By Dr. Alejandro Olloqui Escalona (Licensed Gynecologist – 282867126).
A bicornuate uterus is a congenital malformation (one of the most common) in which the uterine cavity presents a partial division, forming two “horns” that share a common base. This abnormal development occurs during embryonic life, when the Müllerian ducts (the structures that give rise to the uterus, fallopian tubes, and part of the vagina) fail to fuse completely.
The degree of separation varies, and depending on the case, the uterus may present very subtle shapes or almost duplicated cavities. This morphology determines the severity of symptoms and the potential difficulties in achieving pregnancy.
Most women with a bicornuate uterus do not present obvious symptoms or specific discomfort, discovering the condition incidentally during a routine ultrasound or fertility assessment. However, some may experience more painful menstruation, irregular bleeding, or pelvic discomfort often attributed to other gynecological causes.
The presence of uterine malformations does not necessarily mean that achieving a pregnancy is impossible. In many cases, these anomalies go unnoticed throughout a woman’s life and are only detected when she begins trying to conceive and does not succeed.

The origin of a bicornuate uterus is strictly congenital. It does not develop over time but is present from birth. It occurs when the structures that must fuse to form the uterine cavity fail to do so completely, for reasons not yet fully understood. Genetic or environmental factors during the early weeks of gestation may play a role.
Regarding fertility, having a bicornuate uterus does not prevent pregnancy. However, it may increase the risk of first-trimester miscarriage (and second-trimester loss in more severe cases), preterm birth, and restricted fetal growth if the available uterine space is reduced. The severity of symptoms depends on the degree of malformation; the more pronounced the separation, the higher the likelihood of obstetric complications.
Treatment is possible but not always necessary and depends largely on the type of uterine anomaly. In many cases, closer obstetric monitoring during pregnancy is sufficient. Corrective surgery, known as metroplasty, is reserved for selected cases in which the malformation is incomplete and clearly associated with recurrent miscarriage or significant complications. The goal of this procedure is to unify the cavity to improve the space available for pregnancy development, although it is not routinely performed.
Ultrasound of a bicornuate uterus
It is important to note that pregnancy rates depend primarily on embryo quality and other associated reproductive factors. Therefore, this malformation does not contraindicate in vitro fertilization (IVF). Many women discover the diagnosis during the preparatory evaluation prior to treatment without having had previous gynecological issues.
Implantation in a bicornuate uterus mainly depends on the shape and space available within the cavity where the embryo is placed. In most cases, implantation occurs normally, although uterine morphology may affect space and vascularization in certain areas. For this reason, a detailed assessment with 3D ultrasound is usually performed to identify which part of the uterus offers the best conditions for embryo transfer.
Although implantation rates are not typically significantly reduced, careful early pregnancy monitoring in a specialized clinic is recommended, as there may be a slightly increased risk of early miscarriage or preterm birth. This specialized follow-up is essential to minimize complications and ensure optimal conditions throughout gestation.