PT - JOURNAL ARTICLE AU - Schulz, Stephanie AU - Zhao, Hui AU - Wong, Ronald J. AU - Stevenson, David K. TI - Heme Oxygenase Biology (During the Perinatal Period): Part 1: Prenatal Considerations AID - 10.1542/neo.13-3-e151 DP - 2012 Mar 01 TA - NeoReviews PG - e151--e157 VI - 13 IP - 3 4099 - http://neoreviews.aappublications.org/content/13/3/e151.short 4100 - http://neoreviews.aappublications.org/content/13/3/e151.full SO - NeoReviews2012 Mar 01; 13 AB - Heme oxygenase (HO), the rate-limiting enzyme in heme degradation, and its byproducts have antioxidative, antiapoptotic, anti-inflammatory, and cytoprotective properties. The expression of the inducible isoform, HO-1, in various tissues is increased in newborns, decreases toward adulthood, and may be of pivotal importance during the perinatal period. During pregnancy, it may mediate the regulation of maternal blood pressure, placental development, and vascularization, and, therefore, the maintenance of a healthy pregnancy. Pregnancy disorders, such as intrauterine growth restriction and preeclampsia, contribute significantly to preterm births as well as to perinatal morbidity and mortality and manifest even into adulthood. They stem from placental defects mediated by fetal genetic defects, maternal factors, or both. HO-1 has been shown to play a role in the maintenance of maternal inflammatory homeostasis and normal placental vasculature development by regulating angiogenesis and matrix remodeling in early pregnancy. Therefore, a genetic deficiency in HO-1 gene expression may be an underlying cause of pregnancy disorders, in particular, those attributed to placental dysfunction.Abbreviations:BPD; bronchopulmonary dysplasiaCO; carbon monoxideHet; heterozygoteHO; heme oxygenaseORDP; oxygen radical diseases of prematuritySA; spiral arteryuNK; uterine natural killerWT; wild-type