Association between maternal haemoglobin and stillbirth: a��cohort study among a multi-ethnic population in England

�� 2017 The Authors. Published by Wiley. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher���s website: https://doi.org/10.1111/bjh.14961The study objectives were to examine the association of maternal haemoglobin with stillbirth and perinatal death in a multi-ethnic population in England. We conducted a retrospective cohort analysis using anonymised maternity data from 14��001 women with singleton pregnancies ���24��weeks��� gestation giving birth between 2013 and 2015 in two hospitals - the Royal Wolverhampton NHS Trust and Guy's and St Thomas��� NHS Foundation Trust. Multivariable logistic regression analyses were undertaken to analyse the associations between maternal haemoglobin at first visit and at 28��weeks with stillbirth and perinatal death, adjusting for 11 other risk factors. Results showed that 46% of the study population had anaemia (haemoglobin <110��g/l) at some point during their pregnancy. The risk of stillbirth and perinatal death decreased linearly per unit increase in haemoglobin concentration at first visit (adjusted odds ratio [aOR] stillbirth��=��0��70, 95% confidence interval [CI] 0��58���0��85, aOR perinatal death��=��0��71, 95% CI 0��60���0��84) and at 28��weeks (aOR stillbirth��=��0��83, 95% CI 0��66���1��04; aOR perinatal death��=��0��86, 95%CI 0��67���1��12). Compared with women with haemoglobin ���110��g/l, the risk of stillbirth and perinatal death was five- and three-fold higher in women with moderate-severe anaemia (haemoglobin