BackgroundLow birth weight (LBW) and preterm birth (PTB) are major contributors to infant mortality and chronic childhood morbidity. Understanding factors that contribute to or protect against these adverse birth outcomes is an important global health priority. Anaemia and iron deficiency are common in malaria-endemic regions, but there are concerns regarding the value of iron supplementation among pregnant women in malaria-endemic areas due to reports that iron supplementation may increase the risk of malaria. There is a lack of evidence on the impact of iron deficiency on pregnancy outcomes in malaria-endemic regions.MethodsWe determined iron deficiency in a cohort of 279 pregnant women in a malaria-endemic area of Papua New Guinea. Associations with birth weight, LBW and PTB were estimated using linear and logistic regression. A causal model using sequential mediation analyses was constructed to assess the association between iron deficiency and LBW, either independently or mediated through malaria and/or anaemia.ResultsIron deficiency in pregnant women was common (71% at enrolment) and associated with higher mean birth weights (230 g; 95% confidence interval, CI 118, 514; p < 0.001), and reduced odds of LBW (adjusted odds ratio, aOR = 0.32; 95% CI 0.16, 0.64; p = 0.001) and PTB (aOR = 0.57; 95% CI 0.30, 1.09; p = 0.089). Magnitudes of effect were greatest in primigravidae (birth weight 351 g; 95% CI 188, 514; p < 0.001; LBW aOR 0.26; 95% CI 0.10, 0.66; p = 0.005; PTB aOR = 0.39, 95% CI 0.16, 0.97; p = 0.042). Sequential mediation analyses indicated that the protective association of iron deficiency on LBW was mainly mediated through mechanisms independent of malaria or anaemia.ConclusionsIron deficiency was associated with substantially reduced odds of LBW predominantly through malaria-independent protective mechanisms, which has substantial implications for understanding risks for poor pregnancy outcomes and evaluating the benefit of iron supplementation in pregnancy. This study is the first longitudinal study to demonstrate a temporal relationship between antenatal iron deficiency and improved birth outcomes. These findings suggest that iron supplementation needs to be integrated with other strategies to prevent or treat infections and undernutrition in pregnancy to achieve substantial improvements in birth outcomes.Electronic supplementary materialThe online version of this article (10.1186/s12916-018-1146-z) contains supplementary material, which is available to authorized users.

A large proportion of Australian medical students undertake IMEs in developing countries. However, a considerable proportion of students do not undertake formal preparation for, or reflection on, their experiences. Predeparture training and postelective debriefing should be scaled up across Australian medical schools to provide students with the guidance and support to maximise the benefits and minimise risks associated with undertaking IMEs in developing countries.

This study reports the sequence analysis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) from infected individuals within the Greater Geelong region, Victoria, Australia. All but one individual had recently returned from travelling abroad, and all had clinical signs consistent with SARS-CoV-2 infection. SARS-CoV-2 belonging to three lineages were detected and represent separate introductions of the virus into the region. Sequence data were consistent with the recent travel history of each case. Full virus genome sequencing can play an important role in supporting local epidemiological tracing and monitoring for community transmission. Quality of the SARS-CoV-2 sequences obtained was highly dependent on appropriate sample collection and handling.