The impact of tobacco use on preterm premature rupture of the membranes.

Objective: To determine if tobacco use increases the incidence of preterm premature rupture of the membranes (pPROM) or alters perinatal outcomes after pPROM.

Study Design: This is a secondary analysis of the databases of three completed Eunice Kennedy Shriver National Institute of Child Health and Human Development-supported Maternal Fetal Medicine Units Network studies. Self-reported tobacco exposure data was obtained.

Reference ranges for lymphocyte counts of neonates: associations between abnormal counts and outcomes.

Background And Objective: Both high and low lymphocyte counts at birth have been associated with adverse outcomes. However, the validity of defining a lymphocyte count as "abnormal" depends on having an accurate reference range. We established a reference range for neonatal lymphocyte counts by using multihospital data and used this to assess previously reported relationships between abnormal counts and early onset sepsis (EOS), intraventricular hemorrhage (IVH), retinopathy of prematurity (ROP), periventricular leukomalacia, and birth asphyxia.

Reference ranges for blood concentrations of nucleated red blood cells in neonates.

Background: Previous studies reported a relationship between high nucleated red blood cells (NRBC) in neonates and the development of intraventricular hemorrhage (IVH) and/or retinopathy of prematurity (ROP).

Objective: We sought to (1) establish reference ranges for NRBC in neonates based on a large data set, (2) compare NRBC from automated versus manual counts, (3) determine the effect of an elevated NRBC, on the day of birth, on the odds of developing grade ≥3 IVH or ROP.

Methods: We analyzed all NRBC obtained during 8.