Pregnancy outcome in patients with pregestational and gestational diabetes attending Groote Schuur Hospital, Cape Town, South Africa

Abstract

Background. The burden of diabetes mellitus (DM) has increased dramatically worldwide. The association between poorly controlled DM and poor pregnancy outcomes has been well described. Objectives. To describe the pregnancy outcomes of patients with pregestational and gestational DM attending Groote Schuur Hospital, Cape Town, South Africa. Methods. A retrospective audit was undertaken of all women with pregestational and gestational DM (GDM) who attended Groote Schuur Hospital obstetric care from 1 September 2010 to 31 August 2011. Information routinely collected at booking and during the rest of pregnancy was entered onto a data abstraction form. Patients diagnosed with GDM were further subdivided into two groups, GDM and impaired glucose tolerance (IGT), depending on the oral glucose tolerance test results. Results. A total of 725 diabetic pregnancies were managed: 35 women had type 1 DM (T1DM), 194 had type 2 DM (T2DM), 192 had GDM and 304 had IGT. The median glycated haemoglobin (HbA1c) value at booking was highest for T1DM, followed by T2DM and lastly GDM. Overall, 10.7% of women had pre-existing hypertension and 9.8% developed pre-eclampsia (PET). The preterm delivery rate (before 38 weeks) was 68.8% for women with T1DM, 38.7% for those with T2DM, 34.9% for those with GDM and 22.4% for those with IGT. The caesarean section rate exceeded 50% in all groups. The overall perinatal mortality rate was 2.5% (25/1 000 births) for the study population, with T1DM and T2DM contributing most deaths (6.4% and 4.2%). The overall rate of congenital malformations was 2.4% (n=18 cases), but the rate was 5.7% for patients with T1DM and 4.6% for those with T2DM. Conclusion. The audit demonstrated outcomes similar to those in the developed world, with major congenital malformations, unexplained
stillbirths and PET accounting for the majority of perinatal deaths. Stricter control with the aim of achieving lower or normal HbA1c levels before conception may be the only intervention that could bring about change.

S Afr Med J 2018;108(9):772-776