Holger Unger

Holger Unger
Royal Darwin Hospital · Department of Obstetrics and Gynaecology

FRANZCOG MRCOG PhD DTMH

About

77
Publications
22,430
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894
Citations
Citations since 2016
49 Research Items
760 Citations
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2016201720182019202020212022020406080100120140
2016201720182019202020212022020406080100120140
2016201720182019202020212022020406080100120140

Publications

Publications (77)
Article
Purpose of review: Malaria in pregnancy continues to exert a toll on pregnant women and their offspring. Recent findings: The burden of Plasmodium falciparum infection is especially large in Africa, and new data show lasting effects of maternal infection on the infant's neurocognitive development. Elsewhere, P. vivax infection causes relapsing i...
Article
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Background: Iron deficiency (ID) is common in malaria-endemic settings. Intermittent preventative treatment of malaria in pregnancy (IPTp) and iron supplementation are core components of antenatal care in endemic regions to prevent adverse pregnancy outcomes. ID has been associated with reduced risk of malaria infection, and correspondingly, iron...
Article
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Background: Preventing and/or reducing acute lower respiratory infections (ALRIs) in young children will lead to substantial short and long-term clinical benefits. While immunisation with pneumococcal conjugate vaccines (PCV) reduces paediatric ALRIs, its efficacy for reducing infant ALRIs following maternal immunisation has not been studied. Compa...
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Background Iron deficiency (ID) has been associated with adverse pregnancy outcomes, maternal anaemia, and altered susceptibility to infection. In Papua New Guinea (PNG), monthly treatment with sulphadoxine-pyrimethamine plus azithromycin (SPAZ) prevented low birthweight (LBW; <2500 g) through a combination of anti-malarial and non-malarial effects...
Article
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Background Girls and women need effective, safe, and affordable menstrual products. Single-use menstrual pads and tampons are regularly provided by agencies among resource-poor populations. Reusable menstrual pads (RMPs: fabric layers sewn together by an enterprise for manufacture of menstrual products) may be an effective alternative.Methods For t...
Article
The unacceptable discrepancies in health outcomes between First Nations and non‐Indigenous Australians begin at birth. Preterm birth (birth before 37 completed weeks of gestation) is a major contributor to adverse short‐ and long‐term health outcomes and mortality. Australian First Nations infants are more commonly born too early. No tangible reduc...
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Background Plasmodium falciparum causes placental malaria, which results in adverse outcomes for mother and child. P. falciparum -infected erythrocytes that express the parasite protein VAR2CSA on their surface can bind to placental chondroitin sulfate A. It has been hypothesized that naturally acquired antibodies towards VAR2CSA protect against pl...
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Immune effector responses against Plasmodium falciparum include antibody-mediated activation of innate immune cells, which can induce Fc effector functions, including antibody-dependent cellular cytotoxicity, and the secretion of cytokines and chemokines. These effector functions are regulated by the composition of immunoglobulin G (IgG) Fc N-linke...
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Plasmodium vivax malaria is a neglected disease, particularly during pregnancy. Severe vivax malaria is associated with inflammatory responses but in pregnancy immune alterations make it uncertain as to what cytokine signatures predominate, and how the type and quantity of blood immune mediators influence delivery outcomes. We measured the plasma c...
Article
The immune status of women changes during and after pregnancy, differs between blood compartments at delivery and is affected by environmental factors particularly in tropical areas endemic for multiple infections. We quantified the plasma concentration of a set of thirty-one TH1, TH2, TH17 and regulatory cytokines, pro-inflammatory and anti-inflam...
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Background: Infection during pregnancy with Plasmodium falciparum is associated with maternal anaemia and adverse birth outcomes including low birth weight (LBW). Studies using polymerase chain reaction (PCR) techniques indicate that at least half of all infections in maternal venous blood are missed by light microscopy or rapid diagnostic tests....
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Background: Girls and women need effective, safe, and affordable menstrual products. Single-use products are regularly selected by agencies for resource-poor settings; the menstrual cup is a less known alternative. We reviewed international studies on menstrual cup leakage, acceptability, and safety and explored menstrual cup availability to infor...
Article
The Royal College of Obstetricians and Gynaecologists (RCOG) has a long history of advocacy for women’s health, nationally and internationally. There is a demand and interest in global women’s health among a sample of junior doctors training in obstetrics and gynaecology in the UK. There is ongoing debate regarding whether this desire should be nur...
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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...
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Background Determining gestational age in resource-poor settings is challenging because of limited availability of ultrasound technology and late first presentation to antenatal clinic. Last menstrual period (LMP), symphysio-pubis fundal height (SFH) and Ballard Score (BS) at delivery are therefore often used. We assessed the accuracy of LMP, SFH,...
Article
Venous thromboembolism remains a common cause of direct maternal deaths in high-income settings such as the United Kingdom. Pregnancy alone increases the risk of deep vein thrombosis and pulmonary embolus at least five-fold, and many women develop or have additional risk factors for venous thrombosis during pregnancy and the puerperium, the latter...
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Background: In many low- to middle-income countries (LMIC) assisted vaginal birth rates have fallen, while caesarean section (CS) rates have increased, with potentially deleterious consequences for maternal and perinatal mortality. Aims: To review birth mode and perinatal mortality in a large LMIC hospital with strict labour management protocols...
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The World Health Organization recommends HIV testing is included in routine screening tests for all pregnant women in order to prevent mother-to-child-transmission of HIV and reduce maternal morbidity and mortality.To assess the proportion of women approached and tested for HIV at delivery and factors associated with non-testing at the maternity wa...
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There is a lack of published enzyme linked immunosorbent assay (ELISA) protocols which use commercially available reagents for the measurement of ferritin in human plasma for research purposes. ELISA kits are often expensive and do not always provide detailed information about reagents included. A commercially available antibody pair was used to de...
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Background: Stillbirth rates remain high in many low-income settings, with fresh (intrapartum) stillbirths accounting for a large part due to limited obstetrical care. We aimed to determine the stillbirth rate and identify potentially modifiable factors associated with stillbirth in urban Guinea-Bissau. Methods: The study was carried out by the...
Article
Objectives: To estimate the impact of hypothetical antimalarial and nutritional interventions (which reduce the prevalence of low midupper arm circumference [MUAC]) on the incidence of low birth weight (LBW). Methods: We analyzed data from 14 633 pregnancies from 13 studies conducted across Africa and the Western Pacific from 1996 to 2015. We ca...
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Background Plasmodium falciparum in pregnancy results in substantial poor health outcomes for both mother and child, particularly in young, primigravid mothers who are at greatest risk of placental malaria (PM) infection. Complications of PM include maternal anaemia, low birth weight and preterm delivery, which contribute to maternal and infant mor...
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Background The human immunodeficiency virus (HIV) continues to be a major cause of maternal and infant mortality and morbidity in sub-Saharan Africa. Prevention of mother-to-child transmission of HIV (PMTCT) strategies have proven effective in decreasing the number of children infected in utero, intrapartum and during the breastfeeding period. This...
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Background Four studies previously indicated that the effect of malaria infection during pregnancy on the risk of low birthweight (LBW; <2,500 g) may depend upon maternal nutritional status. We investigated this dependence further using a large, diverse study population. Methods and findings We evaluated the interaction between maternal malaria in...
Data
Assessment of risk of bias for the 13 studies included in the individual participant data meta-analysis. (DOCX)
Data
Prevalence of low mid-upper arm circumference (MUAC < 23cm) compared to prevalence of low body mass index (BMI < 18.5 kg/m2) among the 13 studies in the Maternal Malaria and Malnutrition (M3) initiative. (DOCX)
Data
Meta-regression results for the effects of malnutrition at enrollment, (a) low mid-upper arm circumference (MUAC < 23 cm) and (b) low BMI (BMI < 18.5 kg/m2), on risk of low birthweight (LBW) and mean birthweight (BW) by time period, study type, location, and malaria prevalence. Median malaria prevalence across studies was 17% at enrollment and 15%...
Data
Descriptions of the scales used to measure birthweight, how gestational age was assessed, and the median gestational age for each of the 13 studies in the Maternal Malaria and Malnutrition (M3) initiative. (DOCX)
Data
Meta-regression results for the effects of malaria infection at enrollment and delivery on risk of low birthweight (LBW) and mean birthweight (BW) by time period, study type, location, and malaria prevalence. Median malaria prevalence across studies was 17% at enrollment and 15% at delivery. RCT = randomized control trial. (DOCX)
Data
Meta-regression results for the multiplicative and additive interaction effects for malaria at enrollment or delivery and low mid-upper arm circumference (MUAC < 23 cm) on risk of low birthweight (LBW) and mean birthweight (BW) by time period, study type, location, and malaria prevalence. Median malaria prevalence across studies was 17% at enrollme...
Data
Characteristics of the 13 individual studies included in the Maternal Malnutrition and Malaria (M3) initiative. (DOCX)
Data
Characteristics of studies not included in the Maternal Malaria and Malnutrition (M3) initiative cohort. (DOCX)
Data
The independent and joint effects of malaria infection at enrollment, malaria infection at delivery, low mid-upper arm circumference (MUAC), and low body mass index (BMI) on the risk of small for gestational age (SGA) and risk of preterm birth among a subset of 9 studies from the Maternal Malaria and Malnutrition (M3) initiative. (DOCX)
Data
Select sensitivity analysis results for the multiplicative interaction effects for malaria and malnutrition on risk of adverse birth outcomes among the 13 studies in the Maternal Malaria and Malnutrition (M3) initiative. Sensitivity analyses varied the definitions of malaria, malnutrition, the outcome of interest, and the approach taken in pooling...
Data
Individual participant data checklist. (DOCX)
Data
Protocol for the individual participant data project. Written 17 November 2014. (DOCX)
Data
Prevalence of malaria infection at delivery among the 13 studies in the Maternal Malaria and Malnutrition (M3) initiative. (DOCX)
Poster
Full-text available
Many women grieve for a pregnancy terminated for anomaly equivalent to stillbirth.1 As a proxy for how many women made a close emotional connection, we investigated whether the terminated fetus was named and whether this was dependent on maternal history, gestation or type of termination. In our hospital, 128 pregnancies over six years were termina...
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Background Doppler velocimetry studies of umbilical artery (UA) and middle cerebral artery (MCA) flow help to determine the presence and severity of fetal growth restriction. Increased UA resistance and reduced MCA pulsatility may indicate increased placental resistance and intrafetal blood flow redistribution. Malaria causes low birth weight and f...
Article
Introduction: Over 100 million women and their babies are at risk of malaria in pregnancy each year. Malaria prevention in pregnancy relies on long-lasting insecticidal nets (LLINs), and, in Africa, intermittent preventive treatment in pregnancy (IPTp). Increasing resistance of malaria parasites to sulfadoxine-pyrimethamine, the only drug endorsed...
Article
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Purpose The Maternal Malaria and Malnutrition (M3) initiative has pooled together 13 studies with the hope of improving understanding of malaria–nutrition interactions during pregnancy and to foster collaboration between nutritionists and malariologists. Participants Data were pooled on 14 635 singleton, live birth pregnancies from women who had p...
Article
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Background: In low-resource settings, malaria and macronutrient undernutrition are major health problems in pregnancy, contributing significantly to adverse pregnancy outcomes such as preterm birth and fetal growth restriction. Affected pregnancies may result in stillbirth and neonatal death, and surviving children are at risk of poor growth and i...
Article
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Background: The diagnosis of malaria during pregnancy is complicated by placental sequestration, asymptomatic infection, and low-density peripheral parasitaemia. Where intermittent preventive treatment (IPT) with sulfadoxine-pyrimethamine is threatened by drug resistance, or is inappropriate due to low transmission, intermittent screening and trea...
Article
In Papua New Guinea, intermittent preventive treatment with sulphadoxine-pyrimethamine and azithromycin (SPAZ-IPTp) increased birthweight despite limited impact on malaria and sexually transmitted infections. To explore possible nutrition-related mechanisms, we evaluated associations between gestational weight gain (GWG), enrolment body mass index...
Article
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Chewing areca nut (AN), also known as betel nut, is common in Asia and the South Pacific and the habit has been linked to a number of serious health problems including oral cancer. Use of AN in pregnancy has been associated with a reduction in mean birthweight in some studies, but this association and the relationship between AN chewing and other a...
Article
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Background: Passively acquired respiratory syncytial virus (RSV) neutralizing antibody protects against RSV-associated lower respiratory infections, but placental malaria (PM) and maternal hypergammaglobulinemia might interfere with transplacental immunoglobulin transport. Methods: We measured RSV plaque-reduction neutralization (PRN) antibody i...
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Regular anti-malarial therapy in pregnancy, a pillar of malaria control, may affect malaria immunity, with therapeutic implications in regions of reducing transmission. Plasma antibodies to leading vaccine candidate merozoite antigens and opsonizing antibodies to endothelial-binding and placental-binding infected erythrocytes were quantified in pre...
Article
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BACKGROUND: Knowledge of accurate gestational age is required for comprehensive pregnancy care and is an essential component of research evaluating causes of preterm birth. In industrialised countries gestational age is determined with the help of fetal biometry in early pregnancy. Lack of ultrasound and late presentation to antenatal clinic limits...
Article
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Fetal 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 gro...
Article
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Sulphadoxine-pyrimethamine (SP) plus azithromycin (AZ) has the potential for intermittent preventive treatment of malaria in pregnancy (IPTp), but its use could increase circulation of antibiotic-resistant bacteria associated with severe paediatric infections. We evaluated the effect of monthly SPAZ-IPTp compared to a single course of SP plus chlor...
Article
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Background Intermittent preventive treatment in pregnancy has not been evaluated outside of Africa. Low birthweight (LBW, <2,500 g) is common in Papua New Guinea (PNG) and contributing factors include malaria and reproductive tract infections.Methods From November 2009 to February 2013, we conducted a parallel group, randomised controlled trial in...
Article
Full-text available
Knowledge of accurate gestational age is required for comprehensive pregnancy care and is an essential component of research evaluating causes of preterm birth. In industrialised countries gestational age is determined with the help of fetal biometry in early pregnancy. Lack of ultrasound and late presentation to antenatal clinic limits this practi...
Article
Full-text available
We conducted a prospective longitudinal study of fetal size in rural Papua New Guinea (PNG) involving 439 ultrasound-dated singleton pregnancies with no obvious risk factors for growth restriction. Sonographically estimated fetal weights (EFWs; N = 788) and birth weights (N = 376) were included in a second-order polynomial regression model (optimal...
Article
Objective To determine the prevalence of, and risk factors associated with, Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis infection in pregnant women in Madang, Papua New Guinea (PNG). Methods A cross-sectional survey was conducted among 400 pregnant women presenting to antenatal clinics. Sociodemographic and behavioural da...
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Background: As malaria control is intensified, pregnant women may be less exposed to malaria, thus affecting the acquisition of protective antibody. Methods: Plasma samples were collected from Malawian and Papua New Guinean (PNG) pregnant women enrolled over 7-year periods, during which malaria prevalence fell by over two thirds. Immunoglobulin...
Article
Impedance-controlled endometrial ablation (NovaSure) is commonly used to treat premenopausal heavy menstrual bleeding in Lothian, Scotland. Using postal questionnaires, we assessed patient satisfaction, treatment success and post-procedure symptoms in a cohort of women who had NovaSure treatment between January 2007 and May 2009. The response rate...