Kaur Parneet, Carlson Karen, Panneerselvam Deepan
Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar
University of Nebraska Medical Center and Nebraska Medicine
In 2021, the American Society of Reproductive Medicine (ASRM) Müllerian Anomalies Classification created 9 classifications: : Cervical agenesis. Müllerian agenesis. Unicornuate uterus. Bicornuate uterus. Septate uterus. Uterus didelphys. Longitucinal vaginal septum. Transverse vaginal septum. Complex anomalies . The most common subtype of Müllerian anomalies is the unification defect known as a bicornuate uterus (55.1%-73.5%). A bicornuate uterus arises from incomplete fusion of the paired Müllerian ducts during embryogenesis, typically between the sixth and tenth weeks of gestation. This anomaly results in a uterus with 2 distinct endometrial cavities and a single cervix, although variations exist (see Uterus Embryology). Clinically, a bicornuate uterus is associated with an increased risk of infertility, recurrent pregnancy loss, preterm labor, malpresentation, and adverse obstetric outcomes. Accurate diagnosis, often requiring advanced imaging modalities such as 3D transvaginal ultrasound or magnetic resonance imaging (MRI), is essential to differentiate it from other uterine anomalies like a septate uterus, which has markedly different management implications. The risk of severe maternal morbidity for a bicornuate uterus is 3.0%.
子宫先天性畸形是苗勒管发育过程中中隔融合、管道化及吸收异常的结果。1979年，巴特兰和吉本斯最初根据苗勒管发育失败的程度对苗勒管异常进行了分类。1988年，美国生殖医学学会接受并修订了该分类，将苗勒管异常分为七类。I类——发育不全/发育不良。II类——单角子宫，IIa型伴有残角且残角与宫腔相通；IIb型伴有残角但残角与宫腔不相通；IIc型伴有无腔的残角；IId型无残角。III类——双子宫。IV类——双角子宫（IVa型为完全性双角子宫，IVb型为部分性双角子宫）。V类——纵隔子宫。VI类——弓形子宫。VII类——己烯雌酚相关异常。2016年，美国生殖医学学会进一步对分类进行了重组，将弓形子宫和正常子宫归为同一类。双角子宫是苗勒管部分融合的结果，导致子宫呈心形而非梨形。根据宫颈的分隔情况，双角子宫进一步分为两种类型：1. 双角单颈子宫。2. 双角双颈子宫。
