Factors associated with ultrasound-aided detection of suboptimal fetal growth in a malaria-endemic area in Papua New Guinea

Abstract

BackgroundFetal growth restriction (FGR) is associated with increased infant mortality rates and ill-health in adulthood. Evaluation of fetal growth requires ultrasound. As a result, ultrasound-assisted evaluations of causes of FGR in malaria-endemic developing countries are rare. We aimed to determine factors associated with indicators of abnormal fetal growth in rural lowland Papua New Guinea (PNG).MethodsWeights and growth of 671 ultrasound-dated singleton pregnancies (<25 gestational weeks) were prospectively monitored using estimated fetal weights and birthweights. Maternal nutritional status and haemoglobin levels were assessed at enrolment, and participants were screened for malaria on several occasions. FGR was suspected upon detection of an estimated fetal weight or birthweight <10th centile (small-for-gestational age) and/or low fetal weight gain, defined as a change in weight z-score in the first quartile. Factors associated with fetal weight and fetal weight gain were additionally assessed by evaluating differences in weight z-scores and change in weight z-scores. Log-binomial and linear mixed effect models were used to determine factors associated with indicators of FGR.ResultsSGA and low weight gain were detected in 48.3% and 37.0% of pregnancies, respectively. Of participants, 13.8%, 21.2%, and 22.8% had a low mid-upper arm circumference (MUAC, <22 cms), short stature (<150 cms) and anaemia (haemoglobin <90 g/L) at first antenatal visit. 24.0% (161/671) of women had at least one malaria infection detected in peripheral blood. A low MUAC (adjusted risk ratio [aRR] 1.51, 95% CI 1.29, 1.76, P < 0.001), short stature (aRR 1.27, 95% CI 1.04, 1.55, P = 0.009), and anaemia (aRR 1.27, 95% CI 1.06, 1.51, P = 0.009) were associated with SGA, and a low body mass index was associated with low fetal weight gain (aRR 2.10, 95% CI 1.62, 2.71, P < 0.001). Additionally, recent receipt of intermittent preventive treatment in pregnancy was associated with increased weight z-scores, and anaemia with reduced change in weight z-scores. Malaria infection was associated with SGA on crude but not adjusted analyses (aRR 1.13, 95% CI 0.95, 1.34, P = 0.172).ConclusionMacronutrient undernutrition and anaemia increased the risk of FGR. Antenatal nutritional interventions and malaria prevention could improve fetal growth in PNG.

Effects of Plasmodium falciparum infection on umbilical artery resistance and intrafetal blood flow distribution: a Doppler ultrasound study from Papua New Guinea

“…Clearance of infections at study enrolment may have limited their chronic effects on placental development and function [23]. Consistent with this, there were no differences in UARI or MCAPI by treatment arm (single treatment with SP and chloroquine or three doses of SP and AZ (see Additional files 2, 4, 5) or SGA [25]. Nevertheless, in the trial analysis active placental infection was reduced amongst women receiving SPAZ, and placental infection was a risk for LBW [23].…”

“…Interestingly, malaria infection was not associated with measuring SGA in pregnancy or at birth in this cohort [25]. Most malaria infections were detected at enrolment, when all women received presumptive anti-malarial treatment.…”

“…The study cohort consisted of women who participated in both a randomized controlled trial investigating the impact of intermittent preventive treatment (IPTp) with azithromycin (AZ) plus sulfadoxine–pyrimethamine (SP) on birth weight [23] and a nested ultrasound study evaluating factors associated with reduced fetal size and fetal weight gain in PNG [25]. The studies were conducted between November 2009 and February 2013 at nine health centres in Madang and Sumkar districts situated on the north coast of PNG.…”

“…The study area is characterized by perennial transmission of P. falciparum and P. vivax , and infant and adult macronutrient undernutrition is common; malarial infection, anaemia and undernutrition are important risk factors for FGR and LBW [21, 25, 27]. Up to 20% of newborns are LBW, which is an important contributor to PNG’s high infant mortality rate of 47.4 per 1000 live births in 2013 [28].…”

“…Here, macronutrient undernutrition and anaemia were observed to be key risk factors for measuring SGA and for poor fetal weight gain [25]. In the same study, malaria parasitaemia was associated with SGA in univariable but not in adjusted analyses.…”