Third trimester iron status and pregnancy outcome in non-anaemic women; pregnancy unfavourably affected by maternal iron excess

A prospective observational study was performed on 488 women with haemoglob in greater than or equal to 10 g/dl at booking to examine the relationship between serum ferritin concentration quartiles at 28-30 weeks gestation wit h maternal characteristics, pregnancy complications and infant outcome, Whi le there was no difference in the maternal characteristics or gestational a ge, the infant size decreased significantly and progressively from the lowe st to the highest quartile. Despite a significant difference in the inciden ce of multiparous women, there was no difference in the incidence of most c omplications except for prelabour rupture of the membranes and infant admis sion to the neonatal unit. Compared with the other three quartiles, the hig hest quartile was associated with increased risk for preterm delivery and n eonatal asphyxia, while the lowest quartile was associated with decreased r isk of pre-eclampsia, prelabour rupture of the membranes, and infant admiss ion to the neonatal unit. Overall, ferritin quartiles were correlated with other parameters of iron status and red cell indices, and ferritin concentr ation was inversely correlated with infant birthweight, Our findings sugges ted that maternal ferritin concentration is primarily a reflection of mater nal iron status, and a high level is associated with unfavourable outcome. The rationale of routine iron supplementation in non-anaemic women needs to be re-examined.