Congenital Uterine Abnormalities: An Overview

Introduction

The development of the female reproductive system includes complex processes such as differentiation, migration, fusion, and canalization of the Mullerian ducts. Uterine abnormalities occur when these processes are interrupted. When a female fetus develops, its uterus is formed as two separate halves from two tubular structures known as Mullerian ducts, which fuse before birth. Abnormalities may occur during this process, varying from structural defects to the complete absence of the womb. Although complex anomalies can be identified, other defects may be asymptomatic or not affect pregnancy outcomes. Most of the cases of congenital uterine abnormalities are mostly detected during investigations for miscarriage or infertility. The actual impact depends on the type of anomaly, severity, and its influence on sexuality and reproductive potential as the affected females approach child-bearing age. However, understanding the condition and early intervention, along with advances in imaging techniques and treatment modalities, can help successfully manage congenital uterine abnormalities.

What Are Congenital Uterine Abnormalities?

The reproduction process involves sperm transport, embryo formation and implantation, fetal growth in the uterus, and the development and progress of labor, followed by the baby's birth.

As the female embryo forms, two paired mullerian ducts develop to form the female reproductive tract, including the fallopian tubes, uterus, cervix, and upper vagina. Any abnormalities in the uterus, including congenital anomalies, can adversely impact uterine function. Congenital uterine abnormalities are malformations (abnormal shape or size) or developmental defects of the uterus (womb) and vagina that may occur during embryogenesis. In most of the cases, the exact cause of congenital uterine abnormalities is not understood. These are rare and may occur in less than five percent of women. While a majority of women with these conditions have a normal reproductive outcome, some females may experience certain complications. Early detection and appropriate intervention can help manage these defects and prevent the chances of infertility.

What Are the Types of Congenital Uterine Abnormalities?

Congenital uterine abnormalities have wide anatomical variations and may be complex due to a combination of anomalies and changes that occur during different stages of development. These defects can also affect the fallopian tubes, upper vagina, and cervix, leading to infertility or problems during pregnancy. The types of congenital uterine abnormalities include:

• Uterine Agenesis/Hypoplasia: It refers to the complete absence of the uterus (agenesis) or underdevelopment of the uterus (hypoplasia). It is also known as vaginal agenesis or Mayer Rokitansky Kuster Hauser syndrome and occurs due to the failure of Mullerian ducts to develop completely.

• Didelphys: This condition is also known as double uterus and occurs due to the complete failure of Mullerian ducts to fuse, which results in two small separate uterine cavities with a cervix each. It can also affect the vulva, vagina, urinary bladder, and urethra.

• Unicornuate Uterus: It is also known as a one-sided uterus, as only one-half of the uterus is developed. This is due to the development of only one Mullerian duct, resulting in a single-horn uterus. Although it is rare, some women with unicornuate wombs may conceive.

• Bicornuate Uterus:The uterus appears heart-shaped as the two halves remain separate due to partial fusion of the Mullerian ducts with a deep indentation at the top.

• Arcuate Uterus: It is considered a variation of normal uterine development, as it resembles a normal uterus but with a mild indentation of less than one centimeter at the top of the uterine cavity. This anomaly has a minimal impact on reproductive outcomes.

• Septate Uterus: The uterus may have a normal shape but is divided either partially or completely by a band of muscle, forming two separate cavities within the uterus. This occurs due to incomplete resorption of the medial septum of the Mullerian ducts.

What Are the Symptoms of Congenital Uterine Abnormalities?

Some of the symptoms of congenital uterine abnormalities include:

• Severe pelvic pain.

• Amenorrhea (absence of menstrual periods).

• Pain during sexual intercourse.

• Abnormal or prolonged bleeding during menstruation.

• Difficulty in emptying the bladder.

• Recurrent loss of pregnancy.

• Preterm birth.

What Are the Consequences of Congenital Uterine Abnormalities?

The consequences of congenital uterine abnormalities depend on the type of defect and associated issues.

• Uterine agenesis can lead to primary amenorrhea (failure to start menstrual periods), infertility, chronic pelvic pain, and hypoplastic vagina.

• Women with uterine didelphys and bicornuate or arcuate uterus may not experience difficulty in conception but are at risk of preterm labor or miscarriages.

• Females with a unicornuate, bicornuate, or arcuate uterus can conceive, but this is usually associated with fetal malpresentation (the fetus may lie in an abnormal position in later pregnancy), resulting in cesarean section delivery. A unicornuate uterus can cause complications, such as ectopic pregnancy, restrictions in fetal growth, and preterm birth.

• Women with a septate uterus have difficulties in conception and a high risk of early miscarriage, preterm labor, and a cesarean section delivery.

How Are Congenital Uterine Abnormalities Diagnosed?

The majority of women with congenital uterine anomalies may not be aware of their condition unless it is symptomatic. It may be identified during a routine examination or in case of miscarriage or failure to conceive. A healthcare specialist can suspect congenital uterine abnormalities after taking the medical history and physical examination of the patient. However, diagnostic imaging studies are required to visualize the uterus and confirm the anomaly. Investigations include pelvic ultrasound, magnetic resonance imaging, laparoscopy, and hysteroscopy. Transvaginal ultrasound (TVS) and hysterosalpingogram (HSG) are good screening techniques as they help classify these anomalies and define internal and external uterine contours.

How Are Congenital Uterine Abnormalities Managed?

The management of congenital uterine abnormalities depends on the condition and reproductive history of the patient. The healthcare specialist usually discusses the treatment options with the patient, spouse, and caregivers to help them understand the anomaly. Nonsurgical treatments are not available for treating congenital uterine abnormalities. Surgical intervention depends on the condition, severity, associated factors, reproductive goals, and general health of the patient.

Laparoscopic surgery is usually preferred to minimize the risk of infection and promote faster recovery. If a septate uterus is diagnosed, The septum is surgically removed, and the uterus is opened to its normal shape and size to improve the chances of pregnancy. The obstructed portion may be removed surgically in case of a blockage in the unicornuate uterus and if the other half of the uterus is functional. For women with a risk of preterm labor at later stages of pregnancy, cervical cerclage (narrowing of the cervix with a suture) may be performed to prevent premature dilation. In other cases, surrogacy or assisted reproductive technologies (ART), such as in-vitro fertilization (IVF) procedures and intracytoplasmic sperm injection, may be considered for managing fertility problems, which can be reasonably successful.

Conclusion

Congenital uterine abnormalities refer to the malformations of the uterus due to defects in the Mullerian ducts during embryogenesis. It is associated with pelvic pain, heavy menstrual bleeding, or amenorrhea in some patients. It may be asymptomatic in some females while causing complications such as preterm birth, miscarriages, or infertility in others. Accurate diagnosis, correct classification, and appropriate intervention can help improve reproductive outcomes and prevent future complications.