Open Access Study protocol

Adapting iron dose supplementation in pregnancy for greater effectiveness on mother and child health: protocol of the ECLIPSES randomized clinical trial

Victoria Arija12*, Francesc Fargas3, Gemma March3, Susana Abajo3, Josep Basora15, Josefa Canals2, Blanca Ribot2, Estefania Aparicio2, Nuria Serrat4, Carmen Hernández-Martínez2 and Núria Aranda2

Author Affiliations

1 Unitat de Suport a la Recerca Tarragona-Reus, Institut d’Investigació en Atenció Primària Jordi Gol, Tarragona, Spain

2 Research Group in Nutrition and Mental Health (NUTRISAM), Institut d’Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, C/Sant Llorenç 21, Reus 43201, Spain

3 Servei d’Atenció Sexual i Reproductiva de Reus-Tarragona, Institut Català de la Salut, Generalitat de Catalunya, Tarragona, Spain

4 Laboratorio Clínico del Hospital Universitari Joan XXIII, Institut Català de la Salut, Generalitat de Catalunya, Tarragona, Spain

5 CIBERobn (Center for Biomedical Research in Physiopathology of Obesity and Nutrition), Institute of Health Carlos III, Madrid, Spain

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BMC Pregnancy and Childbirth 2014, 14:33  doi:10.1186/1471-2393-14-33

Published: 18 January 2014



Currently, there is no consensus regarding iron supplementation dose that is most beneficial for maternal and offspring health during gestation. Recommended iron supplementation dose does not preempt anemia in around 20% of the pregnancies, nor the risk of hemoconcentration in 15%. This deficit, or excess, of iron prejudices the mother-child wellbeing. Therefore the aims of the study are to determine the highest level of effectiveness of iron supplementation adapted to hemoglobin (Hb) levels in early pregnancy, which would be optimum for mother-child health.


Design: Randomized Clinical Trial (RCT) triple-blinded

Setting: 10 Primary Care Centers from Catalunya (Spain)

Study subjects: 878 non-anemic pregnant women at early gestation stage, and their subsequent newborns

Methods: The study is structured as a RCT with 2 strata, depending on the Hb levels before week 12 of gestation. Stratum #1: If Hb from 110 to 130 g/L, randomly assigned at week 12 to receive iron supplement of 40 or 80 mg/d. Stratum #2: If Hb >130 g/L, randomly assigned at week 12 to receive iron supplement of 40 or 20 mg/d.

Measurements: In the mother: socio-economic data, clinical history, food item frequency, lifestyle and emotional state, and adherence to iron supplement prescription. Biochemical measurements include: Hb, serum ferritin, C reactive protein, cortisol, and alterations in the HFE gene (C282Y, H63D). In children: ultrasound fetal biometry, anthropometric measurements, and temperament development.

Statistical analyses, using the SPSS program for Windows, will include bivariate and multivariate analyses adjusted for variables associated with the relationship under study.


Should conclusive outcomes be reached, the study would indicate the optimal iron supplementation dose required to promote maternal and infant health. These results would contribute towards developing guidelines for good clinical practice.

Trial registration

This clinical trial is registered at webcite as EudraCT number 2012-005480-28