Risk factors for cleft lip and palate in the Czech population - a double center study.

Orofacial clefts (OFC) are common congenital anomalies with complex genetic and environmental etiologies. Although multiple risk factors have been suggested, their role in cleft type and severity remains unclear. This study aimed to assess the relationship between environmental and maternal health factors (body mass index - BMI, parental age, infection, stress, prenatal vitamin supplementation) and the occurrence and severity of cleft types in the Czech population, as well as the effectiveness of prenatal diagnosis by ultrasound. A total of 96 parents of children with nonsyndromic OFC born between 2017 and 2024 in the Czech Republic were surveyed using a custom online questionnaire (RoRis). The data were analyzed using Fisher's exact test (a = 0.05). The distribution of cleft types in this Czech sample was consistent with international data. Prenatal diagnosis by ultrasound was established in 55% of cases. The highest detection rates were observed for bilateral cleft lip and palate, with 100% of cases diagnosed prenatally, and for unilateral cleft lip and palate, with a 93% detection rate. In contrast, cleft palate only (CPO) was the most frequently missed, with 88% of cases undetected. No significant associations were found neither between the cleft type nor the severity of clefts and parental age, maternal BMI, medication use, infection with fever, or stress during pregnancy. Most mothers had a normal BMI (51%), and 85% reported prenatal supplement use. COVID-19 infection during pregnancy was reported in 13 cases, but no clear link with cleft severity was found. While several exogenous factors were studied, no significant associations neither with cleft type nor severity were found. The study highlights the limitations of prenatal screening diagnosis by ultrasound, particularly for CPO, and supports the need for further research into modifiable risk factors.