TY - BOOK AU - Miodovnik, Menachem AU - Umans, Jason G TI - Pharmacology and placental transport of 17-hydroxyprogesterone caproate in singleton gestation SN - 0002-9378 KW - *Hydroxyprogesterones/pk [Pharmacokinetics] KW - *Placenta/me [Metabolism] KW - *Progestins/pk [Pharmacokinetics] KW - Adult KW - Biological Transport/ph [Physiology] KW - Body Mass Index KW - Female KW - Fetal Blood/ch [Chemistry] KW - Humans KW - Hydroxyprogesterones/bl [Blood] KW - Hydroxyprogesterones/pd [Pharmacology] KW - Pregnancy KW - Progestins/bl [Blood] KW - Progestins/pd [Pharmacology] KW - Young Adult KW - MedStar Health Research Institute KW - Clinical Trial KW - Journal Article KW - Research Support, N.I.H., Extramural N1 - Available online from MWHC library: 1995 - present, Available in print through MWHC library: 1999 - 2006 N2 - CONCLUSION: The apparent half-life of 17-OHPC is long, and pharmacokinetic parameters vary widely between subjects and are affected by maternal body mass index. The drug crosses the placental barrier. Copyright 2012 Mosby, Inc. All rights reserved; OBJECTIVE: The purpose of this study was to estimate pharmacokinetic parameters and to evaluate placental transport of 17-hydroxyprogesterone caproate (17-OHPC) in singleton gestation; RESULTS: The half-life (median +/- SD) of 17-OHPC was 16.2 +/- 6 days. Concentrations of 17-OHPC were higher during study 2 than during study 1. Body mass index affected maternal 17-OHPC concentrations. Cord:maternal 17-OHPC concentration ratios averaged 0.2; 17-OHPC was detectible in cord plasma 44 days after the last maternal injection; STUDY DESIGN: Sixty-one women who received weekly injections of 17-OHPC underwent 2 pharmacokinetic studies at 20 + 0 to 24 + 6 weeks' gestation (study 1) and 31 + 0 to 34 + 6 weeks' gestation (study 2); daily blood samples were obtained between injections. In 18 women, blood samples were obtained over a 28-day period beyond the last injection (extended study). Maternal and/or cord blood were obtained at delivery UR - http://dx.doi.org/10.1016/j.ajog.2012.08.015 ER -