Maternal Diabetes Mellitus and Risk of Stillbirth: A Nested Case-Control Study in a Nigerian Tertiary Hospital

Background: Stillbirths have always been a contributor to psychological morbidity amongst women. Diabetes mellitus remains a significant risk factor for its occurrence. Knowledge of the causes and risk factors of this unfortunate problem will help in designing preventive measures to reduce its incidence.

Objective: To determine the relationship between maternal diabetes mellitus and the risk of stillbirths.

Methods: This is a nested case control study conducted in the Obstetrics unit of the Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria from 1st September 2014 to 31st August 2017. Forty-four women who had stillbirth were regarded as the cases and 44 women who had livebirths were regarded as the control group were retrieved from their case files. Information obtained included; type and sex of the stillborn, maternal age, type of stillbirth, parity, educational status, booking status, gestational age, and mode of delivery. Odds ratio (OR) with 95% confidence interval was calculated to determine the relationship between maternal diabetes and the risk of stillbirth.

Results: The risk of stillbirth in diabetic pregnancies irrespective of the type was found to be two times higher than in non-diabetic pregnancies (OR 2.16, 95% CI 0.72-6.30). The mean age of the women was found to be approximately 30 years in both cases and controls. The ratio of macerated stillbirth to fresh stillbirth was 1.4:1 and females were affected more than males in a ratio of 1.3:1. The mean gestational age at delivery was 35 weeks for the cases and 38 weeks for the control group. Majority of the women included in the cases had only a primary level of education (34.1%) and never accessed antenatal care services (79.5%) as against the majority of the women in the control group who had a tertiary level of education (45.5%) and were booked for antenatal care (72.7%).

Conclusion: This study established that there is a significant association between maternal diabetes mellitus and stillbirth. The increased occurrence in the cases could be due to ignorance, lack of antenatal care, low socioenomic class and poor control of glycemic levels found among the women. Hence, the need for effective preventive/control programmes for these group of women.

Keywords:Stillbirths, Diabetes mellitus, Pregnancy