The objective of this study was to determine the prevalence, adverse pregnancy complications, and optimal management of pregnancies complicated by bleeding in the second half of pregnancy of an unknown origin (ABUO). A MEDLINE search from 1966 through November 2004 using the search terms “antepartum hemorrhage” or “hemorrhage” or “uterine hemorrhage” and “pregnancy complications” and “cardiovascular complications” and “second trimester pregnancy” or “third trimester pregnancy” was undertaken. The inclusion criteria focused on bleeding not resulting from placenta previa or abruption or to any known cause. The MEDLINE search provided 24 abstracts for review with 9 studies meeting the inclusion criteria The prevalence of ABUO was 2%. The likelihood of antepartum hemorrhage and delivery before 37 weeks was significant with an odds ratio (OR) of 3.17 and 95% confidence interval (CI) of 2.76–3.64. The risk of intrauterine fetal demise was significantly increased in women with ABUO (OR, 2.09; 95% CI, 1.43–3.06). The association between ABUO and fetal anomalies was increased with an OR 1.42 (95% CI, 1.07–1.87). Only one study with a small sample size (N = 48) compared the outcomes of women using Doppler studies of the umbilical and uterine arteries and biophysical profiles. No differences were observed in the women undergoing antenatal testing and the women not undergoing antenatal testing. The prevalence of ABUO is 2%. Preterm delivery, stillbirth, and fetal anomalies appear to be increased in these pregnancies. Antenatal testing may be of limited value in their management.
Obstetricians & Gynecologists, Family Physicians
After completion of this article, the reader should be able to explain the prevalence of antepartum bleeding of unknown origin (ABUO) in confronting a patient with ABUO, summarize the types and frequency of adverse pregnancy outcomes in ABUO, and recall the limited usefulness of antenatal testing in patients with ABUO.
*Chairman, †PG III Resident, and ‡PG IV Resident, Department of Obstetrics and Gynecology, and §Division Head, Maternal-Fetal Medicine, Naval Medical Center Portsmouth, Portsmouth, Virginia; ¶PG II Resident, Department of Obstetrics and Gynecology, King Edward Memorial Hospital, University of Western Australia, Perth, Australia; and ∥Director, Maternal-Fetal Medicine, Aurora Health Care, West Allis, Wisconsin
Chief Editor's Note: This article is part of a series of continuing education activities in this Journal through which a total of 36 AMA/PRA category 1 credit hours can be earned in 2005. Instructions for how CME credits can be earned appear on the last page of the Table of Contents.
The authors have disclosed that they have no financial relationships with or interests in any commercial companies pertaining to this educational activity.
Wolters Kluwer Health has identified and resolved all faculty conflicts of interest regarding this educational activity.
Correspondence: Suneet P. Chauhan, MD, Aurora Women's Pavilion, PAC-PAW, 8901 W. Lincoln Ave., West Allis, WI 53227. E-mail: email@example.com.