Nearly 1 out of 10 pregnant women with immune thrombocytopenic purpura (ITP) will experience neonatal thrombocytopenia, according to data published in the Journal of Maternal-Fetal and Neonatal Medicine. Additionally, pregnancy-onset ITP may be predictive of neonatal thrombocytopenia.
ITP occurs when the immune system attacks a patient’s platelets, causing thrombocytopenia while bone marrow remains normal and no other causes of destroyed platelets are present. Pregnant women with ITP are at a high risk for neonatal thrombocytopenia, which could result in neonatal hemorrhagic events such as intracranial hemorrhage.
Researchers from 2 medical centers and 1 hospital in Israel reviewed the medical records of 253 pregnancies characterized by ITP with deliveries between 2006 and 2016. The median maternal age at ITP diagnosis was 29 years. The overwhelming majority (87.7%) of patients were diagnosed with ITP prior to pregnancy, with just 31 patients (12.3%) experiencing pregnancy-onset ITP.
Baseline characteristics were similar between the 2 groups with the exception of a higher proportion of patients in the pregnancy-onset group never having previously given birth (P = .002). Maternal nadir platelet count was significantly lower in patients with pregnancy-onset ITP (62 x 109/L) compared with previously diagnosed ITP (81 x 109/L; P =.005).
Neonatal thrombocytopenia, defined as nadir platelet count less than 150 x 109/L, occurred in 9.5% of pregnancies (24/253) and required treatment in half of those cases. Neonatal platelet count correlated with maternal platelet count at delivery (r = .23; P =.01), and maternal platelet count was significantly lower among patients with newborns that experienced thrombocytopenia at birth (P <.001).
A higher proportion of patients with pregnancy-onset ITP delivered babies with neonatal thrombocytopenia (22.6%) compared with patients with previously diagnosed ITP (7.7%; P =.02).
Multivariate analysis indicated an odds ratio of 4.88 for new-onset ITP to predict neonatal thrombocytopenia (95% CI, 1.68-14.16; P =.004). New-onset ITP was the only predictive factor for neonatal thrombocytopenia.
The authors suggested that in addition to prospective studies assessing the relationship between ITP and neonatal thrombocytopenia, vigilant care is warranted in patients with pregnancy-onset ITP.
1. Rottenstreich A, Israeli N, Roth B, et al. Risk factors associated with neonatal thrombocytopenia in pregnant women with immune thrombocytopenic purpura [published online September 13, 2018]. J Matern Fetal Neonatal Med. doi: 10.1080/14767058.2018.1523891