Female Congenital Anomalies
Congenital (present from birth) anomalies are malformations of the female genital tract (vagina, cervix, uterus, fallopian tubes, and ovaries). They occur during embryonic development (before birth) but may not become obvious until puberty or later. The cause of these abnormalities is unknown.
Uterine Abnormalities
Uterine anomalies are caused by incomplete fusion of the tissues from which the uterus, cervix and upper vagina develop during the first few weeks of embryonic growth. The Mullerian ducts are the precursors to the female reproductive tract, producing the fallopian tubes, uterus, cervix, and upper vagina. Mullerian ducts are suppressed in male embryos. The development of the Mullerian ducts is controlled by the presence or absence of antimullerian hormone (AMH). Partial or incomplete development of the Mullerian duct can result in a wide variety of congenital anomalies.
Partial fusion may result in a single vagina, a single cervix and two uteri that are partially fused to each other. Both uteri may or may not connect to the cervix or vagina. Almost any variation of this can (and has) happened. 2 vaginas, each with a cervix; ½ of a uterus (hemi-uterus) connected or not connected to a vagina; a small rudimentary uterine horn not connected to any other structure; 2 cervices (one connected to a uterus, one not), one or two ovaries with or without fallopian tubes, and two uteri, each with its own cervix and vagina; all have happened.
Other anomalies occur solely within the uterus (the ovaries, fallopian tubes, cervix, and vagina are normal). There may be a wall (partial or complete) within the cavity of the uterus. This is called a uterine septum. The uterus may also have an abnormal shape – arcuate uterus (heart shaped), bicornuate, and t-shaped are the most common. The drawings below depict a few of these uterine abnormalities.
With modern 3-D transvaginal ultrasound, the majority of these congenital anomalies can be diagnosed without surgical intervention.
- Some anomalies cause no problems at all, others may be associated with:
- Menstrual cramps
- Collection of blood in the abnormal structures causing pain
- Difficulty attaining pregnancy
- Increased risk of miscarriage
- Complications of pregnancy, including premature labor and abnormal presentations requiring cesarean section
- Vaginal Abnormalities
Congenital abnormalities of the vagina include:
- Vaginal agenesis (absent vagina). Usually, the uterus is absent but ovaries are present.
- Vaginal atresia (absent lower vagina). A normal uterus is usually present.
- Mullerian aplasia (nearly all the vagina and most of the uterus are absent). This may be associated with other anomalies (fused cervical vertebrae and middle ear defects).
- Transverse and longitudinal vaginal septa (may be single or multiple and sometimes there are holes in the septa).
- Any of these may be associated with abnormalities of the urethra.
Hymeneal Abnormalities
An imperforate hymen completely obstructs the vaginal opening and prevents menstrual blood from getting out of the vagina. It may be congenital or the result of an injury.
Cloacal Dysgenesis – This occurs when the outlets for the urinary, genital and intestinal tracts come out in or near the same place.
Ovarian Abnormalities
Ovaries may be congenitally absent or very small (ovarian agenesis or dysgenesis). This is most commonly caused by chromosomal abnormalities (usually absence of one X chromosome, known as Turner’s Syndrome).
Uterine anomalies are commonly associated with abnormalities of the urinary tract, particularly the kidneys and ureters.
The photos below demonstrate some of these abnormalities.
It will be easier to understand the abnormal photos below when you compare them to a normal pelvis. This photo shows a normal uterus, fallopian tubes, and ovaries.
These photos show a normal left tube and ovary (photo on the left) and a right tube and ovary (photo on the right).
These 3 photos demonstrate a double uterus (didelphus), each with a normal cervix and single vagina. The fallopian tubes and ovaries are normal.
This photo shows a “blind”left uterine horn. There is a normal vagina, but no cervix. The left side of the uterus, left fallopian tube, and left ovary did not develop. The right fallopian tube is also absent.
Left photo: A normal right “hemi-uterus” is attached to a normal right fallopian tube and normal right ovary. The left half of the uterus did not develop, but there is a normal left ovary and a rudimentary left fallopian tube. The structure to which the left fallopian tube and left ovary is attached is a small mass of uterine muscle that should have developed into the left side of the uterus. Right photo: The same situation, but there is no development of the left side of the uterus.
Left photo: Demonstrates the same developmental anomaly as the left photo just above. The whitish mass on the top of the left uterus is a small fibroid tumor. Right photo: Complete uterus didelphus – completely separate left and right uterine “halves”, each with its own fallopian tube, ovary, cervix, and vagina.