Maternal Exposure to Carbon Monoxide in the First Trimester of Pregnancy in the Niger Delta as a causative factor of Minor Pregnancy symptoms and signs.

Abstract

Background: There is paucity of knowledge and information on the association of minor pregnancy symptoms and signs with maternal exposure to CO.  

Aim: To ascertain the association of chronic maternal exposure to CO in the Niger Delta with minor early pregnancy symptoms and signs.

Material and methods: It was a cross-sectional study carried out at the Rivers State University Teaching Hospital (RSUTH) in Rivers State, Nigeria. 490 consecutive pregnant women in the first trimester were recruited from the antenatal clinic from January 2021 to January 2022. Their demographic, social and obstetric characteristics were taken. Maternal exhaled CO (ECOC) and carboxyhaemoglobin concentrations (MCOHC) were measured with the aid of a smokerlyzer. Data was analysed, using SPSS version 25.0 (Armonk, NY) software. Ethical approval was obtained from the RSUTH Ethics Committee.

Results: With respect to ECOC and MCOHC, 335(68.4%) and 461(94.08%), 129(26.3%) and 18(3.67%) and 26(5.3%) and 11(2.2%) out of the 490 patients had mild, moderate and severe exposure to CO respectively. Minor pregnancy symptoms and signs were all associated with maternal exposure to CO with the highest numbers in the mild category of exposure with respect to  ECOC and MCOHC. There were statistical significant differences between the proportions of patients who had the symptoms and signs in the mild, moderate and severe exposure categories. For ECOC, headaches - 93(27.8%), 58(45.0%) and 6(23.1%)(X²=13.66; p<0.001) and sensation of weakness - 33(9.9%), 25(19.4%) and 3(11.5%) (X²=7.780; p<0.020). With respect to MCOH concentrations, it was statistically significant for dizziness (X²=5.643; p<0.033) and impaired physical performance (X²=6.436; p<0.035). The differences were not statistically significant with respect to other symptoms and signs.

Conclusion: Maternal exposure to Carbon Monoxide in the Niger Delta was associated with minor pregnancy symptoms and signs which were predominant in the mild category of severity of the exposure.