OCCUPATIONAL EXPOSURE TO ETHYLENE OXIDE DURING PREGNANCY AND ASSOCIATION WITH ADVERSE REPRODUCTIVE OUTCOMES

Abstract

ISEE-52 Aim: To investigate the association between exposure to ethylene oxide during pregnancy and adverse reproductive outcome in women working in sterilising units using ethylene oxide in Gauteng province, South Africa. Methods: We analysed singleton pregnancies that: 1) occurred in women currently working in sterilising units using ethylene oxide in Gauteng, South Africa; 2) were the last recognised pregnancy occurring in these women after 1st January 1992; 3) occurred while the mother was employed. Adverse reproductive outcome was defined as the occurrence of spontaneous abortion, still birth, pregnancy loss, low birth weight or combined adverse reproductive outcome. Information on pregnancies’ evolution and outcome was gathered from mothers using a questionnaire. Information on exposure to ethylene oxide during pregnancy was obtained from three sources: walk-through survey, questionnaire-collected data and measurements of the levels of ethylene oxide in sterilising units at the time of the study (personal and static sampling). Results: The study enrolled 68.8% of the medical facilities in Gauteng using ethylene oxide to sterilise medical equipment. The participation rate for the women employed in these sterilising units was 96.5%. The study population consisted of 98 singleton pregnancies. Measurements of ethylene oxide levels showed that exposure still occurred and the employees most exposed were operators. There was a significantly increased risk of spontaneous abortion (RR=16.6; 95%CI=2.0–140.4; p=0.004) and pregnancy loss (RR=6.2; 95%CI=2.0–19.9; p=0.003) amongst pregnancies exposed to ethylene oxide compared to unexposed. No associations were found between exposure to ethylene oxide and stillbirth (RR=3.5; 95%CI=0.6–19.0; p=0.18), low birth weight (RR=0.6; 95%CI=0.1–4.3; p=0.51), and combined adverse reproductive outcome (RR=2.1; 95%CI=1.0–4.4, p=0.06). Conclusion: An increased risk of spontaneous abortion and pregnancy loss was found to be associated with work as an operator in ethylene oxide sterilising units during pregnancy. These results are consistent with the findings of previous studies addressing this issue.