Relationship between 17-alpha hydroxyprogesterone caproate concentration and spontaneous preterm birth.

Abstract

OBJECTIVE:

17-alpha hydroxyprogesterone caproate 250 mg weekly reduces recurrent spontaneous preterm birth in women with a prior spontaneous preterm birth by 33%. The dose is not based on pharmacologic considerations. A therapeutic concentration has not been determined hampering any attempt to optimize treatment. This study evaluated the relationship between 17-alpha hydroxyprogesterone caproate plasma concentrations and the rate of spontaneous preterm birth in women with singleton gestation.

STUDY DESIGN:

A single blood sample was obtained between 25 and 28 weeks' gestation from 315 women with a spontaneous preterm birth who participated in a placebo-controlled, prospective, randomized clinical trial evaluating the benefit of omega-3 supplementation in reducing preterm birth. All women in the parent study received 17-alpha hydroxyprogesterone caproate and 434 received omega-3 supplementation and 418 received a placebo. Plasma from 315 consenting women was analyzed for 17-alpha hydroxyprogesterone caproate concentration.

RESULTS:

There were no differences between placebo and omega-3 supplemented groups in demographic variables, outcomes or in mean 17-alpha hydroxyprogesterone caproate concentration. Plasma concentrations of 17-alpha hydroxyprogesterone caproate ranged from 3.7-56 ng/mL. Women with plasma concentrations of 17-alpha hydroxyprogesterone caproate in the lowest quartile had a significantly higher risk of spontaneous preterm birth (P = .03) and delivered at significantly earlier gestational ages (P = .002) than did women in the second to fourth quartiles. The lowest preterm birth rates were seen when median 17-alpha hydroxyprogesterone caproate concentrations exceeded 6.4 ng/mL.

CONCLUSION:

Low plasma 17-alpha hydroxyprogesterone caproate concentration is associated with an increased risk of spontaneous preterm birth. This finding validates efficacy of this treatment but suggests that additional studies are needed to determine the optimal dosage.

• Authors: Steve N Caritis, Raman Venkataramanan, Elizabeth Thom, Margaret Harper, Mark A Klebanoff, Yoram Sorokin, John M Thorp Jr, Michael W Varner, Ronald J Wapner, Jay D Iams, Marshall W Carpenter, William A Grobman, Brian M Mercer, Anthony Sciscione, Dwight J Rouse, Susan Ramin, Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network and Obstetric-Fetal Pharmacology Research Units Network
• Journal: American journal of obstetrics and gynecology (Am J Obstet Gynecol) Vol. 210 Issue 2 Pg. 128.e1-6 (Feb 2014) ISSN: 1097-6868 [Electronic] United States
• PMID: 24113254 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Extramural)
• Copyright: Copyright © 2014 Mosby, Inc. All rights reserved.

Chemical References

• Fatty Acids, Omega-3
• Hydroxyprogesterones
• 17 alpha-Hydroxyprogesterone Caproate

Topics

• 17 alpha-Hydroxyprogesterone Caproate
• Fatty Acids, Omega-3 (therapeutic use)
• Female
• Humans
• Hydroxyprogesterones (administration & dosage, blood)
• Pregnancy
• Pregnancy Trimester, Second (blood)
• Premature Birth (blood, prevention & control)
• Recurrence