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

BACKGROUND: The majority of research to understand the risk factors of nonsyndromic orofacial clefts (NSOFCs) has been conducted in high-income populations. Although patients with NSOFCs in low- and middle-income countries (LMICs) are at the highest risk of not receiving care, global health infrastructure allows innovative partnerships to explore the etiologic mechanisms of cleft and targets for prevention unique to these populations. METHODS: The International Family Study (IFS) is an ongoing case-control study with supplemental parental trio data designed to examine genetic, environmental, lifestyle, and sociodemographic risk factors for NSOFCs in 8 LMICs (through August 2020). Interview and biological samples are collected for each family. The interview includes demographics, family history of cleft, diet and water sources, maternal pregnancy history, and other lifestyle and environmental factors. RESULTS: Seven of 8 countries are currently summarized (2012-2017) for a total of 2955 case and 2774 control families with 11 946 unique biological samples from Vietnam, Philippines, Honduras, Madagascar, Morocco, Democratic Republic of the Congo, and Nicaragua. The phenotype distribution was 1641 (55.5%) cases with cleft lip and palate, 782 (26.5%) with cleft lip (CL), and 432 (14.6%) with cleft palate (CP). DISCUSSION: The International Family Study is the largest case set of NSOFCs with an associated biobank in LMICs currently assembled. The biobank, family, and case-control study now include samples from 8 LMICs where local health care infrastructure cannot address the surgical burden of cleft or investigate causal mechanisms. The International Family Study can be a source of information and may collaborate with local public health institutions regarding education and interventions to potentially prevent NSOFCs.

Paternal Risk Factors for Oral Clefts in Northern Africans, Southeast Asians, and Central Americans.

While several studies have investigated maternal exposures as risk factors for oral clefts, few have examined paternal factors. We conducted an international multi-centered case-control study to better understand paternal risk exposures for oral clefts (cases = 392 and controls = 234). Participants were recruited from local hospitals and oral cleft repair surgical missions in Vietnam, the Philippines, Honduras, and Morocco. Questionnaires were administered to fathers and mothers separately to elicit risk factor and family history data. Associations between paternal exposures and risk of clefts were assessed using logistic regression adjusting for potential confounders. A father's personal/family history of clefts was associated with significantly increased risk (adjusted OR: 4.77; 95% CI: 2.41-9.45). No other significant associations were identified for other suspected risk factors, including education (none/primary school v. university adjusted OR: 1.29; 95% CI: 0.74-2.24), advanced paternal age (5-year adjusted OR: 0.98; 95% CI: 0.84-1.16), or pre-pregnancy tobacco use (adjusted OR: 0.96; 95% CI: 0.67-1.37). Although sample size was limited, significantly decreased risks were observed for fathers with selected occupations. Further research is needed to investigate paternal environmental exposures as cleft risk factors.

Patient Barriers to Accessing Surgical Cleft Care in Vietnam: A Multi-site, Cross-Sectional Outcomes Study.

BACKGROUND: Most people who lack adequate access to surgical care reside in low- and lower-middle-income countries. Few studies have analyzed the barriers that determine the ability to access surgical treatment. We seek to determine which barriers prevent access to cleft care in a resource-limited country to potentially enable barrier mitigation and improve surgical program design. METHODS: A cross-sectional, multi-site study of families accessing care for cleft lip and palate deformities was performed in Vietnam. A survey instrument containing validated demographic, healthcare service accessibility, and medical/surgical components was administered. The main patient outcome of interest was receipt of initial surgical treatment prior to 18 months of age. RESULTS: Among 453 subjects enrolled in the study, 216 (48%) accessed surgical care prior to 18 months of age. In adjusted regression models, education status of the patient's father (OR 1.64; 95% CI 1.1-2.5) and male sex (OR 1.61; 95% CI 1.1-2.4) were both associated with timely access to care. Distance and associated cost of travel, to either the nearest district hospital or to the cleft surgical mission site, were not associated with timing of access. In a sensitivity analysis considering care received prior to 24 months of age, cost to attend the surgical mission was additionally associated with timely access to care. CONCLUSIONS: Half of the Vietnamese children in our cohort were not able to access timely surgical cleft care. Barriers to accessing care appear to be socioeconomic as much as geographical or financial. This has implications for policies aimed at reaching vulnerable patients earlier.

Parental risk factors for oral clefts among Central Africans, Southeast Asians, and Central Americans.

BACKGROUND: Several lifestyle and environmental exposures have been suspected as risk factors for oral clefts, although few have been convincingly demonstrated. Studies across global diverse populations could offer additional insight given varying types and levels of exposures. METHODS: We performed an international case-control study in the Democratic Republic of the Congo (133 cases, 301 controls), Vietnam (75 cases, 158 controls), the Philippines (102 cases, 152 controls), and Honduras (120 cases, 143 controls). Mothers were recruited from hospitals and their exposures were collected from interviewer-administered questionnaires. We used logistic regression modeling to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Family history of clefts was strongly associated with increased risk (maternal: OR = 4.7; 95% CI, 3.0-7.2; paternal: OR = 10.5; 95% CI, 5.9-18.8; siblings: OR = 5.3; 95% CI, 1.4-19.9). Advanced maternal age (5 year OR = 1.2; 95% CI, 1.0-1.3), pregestational hypertension (OR = 2.6; 95% CI, 1.3-5.1), and gestational seizures (OR = 2.9; 95% CI, 1.1-7.4) were statistically significant risk factors. Lower maternal (secondary school OR = 1.6; 95% CI, 1.2-2.2; primary school OR = 2.4, 95% CI, 1.6-2.8) and paternal education (OR = 1.9; 95% CI, 1.4-2.5; and OR = 1.8; 95% CI, 1.1-2.9, respectively) and paternal tobacco smoking (OR = 1.5, 95% CI, 1.1-1.9) were associated with an increased risk. No other significant associations between maternal and paternal factors were found; some environmental factors including rural residency, indoor cooking with wood, chemicals and water source appeared to be associated with an increased risk in adjusted models. CONCLUSION: Our study represents one of the first international studies investigating risk factors for clefts among multiethnic underserved populations. Our findings suggest a multifactorial etiology including both maternal and paternal factors.