Abstract
BACKGROUND: Molar pregnancies, encompassing complete and partial moles, represent a rare and enigmatic gestational disorder with potential ethnic variations in incidence. This study aimed to investigate relations of ethnicity with risks of complete and partial molar pregnancies within an Israeli population while accounting for age differences. METHODS: A retrospective study was conducted of data recorded during 2007-2021 in an academic medical center in Israel. The study population comprised 167 women diagnosed with complete or partial moles, for whom data were obtained through histological examination and P57 immunostaining. Maternal age and ethnicity were extracted from electronic medical records. Incidence rates were calculated per 10,000 live births, and a nested case-control study compared demographic characteristics and molar pregnancy incidences between Arab and Jewish women. Statistical analyses included age-adjusted comparisons, relative risk calculations and multivariate logistic regression. RESULTS: The overall risk of molar pregnancy was 22 per 10,000 live births (95% confidence interval [CI] 18-25). Among Arab women, the overall risk was 21 (95% CI 17-25), and for PM and CM: 14 (95% CI 11-17) and 7 (95% CI 5-10), respectively. Among Jewish women, the overall risk was 23 (95% CI 18-29), and for PM and CM: 12 (95% CI 8-17) and 11 (95% CI 7-16), respectively. Among Arab women compared to Jewish women, the proportion of all the partial moles was higher: (65.3% vs. 51.6%, p = 0.05). The incidence of partial mole was higher among Arab than Jewish women, aged 35-39 years (26 vs. 8 per 10,000, p = 0.041), and did not differ in other age groups. After adjusting for age, the relative risk of partial moles was lower among Jews than Arabs (0.7, 95% CI 0.4-1.0, p = 0.053). For Arab compared to Jewish women, the mean age at molar pregnancies was younger: 31.0 vs. 35.1 years. However, other factors did not differ significantly between Arab and Jewish women with molar pregnancies. In multivariate analysis, Jewish ethnicity was significantly associated with a higher risk of complete molar pregnancies (OR = 2.19, 95% CI 1.09-4.41, p = 0.028). CONCLUSION: This study highlights ethnic differences in molar pregnancy risk within the Israeli population. Jewish ethnicity was associated with a higher risk of complete molar pregnancies, while Arab women had a significantly higher risk of partial moles. These findings underscore the need to consider ethnicity when studying gestational disorders. Further research should seek to elucidate the underlying factors contributing to these differences.