Dosage of Sulfadoxine-Pyrimethamine and Risk of Low Birth Weight in a Cohort of Zambian Pregnant Women in a Low Malaria Prevalence Region

Intermittent preventive treatment in pregnancy with sulfadoxine–pyrimethamine and parasite resistance: cross-sectional surveys from antenatal care visit and delivery in rural Ghana

Background

Despite decades of prevention efforts, the burden of malaria in pregnancy (MiP) remains a great public health concern. Sulfadoxine-pyrimethamine (SP), used as intermittent preventive treatment in pregnancy (IPTp-SP) is an important component of the malaria prevention strategy implemented in Africa. However, IPTp-SP is under constant threat from parasite resistance, thus requires regular evaluation to inform decision-making bodies.

Methods

In two malaria endemic communities in the Volta region (Adidome and Battor), a cross-sectional hospital-based study was conducted in pregnant women recruited at their first antenatal care (ANC) visit and at delivery. Basic clinical and demographic information were documented and their antenatal records were reviewed to confirm IPTp-SP adherence. Peripheral and placental blood were assayed for the presence of Plasmodium falciparum parasites by quantitative polymerase chain reaction (qPCR). One hundred and twenty (120) positive samples were genotyped for mutations associated with SP resistance.

Results

At first ANC visit, P. falciparum prevalence was 28.8% in Adidome and 18.2% in Battor. At delivery, this decreased to 14.2% and 8.2%, respectively. At delivery, 66.2% of the women had taken at least the recommended 3 or more doses of IPTp-SP and there was no difference between the two communities. Taking at least 3 IPTp-SP doses was associated with an average birth weight increase of more than 360 g at both study sites compared to women who did not take treatment (p = 0.003). The Pfdhfr/Pfdhps quintuple mutant IRNI-A/FGKAA was the most prevalent (46.7%) haplotype found and the nonsynonymous Pfdhps mutation at codon A581G was higher at delivery among post-SP treatment isolates (40.6%) compared to those of first ANC (10.22%). There was also an increase in the A581G mutation in isolates from women who took 3 or more IPTp-SP.

Conclusions

This study confirms a positive impact following the implementation of the new IPTp-SP policy in Ghana in increasing the birth weight of newborns. However, the selection pressure exerted by the recommended 3 or more doses of IPTp-SP results in the emergence of parasites carrying the non-synonymous mutation on codon A581G. This constant selective pressure calls into question the time remaining for the clinical utility of IPTp-SP treatment during pregnancy in Africa.

Prevalence and Factors Associated with Low Birth Weight and Preterm Delivery in the Ho Municipality of Ghana

Background. Low birth weight and preterm delivery are birth outcomes that can predict newborns’ survival, development, and long-term health outcomes. This study assessed the prevalence and factors associated with low birth weight and preterm delivery in the Ho Municipality of Ghana. Methods. This retrospective, cross-sectional study analysed data from 680 birth records between October and December 2018. Univariate and multivariate logistic regression models predicted low birth weight and preterm delivery factors. Results. The prevalence of low birth weight and preterm delivery was 12.9% and 14.1%, respectively. Increasing maternal age (AOR: 0.52; 95% CI: 0.28–0.98), multiparity (AOR: 0.54; 95% CI: 0.30–0.94) and increasing doses of sulphadoxine-pyrimethamine (AOR: 0.43; 95% CI: 0.22–0.84) significantly reduced the odds of low birth weight. However, caesarean section (AOR: 1.94; 95% CI: 0.1.16–3.27) and hypertension (AOR: 2.06; 95% CI: 1.27–03.33) significantly increased the likelihood of low birth weight. An increasing number of antenatal care visits (AOR: 0.38; 95% CI: 0.18–0.80) and doses of sulphadoxine-pyrimethamine (AOR: 0.43; 95% CI: 0.19–0.97) were significantly associated with decreased odds of preterm delivery, while caesarean section increased the odds of preterm delivery by two folds (AOR: 2.14; 95% CI: 1.15–3.99). Conclusion. This study shows that maternal age, parity, number of antenatal care visits, hypertension, SP/IPTp, and caesarean section were independently associated with low birth weight and preterm delivery. Education and interventions should be prioritised as vitally important on these factors to reduce the risk and complications associated with these birth outcomes.

Intermittent screening and treatment with artemisinin-combination therapy versus intermittent preventive treatment with sulphadoxine-pyrimethamine for malaria in pregnancy: a systematic review and individual participant data meta-analysis of randomised clinical trials

BACKGROUND

In sub-Saharan Africa, the efficacy of intermittent preventive therapy in pregnancy with sulphadoxine-pyrimethamine (IPTp-SP) for malaria in pregnancy is threatened by parasite resistance. We conducted an individual-participant data (IPD) meta-analysis to assess the efficacy of intermittent screening with malaria rapid diagnostic tests (RDTs) and treatment of RDT-positive women with artemisinin-based combination therapy (ISTp-ACT) compared to IPTp-SP, and understand the importance of subpatent infections.

METHODS

We searched MEDLINE and the Malaria-in-Pregnancy Library on May 6, 2021 for trials comparing ISTp-ACT and IPTp-SP. Generalised linear regression was used to compare adverse pregnancy outcomes (composite of small-for-gestational-age, low birthweight (LBW), or preterm delivery) and peripheral or placental Plasmodium falciparum at delivery. The effects of subpatent (PCR-positive, RDT/microscopy-negative) infections were assessed in both arms pooled using multi-variable fixed-effect models adjusting for the number of patent infections. PROSPERO registration: CRD42016043789.

FINDINGS

Five trials conducted between 2007 and 2014 contributed (10,821 pregnancies), two from high SP-resistance areas where dhfr/dhps quintuple mutant parasites are saturated, but sextuple mutants are still rare (Kenya and Malawi), and three from low-resistance areas (West-Africa). Four trials contributed IPD data (N=10,362). At delivery, the prevalence of any malaria infection (relative risk [RR]=1.08, 95% CI 1.00-1.16, I2=67.0 %) and patent infection (RR=1.02, 0.61-1.16, I2=0.0%) were similar. Subpatent infections were more common in ISTp recipients (RR=1.31, 1.05-1.62, I2=0.0%). There was no difference in adverse pregnancy outcome (RR=1.00, 0.96-1.05; studies=4, N=9,191, I2=54.5%). Subpatent infections were associated with LBW (adjusted RR=1.13, 1.07-1.19), lower mean birthweight (adjusted mean difference=32g, 15-49), and preterm delivery (aRR=1.35, 1.15-1.57).

INTERPRETATION

ISTp-ACT was not superior to IPTp-SP and may result in more subpatent infections than the existing IPTp-SP policy. Subpatent infections were associated with increased LBW and preterm delivery. More sensitive diagnostic tests are needed to detect and treat low-grade infections.

FUNDING

Centers for Disease Control and Prevention and Worldwide Antimalarial Resistance Network.

Overall, anti-malarial, and non-malarial effect of intermittent preventive treatment during pregnancy with sulfadoxine-pyrimethamine on birthweight: a mediation analysis

BACKGROUND

Trials of intermittent preventive treatment (IPTp) of malaria in pregnant women that compared dihydroartemisinin-piperaquine with the standard of care, sulfadoxine-pyrimethamine, showed dihydroartemisinin-piperaquine was superior at preventing malaria infection, but not at improving birthweight. We aimed to assess whether sulfadoxine-pyrimethamine shows greater non-malarial benefits for birth outcomes than does dihydroartemisinin-piperaquine, and whether dihydroartemisinin-piperaquine shows greater antimalarial benefits for birth outcomes than does sulfadoxine-pyrimethamine.

METHODS

We defined treatment as random assignment to sulfadoxine-pyrimethamine or dihydroartemisinin-piperaquine before pooling individual participant-level data from 1617 HIV-uninfected pregnant women in Kenya (one trial; n=806) and Uganda (two trials; n=811). We quantified the relative effect of treatment on birthweight (primary outcome) attributed to preventing placental malaria infection (mediator). We estimated antimalarial (indirect) and non-malarial (direct) effects of IPTp on birth outcomes using causal mediation analyses, accounting for confounders. We used two-stage individual participant data meta-analyses to calculate pooled-effect sizes.

FINDINGS

Overall, birthweight was higher among neonates of women randomly assigned to sulfadoxine-pyrimethamine compared with women assigned to dihydroartemisinin-piperaquine (mean difference 69 g, 95% CI 26 to 112), despite placental malaria infection being lower in the dihydroartemisinin-piperaquine group (relative risk [RR] 0·64, 95% CI 0·39 to 1·04). Mediation analyses showed sulfadoxine-pyrimethamine conferred a greater non-malarial effect than did dihydroartemisinin-piperaquine (mean difference 87 g, 95% CI 43 to 131), whereas dihydroartemisinin-piperaquine conferred a slightly larger antimalarial effect than did sulfadoxine-pyrimethamine (8 g, -9 to 26), although more frequent dosing increased the antimalarial effect (31 g, 3 to 60).

INTERPRETATION

IPTp with sulfadoxine-pyrimethamine appears to have potent non-malarial effects on birthweight. Further research is needed to evaluate monthly dihydroartemisinin-piperaquine with sulfadoxine-pyrimethamine (or another compound with non-malarial effects) to achieve greater protection against malarial and non-malarial causes of low birthweight.

FUNDING

Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bill & Melinda Gates Foundation, and Worldwide Antimalarial Resistance Network.

Coverage and effectiveness of intermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) on adverse pregnancy outcomes in the Mount Cameroon area, South West Cameroon

Background

Growing concerns about the waning efficacy of IPTp-SP warrants continuous monitoring and evaluation. This study determined coverage of IPTp-SP and compared the effectiveness of the 3-dose to 2-dose regimen on placental malaria (PM) infection and low birth weight (LBW) in the Mount Cameroon area.

Methods

Consenting pregnant women were enrolled consecutively through a cross-sectional survey at delivery at four antenatal clinics, two each from semi-rural and semi-urban settings from November 2016 to December 2017. Reported IPTp-SP use, demographic and antenatal clinic (ANC) data of the mothers and neonate birth weights were documented. Maternal haemoglobin concentration was measured using a haemoglobinometer and PM infection diagnosed by placental blood microscopy. Logistic regression analysis was used to model study outcomes.

Results

Among the 465 parturient women enrolled, 47.0% (203), 34.7% (150), 18.3% (79) and 7.1% (33) reported uptake of ≥ 3, 2.1 dose(s) and no SP, respectively. Uptake of ≥ 3 doses varied significantly (p < 0.001) according to type of medical facility, timing of ANC initiation and number of ANC visits. The prevalence of PM was 18.5% where uptake of ≥ 3 SP doses (AOR = 2.36: 95% CI  1.41–4.87), primiparity (AOR = 2.13: 95% CI  1.19–3.81), semi-rural setting (AOR = 1.85: 95% CI  1.12–3.04) increased odds of infection. Also, three or more dosing was associated (p < 0.001) with increased PM density notably among women from semi-urban areas. Compared with third trimester, ANC initiation in the second trimester (AOR: 0.39: 95% CI  0.20–0.74) lower odds of infection. The prevalence of LBW infants was 7.3% and were generally those of anaemic (AOR: 4.6: 95% CI  1.03–20.57) and semi-rural (AOR: 5.29: 95% CI  1.73–16.15) women. Although ≥ 3 (AOR: 0.31: 95% CI  0.11–0.87) and 2 (AOR: 0.32: 95% CI  0.11–0.93) doses of SP was associated with lower odds of LBW, ≥ 3 doses were not associated with additional increase in birth weight nor maternal haemoglobin levels when compared with 2 doses.

Conclusion

In the Mount Cameroon area, reported uptake of IPTp with ≥ 3 SP doses did not provide observable prophylactic benefits. SP resistance efficacy studies are necessary.

The efficacy of intermittent preventive therapy in the eradication of peripheral and placental parasitemia in a malaria-endemic environment, as seen in a tertiary hospital in Abuja, Nigeria

OBJECTIVE

To determine whether intermittent preventive therapy in pregnancy (IPTp) eradicates peripheral and placental malaria and improves birth weight.

METHOD

A cross-sectional study was conducted of 426 pregnant mothers on IPTp with sulphadoxine-pyrimethamine against malaria who presented in labor, at National Hospital Abuja, Nigeria between January and June 2017. The hospital is within the malaria-endemic zone of West Africa. Consenting pregnant women with uncomplicated singleton term pregnancy who had antenatal care in the hospital and lived in the study area for at least 6 months were consecutively recruited. Peripheral and placental blood were collected and examined for malaria parasite by microscopy. Babies were weighed at birth.

RESULTS

The prevalence of peripheral malaria parasitemia and placental parasitization were 12.9% (95% confidence interval [CI] 10.0-16.6) and 9.4% (95% CI 7.0-12.7), respectively. Parasite density in both peripheral parasitemia and placental parasitization was low among the women that took IPTp, decreasing with increasing doses, with no parasitemia or parasitization in women that took up to three doses. Birth weight was lower in babies of mothers with plasmodium infestation than in those without infestation (P<0.001, P=0.024).

CONCLUSION

IPTp reduces both peripheral parasitemia and placental parasitization, with the capacity to eliminate or prevent them. IPTp also reduces low birth weight.

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.

Sulphadoxine-pyrimethamine plus azithromycin may improve birth outcomes through impacts on inflammation and placental angiogenesis independent of malarial infection

Intermittent preventive treatment with sulphadoxine-pyrimethamine (SP) and SP plus azithromycin (SPAZ) reduces low birthweight (<2,500 g) in women without malarial and reproductive tract infections. This study investigates the impact of SPAZ on associations between plasma biomarkers of inflammation and angiogenesis and adverse pregnancy outcomes in 2,012 Papua New Guinean women. Concentrations of C-reactive protein (CRP), α-1-acid glycoprotein (AGP), soluble endoglin (sEng), soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) were measured at enrolment and delivery in a trial comparing SPAZ to SP plus chloroquine (SPCQ). At antenatal enrolment higher CRP (adjusted odds ratio 1.52; 95% confidence interval [CI] 1.03–2.25), sEng (4.35; 1.77, 10.7) and sFlt1 (2.21; 1.09, 4.48) were associated with preterm birth, and higher sEng with low birthweight (1.39; 1.11,3.37), in SPCQ recipients only. Increased enrolment sFlt1:PlGF ratios associated with LBW in all women (1.46; 1.11, 1.90). At delivery, higher AGP levels were strongly associated with low birthweight, preterm birth and small-for-gestational age babies in the SPCQ arm only. Restricting analyses to women without malaria infection did not materially alter these relationships. Women receiving SPAZ had lower delivery AGP and CRP levels (p < 0.001). SPAZ may protect against adverse pregnancy outcomes by reducing inflammation and preventing its deleterious consequences, including dysregulation of placental angiogenesis, in women with and without malarial infection.

Timing of Initiation of Antiretroviral Therapy and Risk of Preterm Birth in Studies of HIV-infected Pregnant Women: The Role of Selection Bias

BACKGROUND

Women who initiate antiretroviral therapy (ART) during pregnancy are reported to have lower risk of preterm birth compared with those who enter pregnancy care already receiving ART. We hypothesize this association can be largely attributed to selection bias.

METHODS

We simulated a cohort of 1000 preconceptional, HIV-infected women, where half were randomly allocated to receive immediate ART and half to delay ART until their presentation for pregnancy care. Gestational age at delivery was drawn from population data unrelated to randomization group (i.e., the true effect of delayed ART was null). Outcomes of interest were preterm birth (<37 weeks), very preterm birth (<32 weeks), and extreme preterm birth (<28 weeks). We analyzed outcomes in 2 ways: (1) a prospectively enrolled clinical trial, where all women were considered (the intent-to-treat (ITT) analysis); and (2) an observational study, where women who deliver before initiating ART were excluded (the naïve analysis). We explored the impact of later ART initiation and gestational age measurement error on our findings.

RESULTS

Preconception ART initiation was not associated with preterm birth in ITT analyses. Risk ratios (RRs) for the effect of preconception ART initiation were RR = 1.10 (preterm), RR = 1.41 (very preterm), and RR = 5.01 (extreme preterm) in naïve analyses. Selection bias increased in the naïve analysis with advancing gestational age at ART initiation and with introduction of gestational age measurement error.

CONCLUSIONS

Analyses of preterm birth that compare a preconception exposure to one that occurs in pregnancy are at risk of selection bias. See video abstract at, http://links.lww.com/EDE/B313.

Prevention of malaria in pregnancy

Malaria remains one of the most preventable causes of adverse birth outcomes. Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine is used to prevent malaria, but resistance to this drug combination has decreased its efficacy and new alternatives are needed. In Africa, a meta-analysis showed three-course or monthly IPTp with sulfadoxine-pyrimethamine to be safe and more effective than the original two-course sulfadoxine-pyrimethamine strategy, prompting WHO to update its policy in 2012. Although resistance to sulfadoxine-pyrimethamine reduces the parasitological efficacy of IPTp, this drug combination remains associated with reduced incidence of low birthweight in areas where prevalence of parasites with quintuple Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthetase (Pfdhps) mutations is greater than 90%. Nevertheless, its effectiveness is compromised in women infected with sextuple mutant parasites. Six trials of IPTp showed that neither amodiaquine, mefloquine, nor chloroquine-azithromycin are suitable replacements for sulfadoxine-pyrimethamine because of poor tolerability. Furthermore, four trials showed that intermittent screening and treatment with the current generation of malaria rapid diagnostic tests was not a suitable alternative strategy to IPTp with sulfadoxine-pyrimethamine, even in areas with high prevalence of quintuple mutations. Two trials showed that IPTp with dihydroartemisinin-piperaquine was well tolerated, effective, and acceptable for IPTp, with monthly regimens being the most effective. Coverage of IPTp and insecticide-treated nets continues to lag behind targets. The key barriers to uptake are well documented, and many are open to intervention. Outside of Africa, a single trial suggests a potential role for integrated approaches that combine sulfadoxine-pyrimethamine with azithromycin for IPTp in areas of Papua New Guinea where malaria transmission is high. Modelling analysis suggests the importance of the prevention of malaria early in pregnancy and the need to protect pregnant women declines more slowly than the rate at which transmission declines. Improved funding has led to an increase in the number of prevention trials in the past decade, showing the value of more sustained protection with monthly IPTp regimens. There is a need for confirmatory trials of the safety, efficacy, and feasibility of IPTp with dihydroartemisinin-piperaquine, for studies of intermittent screening and treatment with more sensitive rapid diagnostic tests, for studies of integrated strategies for malaria and other co-infections, and for studies of prevention strategies for malaria in pregnant women who are HIV-positive and living outside of Africa. Additional research is required on how to improve uptake of WHO's updated policy on IPTp with sulfadoxine-pyrimethamine and insecticide-treated nets.