a1 Faculty of Health, Yasuj University of Medical Sciences, Yasuj, Iran
a2 School of Life Sciences, University of Westminster, London, UK
a3 London School of Hygiene and Tropical Medicine, London, UK
a4 Department of Epidemiology and Public Health, Imperial College London, Norfolk Place, St Mary's Campus, London W2 1PG, UK
a5 Institute of Diagnostics, University of Oulu, Oulu, Finland
a6 National Institute of Health and Welfare, Oulu, Finland
a7 Department of Clinical Medicine/Obstetrics and Gynaecology, University of Oulu, Oulu, Finland
a8 Institute of Health Sciences, University of Oulu, Biocenter Oulu, PO Box 5000, Fin-90014 Oulu, Finland
a9 MRC Centre of Epidemiology for Child Health, Centre for Paediatric Epidemiology and Biostatistics, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
The aim of the present study was to examine the association between maternal Hb levels during pregnancy and educational achievement of the offspring in later life. We analysed data obtained from the Northern Finnish Birth Cohort Study conducted in 1966, in which, data on mothers and offspring from pregnancy through to the age of 31 years were collected. The cohort comprised 11 656 individuals born from singleton births (51 % males and 49 % females). Maternal Hb levels were available from the third, seventh and ninth gestational months. Educational achievement was measured as school scores (range 4–10) taken at the ages of 14 (self-reported questionnaires) and 16 (school reports) years as well as the highest level of education at the age of 31 years. The present results showed a direct positive association between Hb levels and educational achievement in later life. After adjustment for sex, birth weight, birth month and a wide range of maternal factors (parity, smoking, mental status, whether pregnancy was wanted or not, education, social class and marital status), only maternal Hb levels that were measured at the ninth month were significantly associated with the offspring's school performance. If the levels were ≥ 110 g/l at all the three measurement points, offspring not only had better school scores at the ages of 14 and 16 years (β = 0·048, P = 0·04 and β = 0·68, P = 0·007, respectively), but also had an increased odds of having a higher level of education at the age of 31 years (OR = 1·14, P = 0·04). The present study suggests that low maternal Hb levels at the final stages of pregnancy are linked to the poorer educational achievement of the offspring. If our observation is confirmed, it would suggest that Fe prophylaxis even at fairly late stages of pregnancy may be beneficial for the subsequent health of the offspring. However, more studies are needed to fully establish the potential pathways and the clinical importance of the present findings.
(Received October 07 2009)
(Revised April 27 2010)
(Accepted April 28 2010)
(Online publication June 04 2010)
† Both authors M.-R. J. and E. H. contributed equally to the work.
Abbreviations: NFBC, Northern Finnish Birth Cohort