Insecticide-treated nets for preventing malaria in pregnancy

In endemic areas, malaria in pregnancy is a major public health problem. It contributes to severe anaemia in the mother and low birth weight for babies, which are associated with poor infant health and early infant death. Also the unborn child and the pregnant woman may die from malaria in pregnancy. Protection with insecticide-treated bednets (ITNs) during pregnancy is widely advocated, but evidence of their benefit has been inconsistent. This review found five trials of ITNs in pregnant women. The four trials in sub-Saharan Africa compared ITNs with no nets and showed a benefit from ITNs in terms of fewer malaria infections, low birthweight babies, and fewer babies died before delivery. The effects on severe anaemia in the mothers were inconclusive. The one trial from Asia compared ITNs with untreated nets and showed a beneficial effect on anaemia in women and fewer babies died before delivery, but it had no impact on other outcomes. ITNs have been shown to be beneficial and should be included in strategies to try to reduce the adverse effects of malaria in pregnant women in endemic areas of the world.

Authors' conclusions: 

ITNs have a beneficial impact on pregnancy outcome in malaria-endemic regions of Africa when used by communities or by individual women. No further trials of ITNs in pregnancy are required in sub-Saharan Africa. Further evaluation of the potential impact of ITNs is required in areas with less intense and Plasmodium vivax transmission in Asia and Latin America.

Read the full abstract...

Malaria in pregnancy is associated with adverse consequences for mother and fetus. Protection with insecticide-treated nets (ITNs) during pregnancy is widely advocated, but evidence of their benefit has been inconsistent.


To compare the impact of ITNs with no nets or untreated nets on preventing malaria in pregnancy.

Search strategy: 

We searched the Cochrane Infectious Diseases Group Specialized Register (February 2009), CENTRAL (The Cochrane Library 2009, Issue 1), MEDLINE (1966 to February 2009), EMBASE (1974 to February 2009), LILACS (1982 to February 2009), and reference lists. We also contacted researchers working in the field.

Selection criteria: 

Individual and cluster randomized controlled trials of ITNs in pregnant women.

Data collection and analysis: 

Three authors independently assessed the risk of bias in the trials and extracted data. Data were combined using the generic inverse variance method.

Main results: 

Six randomized controlled trials were identified, five of which met the inclusion criteria: four trials from sub-Saharan Africa compared ITNs with no nets, and one trial from Asia compared ITNs with untreated nets. Two trials randomized individual women and three trials randomized communities. In Africa, ITNs, compared with no nets, reduced placental malaria in all pregnancies (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.63 to 0.98). They also reduced low birthweight (RR 0.77, 95% CI 0.61 to 0.98) and fetal loss in the first to fourth pregnancy (RR 0.67, 95% CI 0.47 to 0.97), but not in women with more than four previous pregnancies. For anaemia and clinical malaria, results tended to favour ITNs, but the effects were not significant. In Thailand, one trial randomizing individuals to ITNs or untreated nets showed a significant reduction in anaemia and fetal loss in all pregnancies but not for clinical malaria or low birthweight.