Intestinal parasitic infections in pregnant women in Sao Tome &amp; Principe: are there adverse birth outcomes?
Authors: Vasconcelos Alexandra , Sousa Swasilanne , Bandeira Nelson , Alves Marta , Papoila Ana Luisa , Pereira Filomena , Machado Maria Ceu 
Published: November 2022

Background
Up to 70% of pregnant women in Africa are reported to have an intestinal parasitic infection (IPI). However, the pregnancy-related burden of adverse birth outcomes (ABOs) remains unclear. Sao Tome & Principe (STP) is an IPI high-endemic country but there is a paucity of data, especially among pregnant women. This study aimed to identify an association between ABOs and IPI in pregnant women. Infection subgroups, such as helminthiasis (Ascaris lumbricoides, Trichuris trichuria, Ancylostoma duodenale, Strongyloides stercoralis), schistosomiasis (Schistosoma intercalatum) and amebiasis (Entamoeba histolytica) were also individually analysed for possible associations with ABOs.
Methods
A hospital-based cross-sectional study was conducted among pregnant women with coproparasitological antenatal care (ANC) screening admitted to Hospital Dr. Ayres de Menezes for delivery. Pregnant women with HIV, sickle cell disorder, and malaria were excluded for possible confounder causes of ABOs. ANC pregnancy cards were checked for routine coproparasitological results, anthelmintic treatments, and haemoglobin levels. A structured questionnaire was administered by a face-to-face interview to assess sociodemographic and other factors. Newborn clinical records were used for the collection of ABOs: prematurity (PTB), low birth weight (LBW) and stillbirth. The abstracted data were entered into the QuickTapSurvey app and exported to SPSS version 25 for analysis. Pregnant women with a monoparasitic IPI (145) and polyparastic IPI (25) were compared to non-IPI (151) pregnant women for ABOs. IPI subgroups, namely, helminthiasis (162), schistosomiasis (11) and amebiasis (7), were each compared to the non-IPI (151) group. Chi-square and Fisher´s exact tests were used to identify associations between ABOs (maternal anaemia, LBW, PT, and stillbirths) and IPI in pregnant women at p value < 0.05.
Results
A total of 361 pregnant women with a mean age of 26.96 (SD: 7.00) were included, 127 (39.6%) had maternal anaemia and 26 (8.1%) newborns had PTB, 48 (14.9%) had LBW, and 8 (2.5%) stillbirths. From the 210 positive coproparasitological exams, most had Ascaris lumbricoides (90.9%), followed by Trichuris trichiura (13.8%), Schistosoma intercalatum (5.2%) and Entamoeba histolytica (3.3%). Polyparasitism was found in 25 (11.9%) cases. Anaemia in monoparasitic IPIs (145) was 46.7% compared to 38.7% in noninfected group. Adverse neonatal outcomes in women with monoparasitic IPI were 9 (6.2%) PTB, 16 (11%) LBW and 5 (3.4%) stillbirths, without any statistically significant difference (p = 0.175, p = 0.07, p = 0.275), respectively, when compared with noninfected women. ABOs for polyparasitic IPI compared with non-IPI showed no statistically significant difference. A statistically significant difference was also not found for the subgroups helminthiasis (162), schistosomiasis (11) and amebiasis (7) when compared with non-IPI pregnant women.
Conclusion
This study highlights the large burden of maternal intestinal parasitic infections in STP. The lack of adverse maternal and neonatal outcomes in our study can be related to the predominant type – Ascaris lumbricoides – a low pathogenicity parasite. This study is a useful starting point for health policy development for pregnant women in a high-IPI endemic country.