Maternal iron deficiency and neonatal health: a pilot study

Background Iron deficiency (ID) and iron deficiency anemia (IDA) are common. In Finland, there is no routine recommendation of iron supplementation. Moreover, there is little knowledge of actual iron supplement use by pregnant women or the impact of ID and its treatment on offspring health. This preliminary study evaluated the real-life prevalence of ID and iron-supplement use in pregnancy in Finland and studied the short-term neonatal health of the offspring. Methods A total of 822 pregnant women delivering at Tampere University Hospital and their newborns were studied between April 2024 and February 2025. After giving their consent, the participants completed an online questionnaire about their iron-deficiency status, iron-supplement use, and health in pregnancy. They also gave their permission for their health and their newborns’ health to be followed via a review of patient records. Maternal outcomes, such as preterm delivery, delivery mode, blood loss during delivery and the need for transfusions, and neonatal outcomes (i.e., gestational age, Apgar score, birth weight, need for neonatal intensive care unit (NICU) or phototherapy, and respiratory distress) were included in the analysis. Comparisons were made in groups of maternal anemia versus no anemia, maternal ID versus no ID, and iron supplementation versus no iron supplementation. Results 189 study participants (23%) reported having been diagnosed with IDA, 430 (52.3%) reported having been diagnosed with ID, and 732 (89.1%) had used oral iron supplementation during pregnancy. ID was almost always treated with iron supplementation. The participants diagnosed with ID were more often multiparous and had inflammatory bowel disease more often than those without ID. Low Apgar score (< 7) at the age of one minute was more common in the ID group compared to the non-ID group. Otherwise, no differences in maternal or neonatal outcomes were observed. Conclusion Despite no routine recommendation for iron supplementation, maternal use of iron supplements in pregnancy appears more common than previously thought. Maternal IDA is well recognized and treated in Finland. Regardless of the wide use of iron supplementation, maternal ID and IDA may play a role in neonatal short-term health. These findings warrant further investigation in the main study. Trial registration This study was registered in Clinicaltrials.gov. The protocol can be found on ClinicalTrials.gov (ID NCT06879080). Registration date: March 17,2025.