The effect of HIV status on perinatal outcome at Mowbray Maternity Hospital and referring MOUs

Background: 33,4 Million people were living with the Human Immune Deficiency virus by the end of 2009 with sub-Saharan Africa the most affected region. Maternal HIV infection is the leading cause of maternal and child morbidity and mortality in South Africa. A meta-analysis of world literature suggests a clear association between HIV infection and perinatal mortality. Aims and Objectives: To study the effect of HIV status on perinatal outcome at Mowbray Maternity Hospital(a secondary level hospital in Cape Town, South Africa.) and its catchment MOUs. Specific aims: 1) To compare the perinatal mortality rate in the group of HIV exposed with the HIV negative group and the untested group. 2) To determine where possible, the primary obstetric cause of adverse outcome and compare this in HIV exposed to the HIV negative and the untested group. 3) To compare the incidence of Neonatal Encephalopathy in the group of HIV exposed with the HIV negative group and the untested group. Methods: The study was a retrospective descriptive and comparative audit. All deliveries at MMH and its referral midwife obstetric units from January 2008 to December 2008 were audited with respect to HIV status and other demographic data. All deliveries with perinatal mortality and or neonatal encephalopathy were identified and analyzed in detail. U ni ve rs ity o f C ap e To w n 4 Results: There was a total of 18 870 deliveries at the units being studied. The number of deliveries to HIV positive mothers were 3259 (17,2 %). The stillbirth rate in the HIV positive population for the units being studied was 17,1 per 1000 deliveries. In the HIV negative population this rate was 8,3 per 1000 deliveries. The odds ratio was 2,07 [CI, 1.5-2.8] with a p-value of <0,0001. The neonatal death rate in the HIV positive population was 4,6 per 1000 deliveries, this as opposed to a rate of 3,1 per 1000 in the HIV negative population. The odds ratio was calculated as 1,46 [ CI, 0.8-2.6] with a p-value of 0,26. The perinatal mortality rate in the HIV population was 21,7 per 1000 deliveries. In the HIV negative population this rate was 11,7 per 1000 deliveries. The odds ratio was 1,91 [CI, 1.4-2.5] with a p-value of <0,0001. A comparison of the pattern of primary obstetric cause for perinatal mortality showed that infection, intra uterine growth restriction and ante partum haemorrhage were significantly more common as a cause for perinatal death in the HIV positive population. The risk of neonatal encephalopathy in the HIV exposed population was 4,9 per 1000 deliveries as opposed to 2,07 per 1000 deliveries in the HIV negative group. Comparing the two groups found an odds ratio of 2,36 [CI, 1.284. 35] with the p-value 0,008. The untested group of patients is shown in this study to be at particularly high risk of adverse perinatal outcome. This consists mostly of mothers who have had no antenatal care in the index pregnancy. Discussion: The perinatal mortality rate in the group of HIV exposed mothers was significantly higher than the HIV negative group due to a higher stillbirth rate. The lack of difference in neonatal death rate could be due to the high standard of neonatal care at the hospital. There was no significant difference in demographic data between the HIV positive and negative groups. Conclusion: Parturients who were infected with HIV were at significantly increased risk of perinatal mortality. Infection, intra uterine growth restriction and antepartum haemorrhage were significantly more common obstetric causes for mortality in the HIV U ni ve rs ity o f C ap e To w n 5 infected population. The risk of neonatal encephalopathy was also significantly higher in the HIV positive population.