The effect of human immunodeficiency virus infection on birthweight, and infant and child mortality in urban Malawi

Abstract

Background: Low birthweight, prematurity and intra-uterine growth retardation (IUGR) are major determinants of child survival. Therefore, it is important to assess excess mortality due to human immunodeficiency virus (HIV) infection in populations where low birthweight is common.

Methods: A prospective study was conducted on 1385 children born to seropositive and seronegative women in urban Malawi. Children were regularly examined and tested for HIV.

Results: The mortality rate of children of HIV seropositive mothers was substantially higher (223/1000 at 12 months, 317/1000 at 24 months and 360/1000 at 30 months) than that of children of seronegative mothers (68/1000 at 12 months, 106/1000 at 24 months and 118/1000 at 30 months). The incidence of prematurity and IUGR was also higher in infants of HIV seropositive mothers than in infants of seronegative mothers (12.7% versus 3.8%, P < 0.001 for premature and 7.7% versus 4.4%, P = 0.02 for IUGR infants). The mother-to-infant HIV-1 transmission rate was 35.1%. After 12 months of age, HIV infected children showed the highest mortality; however, uninfected children of HIV seropositive and children of HIV seronegative mothers had similar mortality. The mean birthweight of HIV infected and uninfected children was not significantly different. In HIV infected children the most frequent causes of death were diarrhoea, pneumonia and failure to thrive. Less common risk factors for child mortality included active maternal syphilis and cervicitis/vaginitis.

Conclusion: The substantial difference in survival among children of HIV infected and uninfected mothers suggests that mortality could be reduced if HIV infection were not a risk factor. To decrease childhood mortality, a combination of interventions such as treatment of sexually transmitted infections during pregnancy and measures to reduce mother-to-infant transmission should be adopted.

PIP: Low birth weight, prematurity, and intra-uterine growth retardation (IUGR) are major determinants of child survival. Therefore, it is important to assess excess mortality due to human immunodeficiency virus (HIV) infection in populations where low birth weight is common. A prospective study was conducted on a total of 1385 children born to 679 HIV-seropositive and 687 seronegative women in urban Malawi. Children were regularly examined and tested for HIV. The mortality rate of children of HIV-seropositive mothers was substantiality higher (223/1000 at 12 months, 317/1000 at 24 months, and 360/1000 at 30 months, p 0.0001) than that of children of seronegative mothers (68/1000 at 12 months, 106/1000 at 24 months, and 118/1000 at 30 months). The incidence of prematurity and IUGR was also higher in infants of HIV-seropositive mothers than in infants of seronegative mothers (12.5% versus 3.8%, p 0.001 for premature and 7.7% versus 4.4%, p = 0.02 for IUGR infants). The mother-to-infant HIV-1 transmission rate was 35.1%. The overall incidence of low birth weight was 14.1%, but the incidence was 20.1% among children of seropositive mothers and 8.3% among those of seronegative mothers (p 0.001). After 12 months of age, HIV-infected children showed the highest mortality; however, uninfected children of HIV-seropositive and children of HIV-seronegative mothers had similar mortality. The mean birth weight of HIV-infected and uninfected children was not significantly different. In HIV-infected children the most frequent causes of death were diarrhea, pneumonia, and failure to thrive. Less common risk factors for child mortality included active maternal syphilis and cervicitis/vaginitis. A possible enrolment bias could have resulted in lower mortality estimates among babies of HIV-seronegative mothers. To decrease childhood mortality, a combination of interventions such as treatment of sexually transmitted infections during pregnancy and measures to reduce mother-to-infant transmission should be adopted.