ObjectivesTo evaluate the effect of idiopathic thrombocytopenic purpura (ITP) on pregnancies and the role of the delta hemoglobin indices in the evaluation of treatment effectiveness.MethodsThis case–control study was conducted with 23 ITP and 115 low‐risk pregnancies. Obstetric outcomes (fetal growth retardation (FGR), preterm delivery) and neonatal outcomes (weights, APGAR scores, NICU admissions, thrombocytopenia) were recorded. ITP group was subgrouped based on the platelet ratio at the admission for delivery and evaluated the impact of platelet ratios on blood loss amounts at delivery by using delta hemoglobin indices.ResultsEleven patients received treatment during pregnancy. The gestational age at birth and fetal APGAR scores were lower, and the preterm delivery and FGR rates were higher in the ITP group. Four newborns (17.4%) had thrombocytopenia. There were two postpartum hemorrhages. Newborn platelet counts did not correlate with maternal platelet counts. The study showed no difference in delta hemoglobin counts between the ITP and control groups.ConclusionsITP is associated with an increased risk of maternal and fetal complications. The presented study showed by using the delta hemoglobin indices that, hemorrhagic complications could be prevented with appropriate management. Neonatal thrombocytopenia should be considered for all ITP patients.