Neonates

The delivering obstetrician should briefly examine the external genitals of female infants to confirm the patency of the vagina and assess the presence of any obvious genital anomalies. The pediatrician’s newborn examination should note any abnormal findings such as ambiguous genitals, imperforate hymen, urogenital abnormalities, abdominal mass, or inguinal hernia that might herald a gynecologic problem.

Placing the infant in the supine position with thighs flexed against the abdomen allows visualization of the neonate’s external genitals. Estrogenic effects commonly apparent include prominence of the labia majora and a white vaginal discharge. The labia minora and hymen may protrude slightly from the vestibule. The hymen should be evaluated for patency. A small amount of neonatal vaginal bleeding due to endometrial sloughing, following maternal hormone withdrawal, might occur. Bleeding that is excessive or persistent beyond 1 mo of life requires additional evaluation. Breast buds may be palpable and regress in the first months of life; occasionally nipple discharge occurs.

The vaginal orifice may be difficult to see. Gentle lateral traction on the labia majora usually allows complete visualization of the hymen and vaginal orifice. Most hymenal variations—imperforate, microperforate, septate—do not require treatment during the neonatal period. Variations should be noted and readdressed in subsequent visits. The hymen originates from the urogenital sinus, in contrast to the uterus and vagina, which originate from müllerian ducts. The concomitant renal malformations seen with müllerian anomalies are not associated with hymenal anomalies. Hymenal polyps seen in newborns typically regress in size as the maternal estrogen effects subside. Cervicovaginal mucus secretions can accumulate behind the blocked outflow tract of an imperforate hymen and manifest as a mucocolpos. Correction of imperforate hymen in the neonatal period is indicated if urinary obstruction occurs.

The clitoris may appear large in proportion to the other genital structures, especially in premature infants. If the clitoris appears enlarged, the clitoral width should be measured; values >6 mm in a newborn indicate a need for further evaluation. If clitoromegaly and ambiguous genitals are present, the immediate concerns of the obstetrician and pediatrician are to obtain expert consultation for the infant and to counsel the parents. Congenital adrenal hyperplasia is the most common cause of ambiguous genitals (accounting for >90% of cases), and salt-wasting forms can lead to rapid dehydration and fluid and electrolyte imbalance (Chapter 570). Delay of diagnosis and treatment of congenital adrenal hyperplasia may be life-threatening.

In the neonate, the ovaries are <1 cm in diameter and average 1 cm³ in volume. Antenatal or postnatal abdominopelvic ultrasound might reveal small simple ovarian cysts (normal follicles). Because of the abdominal location of ovaries in the neonate, ovarian enlargement can manifest as a palpable abdominal mass. Large cysts (>4-5 cm) or those of a complex nature might signify neonatal ovarian torsion, hemorrhage into the cyst, or, uncommonly, an ovarian tumor. A nonresolving or enlarging neonatal ovarian cyst warrants expert consultation. If the mass causes respiratory compromise or gastrointestinal obstruction, decompression is usually performed. Cyst aspiration can give temporary relief, but the cyst wall should be surgically removed to prevent reaccumulation of fluid and provide a pathologic diagnosis. Preservation of normal ovarian tissue is recommended for all benign lesions, and salpingo-oophorectomy should not be performed unless clinically indicated.

Infants and Prepubertal Girls

As the maternal estrogen effect subsides, the genitals of the female infant change in appearance. The labia begin to flatten. The hymenal membrane loses its redundancy and becomes translucent. The hypoestrogenic prepubertal vaginal epithelium appears thin, red, and sensitive to the touch. The vaginal mucosa of young children can have longitudinal ridges running along the axis of the vagina at 3 o’clock, 6 o’clock, and 9 o’clock, which can cause small protrusions on the hymen at these locations. The cervix usually appears flat and flush with the vaginal vault. During infancy, the uterus regresses in size and does not return to its birth size until the 5th or 6th year. The prepubertal cervix:fundus ratio is 2 : 1.

As puberty approaches, the child experiences increasing endocrine activity of the hypothalamus, pituitary gland, adrenal gland, and ovaries (Chapter 555). The labia majora begin to fill out and the labia minora thicken and elongate as a result of increased estrogen levels. The hymen thickens and becomes more redundant. Clear or white physiologic secretions may be present. Breast buds begin to appear, initially with one side first, or as a pair.