Interventions to prevent malaria-related morbidity and mortality in pregnancy

Sleeping under insecticide-treated nets during pregnancy improves pregnancy outcomes, and routine use of antimalarial drugs reduces sever antenatal anaemia in the mother. The challenge in implementing these interventions lies in creating awareness among health-care providers and the public regarding the benefits of preventing malaria, especially during pregnancy.

RHL Commentary by Fawole B

1. EVIDENCE SUMMARY

The Cochrane systematic review assessed drugs given to prevent malaria infection and its consequences in pregnant women living in malarial areas. All 14 trials included in the review except Nosten 94 trial conducted in Thailand (1), were from sub-Saharan Africa, where rates of parasitaemia during pregnancy are generally high. The results are presented in three broad categories:

a) Drug prevention versus no prevention in women of all parity groups

Maternal

There was a statistically significant reduction in placental malaria between women who had prophylaxis compared with no prophylaxis (Three trials, Relative Risk [RR]: 0.34; 95% Confidence interval [CI]: 0.26 to 0.45). Although all three trials showed benefit, there was heterogeneity with regard to the level of benefit. Other maternal outcomes were reported in single trials and overall there was scanty evidence.

Newborn

Four studies reported mean birthweight. There was no statistically significant difference between drug prevention and no prevention. Similarly, there were no significant differences in perinatal death reported in four studies involving 2890 patients.

b) Drug prevention versus no prevention in women of low parity

Maternal

Drug prevention was associated with clinically and statistically significant reduction in the incidence of severe antenatal anaemia compared with no prevention in women of low parity (RR: 0.62; 95% CI: 0.50 to 0.78). This comparison was reported by four studies involving 3809 women. Placental malaria was reported in five studies. There was a trend towards protection by drug prevention but there was inconsistency between the trials reviewed.

Newborn

Eight trials involving 2245 women reported mean birthweight. Drug prevention was associated with clinical and statistically significant higher mean birthweight (Weighted mean difference [WMD]:122.62g; 95% CI: 81.49 to 163.74g). Accordingly, drug prevention also reduced the incidence of low birthweight. This difference was clinically and statistically significant (RR: 0.55; 95% CI: 0.43 to 0.70).

c) Any antimalarial (except chloroquine) compared with chloroquine

Only two studies with very few patients compared either sulfadoxine-pyrimethamine or proguanil with chloroquine. The small numbers do not permit definitive conclusions.

The methodology of the review is sufficiently rigorous. All adequately controlled trials have been included and appropriately analysed. The reviewers have made adequate efforts to contact investigators in this field.

2. RELEVANCE TO UNDER-RESOURCED SETTINGS

2.1. Magnitude of the problem

Malaria during pregnancy is a major cause of maternal and perinatal morbidity and mortality in malaria-endemic areas. It is estimated that globally 75,000 to 200,000 infant deaths might be attributable to malaria infection during pregnancy (2). Failure to use chemoprophylaxis during pregnancy contributes significantly to maternal and perinatal morbidity and mortality.

The burden of malaria in pregnancy is most severe in sub-Saharan Africa where malaria is endemic. Young women in this region are particularly susceptible to malaria(3).

2.2 Applicability of the results

The results of this review are particularly relevant to areas with high rates of malaria parasitaemia in pregnancy. All the trials included in this review except one were conducted in sub-Saharan Africa. The findings justify the use of drug prevention in women of low parity in the region.

2.3 Implementation of the results

The major challenge facing implementation of the results of this review is in creating awareness among health care providers. Incorporating these findings into routine antenatal care programmes will require active dissemination of this information among the various cadres of health workers providing antenatal care. Lack of awareness is apparently the major obstacle to changing practice.

Additional efforts through provision of health education for the population are needed to reach women who do not access the formal health sector.

3. RESEARCH

Since the resistance patterns vary among regions it is imperative that studies to assess resistance patterns are conducted before implementing certain drug regimens.

Multi-centre trials with larger numbers of patients are recommended to further evaluate the benefits of drugs for prevention of malaria during pregnancy on substantive outcomes. The enormous burden which malaria poses during pregnancy deserves well-designed trials with sufficient power to resolve the remaining unanswered questions.

References

  • Nosten F, ter Kuile F, Melankiri L, Chongsuphajaisidhi T, Nopdonrattakoon L, Tangkitchot S, Boudreau E, Bunnag D, White NJ. Mefloquine prophylaxis in pregnancy: a double blind placebo controlled trial. Journal of infectious diseases 1994;169:595-603.
  • Steketee RW, Nahlen BL, Parise ME, Menedez C. The burden of malaria in pregnancy in malaria-endemic areas. American journal of tropical medicine and hygiene 2001;64(1,2)S:28-35.
  • Zhou A, Megnekou R, Leke R, Fogako J, Metenou S, Trock B, Taylor DW, Leke RFG. Prevalence of plasmodium falciparum infection in pregnant Cameroonian women. American journal of tropical medicine and hygiene 2002;67(6):566-570.

This document should be cited as: Fawole B. Interventions to prevent malaria-related morbidity and mortality in pregnancy: RHL commentary (last revised: 23 June 2009). The WHO Reproductive Health Library; Geneva: World Health Organization.

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