Dear Editor:
We have read with interest the article of Ayrim et al.
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on the coexistence of breastfeeding and pregnancy in a Turkish population. Indeed, research data on the safety of breastfeeding during pregnancy are greatly needed in order to support current medical advice. The authors reported a significantly decreased level of hemoglobin in women who breastfeed throughout pregnancy (9.7 g/dL) compared with women not breastfeeding (12.3 g/dL). The difference is also clinically relevant and possibly due to an imbalance between iron intake (from diet and supplementation) and increased iron needs related to concurrent pregnancy and lactation.
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Iron requirements double during pregnancy because extra iron is required for the growing fetus, for the formation of the placenta, for the expansion of the maternal red blood cell mass, and to compensate for the loss of blood during delivery.
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Consequently, iron deficiency during pregnancy is the most widely observed micronutrient deficiency in both developing and developed countries
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and is even worsened by a short interpregnancy interval.
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Current concern is that iron status has been implicated in some pregnancy disorders affecting both the mother and the fetus, such as preeclampsia and intrauterine growth restriction,
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and is associated with mental development of the child.
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Ayrim et al.,
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however, do not adjust their results for socioeconomic and formal education status of the studied women and for iron supplementation during pregnancy. The reasons why women were iron deficient should be explored more in depth. In any case, in our opinion, the conclusion by Ayrim et al.
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that “breastfeeding is not harmful” minimizes their own reported results on hemoglobin levels.
A recent consensus review co-produced by the Italian Society of Perinatal Medicine
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supports breastfeeding during pregnancy in the first two trimesters, and possibly also in the third trimester, provided an adequate diet is followed and supplementation is given to mothers, as expected at least in developed countries. Despite the fact that the results by Ayrim et al.
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are not adjusted for relevant factors, we believe it is plausible that the risk of anemia increases when breastfeeding continues throughout pregnancy, in particular if iron supplementation is not routinely implemented and socioeconomic settings are suboptimal. Indeed, further studies are needed to verify whether these data are replicable and whether a timely iron supplementation might succeed to prevent iron deficiency.
