Association of Prenatal Maternal Anemia with Tics and Tourette's Syndrome in Offspring

Iron deficiency anemia (IDA) accounts for most of the anemia in pregnancy, and iron is essential for neurodevelopment. Tics and Tourette’s syndrome (TS) are neurodevelopmental disorders that manifest in childhood. A few studies reported an inconclusive association between iron deficiency and tics in children. No study has investigated the relationship between prenatal maternal anemia and tics in children. We aimed to assess the relationship between prenatal anemia exposure and the incidence of tics or TS in offspring. We linked the Taiwan National Health Insurance Research Database to the Maternal and Child Health Database for the analysis and identified 153,854 children with prenatal anemia exposure and 2,014,619 children without prenatal anemia exposure from 2004 to 2016 and followed them through 2017. Cox regression models were applied to compare the risk of tics or TS between the exposed and nonexposed groups. Among the exposed group, 37,832 were exposed at ≤12 weeks of gestational age (GA) and 116,022 at >12 weeks of GA. We observed an increased risk of tics and TS in those exposed at ≤12 weeks compared with the nonexposed group (adjusted hazard ratio (aHR) = 1.23, 95% confidence interval (CI): 1.12–1.34). The result remained consistent after adjusting for birth year, sex, birth order, maternal age, low-income levels, gestational age, birth weight, and alcohol use and smoking during pregnancy (aHR = 1.16, CI: 1.04–1.28). Fetuses exposed to maternal anemia at ≤12 weeks of GA are at high risk of tics or TS. However, this effect was attenuated to insignificance in the sibling comparison. Our study highlights the importance of detection of anemia during pregnancy and proper timing of iron supplementation.

Prenatal anemia and postpartum hemorrhage risk: A systematic review and meta-analysis

INTRODUCTION

Postpartum hemorrhage (PPH) has remained the leading cause of maternal mortality. While anemia is a leading contributor to maternal morbidity, molecular, cellular and anemia-induced hypoxia, clinical studies of the relationship between prenatal-anemia and PPH have reported conflicting results. Therefore, our objective was to investigate the outcomes of studies on the relationships between prenatal anemia and PPH-related mortality.

MATERIALS AND METHODS

Electronic databases (MEDLINE, Scopus, ClinicalTrials.gov, PROSPERO, EMBASE, and the Cochrane Central Register of Controlled Trials) were searched for studies published before August 2019. Keywords included "anemia," "hemoglobin," "postpartum hemorrhage," and "postpartum bleeding." Only studies involving the association between anemia and PPH were included in the meta-analysis. Our primary analysis used random effects models to synthesize odds-ratios (ORs) extracted from the studies. Heterogeneity was formally assessed with the Higgins' I² statistics, and explored using meta-regression and subgroup analysis.

RESULTS

We found 13 eligible studies investigating the relationship between prenatal anemia and PPH. Our findings suggest that severe prenatal anemia increases PPH risk (OR = 3.54; 95% CI: 1.20, 10.4, p-value = 0.020). There was no statistical association with mild (OR = 0.60; 95% CI: 0.31, 1.17, p-value = 0.130), or moderate anemia (OR = 2.09; 95% CI: 0.40, 11.1, p-value = 0.390) and the risk of PPH.

CONCLUSION

Severe prenatal anemia is an important predictive factor of adverse outcomes, warranting intensive management during pregnancy. PROSPERO Registration Number: CRD42020149184; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=149184.