Numerous factors contribute to perinatal risk, many of which remain undefined. This study sought to determine the frequency of fish intake in postpartum women, and to establish a relationship between the rates of immunoreactivity for antigens from Anisakis spp. and high-risk pregnancy. In this prospective noninterventional study, a structured questionnaire was administered and serum was collected from postpartum women at two perinatal centers (a high-risk birth unit [HRBU] and a low-risk birth unit [LRBU]) in the Niteroi municipality of Brazil. Anisakis species-specific IgG and IgE were measured by ELISA. The chisquared test was performed, and odds ratios (ORs) with their 95% confidence intervals were estimated. The t-test or Mann-Whitney test was applied to continuous, normally distributed variables. In total, 309 women (170 from HRBU, 139 from LRBU) between 24.8 and 26.7 years old with a median of 6 to 8 prenatal visits were enrolled. Women in the two units exhibited differences in some variables, including prenatal care (p = 0.01), maternal and fetal risk (p = 0.00; OR = 6.17), and gestational age (p = 0.00), but no differences in fish consumption (p = 0.29), frequency of fish intake (p = 0.40), allergic symptoms (p = 0.51), or frequency of anti-Anisakis reactivity (p = 0.22). Logistic regression analysis revealed that only age was independently associated with postpartum anti-Anisakis reactivity. This study confirmed a low prevalence of fish intake and suggested that Anisakis spp. had no impact on high-risk pregnancies among this postpartum study population.