We provide an approach to the use of phototherapy and exchange transfusion in the management of hyperbilirubinemia in preterm infants of <35 weeks of gestation. Because there are limited data for evidence-based recommendations, these recommendations are, of necessity, consensusbased. The recommended treatment levels are based on operational thresholds for bilirubin levels and represent those levels beyond which it is assumed that treatment will likely do more good than harm. Long-term follow-up of a large population will be needed to evaluate whether or not these recommendations should be modified.

Short and long IPI after live birth, but not after pregnancy termination, showed increased odds for PTB.

The heme oxygenase inhibitor, tin protoporphyrin, is being studied for the prevention of neonatal jaundice. This potential drug, however, is also a photosensitizer that could cause serious and unknown side effects when administered to newborns. Therefore, we have developed in vitro and in vivo procedures for the screening and further characterization of potentially safe heme oxygenase inhibitors. The ideal inhibitor: 1) contains a biocompatible metal, 2) is not degraded in tissues, 3) is a highly potent inhibitor of heme oxygenase, and 4) does not participate in photochemical reactions. Proto- and mesoporphyrin derivatives with the tin, zinc, manganese, chromium, nickel, and magnesium were screened in vitro for suitability. Chromium protoporphyrin and mesoporphyrin were further studied in vitro and in vivo and were found to meet the ideal criteria. Chromium mesoporphyrin appeared to be the most potent in vitro inhibitor of adult Wistar rat tissue heme oxygenase. Four mumol of chromium protoporphyrin or chromium mesoporphyrin/kg body weight, administered intraperitoneally to adult male Wistar rats given a heme load through intraperitoneal administration of 30 mumol heme/kg body weight, caused significant suppression of hemolysis-induced increase in carbon monoxide production to 72 and 44% of control, respectively, 5.5 h after treatment. At t = 6 h, the tissue heme oxygenase activity, measured in vitro, was significantly reduced to 33 and < 5% in liver and to 22 and < 5% in spleen after the administration of chromium protoporphyrin and mesoporphyrin, respectively, but was not reduced in brain. The results show that there exist effective metalloporphyrin heme oxygenase inhibitors without photosensitizing properties.

Objective To examine the relationship between maternal characteristics, serum biomarkers, and preterm birth (PTB) by spontaneous and medically-indicated subtypes. Design Population-based cohort. Setting California, United States of America. Population From a total population of 1,004,039 live singleton births in 2009 and 2010, 841,665 pregnancies with linked birth certificate and hospital discharge records were included. Methods Characteristics were compared for term and preterm deliveries by PTB subtype using logistic regression and odds ratios adjusted for maternal characteristics and obstetric factors present in final stepwise models (adjORs) and 95% confidence intervals (CIs). First and second trimester serum marker levels were analyzed in a subset of 125,202 pregnancies with available first and second trimester serum biomarker results. Main Outcome Measure PTB by subtype. Results In fully adjusted models, ten characteristics and three serum biomarkers were associated with increased risk in each PTB subtype (Black race/ethnicity, preexisting hypertension with and without preeclampsia, gestational hypertension with preeclampsia, preexisting diabetes, anemia, previous PTB, one or ≥ two previous cesarean section(s), interpregnancy interval ≥ 60 months, low first trimester pregnancy-associated plasma protein A, high second trimester alpha-fetoprotein, and high second trimester dimeric inhibin A). These risks occurred in 51.6 to 86.2% of all pregnancies ending in PTB depending on subtype. The highest risk observed was for medically-indicated PTB < 32 weeks in women with preexisting hypertension and preeclampsia (adjOR 89.7, 27.3 – 111.2). Conclusions Our findings suggest a shared etiology across PTB subtypes. These commonalities point to targets for further study and exploration of risk reduction strategies.