Assessment of the Incidence of Müllerian Anomalies in Central Illinois

Abstract

Introduction: Müllerian anomalies include a spectrum of malformations resulting from the underdevelopment of the Müllerian duct during embryological development. This results in a malformed vagina, uterus or both. Complete agenesis of one or both of these structures in a subset of these cases is known as Mayer‐Rokitansky‐Küster‐Hauser (MRKH) syndrome. There are two types of Müllerian agenesis: Type I MRKH only affects the upper vagina, cervix and uterus, whereas Type II MRKH has associated malformations affecting the renal, auditory and skeletal systems. The reported prevalence is approximately 1 in 5,000 for MRKH syndrome and ~5.5 in 100 for all Müllerian anomalies; however, there is a broad range in the described incidence rates. Purpose: We hypothesized the patient population served by the Department of Ob/Gyn, Division of Reproduction, Endocrinology and Infertility (REI) at Southern Illinois University (SIU) School of Medicine has a higher incidence of Müllerian anomalies and MRKH. Our objective was to assess the incidence of these Müllerian anomalies and describe the types of anomalies that affect women in Central Illinois. Methods: All patients receiving care at SIU Ob/Gyn, Division of REI from 01/1/2010-07/31/2021 were queried using specific ICD-9 and 10 codes and further screened to verify eligibility. A retrospective review (IRB# 21-893) was then conducted on all eligible subjects and relevant health information was extracted from the electronic health record. Continuous variables were measured by central tendency (mean or median) and dispersion (standard deviation or range). Categorical variables were described using frequencies and percentages. Results: The initial query identified 282 individuals of which 81 were deemed eligible (i.e., confirmed Müllerian anomaly). The total number of unique patients who underwent an ultrasound at REI during that time of study approval was 697. Based on these data, the calculated incidence of Müllerian anomalies in the REI patient population is ~11.6% and the incidence of MRKH is 57 in 5000. Demographics included: 74 subjects were White (91.4%), two Black or African American (2.5%), one Asian (1.2%) and 4 declined to report their race or identified as more than one race (4.9%); two subjects were of Hispanic ethnicity (2.5%). Mean ages at menarche and diagnosis were 12.7 ± 1.7 and 27.8 ± 6.4 years, respectively. Eight subjects diagnosed with MRKH had Type I MRKH. The specific type of anomalies identified included: uterine septum (29.1%), arcuate uterus (25.3%), unicornuate uterus (19.0%), agenesis (10.1%), bicornuate uterus (6.3%), uterus didelphys (6.3%) and 3.8% had another type of anomaly. The majority of patients underwent surgery within approximately one year of diagnosis (74%). Postoperative complications were rare (~7%) and included mild constipation, urinary retention and bleeding from the incision site. Pregnancy outcomes were as follows: prior to diagnosis, 3 (30%) infants were preterm vs. 7 (70%) term and those were spontaneous conceptions; after diagnosis 4 (30%) infants were preterm vs 9 (70%) term deliveries and the most common methods of conception were spontaneous and ovulation induction; post-surgery 11 (31%) infants were born preterm vs 24 (69%) term deliveries, and the most common methods of conception were ovulation induction and in-vitro fertilization. Conclusions: From this initial investigation, we found the incidence of Müllerian anomalies in the SIU Ob/Gyn, REI population is higher than the wide range of reported values. As expected, the vast majority of these patients underwent surgical management with little or no complications. We aim to further study what factors/exposures may be impacting the development of female fetuses resulting in Müllerian anomalies.