The effect of maternal HIV status on perinatal outcome at Mowbray Maternity Hospital and referring midwife obstetric units, Cape Town

Abstract

Objectives. To study the effect of maternal HIV status on perinatal outcome at Mowbray Maternity Hospital (a secondary-level hospital in Cape Town) and its satellite community midwife obstetric units.
Design. A retrospective descriptive and comparative study.
Setting. Public sector maternity facilities serving historically disadvantaged populations.
Subjects. All deliveries at Mowbray Maternity Hospital and its referral midwife obstetric units from January to December 2008.
Outcome measures. Stillbirth, early neonatal death, perinatal mortality and neonatal encephalopathy rates in HIV-positive and HIV-negative subjects.
Results. There was a total of 18 870 deliveries at the units being studied, 3 259 (17.2%) of them to HIV-positive mothers. The stillbirth rate in the HIV-positive population was 17.1/1 000 births, compared with 8.3/1 000 in the HIV-negative population {odds ratio (OR), 2.07, 95% confidence interval (CI) 1.5 - 2.8}. The early neonatal death rate in the HIV-positive population was 4.6/1 000 live births, compared with 3.1/1 000 in the HIV-negative population (OR 1.46, 95% CI 0.8 - 2.6). The perinatal mortality rate in the HIV-positive population was 21.7/1 000 births, compared with 11.7 in the HIV-negative population (OR 1.91, 95% CI 1.4 - 2.5). A comparison of the pattern of primary obstetric causes of perinatal mortality showed that infection, intra-uterine growth restriction (IUGR) and antepartum haemorrhage (APH) were significantly more common as causes for perinatal death in the HIV-positive population. The risk of neonatal encephalopathy in the HIV-exposed population was 4.9/1 000 live births compared with 2.07 in the HIV-negative group (OR 2.36, 95% CI 1.28 - 4.35). The 1 643 women (8.7% of total deliveries) who were not tested for HIV were at particularly high risk of adverse perinatal outcome. This group included women who had either declined testing or not attended for antenatal care.
Conclusion. The perinatal mortality rate in the group of HIV-exposed mothers was significantly higher than that in the HIV-negative group due to a higher stillbirth rate. Infection, IUGR and APH were significantly more common obstetric causes for mortality in the HIV-infected population. The risk of neonatal encephalopathy was also significantly higher in the HIV-positive population.