Effect of mass deworming with antihelminthics for soil-transmitted helminths during pregnancy

BACKGROUND

Helminthiasis is an infestation of the human body with parasitic worms. It is estimated to affect 44 million pregnancies, globally, each year. Intestinal helminthiasis (hookworm infestation) is associated with blood loss and decreased supply of nutrients for erythropoiesis, resulting in iron-deficiency anaemia. Over 50% of the pregnant women in low- and middle-income countries (LMIC) suffer from iron-deficiency anaemia. Though iron-deficiency anaemia is multifactorial, hookworm infestation is a major contributory cause in women of reproductive age in endemic areas. Antihelminthics are highly efficacious, but evidence of their beneficial effect and safety when given during pregnancy has not been established. This is an update of a Cochrane Review last published in 2015.

OBJECTIVES

To determine the effects of mass deworming with antihelminthics for soil-transmitted helminths (STH) during the second or third trimester of pregnancy on maternal and pregnancy outcomes.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP) (8 March 2021) and reference lists of retrieved studies.

SELECTION CRITERIA

We included all prospective randomised controlled trials evaluating the effect of administration of antihelminthics versus placebo or no treatment during the second or third trimester of pregnancy; both individual-randomised and cluster-randomised trials were eligible. We excluded quasi-randomised trials and studies that were only available as abstracts with insufficient information.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data, checked accuracy and assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included a total of six trials (24 reports) that randomised 7873 pregnant women. All of the included trials were conducted in antenatal clinics within hospitals in LMICs (Uganda, Nigeria, Peru, India, Sierra Leone and Tanzania). Among primary outcomes, five trials reported maternal anaemia, one trial reported preterm birth and three trials reported perinatal mortality. Among secondary outcomes, included trials reported maternal worm prevalence, low birthweight (LBW) and birthweight. None of the included studies reported maternal anthropometric measures or infant survival at six months. Overall, we judged the included trials to be generally at low risk of bias for most domains, while the certainty of evidence ranged from low to moderate. Analysis suggests that administration of a single dose of antihelminthics in the second trimester of pregnancy may reduce maternal anaemia by 15% (average risk ratio (RR) 0.85, 95% confidence interval (CI) 0.72 to 1.00; I²= 86%; 5 trials, 5745 participants; low-certainty evidence). We are uncertain of the effect of antihelminthics during pregnancy on preterm birth (RR 0.84, 95% CI 0.38 to 1.86; 1 trial, 1042 participants; low-certainty evidence) or perinatal mortality (RR 1.01, 95% CI 0.67 to 1.52; 3 trials, 3356 participants; low-certainty evidence). We are uncertain of the effect of antihelminthics during pregnancy on hookworm (average RR 0.31, 95% CI 0.05 to 1.93; Tau² = 1.76, I² = 99%; 2 trials, 2488 participants; low-certainty evidence). Among other secondary outcomes, findings suggest that administration of antihelminthics during pregnancy may reduce the prevalence of trichuris (average RR 0.68, 95% CI 0.48 to 0.98; I²=75%; 2 trials, 2488 participants; low-certainty evidence) and ascaris (RR 0.24, 95% CI 0.19 to 0.29; I²= 0%; 2 trials, 2488 participants; moderate-certainty evidence). Antihelminthics during pregnancy probably make little or no difference to LBW (RR 0.89, 95% CI 0.69 to 1.16; 3 trials, 2960 participants; moderate-certainty evidence) and birthweight (mean difference 0.00 kg, 95% CI -0.03 kg to 0.04 kg; 3 trials, 2960 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

The evidence suggests that administration of a single dose of antihelminthics in the second trimester of pregnancy may reduce maternal anaemia and worm prevalence when used in settings with high prevalence of maternal helminthiasis. Further data is needed to establish the benefit of antihelminthic treatment on other maternal and pregnancy outcomes. Future research should focus on evaluating the effect of these antihelminthics among various subgroups in order to assess whether the effect varies. Future studies could also assess the effectiveness of co-interventions and health education along with antihelminthics for maternal and pregnancy outcomes.

Adverse birth outcomes among mothers who received intermittent preventive treatment with Sulphadoxine-Pyrimethamine in the low malaria transmission region

BACKGROUND

Malaria in pregnancy increases the risk of adverse birth outcomes such as low birth weight (LBW), maternal and foetal anemia. In Tanzania, some areas have attained low malaria transmission. However, data on the burden of preterm delivery, LBW, maternal and foetal anemia following substantial reduction of malaria transmission in recent years is still scarce in these settings.

METHODS

A study involving 631 pregnant women was conducted at Mwananyamala referral hospital in Dar es Salaam from April to August, 2018. Study enrollment was done prior to delivery. Structured interview and antenatal clinic cards were used to obtain data including the use of intermittent preventive therapy in pregnancy using sulfadoxine-pyrimethamine (IPTp-SP). Infants birth weights were recorded, maternal venous and cord blood were taken for testing of malaria and determination of haemoglobin (Hb) levels. Chi-square test and regression analysis were done to identify risk factors for preterm delivery, LBW, maternal and foetal anemia.

RESULTS

The prevalence of malaria among mothers who used at least one dose of IPTp-SP was 0.6% (4/631). Fourteen mothers (2.2%) did not use IPTp-SP and had no malaria infection. The prevalence of maternal anemia, LBW, foetal anemia and preterm delivery was 40.6, 6.5, 5.9 and 9.2% respectively. Participants who were malaria positive had 11 times more risk of LBW compared to those who were negative (AOR, 11; 95%, CI 1.07-132.2; p = 0.04). The risk of delivering babies with LBW was 1.12 times high among mothers who were ≤ 36 weeks of gestation (AOR, 1.12; 95% CI, 0.06-0.25; p = < 0.001). The use of ≥3 doses of IPTp-SP was associated with 83% decrease in risk of LBW compared to those who did not use any dose of IPTp-SP (AOR, 0.17; 95% CI, 0.03-0.88; p = 0.05). Severe anaemia at delivery was associated with seven times increased risk of preterm delivery compared to non-anemic participants (AOR, 6.5; 95% CI, 1.49-28.16; p = 0.013).

CONCLUSION

Despite the reduced malaria transmission and use of IPTp-SP, prevalence of preterm delivery, maternal anemia, LBW and foetal anemia is still high in Tanzania. The recommended ≥3 doses of IPTp-SP should continue be provided even in areas with substantial reduction of malaria.

Intestinal Worm Infestation and Anaemia in Pregnant Women

INTRODUCTION

Severe Anaemia during pregnancy is an important contributor to maternal mortality, as well as to the low birth weight which is in turn an important risk factor for infant mortality. We aim to determine the prevalence of anaemia in the region amongst pregnant women and identify their problems and to easily provide them with the clinical services.

METHODS

A community based cross sectional study done in PHCRC Chapagaun, Lalitpur from July 17,2011 to September 17,2011. Date from pregnant women presenting at PHCRC, , were filled and analysed using standard guidelines from WHO and Indian council of Medical research.

RESULTS

Out of 192 pregnant women, the average age of pregnancy was 21-25 years (46.55), mean haemoglobin (Hb) in pregnancy was 11g/dl. Majority pregnant women are Newar (35.4%) ethnicity,67.7% of them housewives and 31.5% have primary level education. Only 24% was found to have their haemoglobin level in anaemic range. Among the pregnant women (n) =192; 48 (25%) had worm infestation, 119 (62%) had negative stool report and 25 (13%) had other than worms were found. Only about one third of the sample has actually taken albendazole.

CONCLUSIONS

Aanaemia is prevalent in pregnant women of PHCRC, chapagaun and there was a significant correlation between anaemia and worm infestation. However, the relation among the haemoglobin level, iron, folic acid and albendazole was not significant.

Effect of administration of antihelminthics for soil-transmitted helminths during pregnancy

BACKGROUND

Helminthiasis is infestation of the human body with parasitic worms and it is estimated to affect 44 million pregnancies, globally, each year. Intestinal helminthiasis (hook worm) is associated with blood loss and decreased supply of nutrients for erythropoiesis, resulting in iron-deficiency anaemia. Over 50% of the pregnant women in low- and middle-income countries suffer from iron-deficiency anaemia. Though iron-deficiency anaemia is multifactorial, hook worm infestation is a major contributory cause in women of reproductive age in endemic areas. Antihelminthics are highly efficacious in treating hook worm but evidence of their beneficial effect and safety, when given during pregnancy, has not been established.

OBJECTIVES

To determine the effects of administration of antihelminthics for soil-transmitted helminths during the second or third trimester of pregnancy on maternal anaemia and pregnancy outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

All prospective randomised controlled trials evaluating the effect of administration of antihelminthics during the second or third trimester of pregnancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.

MAIN RESULTS

A total of four trials including 4265 participants were included in this review. Two of the included trials were of high quality, while two were of relatively low quality with limitations and biases in design and conduct.Analysis showed that administration of a single dose of antihelminthic in the second trimester of pregnancy is not associated with any impact on maternal anaemia in the third trimester (risk ratio (RR) 0.94; 95% confidence interval (CI) 0.81 to 1.10; 3266 participants; four trials; low quality evidence). Subgroup analysis on the basis of co-interventions other than antihelminthic, which included iron supplementation given to both groups was also not associated with any impact on maternal anaemia (RR 0.76; 95% CI 0.47 to 1.23; 1290 participants; three trials; moderate quality evidence). No impact was found for the outcomes of low birthweight (RR 1.00; 95% CI 0.79 to 1.27; 3255 participants; three trials; moderate quality evidence), preterm birth (RR 0.88; 95% CI 0.43 to 1.78; 1318 participants; two trials, moderate quality evidence) and perinatal mortality (RR 1.09; 95% CI 0.71 to 1.67; 3385 participants; two trials; moderate quality evidence). None of the included studies reported impact on infant survival at six months of age.

AUTHORS' CONCLUSIONS

The evidence to date is insufficient to recommend use of antihelminthic for pregnant women after the first trimester of pregnancy. More well-designed, large scale randomised controlled trials are needed to establish the benefit of antihelminthic treatment during pregnancy.

Evaluation of the effectiveness and compliance of intermittent preventive treatment (IPT) in the control of malaria in pregnant women in south eastern Nigeria

Controlling malaria in pregnancy has been an important component of the millennium development goal and intermittent preventive treatment (IPT) is considered an important tool in controlling malaria among pregnant women. In this study, we evaluated the level of compliance to IPT use as well as its effect on malaria infection among pregnant women attending antenatal clinic in south eastern Nigeria. Peripheral blood smears and placental histology were used as diagnostic tools to determine infection rate. Our data show that compliance to IPT use was poor (33%) when compared with non-compliance (67%). Infection rate was significantly lower among IPT users (39%) than in non-users (71%) (X(2) = 39·95; P<0·05). Maternal anaemia was also lower in IPT users (4%) than in non-users (18%). Taken together, IPT use appears to be important in reducing infection rate and maternal anaemia. Therefore, its adoption is highly recommended and this could be improved through public enlightenment campaign and adequate funding.

Prevalence of malaria parasitaemia and malaria related anaemia among pregnant women in Abakaliki, South East Nigeria

BACKGROUND

Malaria currently is regarded as the most common and potentially the most serious infection occurring in pregnancy in many sub Saharan African countries. This study was undertaken to evaluate the prevalence of malaria parasitaemia and malaria related anaemia among pregnant women in Abakaliki, South East, Nigeria.

MATERIALS AND METHODS

This is a cross sectional, descriptive study conducted in two tertiary health institutions in Abakaliki, South East, Nigeria (Ebonyi State University Teaching Hospital And Federal Medical Centre). Using systematic sampling method, 193 pregnant women were selected from the health institutions for the study. Their blood were analysed for haemoglobin status and malaria parasite. Data were also collected using an interviewer administered questionnaire. All the data were analysed using Epi info version 6 statistical software.

RESULTS

Response rate was 100%. Twenty nine percent prevalence of malaria parasitaemia was detected, more common among primigravidae. Women with higher parity had higher frequency of anaemia in pregnancy. More than half of the pregnant women (51%) were in their second trimester at the time of booking. There was no case of severe anaemia requiring blood transfusion.

CONCLUSION

Our pregnant women register late for antenatal care. Prevalence of malaria parasitaemia is high in our environment as well as anaemia in pregnancy, using the standard WHO definition. It is suggested that effort should be intensified to make our women register early for antenatal care in order to identify complications early. Intermittent preventive treatment for malaria should be incorporated into routine drugs for antenatal women.

Effect of administration of antihelminthics for soil transmitted helminths during pregnancy

BACKGROUND

Helminthiasis is infestation of the human body with parasitic worms and it is estimated to affect 44 million pregnancies, globally, each year. Intestinal helminthiasis is associated with blood loss and decreased supply of nutrients for erythropoiesis, resulting in iron deficiency anaemia. Over 50% of the pregnant women in low- and middle-income countries suffer from iron deficiency anaemia. Though iron deficiency anaemia is multifactorial, hook worm infestation is a major contributory cause in women of reproductive age in endemic areas. Antihelminthics are highly efficacious in treating hook worm but evidence of their beneficial effect and safety, when given during pregnancy, has not been established.

OBJECTIVES

To determine the effects of administration of antihelminthics for soil transmitted helminths during the second or third trimester of pregnancy on maternal anaemia and pregnancy outcomes.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (September 2008).

SELECTION CRITERIA

All prospective randomised controlled trials evaluating the effect of administration of antihelminthics during the second or third trimester of pregnancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted the data.

MAIN RESULTS

Three studies (1329 women) were included in this review. Analysis showed that administration of a single dose of antihelminth in the second trimester of pregnancy is not associated with any impact on maternal anaemia in the third trimester (risk ratio (RR) 0.90; 95% confidence interval (CI) 0.68 to 1.19, random effects (2 studies, n = 1075)). Subgroup analysis on the basis of co-interventions other than antihelminthics which included iron supplementation given to both groups in the study by Larocque et al, and a subset of the study by Torlesse et al, showed that a single dose of antihelminth along with iron supplementation throughout the second and third trimester of pregnancy was not associated with any impact on maternal anaemia in the third trimester as compared to iron supplementation alone (RR 0.76; 95% CI 0.39 to 1.45, random-effects (2 studies, n = 1017)). No impact was found for the outcomes of low birthweight (RR 0.94; 95% CI 0.61 to 1.42 (1study; n = 950)), perinatal mortality (RR 1.10; 95% CI 0.55 to 2.22 (2 studies, n = 1089)) and preterm birth (RR 0.85; 95% CI 0.38 to 1.87 (1 study, n = 984)). Impact on infant survival at six months of age could not be evaluated because no data were available.

AUTHORS' CONCLUSIONS

The evidence to date is insufficient to recommend use of antihelminthics for pregnant women after the first trimester of pregnancy. More well-designed, large scale randomised controlled trials are needed to establish the benefit of antihelminthic treatment during pregnancy.

Maternal anaemia as an indicator for monitoring malaria control in pregnancy in sub-Saharan Africa

DESIGN

Malarial anaemia is a major problem in many developing countries and often occurs more frequently in first pregnancies, as primigravidae are more susceptible to Plasmodium falciparum malaria and are at excess risk of malarial anaemia.

OBJECTIVE AND METHODS

To analyse the excess risk of anaemia in primigravidae as a potential indicator of malaria control and exposure in pregnant women living in sub-Saharan Africa. The sensitivity, specificity and predictive values for anaemia in first compared with later pregnancies are calculated for 27 studies from malarious and 7 studies from nonmalarious areas.

SETTING

Surveys of pregnancy anaemia reported for highly malarious and nonmalarious areas.

RESULTS

In malarious areas, the weighted odds ratio for excess anaemia (haemoglobin [Hb] <11 g/dl) in primigravidae compared with multigravidae for all studies was 1.34 (95% CI 1.14-1.58). At an Hb cutoff below 8 g/dl, the weighted odds ratio was 1.79 (95% CI 1.52-2.10). In nonmalarious areas, there was no increased risk of anaemia in primigravidae with Hb below 11 g/dl (OR 0.80; 95% CI 0.63-1.90) or below 8 g/dl (OR 0.82, 95% CI 0.51-1.28).

CONCLUSIONS

In view of the consistency of results across highly malarious areas compared with nonmalarious areas, maternal anaemia has the potential to be used for surveillance of malaria control in pregnancy. Based on the analysis, an anaemia nomogram is developed for use as a surveillance indicator in malarious areas in sub-Saharan Africa.

Malaria and anaemia in pregnancy in Enugu, south east Nigeria

Malaria and anaemia contribute tremendously to maternal and prenatal morbidity and mortality. This study was carried out to document the magnitude of the problem in pregnancy with a view to identifying areas of intervention. The subjects were 108 consecutive pregnant women aged 18 to 44 years recruited from the antenatal clinics. 23 (21.3%) had malaria, 35 (32.4%) had anaemia while 20(18.5%) had both malaria and anaemia. The highest incidence of malaria occurred in the second trimester, while anaemia was most prevalent in the third trimester (62.86%) and among primigravidae (37.14%). All the cases of malaria were due to plasmodium falciparum. Six out of the 20 women with both anemia and malaria were admitted and treated. Two low birth weight babies were delivered among the malaria and anaemia group. The incidence rates of malaria and anaemia were 215 and 327 per 1000 pregnant women respectively while the incidence rate of anaemia due to malaria was 571 per 1000 infected pregnant women. There is a need for a more effective intervention to reduce the incidence of both malaria and anaemia in pregnancy.

Malaria infection in pregnancy and its effects on haemoglobin levels in women from a malaria endemic area of Fako Division, South West Province, Cameroon

Anaemia in pregnancy has been associated with maternal morbidity and mortality and is a risk factor for low birthweight. The importance of malaria as a major cause of anaemia in pregnancy in malaria endemic areas has not been fully elucidated. In two cross-sectional studies of pregnant women at antenatal enrolment and at delivery, we determined the prevalence of anaemia and assessed some risk factors associated with anaemia such as malaria parasitaemia and parity, in women from a malaria endemic area of south western Cameroon. Of the 1118 women whose Hb levels were analysed at first antenatal enrolment, 68.9% were anaemic (Hb<11.0 g/dL) although only 1.3% were severely anaemic (Hb<7 g/dl). At delivery, 69.9% (485/694) of the parturient women were anaemic with 4.3% having severe anaemia. The mean haemoglobin (Hb) level of the pregnant women at enrolment and at delivery was not significantly different. The mean Hb level of malaria parasite positive pregnant women (P=0.0001) and parturient women (P=0.0001) were significantly lower than those who were malaria parasite free. Similarly, the mean Hb level of primigravidae at antenatal enrolment (P=0.0001) and at delivery (primiparae; P=0.0001) was markedly lower than that of multigravidae or multiparae, respectively. Of the anaemic cases, 52.1% were malaria positive while 47.9% were malaria free at enrolment. By contrast, 36.9% (179/485) of the anaemic cases were associated with maternal malaria parasitaemia while 37.3% (174/466) were associated with placental malaria parasitisation. Thus at delivery, anaemia was more common in women without malaria parasitaemia (P=0.0003) or whose placentas were malaria free (63.1% vs 36.9%; P<0.05). The prevalence of anaemia was significantly higher (OR=2.399; P=0.001) in mothers whose peripheral blood and placental biopsy were free of malaria parasites (69.9%) than in those whose peripheral and placental samples had malaria parasites. The mean birthweight and placental weights of newborns of mothers with and without anaemia were similar. In addition, there was no association between maternal anaemia and the incidence of low birthweight. Our study demonstrates a high prevalence of mild to moderate anaemia amongst the study population with relatively low incidences of severe anaemia. Furthermore, at delivery >50% of the anaemic cases were not associated with maternal or placental malaria parasitaemia suggesting the existence of other causes of anaemia in this community. This observation is important in developing a strategy for controlling anaemia in the community.

Schistosoma mansoni in pregnancy and associations with anaemia in northwest Tanzania

Schistosomiasis among pregnant women has been inadequately investigated. In order to determine the importance of Schistosoma mansoni in this subgroup, we conducted a cross-sectional survey of 972 women in Tanzania and investigated the prevalence of Schistosoma mansoni, hookworm and malaria and their associations with anaemia. Overall, 63.5% of women were infected with S. mansoni, with prevalence highest among younger women and decreasing with increasing age. The prevalence of hookworm was 56.3%, and 16.4% of women had malaria parasitaemia. Overall, 66.4% of women were anaemic. Increased risk of anaemia was associated with heavy infection with S. mansoni but not hookworm or Plasmodium falciparum parasitaemia.

Prevalence and risk factors for anaemia in pregnant women of eastern Sudan

The prevalence and possible risk factors for anaemia were investigated in 744 pregnant Sudanese women attending the antenatal clinic of New Halfa teaching hospital, eastern Sudan between October 2003 and April 2004. Of those, 466 (62.6%) had anaemia (haemoglobin [Hb]: <11 gm/dl); 52.4% had mild anaemia (Hb: 9.0-10.9 gm/dl); 8.1% had moderate anaemia (Hb: 7.0-8.9 gm/dl); and 2.2% had severe anaemia (Hb: <7 gm/dl), respectively. The prevalence of anaemia (73.2%) was significantly high in grandmultigravidae. Univariate and multivariate analysis showed that age and parity were not significantly associated with anaemia. Malaria (OR = 4.5, 95% CI 2.5-8.1; P < 0.0001) and pica (OR = 1.6, 95% CI 1.05-2.6; P = 0.03) were the risk factors for anaemia. Thus, preventive measures against malaria (chemoprophylaxis and insecticide-treated bednets) may be needed for all pregnant women irrespective of their age or parity.

Alterations in the profile of blood cell types during malaria in previously unexposed primigravid monkeys

Malaria in nonimmune, primigravid women threatens both mother and fetus. We used the Plasmodium coatneyi/rhesus monkey model to examine factors associated with this. Clinical and immunologic responses during the blood stage of chronic malaria (4 months) were evaluated in 8 malaria-naive primigravid (PMI) and 8 age-matched nulligravid (NMI) infected monkeys, compared with those in 8 primigravid, noninfected control monkeys. Although parasitemia levels were similar, recrudescence was more frequent and prolonged, and anemia was more severe in PMI than in NMI monkeys. During infection, CD2+, CD4+, and CD8+ lymphocyte levels were higher in NMI than in PMI monkeys. Monocyte and neutrophil levels were lower in PMI than in NMI monkeys. During chronic, untreated malaria, NMI monkeys had a B lymphocyte count 23 times greater than that of PMI monkeys. Pregnancy-induced immunomodulation, defined as a lack of appropriate cellular responses to malaria, was indiscernible until the immune system was challenged by a pathogen.

Prevention of anaemia in pregnancy using insecticide-treated bednets and sulfadoxine-pyrimethamine in a highly malarious area of Kenya: a randomized controlled trial

To compare the effects of intermittent treatment with sulfadoxine-pyrimethamine (SP) given during the second and third trimester of pregnancy, the use of insecticide-treated nets (ITN), or the combination of both on haemoglobin (Hb) levels during pregnancy, a randomized, placebo-controlled intervention trial was conducted in a malaria-endemic area of western Kenya from July 1997 to September 1999. Primigravidae and secundigravidae were enrolled into the study and randomized into 4 intervention groups: (i) ITNs and SP, (ii) ITNs and placebo SP, (iii) SP alone, and (iv) placebo SP. All groups were offered case management and iron and folic acid supplementation. Seven hundred and fifty-two women were followed until delivery (53.2% were primigravidae and 46.8% secundigravidae). Among primigravidae in all the groups there was a significant improvement in Hb levels at delivery (107.6 g/L) compared with recruitment (101.9 g/L) (P < 0.006) with the greatest improvement in the combination ITNs + SP group. The protective efficacy of ITNs + SP on anaemia was 55.8% (95% CI 30.6-71.8), of SP alone 50.9% (95% CI 22.2-69.0), and of ITNs 41.6% (95% CI 9.8-62.3). Among secundigravidae, Hb levels were slightly lower at delivery compared with recruitment (P = 0.03). It was concluded that malaria is a major cause of anaemia in primigravidae but that other causes play a more significant role in secundigravidae, and that intermittent treatment with SP or use of ITNs benefits primigravidae more than secundigravidae.

Chloroquine prophylaxis, iron-folic acid supplementation or case management of malaria attacks in primigravidae in western Uganda: effects on maternal parasitaemia and haemoglobin levels and on birthweight

The effects of weekly chloroquine prophylaxis, daily iron-weekly folic acid supplementation or passive case management on maternal haemoglobin and parasitaemia and on birthweight were examined in primigravidae in a randomized, double-blind placebo-controlled intervention trial in 1996-98 in Hoima District, western Uganda. Iron-folic acid supplementation significantly increased mean birthweight as compared to case management (P = 0.03). Low birthweight (< 2.5 kg) occurred in 2% of babies of women receiving chloroquine prophylaxis for > or = 8 weeks and in 9% in the case management group (RR = 0.36, 95% CI 0.13-1.00, P = 0.009). Parasitaemia at enrolment significantly correlated with low birthweight in the case management group as compared to the intervention groups (P = 0.02). Women in the case management group who were parasitaemia and had haemoglobin levels < 100 g/L at delivery had babies with lower mean birthweight as compared to babies in the other groups (P = 0.04). Low haemoglobin level at enrolment, irrespective of parasitaemia status, was a predictor of low birthweight in the case management group only (P = 0.04). Chloroquine prophylaxis and iron-folic acid supplementation significantly increased maternal haemoglobin levels during pregnancy as compared to case management (P = 0.01 and 0.007, respectively) and the increase correlated to the duration of the intervention.

Plasmodium coatneyi in the rhesus monkey (Macaca mulatta) as a model of malaria in pregnancy

Pregnant women with Plasmodium falciparum infection are at increased risk for complications such as anemia and cerebral malaria. In addition, the infants of these women suffer intrauterine growth retardation (IUGR), low birth weight (LBW), congenital infection, and high infant mortality. Although much has been learned from studies of malaria during human pregnancy, progress has been limited by the lack of a suitable animal model. Nonhuman primates are of particular interest because, other than the armadillo, they are the only animals with a discoidal, villous, hemochorial placenta like that of humans. We have established a model of malaria during human pregnancy by inoculating pregnant rhesus monkeys (Macaca mulatta) with Plasmodium coatneyi (a sequestering parasite) during the first trimester. In our initial experiment, four monkeys were inoculated with a fresh inoculum containing 10(8) viable parasites from an infected donor monkey. All four monkeys became parasitemic seven days postinoculation (PI) and three monkeys aborted 7-10 days PI coincident with high peak parasitemias (41,088-374,325 parasites/mm3). Although abortion is one of the outcomes observed in Plasmodium-infected women, the intent of this study was to examine the effects of Plasmodium infection throughout gestation. Since the rapid onset of high parasitemia may have been responsible for the abortions, a decision was made to reduce the size of the effective inoculum. Six additional pregnant monkeys were inoculated with a frozen isolate taken from the same donor containing 10(6) parasites. These six animals became parasitemic by 14 days PI and, along with monkey E412, carried their infants to term. These seven infants weighed significantly less at term than the infants of uninfected mothers (P = 0.0355). Symmetrical IUGR was detected by ultrasound in one fetus with an LBW of 334 g. Another LBW infant (300 g) had asymmetrical growth retardation, which has been associated with uteroplacental insufficiency and was consistent with the lower placental weights found in infected dams compared with controls (P = 0.0455). The infant with symmetric IUGR died at five days of age, while the other is alive but congenitally infected. The IUGR, LBW, congenital infection, postnatal infant mortality, and early abortions observed in these animals suggest that P. coatneyi in pregnant rhesus monkeys is a valid model of malaria in human pregnancy. This model should provide the opportunity to study questions about malaria in pregnancy that have been difficult to study in humans.

Malaria and anaemia in pregnant women in urban Zanzibar, Tanzania

Severe anaemia in pregnancy is a major obstetric problem in malaria-endemic areas. This study reports a cross-sectional investigation of malaria infection and haematological values at delivery in 440 women from urban Zanzibar. Severe anaemia [with haemoglobin (Hb) < or = 7 g/dl] was identified in 36 women (9.3%) and mild anaemia (7 < Hb < 10 g/dl) in 269 (69.7%) while 81 women (21.0%) had normal Hb values. Malaria infection was diagnosed in 187/385 women (48.6%) on the basis of either peripheral blood examination or placental histology. Univariate analysis indicated that the proportion of women with anaemia was similar in those with (85%) and without (80%) malaria infection. However, when primigravidae were considered alone, malaria infection was significantly more frequent among anaemic women (65.2%) than in those with normal Hb values (40.0%). In the logistic regression analysis, including age, parity, education level, malaria and free serum iron as independent variables and anaemia (Hb < or = 10 g/dl) as response variable, the odds ratio (OR) for malaria infection was 1.2 (P > 0.1). However, a similar analysis indicated that malaria was significantly associated with anaemia in the primigravidae, with an OR of 3.2 (95% confidence interval: 1.1-9.6; P < 0.05). In conclusion, this cross-sectional investigation indicated that malaria plays a significant role in the determination of anaemia in primigravidae, but not in multiparae, in the urban study area.