Malaria during pregnancy and foetal haematological status in Blantyre, Malawi

Impact of fetal inflammatory response on the severity of necrotizing enterocolitis in preterm infants

OBJECTIVE

Neonates born with fetal inflammatory response (FIR) are at increased risk for adverse neonatal outcomes. Our objective was to determine whether FIR and its severity is associated with severity of necrotizing enterocolitis (NEC) in preterm infants.

METHODS

A case-control retrospective study of infants <33 weeks gestational age or <1500 g birthweight, including 260 with stage I-III NEC and 520 controls matched for gestational age. Placental pathology was evaluated, and FIR progression and its severity were defined according to Amsterdam classification.

RESULTS

In this study, mild FIR (i.e., stage 1 FIR) was present in 52 controls (10.0%) and 22 infants with stage I-III NEC (8.5%), while moderate to severe FIR (i.e., ≥stage 2 FIR) was present in 16 controls (3.1%) and 47 infants with stage I-III NEC (18.1%). Both stage and grade of FIR were associated with stage of NEC (P < 0.001). On multinomial logistic regression, stage III NEC was associated with stage of FIR (P < 0.001).

CONCLUSION

This is the first report demonstrating the association between progression and increasing severity of FIR and stage of NEC.

IMPACT

Fetal Inflammatory Response (FIR) and its progression and severity are associated with the stages of necrotizing enterocolitis (NEC). This is the first study demonstrating the impact of progression and severity of FIR on stage III NEC. These observations provide additional insight into understanding the impact of intrauterine exposure to inflammation on the severity of NEC in preterm infants.

Risk Factors for Admission Hyperthermia and Associated Outcomes in Infants Born Preterm

Maternal, placental, and neonatal factors were compared between infants born at ≤29 weeks of gestational age with admission hyperthermia (>37.5○C) and euthermia (36.5-37.5○C). Admission hyperthermia was associated with longer duration of face-mask positive-pressure ventilation and infant's temperature ≥37.5○C in the delivery room. Infants born preterm with admission hyperthermia had greater odds of developing necrotizing enterocolitis and neurodevelopmental impairment.

CCR5 contributes to adverse outcomes during malaria in pregnancy

CCR5 is a chemokine receptor that mediates cell recruitment to sites of inflammation. It has been previously reported that the expression of CCR5 is increased in the placentas of women with malaria, a disease characterized by causing deliveries with low birth weight among other complications. CCR5 has been associated with pathology of protozoan infections during pregnancy but its role during malaria in pregnancy has not been elucidated. In the present work, we assessed the pregnancy outcome, placental structure, and levels of inflammatory markers of pregnant C57BL/6 and CCR5-/- mice infected or not with Plasmodium berghei NK65, with the purpose of determine the role of CCR5 in pregnancy associated malaria complications. We demonstrated that the expression of CCR5 mRNA increases in late pregnancy placentas of C57BL/6 when compared to uninfected controls. Infected pregnant C57BL/6 mice showed preterm birth, decreased fetal weight, placental inefficiency, and reduced placental vascular space. On the other hand, CCR5 deficiency led to increased levels of maternal parasitemia, reduced fetal weight and placental inefficiency compared to C57BL/6 mice. However, the infection did not cause additional changes in these parameters or in the incidence of preterm delivery in infected CCR5-/- mice in relation to C57BL/6 mice, showing that CCR5 may contribute to the adverse effects caused by infection during pregnancy. This improvement in pregnancy outcome, observed in infected CCR5-/- mice, was accompanied by lower placental levels of the inflammatory markers, such as TNF and NAG. Furthermore, it was observed that the placentas of CCR5-/- animals showed structural differences in relation to C57BL/6 mice, which could improve the efficiency of maternal-fetal exchanges, reflecting on fetal weight. Taken together, these results indicate that CCR5 expression contributes to the adverse outcomes caused by malaria in late pregnancy.

Inhibition of Heme Oxygenase-1 by Zinc Protoporphyrin IX Improves Adverse Pregnancy Outcomes in Malaria During Early Gestation

The enzyme heme oxygenase-1 (HO-1) has cytoprotective effects by catalyzing the degradation of heme to produce carbon monoxide, iron and biliverdin. Furthermore, HO-1 activity has been associated with successful pregnancy. On the other hand, in the context of certain inflammatory conditions, HO-1 can induce iron overload and cell death. To investigate the role of HO-1 in gestational malaria, pregnant BALB/c mice were infected with Plasmodium berghei ANKA in early, mid and late gestation. We found that malaria affected the pregnancy outcome in the three periods evaluated. However, only poor pregnancy outcomes in early pregnancy were related to HO-1 upregulation, iron overload, lipid peroxidation and necrosis of the decidua, which were prevented by HO-1 inhibition. In conclusion, HO-1 expression must be finely tuned in gestational malaria to avoid the deleterious effect of increased enzyme activity.

Malaria and Helminthic Co-Infection during Pregnancy in Sub-Saharan Africa: A Systematic Review and Meta-Analysis

Malaria and helminthic co-infection during pregnancy causes fetomaternal haemorrhage and foetal growth retardation. This study determined the pooled burden of pregnancy malaria and helminthic co-infection in sub-Saharan Africa. CINAHL, EMBASE, Google Scholar, Scopus, PubMed, and Web of Science databases were used to retrieve data from the literature, without restricting language and publication year. The Joanna Briggs Institute's critical appraisal tool for prevalence studies was used for quality assessment. STATA Version 14.0 was used to conduct the meta-analysis. The I2 statistics and Egger's test were used to test heterogeneity and publication bias. The random-effects model was used to estimate the pooled prevalence at a 95% confidence interval (CI). The review protocol has been registered in PROSPERO, with the number CRD42019144812. In total, 24 studies (n = 14,087 participants) were identified in this study. The pooled analysis revealed that 20% of pregnant women were co-infected by malaria and helminths in sub-Saharan Africa. The pooled prevalence of malaria and helminths were 33% and 35%, respectively. The most prevalent helminths were Hookworm (48%), Ascaris lumbricoides (37%), and Trichuris trichiura (15%). Significantly higher malaria and helminthic co-infection during pregnancy were observed. Health systems in sub-Saharan Africa must implement home-grown innovative solutions to underpin context-specific policies for the early initiation of effective intermittent preventive therapy.

Fetal Cytokine Balance, Erythropoietin and Thalassemia but Not Placental Malaria Contribute to Fetal Anemia Risk in Tanzania

Fetal anemia is common in malaria-endemic areas and a risk factor for anemia as well as mortality during infancy. Placental malaria (PM) and red cell abnormalities have been proposed as possible etiologies, but the relationship between PM and fetal anemia has varied in earlier studies, and the role of red cell abnormalities has not been studied in malaria-endemic areas. In a Tanzanian birth cohort study designed to elucidate the pathogenesis of severe malaria in young infants, we performed a cross-sectional analysis of risk factors for fetal anemia. We determined PM status, newborn red cell abnormalities, and maternal and cord blood levels of iron regulatory proteins, erythropoietin (EPO), cytokines and cytokine receptors. We examined the relationship between these factors and fetal anemia. Fetal anemia was present in 46.2% of the neonates but was not related to PM. Maternal iron deficiency was common (81.6%), most frequent in multigravidae, and interacted with parity to modify risk of fetal anemia, but it was not directly related to risk. Among offspring of iron-deficient women, the odds of fetal anemia increased with fetal α⁺-thalassemia, as well as these patterns of cord blood cytokines: increased cord IL-6, decreased TNF-RI, and decreased sTfR. The EPO response to fetal anemia was low or absent and EPO levels were significantly decreased in newborns with the most severe anemia. This study from an area of high malaria transmission provides evidence that 1) fetal α⁺-thalassemia and cytokine balance, but not PM at delivery, are related to fetal anemia; 2) maternal iron deficiency increases the risk that other factors may cause fetal anemia; and 3) fetal anemia has a multifactorial etiology that may require a variety of interventions, although measures that reduce maternal iron deficiency may be generally beneficial.

Iron absorption during pregnancy is underestimated when iron utilization by the placenta and fetus is ignored

BACKGROUND

Maternal iron absorption during pregnancy can be evaluated using RBC incorporation of orally administered stable iron isotope. This approach underestimates true maternal absorption of iron as it does not account for absorbed iron that is transferred to the fetus or retained within the placenta.

OBJECTIVE

Our objective was to re-evaluate maternal iron absorption after factoring in these losses and identify factors associated with iron partitioning between the maternal, neonatal, and placental compartments.

METHODS

This study utilized data from stable iron isotope studies carried out in 68 women during the third trimester of pregnancy. Iron status indicators and stable iron isotopic enrichment were measured in maternal blood, umbilical cord blood, and placental tissue when available. Factors associated with iron isotope partitioning between the maternal, neonatal, and placental compartments were identified.

RESULTS

On average, true maternal absorption of iron increased by 10% (from 19% to 21%) after accounting for absorbed iron present in the newborn (P < 0.001), and further increased by 7%, (from 39% to 42%, P < 0.001) after accounting for iron retained within the placenta. On average, 2% of recovered tracer was present in the placenta and 6% was found in the newborn. Net transfer of iron to the neonate was higher in women with lower total body iron (standardized β = -0.48, P < 0.01) and lower maternal hepcidin (standardized β = -0.66, P < 0.01). In women carrying multiple fetuses, neonatal hepcidin explained a significant amount of observed variance in net placental transfer of absorbed iron (R = 0.95, P = 0.03).

CONCLUSIONS

Maternal RBC iron incorporation of an orally ingested tracer underestimated true maternal iron absorption. The degree of underestimation was greatest in women with low body iron. Maternal hepcidin was inversely associated with maternal RBC iron utilization, whereas neonatal hepcidin explained variance in net transfer of iron to the neonatal compartment.These trials were registered at clinicaltrials.gov as NCT01019096 and NCT01582802.

The fetal inflammatory response syndrome: the origins of a concept, pathophysiology, diagnosis, and obstetrical implications

The fetus can deploy a local or systemic inflammatory response when exposed to microorganisms or, alternatively, to non-infection-related stimuli (e.g., danger signals or alarmins). The term "Fetal Inflammatory Response Syndrome" (FIRS) was coined to describe a condition characterized by evidence of a systemic inflammatory response, frequently a result of the activation of the innate limb of the immune response. FIRS can be diagnosed by an increased concentration of umbilical cord plasma or serum acute phase reactants such as C-reactive protein or cytokines (e.g., interleukin-6). Pathologic evidence of a systemic fetal inflammatory response indicates the presence of funisitis or chorionic vasculitis. FIRS was first described in patients at risk for intraamniotic infection who presented preterm labor with intact membranes or preterm prelabor rupture of the membranes. However, FIRS can also be observed in patients with sterile intra-amniotic inflammation, alloimmunization (e.g., Rh disease), and active autoimmune disorders. Neonates born with FIRS have a higher rate of complications, such as early-onset neonatal sepsis, intraventricular hemorrhage, periventricular leukomalacia, and death, than those born without FIRS. Survivors are at risk for long-term sequelae that may include bronchopulmonary dysplasia, neurodevelopmental disorders, such as cerebral palsy, retinopathy of prematurity, and sensorineuronal hearing loss. Experimental FIRS can be induced by intra-amniotic administration of bacteria, microbial products (such as endotoxin), or inflammatory cytokines (such as interleukin-1), and animal models have provided important insights about the mechanisms responsible for multiple organ involvement and dysfunction. A systemic fetal inflammatory response is thought to be adaptive, but, on occasion, may become dysregulated whereby a fetal cytokine storm ensues and can lead to multiple organ dysfunction and even fetal death if delivery does not occur ("rescued by birth"). Thus, the onset of preterm labor in this context can be considered to have survival value. The evidence so far suggests that FIRS may compound the effects of immaturity and neonatal inflammation, thus increasing the risk of neonatal complications and long-term morbidity. Modulation of a dysregulated fetal inflammatory response by the administration of antimicrobial agents, anti-inflammatory agents, or cell-based therapy holds promise to reduce infant morbidity and mortality.

Effect of sulfadoxine-pyrimethamine doses for prevention of malaria during pregnancy in hypoendemic area in Tanzania

BACKGROUND

Malaria in pregnancy increases the risk of deleterious maternal and birth outcomes. The use of ≥ 3 doses of sulfadoxine-pyrimethamine (SP) for intermittent preventive treatment of malaria (IPTp-SP) is recommended for preventing the consequences of malaria during pregnancy. This study assessed the effect of IPTp-SP for prevention of malaria during pregnancy in low transmission settings.

METHODS

A cross-sectional study that involved consecutively selected 1161 pregnant women was conducted at Mwananyamala regional referral hospital in Dar es Salaam. Assessment of the uptake of IPTp-SP was done by extracting information from antenatal clinic cards. Maternal venous blood, cord blood, placental blood and placental biopsy were collected for assessment of anaemia and malaria. High performance liquid chromatography with ultraviolet detection (HPLC-UV) was used to detect and quantify sulfadoxine (SDX). Dried blood spots (DBS) of placental blood were collected for determination of sub-microscopic malaria using polymerase chain reaction (PCR).

RESULTS

In total, 397 (34.2%) pregnant women reported to have used sub-optimal doses (≤ 2) while 764 (65.8%) used optimal doses (≥ 3) of IPTp-SP at the time of delivery. The prevalence of placental malaria as determined by histology was 3.6%. Submicroscopic placental malaria was detected in 1.4% of the study participants. Women with peripheral malaria had six times risk of maternal anaemia than those who were malaria negative (aOR, 5.83; 95% CI 1.10-30.92; p = 0.04). The geometric mean plasma SDX concentration was 10.76 ± 2.51 μg/mL. Sub-optimal IPTp-SP dose was not associated with placental malaria, premature delivery and fetal anaemia. The use of ≤ 2 doses of IPTp-SP increased the risk of maternal anaemia by 1.36-fold compared to ≥ 3 doses (aOR, 1.36; 95% CI 1.04-1.79; p = 0.02).

CONCLUSION

The use of < 2 doses of IPTp-SP increased the risk of maternal anaemia. However, sub-optimal doses (≤ 2 doses) were not associated with increased the risk of malaria parasitaemia, fetal anaemia and preterm delivery among pregnant women in low malaria transmission setting. The use of optimal doses (≥ 3 doses) of IPTp-SP and complementary interventions should continue even in areas with low malaria transmission.

Social determinants of malaria in an endemic area of Indonesia

Background

Malaria is an increasing concern in Indonesia. Socio-demographic factors were found to strongly influence malaria prevalence. This research aimed to explore the associations between socio-demographic factors and malaria prevalence in Indonesia.

Methods

The study used a cross-sectional design and analysed relationships among the explanatory variables of malaria prevalence in five endemic provinces using multivariable logistic regression.

Results

The analysis of baseline socio-demographic data revealed the following independent risk variables related to malaria prevalence: gender, age, occupation, knowledge of the availability of healthcare services, measures taken to protect from mosquito bites, and housing condition of study participants. Multivariable analysis showed that participants who were unaware of the availability of health facilities were 4.2 times more likely to have malaria than those who were aware of the health facilities (adjusted odds ratio = 4.18; 95% CI 1.52–11.45; P = 0.005).

Conclusions

Factors that can be managed and would favour malaria elimination include a range of prevention behaviours at the individual level and using the networks at the community level of primary healthcare centres. This study suggests that improving the availability of a variety of health facilities in endemic areas, information about their services, and access to these is essential.

Electronic supplementary material

The online version of this article (10.1186/s12936-019-2760-8) contains supplementary material, which is available to authorized users.

Factors associated with compliance to recommended micronutrients uptake for prevention of anemia during pregnancy in urban, peri-urban, and rural communities in Southeast Nigeria

BACKGROUND

The study investigated the factors associated with compliance to the recommended ≥90-day uptake of micronutrients for prevention of iron-deficiency anemia during pregnancy in Nigeria.

METHODS

A cross-sectional study of 1500 women who had babies within 6 months prior to the survey, drawn from six urban, peri-urban, and rural local government areas in Enugu and Imo States of Nigeria, was conducted, using a structured questionnaire. A focus group discussion was held with grandmothers and fathers of the new baby. In-depth interviews were held with health workers.

RESULTS

There were six demographic factors in the bivariate analysis: living in an urban center and close to health facility, and being wealthy, with post-secondary education as well as older and engaged in civil service showed significant association with compliance. The urban residents complied more than the peri-urban and rural residents (χ 2 = 12.749; p = 0.002). Those living close to the health facilities complied more than those living far away (χ 2 = 24.638; p < 0.001). Those in higher wealth quintile complied more (χ 2 = 13.216; p < 0.010). Utilization of antenatal clinics during pregnancy showed statistically significant association with compliance. Those who used the ANC services complied more than those that did not (χ 2 = 6.324; p = 0.010) and the more frequent the use of ANC services the more the compliance (χ 2 = 14.771; p < 0.001). These results were confirmed when the opinions expressed in the urban, peri-urban, and rural communities are compared. However, the multivariate binary logistic regression highlighted only urban residence, closeness to health facilities, and utilization of ANC services as positively associated with compliance.

CONCLUSION

These findings could help in targeting health education program to increase compliance to the recommended uptake of micronutrients in prevention of anemia during pregnancy.

The risk of malaria in Ghanaian infants born to women managed in pregnancy with intermittent screening and treatment for malaria or intermittent preventive treatment with sulfadoxine/pyrimethamine

Background

Several studies have reported an association between malaria infection of the placenta and the risk of malaria in young children in the first year of life, but it is not known if this is causal, or influenced by malaria control measures during pregnancy. This paper compares the incidence of malaria in infants born to mothers who received either intermittent preventive treatment with sulfadoxine/pyrimethamine (IPTp-SP) or screening with a rapid diagnostic test and treatment with artemether–lumefantrine (ISTp-AL) during their pregnancy.

Methods

From July 2011 to April 2013, 988 infants of women enrolled in a trial of IPTp-SP versus ISTp-AL in the Kassena-Nankana districts of northern Ghana were followed to determine the risk of clinical malaria during early life, and their risk of parasitaemia and anaemia at 6 and 12 months of age. In addition, the incidence of clinical malaria in infants whose mothers had malaria infection of the placenta was compared with that in infants born to women free of placental malaria.

Results

The incidence of clinical malaria was 0.237 and 0.211 episodes per child year in infants whose mothers had received ISTp-AL or IPTp-SP, respectively. The adjusted incidence rate ratio and the adjusted rate difference were 0.94 (95 % CI 0.68, 1.33) and 0.029 (95 % CI −0.053, 0.110) cases per child year at risk respectively. The incidence of clinical malaria was similar in infants born to women with placental malaria (0.195 episodes per child year) and in infants of women without placental malaria (0.224 episodes per child year) (rate ratio = 0.86 [95 % CI 0.54, 1.37]).

Conclusion

Infants born to women managed with ISTp-AL during pregnancy were not at greatly increased risk of malaria compared with infants born to women who had received IPTp-SP. The incidence of malaria in infants was similar whether or not their mother had had placental malaria.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-016-1094-z) contains supplementary material, which is available to authorized users.

Peripheral and placental biomarkers in women with placental malaria: a systematic review

Placental malaria (PM) causes significant morbidity in mothers and infants. Diagnosis of PM during pregnancy is however problematic due to placental sequestration of parasites. Host biomarkers may therefore be used as a diagnostic method. In this systematic review most studies focused on inflammatory markers. A trend was observed for increased IL-10 and TNF-α in PM positives. These markers are however unspecific, thus a combination of multiple biomarkers involved in different pathophysiological pathways of PM is indicated. Of interest are inflammatory markers (TNF-R2, CXCL-13), markers of lipid metabolism (APO-B), angiogenesis (sFlt-1) and hormones (estradiol). As the majority of published studies tested biomarker levels only at delivery, more longitudinal cohort studies will be necessary to detect biomarkers during pregnancy that can predict PM.

The prevalence of malaria at first antenatal visit in Blantyre, Malawi declined following a universal bed net campaign

Background

Preventing malaria during pregnancy is important for the health of mothers and newborns. Interventions, which include distribution of bed nets and administration of intermittent preventive treatment (IPT), typically occur at the first antenatal visit, usually in the second or third trimester of pregnancy. In 2012, during the course of ongoing clinical studies of malaria among pregnant women in Malawi, a universal bed net campaign was implemented by the Government. This study tested the hypothesis that a universal bed net campaign would decrease the prevalence of malaria among pregnant women at their first antenatal visit.

Methods

Some 1661 women were recruited for two studies from 2009 to 2014. Quantitative PCR (qPCR) was conducted from dried blood spots collected at the first antenatal care visit (prior to administration of IPT or any study interventions) from women who were in their first or second pregnancy and less than 28 weeks gestation by clinical assessment.

Results

Overall, 320 of 1629 (19.6 %) women tested for malaria at their first antenatal visit were infected. Malaria infection rates declined from 28.4 % before the universal bed net campaign, to 18.5 % in 2012, to 15.0 % in the years following the universal bed net campaign. The odds of malaria infection at the time of first antenatal visit in 2012 and the years following the bed net campaign were significantly lower than in the years prior to the intervention (OR 0.6, 95 % CI 0.4–0.8; and OR 0.4, 95 % CI 0.3–0.6, respectively). A similar pattern was observed for the prevalence of clinical malaria. The inverse trend was observed for reported bed net use. However bed net use and malaria infection were not significantly associated on the individual level.

Conclusions

Malaria infection in pregnant women is common even after a bed net campaign in Malawi, though prevalence rates declined. These early infections may cause maternal anaemia and placental malaria resulting in adverse maternal and fetal outcomes. Infection early in pregnancy may also contribute to malaria transmission as pregnant women represent a significant untreated reservoir of parasites. Universal bed net distribution appears to have moderate success in preventing malaria early in pregnancy and these findings support continued efforts to target women early in pregnancy and all women of childbearing age.

Parasitemia Induces High Plasma Levels of Interleukin-17 (IL-17) and Low Levels of Interleukin-10 (IL-10) and Transforming Growth Factor-ß (TGF-ß) in Pregnant Mice Infected with Malaria

BACKGROUND

During pregnancy, the balanced dominance of the T helper17 response shifts to a Th2 response that is characterised by the production of IL-10, following the completion of the implantation process. Transforming growth factor-β (TGF-β) expression is associated with the completion of trophoblast invasion and placental growth. This study assessed the effect of malaria infection on the levels of IL-17, IL-10, and TGF-β in the plasma of pregnant mice with malaria.

METHODS

Seventeen pregnant BALB/C mice were divided into two groups: mice infected with Plasmodium berghei (treatment group) and uninfected mice (control group). The mice were sacrificed on day 18 post-mating. Parasitemia was measured by Giemsa staining. The levels of IL-17, IL-10, and TGF-β were measured by ELISA.

RESULTS

Using independent t test, the IL-17 levels in the treatment group were higher than those in the control group (= = 0.040). The IL-10 levels in the treatment group were lower than those in the control group (= = 0.00). There was no significant difference in the TGF-β levels (= = 0.055) between two groups. However, using SEM analysis the degree of parasitemia decreased the plasma TGF-β levels (tcount = 5.148; ≥ ttable = 1.96). SEM analysis showed that a high degree of parasitemia increased the IL-17 levels and decreased the IL-10 and TGF-β levels.

CONCLUSION

Malaria infection during pregnancy interferes with the systemic balance by increasing the IL-17 levels and decreasing the IL-10 and TGF-β levels.

Pregnant women are a reservoir of malaria transmission in Blantyre, Malawi

Background

During pregnancy, women living in malaria-endemic regions are at increased risk of malaria infection and can harbour chronic placental infections. Intermittent preventive treatment with sulphadoxine-pyrimethamine (SP-IPTp) is administered to reduce malaria morbidity. It was hypothesized that the presence of placental malaria infection and SP-IPTp use would increase the risk of peripheral blood gametocytes, the parasite stage that is transmissible to mosquitoes. This would suggest that pregnant women may be important reservoirs of malaria transmission.

Methods

Light microscopy was used to assess peripheral gametocytaemia in pregnant women enrolled in a longitudinal, observational study in Blantyre, Malawi to determine the association between placental malaria and maternal gametocytaemia. The relationship between SP-IPTp and gametocytaemia was also examined.

Results

2,719 samples from 448 women were analysed and 32 episodes of microscopic gametocytaemia were detected in 27 women. At the time of enrolment 22 of 446 women (4.9%) had gametocytaemia and of the 341 women for whom there was sufficient sampling to analyse infection over the entire course of pregnancy, 27 (7.9%) were gametocytaemic at least once. Gametocytaemia at enrolment was associated with placental malaria, defined as malaria pigment or parasites detected by histology or qPCR, respectively (OR: 32.4, 95% CI: 4.2-250.2), but was not associated with adverse maternal or foetal outcomes. Administration of SP-IPTp did not affect gametocyte clearance or release into peripheral blood.

Conclusions

Gametocytaemia is present in 5% of pregnant women at their first antenatal visit and associated with placental malaria. SP-IPTp does not alter the risk of gametocytaemia. These data suggest that pregnant women are a significant reservoir of gametocyte transmission and should not be overlooked in elimination efforts. Interventions targeting this population would benefit from reaching women prior to first antenatal visit.

Haemoglobin status and predictors of anaemia among pregnant women in Mpigi, Uganda

Background

Anaemia in pregnancy is a major public health problem especially in the low-income countries where it is highly prevalent. There has been no recent study in Uganda about the factors associated with anaemia in pregnancy. We aimed to assess the current haemoglobin (Hb) status and factors associated with anaemia (Hb < 11.0 g/dl) in pregnant women in Mpigi, Uganda.

Methods

We assessed Hb levels of 2436 pregnant women at 28+ weeks of gestation at six health facilities, who were approached to participate in a stepped-wedge cluster-randomised trial of antenatal distribution of misoprostol (for self-administration after home birth or when oxytocin is not available). Women were administered a questionnaire and their baseline blood haemoglobin was examined using portable HemoCueR Hb 301 system. Predictors of anaemia were estimated using linear and logistic regression analysis.

Results

The mean Hb was 11.5 (±1.38) g/dl and prevalence of anaemia (Hb < 11.0 g/dl) was 32.5% (95% CI 30.6%, 34.3%). After adjusting for measured confounders, factors associated with increased risk of anaemia in pregnancy were malaria infection (OR: 1.32, 95% CI: 1.11, 1.58), Human Immuno-deficiency Virus infection (OR: 2.13, 95% CI: 1.36, 2.90) and lack of iron supplementation (OR: 1.66, 95% CI: 1.36, 2.03). Intermittent presumptive treatment of malaria, maternal age and parity showed a weak association with anaemia in pregnancy

Conclusion

The high prevalence of anaemia in pregnancy in our setting highlights the need to put more effort in the fight against malaria and HIV, and also ensure that pregnant women access iron supplements early in pregnancy.

Iron overload in Plasmodium berghei-infected placenta as a pathogenesis mechanism of fetal death

Plasmodium infection during gestation may lead to severe clinical manifestations including abortion, stillbirth, intrauterine growth retardation, and low birth weight. Mechanisms underlying such poor pregnancy outcomes are still unclear. In the animal model of severe placental malaria (PM), in utero fetal death frequently occurs and mothers often succumb to infection before or immediately after delivery. Plasmodium berghei-infected erythrocytes (IEs) continuously accumulate in the placenta, where they are then phagocytosed by fetal-derived placental cells, namely trophoblasts. Inside the phagosomes, disruption of IEs leads to the release of non-hemoglobin bound heme, which is subsequently catabolized by heme oxygenase-1 into carbon monoxide, biliverdin, and labile iron. Fine-tuned regulatory mechanisms operate to maintain iron homeostasis, preventing the deleterious effect of iron-induced oxidative stress. Our preliminary results demonstrate that iron overload in trophoblasts of P. berghei-infected placenta is associated with fetal death. Placentas which supported normally developing embryos showed no iron accumulation within the trophoblasts. Placentas from dead fetuses showed massive iron accumulation, which was associated with parasitic burden. Here we present preliminary data suggesting that disruption of iron homeostasis in trophoblasts during the course of PM is a consequence of heme accumulation after intense IE engulfment. We propose that iron overload in placenta is a pathogenic component of PM, contributing to fetal death. The mechanism through which it operates still needs to be elucidated.

The association between malaria and iron status or supplementation in pregnancy: a systematic review and meta-analysis

Introduction

Malaria prevention and iron supplementation are associated with improved maternal and infant outcomes. However, evidence from studies in children suggests iron may adversely modify the risk of malaria. We reviewed the evidence in pregnancy of the association between malaria and markers of iron status, iron supplementation or parenteral treatment.

Methods and Findings

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, the Global Health Library, and the Malaria in Pregnancy library to identify studies that investigated the association between iron status, iron treatment or supplementation during pregnancy and malaria. Thirty one studies contributed to the analysis; 3 experimental and 28 observational studies. Iron supplementation was not associated with an increased risk of P. falciparum malaria during pregnancy or delivery in Africa (summary Relative Risk = 0.89, 95% Confidence Interval (CI) 0.66–1.20, I² = 78.8%, 5 studies). One study in Asia reported an increased risk of P. vivax within 30 days of iron supplementation (e.g. adjusted Hazard Ratio = 1.75, 95% CI 1.14–2.70 for 1–15 days), but not after 60 days. Iron deficiency (based on ferritin and C-reactive protein) was associated with lower odds for malaria infection (summary Odds Ratio = 0.35, 0.24–0.51, I² = 59.2%, 5 studies). With the exception of the acute phase protein ferritin, biomarkers of iron deficiency were generally not associated with malaria infection.

Conclusions

Iron supplementation was associated with a temporal increase in P vivax, but not with an increased risk of P. falciparum; however, data are insufficient to rule out the potential for an increased risk of P. falciparum. Iron deficiency was associated with a decreased malaria risk in pregnancy only when measured with ferritin. Until there is more evidence, it is prudent to provide iron in combination with malaria prevention during pregnancy.

Predictors of fetal anemia and cord blood malaria parasitemia among newborns of HIV-positive mothers

Background

Malaria and HIV infections during pregnancy can individually or jointly unleash or confound pregnancy outcomes. Two of the probable outcomes are fetal anemia and cord blood malaria parasitemia. We determined clinical and demographic factors associated with fetal anemia and cord blood malaria parasitemia in newborns of HIV-positive women from two districts in Ghana.

Results

We enrolled 1,154 antenatal attendees (443 HIV-positive and 711 HIV-negative) of which 66% were prospectively followed up at delivery. Maternal malaria parasitemia, and anemia rates among HIV+ participants at enrolment were 20.3% and 78.7% respectively, and 12.8% and 51.6% among HIV- participants. Multivariate linear and logistic regression models were used to study associations. Prevalence of fetal anemia (cord hemoglobin level < 12.5 g/dL) and cord parasitemia (presence of P. falciparum in cord blood at delivery) were 57.3% and 24.4% respectively. Factors found to be associated with fetal anemia were maternal malaria parasitemia and maternal anemia. Infant cord hemoglobin status at delivery was positively and significantly associated with maternal hemoglobin and gestational age whilst female gender of infant was negatively associated with cord hemoglobin status. Maternal malaria parasitemia status at recruitment and female gender of infant were positively associated with infant cord malaria parasitemia status.

Conclusions

Our data show that newborns of women infected with HIV and/or malaria are at increased risk of anemia and also cord blood malaria parasitemia. Prevention of malaria infection during pregnancy may reduce the incidence of both adverse perinatal outcomes.

Body iron delocalization: the serious drawback in iron disorders in both developing and developed countries

Over 2 billion people in both developing as well as developed countries - over 30% of the world's population - are anaemic. With the classical preconception that oral iron administration or the intake of foods rich in iron increase haemoglobin concentration and reduce the prevalence of anaemia, specific programs have been designed, but iron supplementations have been less effective than expected. Of note, this hazardous simplification on iron status neglects its distribution in the body. The correct balance of iron, defined iron homeostasis, involves a physiological ratio of iron between tissues/secretions and blood, thus avoiding its delocalization as iron accumulation in tissues/secretions and iron deficiency in blood. Changes in iron status can affect the inflammatory response in multiple ways, particularly in the context of infection, an idea that is worth remembering when considering the value of iron supplementation in areas of the world where infections are highly prevalent. The enhanced availability of free iron can increase susceptibility and severity of microbial and parasitic infections. The discovery of the hepcidin-ferroportin (Fpn) complex, which greatly clarified the enigmatic mechanism that supervises the iron homeostasis, should prompt to a critical review on iron supplementation, ineffective on the expression of the most important proteins of iron metabolism. Therefore, it is imperative to consider new safe and efficient therapeutic interventions to cure iron deficiency (ID) and ID anaemia (IDA) associated or not to the inflammation. In this respect, lactoferrin (Lf) is emerging as an important regulator of both iron and inflammatory homeostasis. Oral administration of Lf in subjects suffering of ID and IDA is safe and effective in significantly increasing haematological parameters and contemporary decreasing serum IL-6 levels, thus restoring iron localization through the direct or indirect modulation of hepcidin and ferroportin synthesis. Of note, the nuclear localization of Lf suggests that this molecule may be involved in the transcriptional regulation of some genes of host inflammatory response. We recently also reported that combined administration of oral and intravaginal Lf on ID and IDA pregnant women with preterm delivery threat, significantly increased haematological parameters, reduced IL-6 levels in both serum and cervicovaginal fluid, cervicovaginal prostaglandin PGF2α, and suppressed uterine contractility. Moreover, Lf combined administration blocked further the shortening of cervical length and the increase of foetal fibronectin, thus prolonging the length of pregnancy until the 37th-38th week of gestation. These new Lf functions effective in curing ID and IDA through the restoring of iron and inflammatory homeostasis and in preventing preterm delivery, could have a great relevance in developing countries, where ID and IDA and inflammation-associated anaemia represent the major risk factors of preterm delivery and maternal and neonatal death.

Determinants of anemia in postpartum HIV-negative women in Dar es Salaam, Tanzania

OBJECTIVE

The determinants of anemia during both pregnancy and postpartum recovery remain incompletely understood in sub-Saharan African women.

SUBJECTS/METHODS

In a prospective cohort study among pregnant women, we assessed dietary, biochemical, anthropometric, infectious and sociodemographic factors at baseline. In multivariate Cox proportional hazards models, we examined predictors of incident anemia (hemoglobin <11 g/dl) and iron deficiency anemia (anemia plus mean corpuscular volume <80fL), and recovery from anemia and iron deficiency anemia through 18 months postpartum at antenatal clinics in Dar es Salaam, Tanzania between 2001 and 2005. A total of 2364 non-anemic pregnant women and 4884 anemic women were enrolled between 12 and 27 weeks of gestation.

RESULTS

In total, 292 women developed anemia during the postpartum period and 165 developed iron deficiency anemia, whereas 2982 recovered from baseline anemia and 2044 from iron deficiency anemia. Risk factors for postpartum anemia were delivery complications (RR 1.6, 95% confidence interval (CI) 1.13, 2.22) and low postpartum CD4 cell count (RR 1.73, 95% CI 0.96, 3.17). Iron/folate supplementation during pregnancy had a protective relationship with the incidence of iron deficiency anemia. Absence of delivery complications, education status and iron/folate supplementation were positively associated with time to recovery from iron deficiency.

CONCLUSION

Maternal nutritional status during pregnancy, prenatal iron/folate supplementation, perinatal care, and prevention and management of infections, such as malaria, are modifiable risk factors for the occurrence of, and recovery from, anemia.

Placental histopathological changes associated with Plasmodium vivax infection during pregnancy

Histological evidence of Plasmodium in the placenta is indicative of placental malaria, a condition associated with severe outcomes for mother and child. Histological lesions found in placentas from Plasmodium-exposed women include syncytial knotting, syncytial rupture, thickening of the placental barrier, necrosis of villous tissue and intervillositis. These histological changes have been associated with P. falciparum infections, but little is known about the contribution of P. vivax to such changes. We conducted a cross-sectional study with pregnant women at delivery and assigned them to three groups according to their Plasmodium exposure during pregnancy: no Plasmodium exposure (n = 41), P. vivax exposure (n = 59) or P. falciparum exposure (n = 19). We evaluated their placentas for signs of Plasmodium and placental lesions using ten histological parameters: syncytial knotting, syncytial rupture, placental barrier thickness, villi necrosis, intervillous space area, intervillous leucocytes, intervillous mononucleates, intervillous polymorphonucleates, parasitized erythrocytes and hemozoin. Placentas from P. vivax-exposed women showed little evidence of Plasmodium or hemozoin but still exhibited more lesions than placentas from women not exposed to Plasmodium, especially when infections occurred twice or more during pregnancy. In the Brazilian state of Acre, where diagnosis and primary treatment are readily available and placental lesions occur in the absence of detected placental parasites, relying on the presence of Plasmodium in the placenta to evaluate Plasmodium-induced placental pathology is not feasible. Multivariate logistic analysis revealed that syncytial knotting (odds ratio [OR], 4.21, P = 0.045), placental barrier thickness (OR, 25.59, P = 0.021) and mononuclear cells (OR, 4.02, P = 0.046) were increased in placentas from P. vivax-exposed women when compared to women not exposed to Plasmodium during pregnancy. A vivax-score was developed using these three parameters (and not evidence of Plasmodium) that differentiates between placentas from P. vivax-exposed and unexposed women. This score illustrates the importance of adequate management of P. vivax malaria during pregnancy.

Malaria during pregnancy remains a risk for approximately 125 million women each year. Adverse outcomes of malaria during pregnancy include maternal anemia and low infant birth weight. Additionally, the presence of malaria parasites, namely Plasmodium falciparum, has been associated with the occurrence of placental lesions. In the Amazonian region of Brazil Plasmodium vivax is the primary parasite species. To date, little is known about the capacity of this parasite to induce placental lesions. In this study we have used ten histological parameters to evaluate the effect of exposure to Plasmodium vivax during pregnancy on the occurrence of placental lesions when compared to placentas from non-exposed women. Placentas from women exposed to Plasmodium falciparum were used as controls. Placentas from Plasmodium vivax-exposed placentas did not have strong evidence of placental parasites but had increased syncytial knotting, thickness of the placental barrier and mononuclear cells when compared to non-exposed women. We developed a score based on these three parameters and not on the presence of placental parasites that enables us to visualize the effect that Plasmodium vivax has on placentas from women infected during pregnancy.

Acute-phase proteins in pregnant Sudanese women with severe Plasmodium falciparum malaria

A case-control study was carried out in Kassala and Medani Maternity Hospitals in Sudan to investigate acute-phase proteins [haptoglobin, C-reactive protein (CRP), ferritin and albumin] in three groups of pregnant women (32 in each arm) comprising those with severe Plasmodium falciparum malaria or uncomplicated P. falciparum malaria and healthy controls. Whilst there was no significant difference in the levels of albumin and haptoglobin, ferritin and CRP levels were significantly higher in pregnant women with severe P. falciparum malaria. There were significant positive correlations between parasite count and haptoglobin, and medium positive correlations between parasite count and CRP.

The effects of malaria and intermittent preventive treatment during pregnancy on fetal anemia in Malawi

BACKGROUND

Fetal anemia is common in malarious areas and is a risk factor for infant morbidity and mortality. Malaria during pregnancy may cause decreased cord hemoglobin (Hb) and fetal anemia among newborns. Intermittent preventive treatment during pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is protective against malaria but may also affect hematopoiesis and contribute to fetal anemia.

METHODS

Peripheral, placental, and cord blood were examined for malaria parasitemia and Hb concentration in a cross-section of 3848 mothers and infants delivered at Queen Elizabeth Central Hospital in Blantyre, Malawi between 1997 and 2006. Unconditional linear and logistic regressions were performed with multiple imputation for missing covariates to assess the associations between malaria, IPTp with SP, and fetal anemia.

RESULTS

The overall prevalence of fetal anemia was 7.9% (n = 304). Malaria parasitemia at delivery was associated with an adjusted decrease in cord Hb of -0.24 g/dL (95% confidence interval [CI], -.42 to -.05). The adjusted prevalence odds ratio for the effect of malaria on fetal anemia was 1.41 (95% CI, 1.05-1.90). Primigravidae who did not take IPTp had infants at highest risk for fetal anemia, and density of parasitemia was correlated with the decrease in cord Hb. There was no significant association between SP use and cord Hb or fetal anemia.

CONCLUSIONS

Malaria during pregnancy, but not IPTp, decreases cord Hb and is a risk factor for fetal anemia in Malawi. Intermittent preventive treatment during pregnancy with SP may continue to be safe and effective in preventing malaria during pregnancy and fetal anemia despite development of SP resistance.

Anemia and pregnancy: a link to maternal chronic diseases

Anemia is a global public health problem. It has serious short- and long-term consequences during pregnancy and beyond. The anemic condition is often worsened by the presence of other chronic diseases such as malaria, tuberculosis, HIV, and diabetes. Untreated anemia also leads to increased morbidity and mortality from these chronic conditions as well. It is surprising that despite these chronic conditions (such as malaria, tuberculosis, and HIV) often being preventable, they still pose a real threat to public health. This article aims to review the current understanding of the pathophysiology, risks, prevention, and treatment of anemia in the light of these chronic conditions.

Circulating soluble endoglin levels in pregnant women in Cameroon and Malawi--associations with placental malaria and fetal growth restriction

Placental infections with Plasmodium falciparum are associated with fetal growth restriction resulting in low birth weight (LBW). The mechanisms that mediate these effects have yet to be completely described; however, they are likely to involve inflammatory processes and dysregulation of angiogenesis. Soluble endoglin (sEng), a soluble receptor of transforming growth factor (TGF)-β previously associated with preeclampsia in pregnant women and with severe malaria in children, regulates the immune system and influences angiogenesis. We hypothesized that sEng may play a role in development of LBW associated with placental malaria (PM). Plasma levels of sEng were measured in women (i) followed prospectively throughout pregnancy in Cameroon (n = 52), and (ii) in a case-control study at delivery in Malawi (n = 479). The relationships between sEng levels and gravidity, peripheral and placental parasitemia, gestational age, and adverse outcomes of PM including maternal anemia and LBW were determined. In the longitudinal cohort from Cameroon, 28 of 52 women (54%) experienced at least one malaria infection during pregnancy. In Malawi we enrolled two aparasitemic gravidity-matched controls for every case with PM. sEng levels varied over the course of gestation and were significantly higher in early and late gestation as compared to delivery (P<0.006 and P<0.0001, respectively). Circulating sEng levels were higher in primigravidae than multigravidae from both Cameroon and Malawi, irrespective of malarial infection status (p<0.046 and p<0.001, respectively). Peripheral parasitemia in Cameroonian women and PM in Malawian women were each associated with elevated sEng levels following correction for gestational age and gravidity (p = 0.006 and p = 0.033, respectively). Increased sEng was also associated with the delivery of LBW infants in primigravid Malawian women (p = 0.017); the association was with fetal growth restriction (p = 0.003) but not pre-term delivery (p = 0.286). Increased circulating maternal sEng levels are associated with P. falciparum infection in pregnancy and with fetal growth restriction in primigravidae with PM.

Iron homeostasis in mother and child during placental malaria infection

In malaria-endemic areas, iron deficiency and placental Plasmodium falciparum infection commonly coexist. In primigravidae and their newborns, hepcidin and other iron parameters were evaluated in groups and classified according to placental P. falciparum and maternal anemia status. Mothers had relatively high hepcidin levels considering their low iron status. In cord blood, levels of hepcidin, hemoglobin, and other iron parameters were also similar for groups. We conclude that maternal hepcidin is not significantly altered as a function of placental infection and/or anemia. Importantly, fetal hemoglobin and iron status were also unaffected, regardless of the presence of placental infection or maternal anemia.

Marked differences in CRP genotype frequencies between the Fulani and sympatric ethnic groups in Africa

Background

C-reactive protein (CRP) is an acute phase protein that can activate various immune cells and bind to certain Fcγ receptors. The latter may compete with the binding of IgG antibodies to these receptors and could thereby interfere with the antigen-specific immune response. Polymorphisms in the promoter region of the CRP gene have been strongly associated with the plasma concentration of CRP. The known lower susceptibility to malaria in the Fulani ethnic group, as compared to their sympatric neighbours in Africa, has been linked to different genetic backgrounds. The present study was performed to investigate if polymorphisms in the CRP gene could contribute to the lower susceptibility to malaria seen in the Fulani ethnic group.

Methods

The CRP -717 T>C, -286 C>T>A, and +1444 C>T polymorphisms were analysed in asymptomatic Fulani and non-Fulani individuals from Mali and Sudan using Pyrosequencing T and TaqMan r MGB probes.

Results

The rare -286 A allele, previously shown to be associated with increased CRP expression and plasma levels, was shown to be more frequent in the non-Fulani ethnic groups as compared to the sympatric Fulani ethnic group both in Mali and Sudan. The common -717 T allele was more prevalent in the non-Fulani ethnic group compared to the sympatric Fulani ethnic group, but only in Mali. The parasite prevalence was increased for the -286 A allele, but not for the -717 T allele. No differences regarding genotype frequency or parasite prevalence were seen for +1444 C>T.

Conclusion

This study indicate that CRP may play an important role in the immune responses to malaria, and that the -286 C/T/A CRP polymorphism may be a contributing factor to the lower susceptibility to malaria seen in the Fulani.

Pregnancy-associated malaria affects toll-like receptor ligand-induced cytokine responses in cord blood

BACKGROUND

Pregnancy-associated malaria is known to modify fetal immunity. Most previous studies have been cross-sectional in nature and have focused on the priming of acquired immune responses in utero. In this context, the influence of the timing and/or duration of placental infection with Plasmodium falciparum are unknown, and changes to innate immune responses have not been studied extensively.

METHODS

Pregnant women in Gabon, where P. falciparum infection is endemic, were followed up through monthly clinical and parasitological examinations from the second trimester to delivery. Cells of neonates born to mothers who had acquired P. falciparum infection <or=1 month before delivery had significantly altered interferon-gamma and tumor necrosis factor-alpha responses after stimulation with the Toll-like receptor (TLR) ligands lipopolysaccharide and polyinosine-polycytidylic acid, compared with cells of neonates born either to mothers free of P. falciparum infection or to mothers who were successfully treated for malaria during pregnancy. An independent association between parity and neonatal TLR responsiveness was also discerned in our study.

CONCLUSION

P. falciparum infection history during pregnancy appears to have a pronounced effect on neonatal innate immune responses. The observed effects may have profound implications for the outcome of newly encountered infections in early life.

Impact of maternal malaria and under-nutrition on intrauterine growth restriction: a prospective ultrasound study in Democratic Republic of Congo

Maternal malaria and under-nutrition are established risk factors for small-for-gestational-age (SGA) births; however, whether malaria is associated with intrauterine growth restriction (IUGR) is unknown. We investigated IUGR risk among 177 HIV-negative pregnant women enrolled in a longitudinal ultrasound study conducted in Democratic Republic of Congo from May 2005 to May 2006. Malaria infection, maternal anthropometrics, and ultrasound estimated fetal weight were measured monthly. All positive malaria cases were treated and intermittent presumptive therapy (IPTp) provided. Log-binomial regression models for IUGR were fitted using generalized estimating equations to account for statistical clustering of repeat IUGR measurements. Twenty-nine percent of fetuses experienced an episode of IUGR with the majority occurring in the third trimester. The risk of IUGR associated with malaria was greatest after three or more cumulative infections (RR 3·3, 95% CI 1·3–8·2) and was two- to eight-fold higher among women with evidence of under-nutrition. Receiving antimalarial treatment in the previous month (for IPTp or treatment) was significantly protective against IUGR (RR 0·5, 95% CI 0·3–0·7). The interaction observed between malaria and under-nutrition suggests that antenatal programmes in malaria endemic areas should incorporate nutritional screening and supplementation in addition to IPTp.

Fetal responses during placental malaria modify the risk of low birth weight

Inflammation during placental malaria (PM) is associated with low birth weight (LBW), especially during the first pregnancy, but the relative contribution of maternal or fetal factors that mediate this effect remains unclear and the role of gamma interferon (IFN-gamma) has been controversial. We examined the relationship of maternal and cord plasma levels of IFN-gamma, tumor necrosis factor alpha, interleukin-10, ferritin, and leptin to birth weight for Tanzanian women delivering in an area where there is a high rate of malaria transmission. The placental levels of inflammatory cytokines, including IFN-gamma, increased significantly during PM in primigravid and multigravid women but not in secundigravid women. PM also increased maternal peripheral levels of all inflammatory markers except IFN-gamma but had strikingly little effect on cord levels of these proteins. In a multivariate analysis, placental IFN-gamma was negatively associated (P = 0.01) and cord ferritin was positively associated (P < 0.0001) with birth weight in infected (PM-positive [PM+]) first-time mothers. This relationship was not observed in other mothers, consistent with the epidemiology of PM and disease. Cord leptin had a strong positive relationship with birth weight in offspring of PM-negative women (P = 0.02 to P < 0.0001) but not in offspring of PM+ women (all differences were not significant) in the three gravidity groups. The results confirmed that placental IFN-gamma is related to LBW due to PM during first pregnancies and suggest that fetal ferritin plays a protective role. Because fetal cells are a source of placental IFN-gamma and cord ferritin, the fetal response to PM may modify the risk of LBW.

Placental Plasmodium falciparum infection: causes and consequences of in utero sensitization to parasite antigens

Available evidence suggests that, in African populations, systemic blood-dwelling parasitoses of mothers are associated with enhanced susceptibility to infection of their offspring. Thus, children born to mothers with filariasis or schistosomiasis are infected earlier, and offspring of mothers with placental Plasmodium falciparum at delivery, commonly referred to as pregnancy-associated malaria or PAM, are themselves at higher risk of developing parasitaemia during infancy. Since foetal/neonatal antigen-presenting cells (APC) are either immature or provide insufficient costimulatory signals to T cells, thus favouring tolerance induction, it is commonly assumed that soluble parasite components [protein antigens], transferred transplacentally and inducing foetal immune tolerance, are largely, if not exclusively, responsible for these outcomes. Plasmodial asexual blood stage antigen-specific T cells are detectable in as many as two-thirds of all cord blood samples in malaria-endemic countries of sub-Saharan Africa, indicating that in utero sensitization may be a common phenomenon during pregnancy in these populations. Parasite antigen-specific T cell responses of neonates born to helminth-infected mothers display a highly skewed Th2-type cytokine pattern, with a prominent role for the regulatory cytokine interleukin (IL)-10. Similarly, the cord blood immune response of those born to mothers identified with on-going PAM is characterised by inducible parasite antigen-specific IL-10-producing regulatory T cells that can inhibit both APC HLA expression and Th1-type T cell responses. In contrast, plasmodial antigen-specific Th1-type responses, characterised by IFN-gamma production, predominate in cord blood of those born to mothers successfully treated for Pf malaria during gestation, suggesting that the duration and/or the nature of antigen exposure in utero governs the outcome with respect to neonatal immune responses. Aspects of APC function in the context of these differentially modulated responses, whether and how the latter translate into altered susceptibility to Pf infection during infancy, as well as the possible implications for vaccination in early life, are aspects that are discussed in this review.