Background: A prospective study aiming at assessing the effect of adding a third dose sulphadoxine-pyrimethamine (SP) to the standard two-dose intermittent preventive treatment for pregnant women was carried out in Hounde, Burkina Faso, between March 2006 and July 2008. Pregnant women were identified as earlier as possible during pregnancy through a network of home visitors, referred to the health facilities for inclusion and followed up until delivery. Methods. Study participants were enrolled at antenatal care (ANC) visits and randomized to receive either two or three doses of SP at the appropriate time. Women were visited daily and a blood slide was collected when there was fever (body temperature > 37.5°C) or history of fever. Women were encouraged to attend ANC and deliver in the health centre, where the new-born was examined and weighed. The timing and frequency of malaria infection was analysed in relation to the risk of low birth weight, maternal anaemia and perinatal mortality. Results: Data on birth weight and haemoglobin were available for 1,034 women. The incidence of malaria infections was significantly lower in women having received three instead of two doses of SP. Occurrence of first malaria infection during the first or second trimester was associated with a higher risk of low birth weight: incidence rate ratios of 3.56 (p < 0.001) and 1.72 (p = 0.034), respectively. After adjusting for possible confounding factors, the risk remained significantly higher for the infection in the first trimester of pregnancy (adjusted incidence rate ratio = 2.07, p = 0.002). The risk of maternal anaemia and perinatal mortality was not associated with the timing of first malaria infection. Conclusion: Malaria infection during first trimester of pregnancy is associated to a higher risk of low birth weight. Women should be encouraged to use long-lasting insecticidal nets before and throughout their pregnancy. © 2012 Valea et al; licensee BioMed Central Ltd.
Two peripheral health centres (Koho and Karaba) in the Houndé health district, south-west Burkina-Faso, were selected for the study. In this area, malaria is markedly seasonal with high transmission during the rainy season (June to December) [21]. The district hospital and the 28 peripheral health facilities cover a population of approximately 247,500 people. In 2007, the number of pregnant women at risk of malaria was estimated at 12,500, while malaria was the main disease in the health district, accounting for about 38% of all consultations and 52% of hospitalizations. This was part of a larger study investigating both the effect of multiple micronutrients supplementation (MMS) versus fortified food supplementation (FFS) and that of IPTp/SP, two versus three doses on the health of pregnant women and that of their offspring. Participants were randomized in permuted blocks of four to receive either two doses of SP as recommended by the National Malaria Control Programme (NMCP) or three doses. Randomization numbers were generated by a computer program, sealed in opaque envelopes and opened only when an eligible subject was identified. These numbers were then transmitted to the study pharmacist who packaged the drugs in individual plastic zip bags. Each bag was labelled with the participant's name, identification, residence, and randomization group. The field pharmacist prepared for each woman an individual schedule for SP administration according to the gestational age at randomization and transmitted it to the trained home visitors who administered both SP and either MMS or FSS. Results of the nutrition intervention have been reported elsewhere [22]. The effect of IPTp with three doses of SP versus two doses of SP on LBW and pregnancy outcomes have also been reported in a previous publication [23]. Pregnant women were identified through a community-based network of home visitors, as described elsewhere [22]. All women of child-bearing age in the study area were identified and paid monthly visits during which they were screened for pregnancy. Women suspected to be pregnant were referred to the health facilities for a pregnancy test. The study protocol and procedures were then explained to the potential participants in the local language and those agreeing to participate were asked to provide a written inform consent. Women with known hypersensibility to SP or not planning to stay in the study area for the next two years were excluded. Study participants were recruited at ANC clinics, where the health staff recorded demographic data, medical and pregnancy history. In addition, a clinical examination was performed and vital signs, weight, height and arm circumference were measured. All measures were repeated at each ANC visit. Gestational age was assessed as early as possible by the study obstetrician using trans-abdominal ultrasound fetal biometry. Women included in the study were visited at home daily by the home visitors who recorded the body temperature and registered any complaint. In case of fever (body temperature ≥ 37.5°C) or history of fever since the last visit, a blood sample for thick and thin film was collected and sent to the health district laboratory. All women with a confirmed malaria infection were treated with a full course of quinine (24 mg/kg/day for seven days), regardless of their gestational age. Pregnant women were encouraged to attend their scheduled ANC visits and to deliver at the health facilities where the new-borns was examined, weighed and measured twice by two different members of the health staff. Thick and thin blood smears were collected in duplicate and stained with Giemsa 10% (pH 7.2) for 10 minutes. Parasite densities were determined on the thick smears by counting asexual parasites per 200 white blood cells (WBC) and assuming a WBC count of 8,000/μl. A thick blood smear was considered negative after reading 100 high-power fields. Ten percent of the slides were randomly selected and sent to the Laboratory of Parasitology/Centre Muraz for quality control. Haemoglobin (Hb) was measured by using a portable spectrophotometer (HemoCue, Angelholm, Sweden). The study protocol was approved by the ethical committees of the Centre Muraz, Bobo-Dioulasso, Burkina Faso, and the University of Antwerp, Belgium. The trial was registered in the ClinicalTrial.gov registry (identifier: {"type":"clinical-trial","attrs":{"text":"NCT00909974","term_id":"NCT00909974"}}NCT00909974). The study purpose and procedures where explained to the potential participants by the study clinician in the local languages. Women who fulfilled the inclusion criteria and agreed to participate in the study were asked to provide a written inform consent. A new-born was classified as LBW if the birth weight was < 2,500 g. Women with haemoglobin levels < 11 g/dl were classified as anaemic, those with haemoglobin levels < 8 g/dl were classified as having moderate-to-severe anaemia. Neonatal death was defined as one occurring between delivery and 28 days of life. Malaria infection was defined as a slide positive for Plasmodium falciparum, any density. Incidence rates were computed considering the follow-up duration time (in months) of each woman. Women with a malaria infection after previous treatment with quinine were considered as re-infected. Time to re-infection was defined as the period between the first infection parasite clearance and the second infection. As the parasite clearance was not monitored, we calculated an adjusted time to re-infection considering that all parasites were cleared after three days as indicated in a previous publication [24]. Data were double entered in a Microsoft Access® database by two data clerks. Validation and analysis were performed using Stata 10 IC® software. Only singleton pregnancies were included in the analysis. The Chi2 or Fisher exact test were used to compare proportions for categorical variables while a t-test for normally distributed or Mann-Whitney test for non-normally distributed was used for continuous variables at baseline. A multivariate analysis using a Poisson regression model with robust standard error estimates to evaluate the relationship between explanatory variables and outcomes was also performed. Crude and adjusted incidence rate ratios (IRR) with 95% CI were computed. A p-value ≤ 0.05 was considered as statistically significant. The timing of malaria infection was defined according to the first infection detected at the first, second or third trimester of pregnancy. The frequency of malaria infection was categorized according to the number of positive slides detected during the whole pregnancy, i.e. 0, 1, or ≥ 2. Explanatory variables and possible confounders included the number of SP doses received (two or three), the nutritional supplementation (FFS or MMS), gravidity, body mass index at enrolment (underweight: body mass index < 18.5 kg/m2; or normal weigh, BMI ≥ 18.5 kg/m2), and malaria transmission season at delivery (low transmission season between December and May and high transmission season between June and November).
N/A