An exploration of anaemia in low birth weight infants exposed to perinatal zidovudine at the neonatal unit in King Edward VIII Hospital.

Abstract

Large clinical trials beginning with the PACTG-076 trial and other trials across Europe and America have showed that perinatal exposure to Zidovudine (AZT) results in haematological side effects in the neonate, mainly anaemia, which are clinically insignificant and reversible. There is however limited data in sub-Saharan Africa on the impact of intrauterine exposure to AZT on neonates, particularly low birth weight neonates, at the height of the HIV/PMTCT era. The aim of the study was to evaluate the prevalence and clinical significance of anaemia among low birth weight neonates, in a diverse South African setting. This observational descriptive study looked at medical records of HIV-exposed, low-birth weight neonates (less than 2500g) admitted to the neonatal unit at King Edward VIII Hospital from May 2008 to February 2010, who have had intrauterine exposure to AZT. A total of 95 neonatal birth and medical records were analysed. The total prevalence of anaemia was 47%. The neonates were placed into categories according to gestational age. The prevalence of anaemia was 16.7% and the mean Hb was 17g/dL in the 26-28 week gestational age category, prevalence of anaemia was 37% and mean Hb was 16g/dL in the 29-31 week category, and the prevalence of anaemia was 54.8% with a mean of 17g/dL in the over 31 week gestational age category. The minimum haemoglobin was 11.0g/dL and maximum haemoglobin was 24g/dL. The mean haemoglobin in the neonates exposed to more than 28 days of Zidovudine was lower than the mean Hb in neonates exposed to less than 28 days in the 29-31week and over 31 week gestational age categories. The haematological side effects of anaemia in neonates resulting from AZT exposure inutero were found to be prevalent but of a mild and clinically insignificant nature in keeping with existing international and continental studies. The severity of anaemia in low birth weight/ pre-term neonates appears to be the same as in term neonates of normal birth weight depicted in these studies. The presence of neonatal anaemia at birth has been shown to be related to the duration of exposure to intrauterine AZT in one of the three age groups. There were no identified issues that would warrant amending current recommendations for the routine use of AZT for the prevention of mother-child HIV transmission however these findings require further research involving larger numbers and follow up of neonates in order to adequately analyse current PMTCT guidelines.