Operative Concerns in Patients With Congenital Anomalies of the Reproductive Tract and External Genitalia for the Obstetrician
Oluyemisi Adeyemi-Fowode
Jennifer E. Dietrich
GENERAL PRINCIPLES
Reproductive tract development begins at 6 to 7 weeks gestational age and is initially guided by the presence or absence the sex-determining gene (SRY gene). In the absence of SRY gene (located on the Y chromosome), female anatomy ensues (see Figure 2.1.1) (1).
Definitions
Müllerian Anomaly
Müllerian anomaly: Anatomic abnormality of the female reproductive tract
Figure 2.1.1. Gestational age (GA) and reproductive tract development.
Figure 2.1.2. Müllerian anomaly classification system. A: Type I, B: Type II, C: Type III, D: Type IV, and E: Type V. Illustrations by Donald A. Dyer, MD, with permission granted for use by Jennifer E. Dietrich, MD, MSc.
Incidence: ˜7% of females (1)
Causes: Abnormality in the development or migration of the Müllerian duct, which can lead to agenesis, vertical fusion defects, lateral fusion defects, or resorption defects of the Müllerian duct
Classification system: The most commonly used classification for uterine anomalies is the American Fertility Society (see Figure 2.1.2) (2,3).
Reproductive tract anomalies, including Müllerian anomalies, can be classified into nonobstructive versus obstructive (see Table 2.1.1).
Table 2.1.1 Müllerian Classification | |||||||||||||
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Disorders of Sex Development (DSD)
DSD: Rare congenital conditions in which the development of the chromosomal, gonadal, or anatomic sex is atypical (4).
Incidence: Approximately 1:2,000, but data are limited (5).
Causes/classification system: DSDs are categorized into three main types: 46, XX DSD, 46, XY DSD, and sex chromosome DSD (see Table 2.1.2) (4).
Congenital adrenal hyperplasia (CAH) is the most common cause of ambiguous genitalia, which results from a deficiency in one of the several enzymatic steps necessary for normal steroid synthesis. A cardinal feature of classic or severe virilizing CAH in newborn females is abnormal development of the external genitalia with a variable extent of virilization (see Figure 2.1.3) (6).
Anorectal Malformation (ARM)
ARM: A spectrum of disorders that may affect males and females, with varying severity in the presentation, which involves abnormal development of the anus and rectum. These disorders are commonly associated with abnormal urogenital development, including Müllerian anomalies, in females.
Incidence: 1:5,000 (7)
Cloaca: The most severe type of ARM where the urethra, vagina, and rectum fail to develop separately, creating a common channel that opens into a single orifice at the perineum (see Figure 2.1.4). Cloaca is a rare form of ARM with an incidence of 1:50,000 (8). This type of anomaly is also associated with a higher risk for Müllerian anomaly (9).
Table 2.1.2 Disorders of Sexual Differentiation Classification | ||||||||||||||
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 Figure 2.1.3. Prader scale. |
 Figure 2.1.4. Cloacal malformation. (Illustrations by Donald A. Dyer, MD, with permission granted for use by Jennifer E. Dietrich, MD, MSc.) |
Physical Examination (Table 2.1.3)
Table 2.1.3 Basic Physical Examination Features | ||||||||||
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IMAGING AND OTHER DIAGNOSTICS
Besides obtaining a proper history and physical examination, imaging plays an important role in the diagnostic process of reproductive tract anomalies.
The initial imaging modality for reproductive organs is pelvic ultrasonography. Transvaginal ultrasonography has a reported accuracy rate of 90% to 92% in diagnosing Müllerian anomalies in adult women (10). In the prepubertal/adolescent gynecology population, the transvaginal ultrasound is typically not tolerated or possible. In such cases, transabdominal ultrasound is more easily accomplished; however, its accuracy rate is less compared to transvaginal approach (10). On occasion, translabial or transperineal ultrasonography, in addition to a transabdominal sonographic approach, may be helpful to delineate an obstruction and sometimes may be better tolerated than a vaginal approach to ultrasonography (1).
The ideal imaging modality for the evaluation of a Müllerian anomaly is magnetic resonance imaging (MRI). It is noninvasive, does not involve ionizing radiation, has multiplanar capability, and allows for detailed delineation of the uterovaginal anatomy (11,12). Although 3D pelvic ultrasonography has been shown to be comparable to MRI, these conclusions were based on studies in adult women with the use of transvaginal ultrasonography (13,14).
It is also important to keep in mind that there are other anomalies associated with Müllerian and vaginal anomalies. Renal tract abnormalities are the most common abnormality associated with congenital anomalies of the female reproductive tract (15). Approximately 30% of the time, urinary tract abnormalities will arise and include ipsilateral renal agenesis, duplex collecting systems, renal duplication, horseshoe-shaped kidneys, crossed renal ectopy, and cystic renal dysplasia (13,15).
Spinal abnormalities are also seen in this population and may preclude spinal anesthesia in some cases. For instance, among patients with ARMs, renal, cardiac, esophageal, and spinal abnormalities can also occur concurrently (7).
PREOPERATIVE PLANNING
General Overview
Nonobstructive Reproductive Tract Anomalies (16)
Nonobstructive anomalies typically do not need surgical management except for the septate uterus or a didelphic uterus with a nonobstructive longitudinal septum.
Septate uterus: Resection of the uterine septum is typically performed before pregnancy as persistence of the septum can predispose to abnormal implantation of the placenta in future pregnancies or recurrent pregnancy loss.
Nonobstructive longitudinal vaginal septum: A vaginal approach is typically used to resect the septum up to the level of the cervix. Rarely, post vaginal septum resection, there may be a residual vaginal scar or stenosis that may obstruct labor (see Table 2.1.4).
Obstructive anomalies are typically not an emergency; however, hematocolpos and hematometra can occasionally cause a mass effect on surrounding structures, potentially leading to urinary retention, hydronephrosis, acute kidney injury, and constipation.
Consulting with providers familiar with the anatomy as well as preoperative imaging may be helpful for delivery planning.
Reviewing the typical surgical management can aid in understanding whether certain patients are at risk of having a vaginal or uterine scar (see Table 2.1.4).
With an understanding of the typical approach to reproductive tract anomalies, subsequent questions then become paramount to decide which mode of delivery may be safest for a particular patient. These can be categorized into several major groups: history of prior surgery for Müllerian or vaginal Anomaly, history of prior surgery for cloaca or ARM, history of surgery for DSD, discovery of Müllerian or vaginal anomaly antenatally or in labor, and history of uterine transplant (Table 2.1.5). Each category includes unique features that should prompt evaluation for underlying risks and should be based on a review of old records, imaging, and any other special concerns (see Table 2.1.5).
