across studies, 0.9–3.2 % of control mothers reported drinking an average of 5+ drinks/sitting, while 1.4–23.5 % reported drinking a maximum of 5+ drinks/sitting. Compared with non-drinkers, mothers who drank an average of 5+ drinks/sitting were more likely to deliver an infant with cleft lip only (pooled OR 1.48; 95 % confidence intervals 1.01, 2.18). The estimate was higher among women who drank at this level 3+ times (pooled OR 1.95; 1.23, 3.11). Ever drinking a maximum of 5+ drinks/sitting and non-binge drinking were not associated with cleft risk. Repeated heavy maternal alcohol consumption was associated with an increased risk of cleft lip only in offspring. There was little evidence of increased risk for other cleft types or alcohol measures.     

Maternal occupational risk factors for oral clefts. Occupational Exposure and Congenital Malformation Working Group

OBJECTIVES: This study investigated the role of maternal exposures at work during pregnancy in the occurrence of oral clefts. METHODS: The occupational exposures of 851 women (100 mothers of babies with oral clefts and 751 mothers of healthy referents) who worked during the first trimester of pregnancy were studied. All the women were part of a multicenter European case-referent study conducted using 6 congenital malformation registers between 1989 and 1992. In each center, the mother's occupational history, obtained from an interview, was reviewed by industrial hygienists who were blinded to the subject's status and who assessed the presence of chemicals and the probability of exposure. Odds ratios (OR) were estimated by a multivariate analysis including maternal occupation or occupational exposures during the first trimester of pregnancy and possible confounding factors such as center of recruitment, maternal age, urbanization, socioeconomic status, and country of origin. RESULTS: After adjustment for confounding factors, cleft palate only was significantly associated with maternal occupation in services such as hairdressing [OR 5.1, 95% confidence interval (95% CI) 1.0-26.0] and housekeeping (OR 2.8, 95% CI 1.1-7.2). The analysis suggests that the following occupational exposures are associated with orofacial clefts: aliphatic aldehydes (OR 2.1, 95% CI 0.8-5.9) and glycol ethers (OR 1.7, 95% CI 0.9-3.3) for cleft lip with or without cleft palate and lead compounds (OR 4.0, 95% CI 1.3-12.2), biocides (OR 2.5, 95% CI 1.0-6.0), antineoplastic drugs (OR 5.0, 95% CI 0.8-34.0), trichloroethylene (OR 6.7, 95% CI 0.9-49.7), and aliphatic acids (OR 6.0, 95% CI 1.5-22.8) for cleft palate only. CONCLUSIONS: Due to the limited number of subjects, these results must be interpreted with caution. However, they point out some chemicals already known or suspected as reproductive toxins.     

Socio-economic factors associated with preterm delivery in Greece: a population-based study

A total population sample of singleton births to mothers with certain last menstrual period dates was identified from the Greek National Perinatal Survey of April 1983. Two groups were considered (3116 primigravidae and 6524 multigravidae) with preterm rates of 5.9% and 8.4% respectively. Of all 17 factors considered, primigravidae showed unadjusted significant associations between preterm delivery and marital status, region of mother's residence, maternal occupation, maternal education and paternal education level. Multigravidae preterm deliveries were associated with marital status, mother's age at marriage, father's age at marriage, mother's age at delivery, mother's education, father's education and maternal smoking at the end of the pregnancy. Logistic regression was used to identify the socio-economic and demographic characteristics independently associated with preterm delivery. For primigravidae, the only significant factors were maternal marital status and region of the country. For multigravidae, significant factors were maternal age at delivery, marital status and smoking habit at the end of pregnancy.     

Increasing risk of gastroschisis in Norway: an age-period-cohort analysis

The prevalence of gastroschisis in Norway, as reported to the Medical Birth Registry of Norway, increased regularly and sixfold from 0.5 to 2.9 per 10,000 births during 1967-1998. The prevalence was also consistently higher among children of younger mothers. The authors used age-period-cohort analysis to assess effects of both parents' age and year of birth (parental cohorts). Mother's and father's age were included in three different regression models. Apart from a significantly higher risk at a young maternal age, the authors also found higher risk at a young paternal age (1.6-fold per 10 years' reduction in father's age, 95% confidence interval: 1.0, 2.4). The time trend was highly significant regardless of whether it was ascribed to period, mother's year of birth, or father's year of birth. However, when father's year of birth was used to describe the time trend, no apparent additional effect of father's age was found, only for mother's age. The time trend is likely caused by environmental factors. Persistently increasing risks among children of young mothers may hypothetically be related to lifestyle factors. A contribution to risk also from fathers born in more recent years or from young fathers increases the likelihood that a factor related to modern lifestyles of young couples may be related to risk.     

Evaluation of two putative susceptibility loci for oral clefts in the Danish population

Previous studies suggest that the risk of nonsyndromic cleft lip with or without cleft palate (CL+/-P) and isolated cleft palate (CP) is influenced by genetic variation at several loci and that the relation between specific genetic variants and disease risk may be modified by environmental factors. The present study evaluated potential associations between CL+/-P and CP and two putative clefting susceptibility loci, MSX1 and TGFB3, using data from a nationwide case-control study conducted in Denmark from 1991 to 1994. The potential effects of interactions between these genes and two common environmental exposures, first trimester exposure to maternal cigarette smoke and alcohol intake, were also examined. Analyses of these data provide evidence of an association between the risk of CP and variation at the TGFB3 locus. However, there is no evidence that the risk of CL+/-P or CP is influenced by gene-environment interactions involving MSX1 or TGFB3 and either first trimester exposure to maternal cigarette smoke or alcohol consumption.     

Association of Parental Environmental Exposures and Supplementation Intake with Risk of Nonsyndromic Orofacial Clefts: A Case-Control Study in Heilongjiang Province,China

The aim of present study was to check the possible association of potential parental environmental exposures and maternal supplementation intake with the risk of nonsyndromic orofacial clefting (NSOC). A retrospective study comprised 499 cases and 480 controls was conducted in Heilongjiang Province. Chi-square analysis and unconditional multiple logistic regression were used in the study. The results showed that maternal history of fever and the common cold without fever (OR_CL/P = 3.11 and 5.56, 95%CI: 1.67–5.82 and 2.96–10.47, OR_CPO = 3.31 and 8.23, 95%CI: 1.58–6.94 and 4.08–16.95), paternal smoking and alcohol consumption (OR_CL/P = 2.15 and 5.04, 95%CI: 1.37–3.38 and 3.00–8.46, OR_CPO = 1.82 and 4.40, 95%CI: 1.06–3.13 and 2.50–7.74), maternal exposure to organic solvents, heavy metals, or pesticides (OR_CL/P = 6.07, 5.67 and 5.97, 95%CI: 1.49–24.76, 1.34–24.09 and 2.10–16.98, OR_CPO = 10.65, 7.28 and 3.48, 95%CI: 2.54–44.67, 1.41–37.63 and 1.06–11.46) and multivitamin use during the preconception period (OR_CL/P = 0.06, 95%CI: 0.02–0.23, OR_CPO = 0.06, 95%CI: 0.01–0.30) were associated with cleft lip or without cleft palate (CL/P) and cleft palate only (CPO). Maternal history of skin disease and negative life events (OR_CL/P = 12.07 and 1.67, 95%CI: 1.81–80.05 and 1.95–2.67) were associated with CL/P. Some potential parental hazardous exposures during the periconception period and maternal use of multivitamins during the preconception period were associated with risk of NSOC.     

The contribution of maternal epilepsy and its treatment to the etiology of oral clefts: A population based case-control study

The associations between maternal epilepsy and anticonvulsant drug therapy with the risk of oral clefts in the offspring were investigated using data from a population-based case-control study. Cases included 238 infants with cleft lip ± cleft palate (CLP) and 107 infants with cleft palate (CP) ascertained through the Metropolitan Atlanta Congenital Defects Program (MACDP) between 1968 and 1980. Controls included 3029 population-based normal infants. Histories of maternal epilepsy and drug therapy during pregnancy were compared between cases and controls using maternal interviews and reviews of hospital medical records. Maternal epilepsy was associated with increased risk of nonsyndromic CLP (OR = 3.78, 95% C.I. 1.65–7.88), and less with CP (OR = 1.75, 95% C.I. 0.20–6.99). Therapy during pregnancy was associated with the greatest excess risk (CLP OR = 7.77, C.I. 2.02–26.0; CP OR = 3.61, C.I. 0.08–26.5). The use of polytherapy was associated with the highest risk (CLP OR = 10.5, C.I. 1.52–59.9). Adjustment for potential confounding variables in the study did not change these findings. In this well-defined population, maternal epilepsy and its treatment account for a small proportion of nonsyndromic oral clefts (attributable fraction CLP = 3.3%, CP = 0.9%). © 1994 Wiley-Liss, Inc.     

Maternal cigarette smoking during pregnancy and risk of oral clefts in newborns.

The results of previous epidemiologic research on the possible association between maternal smoking during pregnancy and risk of oral clefts in offspring have been inconsistent. This may be due in part to methodological limitations, including imprecise measurement of tobacco use, failure to consider etiologic heterogeneity among types of oral clefts, and confounding. This analysis, based on a large case-control study, further evaluated the effect of first trimester maternal smoking on oral facial cleft risk by examining the dose-response relationship according to specific cleft type and according to whether or not additional malformations were present. A number of factors, including dietary and supplemental folate intake and family history of clefts, were evaluated as potential confounders and effect modifiers. Data on 3,774 mothers interviewed between 1976 and 1992 by the Slone Epidemiology Unit Birth Defects Study were used. Study subjects were actively ascertained from sites in areas around Boston, Massachusetts and Philadelphia, Pennsylvania; the state of Iowa; and southeastern Ontario, Canada. Cases were infants with isolated defects--cleft lip alone (n = 334), cleft lip and palate (n = 494), or cleft palate alone (n = 244)--and infants with clefts plus (+) additional malformations: cleft lip+ (n = 58), cleft lip and palate+ (n = 140), or cleft palate+ (n = 209). Controls were infants with defects other than clefts, excluding defects possibly associated with maternal cigarette use. There were no associations with maternal smoking for any oral cleft group, except for a positive dose response among infants with cleft lip and palate+ (for light smokers, odds ratio (OR) = 1.09 (95% confidence interval (CI): 0.6, 1.9); for moderate smokers, OR = 1.84 (95% CI: 1.2, 2.9); and for heavy smokers, OR = 1.85 (95% CI: 1.0, 3.5), relative to nonsmokers). This finding may be related to the additional malformations rather than to the cleft itself.