f
FERTILITY AND STERILITY Copyright © 1992 The American Fertility Society
Vol. 58, No.1, July 1992
Printed on acid-free paper in U.S.A.
A comparison of the reproductive outcome between women with a unicornuate uterus and women with a didelphic uterus*
Dean M. Moutos, M.D. Marian D. Damewood, M.D. William D. Schlaff, M.D.t John A. Rock, M.D.:j: Department of Gynecology and Obstetrics, Division of Reproductive Endocrinology, The Johns Hopkins Medical School, Baltimore, Maryland
Objective: To compare the reproductive performance of women with a unicornuate uterus with the reproductive performance of women with a didelphic uterus. Design: Retrospective. Setting: Reproductive endocrinology service of a tertiary referral hospital. Main Outcome Measures: The proportion of pregnancies resulting in spontaneous abortion, preterm delivery, term delivery, and living children was determined for each group. Results: Twenty-nine women with a unicornuate uterus and 25 women with a didelphic uterus were identified. Twenty women with a unicornuate uterus produced a total of 40 pregnancies, whereas 13 women with a didelphic uterus produced a total of 28 pregnancies. The 33 % spontaneous abortion rate in the unicornuate group was not significantly different from the 23% rate in the didelphic group. The proportion of pregnancies resulting in preterm delivery, term delivery, and living children was similar in both groups. Conclusions: The reproductive performance of women with a unicornuate uterus is similar to the performance of women with a didelphic uterus. Fertil Steril 1992;58:88-93 Key Words: Unicornuate uterus, uterus didelphys, uterine anomalies, reproductive potential
Women with Mullerian anomalies are known to have an increased risk of obstetric complications including spontaneous abortion, preterm delivery, postpartum hemorrhage, malpresentation, and cesarean delivery. Disorders of lateral fusion of the mullerian ducts can result in various malformations including the unicornuate, didelphic, bicornuate, and septate uteri. The unicornuate uterus arises when
Received October 7,1991; revised and accepted March 3,1992. * Presented in part at the 47th Annual Meeting of The American Fertility Society, Orlando, Florida, October 21 to 24, 1991. t Present address: Department of Obstetrics and Gynecology, The University of Colorado Health Sciences Center, Denver, Colorado. :j: Reprint requests and present address: John A. Rock, M.D., Department of Gynecology and Obstetrics, The Union Memorial Hospital, 201 East University Parkway, Baltimore, Maryland 21218-2895.
88
Moutos et al.
Unicornuate and didelphic uteri
there is either complete or partial failure in the development of one of the Mullerian ducts. Partial development of one of the ducts results in a rudimentary uterine horn or anlage, whereas complete failure of ductal development results in an isolated hemiuterus without an anlage. Complete failure of the paried Mullerian ducts to fuse results in the uterus didelphys, which is characterized by two hemiuteri and two cervices. A longitudinal vaginal septum is present in the majority of women with uterus didelphys. The unicornuate uterus is reported to have the poorest fetal survival (1, 2), whereas the didelphic uterus is purported to have a more favorable prognosis (1, 3). The didelphic uterus can be visualized as a symmetrically duplicated unicornuate uterus. Because pregnancy usually occurs in only one of the hemiuteri of a didelphic uterus, it is not clear why Fertility and Sterility
the reproductive outcome of women with a didelphic uterus should be different from the outcome of women with a unicornuate uterus. Most reports in the literature describing the outcome of these two anomalies consist of small case series, whereas other reports have not made a distinction between the unicornuate and the didelphic uterus and have combined the two malformations under the term double uterus. The purpose of this report is to compare the reproductive outcome of women with a unicornuate uterus with the outcome of women with a didelphic uterus. The null hypothesis states that the reproductive outcome between the two groups does not differ; the alternative hypothesis states that there is a difference in outcome between the two groups . MATERIALS AND METHODS
A computerized search of the medical records of patients evaluated at the Johns Hopkins Hospital from approximately 1950 until 1990 was made. The charts of patients with a diagnosis of unicornuate uterus, didelphic uterus, or double uterus were reviewed. The classification scheme proposed by The American Fertility Society (4) was used to classify uterine malformations as either unicornuate (class II) or didelphic (class III). Patients were included in the study if there was sufficient information available in the medical record to accurately classify the uterine anomaly. Patients were excluded if the information in the medical record was insufficient to support the diagnosis or if, after review of the medical record, it was determined that the patient had a malformation other than a unicornuate or a didelphic uterus. The patient population consisted of both inpatients and outpatients in the gynecology and reproductive endocrinology services at the Johns Hopkins Hospital. Patient follow-up was obtained by one or more of the following methods: (1) review of the medical record; (2) consultation with referring physicians; or (3) phone conversations with the patients. Duration of follow-up was determined as the interval of time from the first evaluation at our institution until the time of the last patient contact. Follow-up was obtained for a minimum of 1 year on all study patients. Statistical Analysis
For each patient, the proportion of pregnancies resulting in a given outcome was calculated. Patients in both groups with a given outcome were then ranked, and Wilcoxon's rank sum test was used to Vol. 58, No.1, July 1992
compare the two groups. Differences between means were evaluated by a two-tailed t-test for independent samples. The X2 test was used to compare fetal presentation and delivery mode between the two groups. A P value
FERTILITY AND STERILITY Copyright © 1992 The American Fertility Society
Vol. 58, No.1, July 1992
Printed on acid-free paper in U.S.A.
A comparison of the reproductive outcome between women with a unicornuate uterus and women with a didelphic uterus*
Dean M. Moutos, M.D. Marian D. Damewood, M.D. William D. Schlaff, M.D.t John A. Rock, M.D.:j: Department of Gynecology and Obstetrics, Division of Reproductive Endocrinology, The Johns Hopkins Medical School, Baltimore, Maryland
Objective: To compare the reproductive performance of women with a unicornuate uterus with the reproductive performance of women with a didelphic uterus. Design: Retrospective. Setting: Reproductive endocrinology service of a tertiary referral hospital. Main Outcome Measures: The proportion of pregnancies resulting in spontaneous abortion, preterm delivery, term delivery, and living children was determined for each group. Results: Twenty-nine women with a unicornuate uterus and 25 women with a didelphic uterus were identified. Twenty women with a unicornuate uterus produced a total of 40 pregnancies, whereas 13 women with a didelphic uterus produced a total of 28 pregnancies. The 33 % spontaneous abortion rate in the unicornuate group was not significantly different from the 23% rate in the didelphic group. The proportion of pregnancies resulting in preterm delivery, term delivery, and living children was similar in both groups. Conclusions: The reproductive performance of women with a unicornuate uterus is similar to the performance of women with a didelphic uterus. Fertil Steril 1992;58:88-93 Key Words: Unicornuate uterus, uterus didelphys, uterine anomalies, reproductive potential
Women with Mullerian anomalies are known to have an increased risk of obstetric complications including spontaneous abortion, preterm delivery, postpartum hemorrhage, malpresentation, and cesarean delivery. Disorders of lateral fusion of the mullerian ducts can result in various malformations including the unicornuate, didelphic, bicornuate, and septate uteri. The unicornuate uterus arises when
Received October 7,1991; revised and accepted March 3,1992. * Presented in part at the 47th Annual Meeting of The American Fertility Society, Orlando, Florida, October 21 to 24, 1991. t Present address: Department of Obstetrics and Gynecology, The University of Colorado Health Sciences Center, Denver, Colorado. :j: Reprint requests and present address: John A. Rock, M.D., Department of Gynecology and Obstetrics, The Union Memorial Hospital, 201 East University Parkway, Baltimore, Maryland 21218-2895.
88
Moutos et al.
Unicornuate and didelphic uteri
there is either complete or partial failure in the development of one of the Mullerian ducts. Partial development of one of the ducts results in a rudimentary uterine horn or anlage, whereas complete failure of ductal development results in an isolated hemiuterus without an anlage. Complete failure of the paried Mullerian ducts to fuse results in the uterus didelphys, which is characterized by two hemiuteri and two cervices. A longitudinal vaginal septum is present in the majority of women with uterus didelphys. The unicornuate uterus is reported to have the poorest fetal survival (1, 2), whereas the didelphic uterus is purported to have a more favorable prognosis (1, 3). The didelphic uterus can be visualized as a symmetrically duplicated unicornuate uterus. Because pregnancy usually occurs in only one of the hemiuteri of a didelphic uterus, it is not clear why Fertility and Sterility
the reproductive outcome of women with a didelphic uterus should be different from the outcome of women with a unicornuate uterus. Most reports in the literature describing the outcome of these two anomalies consist of small case series, whereas other reports have not made a distinction between the unicornuate and the didelphic uterus and have combined the two malformations under the term double uterus. The purpose of this report is to compare the reproductive outcome of women with a unicornuate uterus with the outcome of women with a didelphic uterus. The null hypothesis states that the reproductive outcome between the two groups does not differ; the alternative hypothesis states that there is a difference in outcome between the two groups . MATERIALS AND METHODS
A computerized search of the medical records of patients evaluated at the Johns Hopkins Hospital from approximately 1950 until 1990 was made. The charts of patients with a diagnosis of unicornuate uterus, didelphic uterus, or double uterus were reviewed. The classification scheme proposed by The American Fertility Society (4) was used to classify uterine malformations as either unicornuate (class II) or didelphic (class III). Patients were included in the study if there was sufficient information available in the medical record to accurately classify the uterine anomaly. Patients were excluded if the information in the medical record was insufficient to support the diagnosis or if, after review of the medical record, it was determined that the patient had a malformation other than a unicornuate or a didelphic uterus. The patient population consisted of both inpatients and outpatients in the gynecology and reproductive endocrinology services at the Johns Hopkins Hospital. Patient follow-up was obtained by one or more of the following methods: (1) review of the medical record; (2) consultation with referring physicians; or (3) phone conversations with the patients. Duration of follow-up was determined as the interval of time from the first evaluation at our institution until the time of the last patient contact. Follow-up was obtained for a minimum of 1 year on all study patients. Statistical Analysis
For each patient, the proportion of pregnancies resulting in a given outcome was calculated. Patients in both groups with a given outcome were then ranked, and Wilcoxon's rank sum test was used to Vol. 58, No.1, July 1992
compare the two groups. Differences between means were evaluated by a two-tailed t-test for independent samples. The X2 test was used to compare fetal presentation and delivery mode between the two groups. A P value
