While embryos are male or female from the day of conception, gender isn't obvious on ultrasound until at least 12 weeks, and more often 16 to 20 weeks, Dr. Joseph Woo of Hong Kong states in Obstetric Ultrasound. Male and females fetuses have identical genitalia until the male sex organs differentiate under the influence of testosterone. Genital defects arise either from abnormal hormone levels or from genetic metabolic or chromosomal disorders, the Merck Manuals states. Genital defects can affect a child's physical and emotional status, as well as having strong emotional effects on the parents.
Ambiguous Genitalia
The number one question parents ask during prenatal ultrasounds, according to Dr. Joseph Woo, is whether their baby is a boy or girl. In around 1 in 4,500 cases, according to the March of Dimes, the answer isn't obvious, even after birth. Babies with ambiguous genitalia don't have a definite male or female appearance, although chromosomal testing will reveal whether the baby is male or female. Assigning gender when genitalia are ambiguous isn't always as simple as chromosomal testing, though. Environmental and psychological factors, as well as parental feeling, must be taken into account, the Merck Manuals advises.
Most newborns with ambiguous genitalia have normal male or female internal organs, Merck states. Surgical correction of external genitalia and testosterone administration can help in cases of male ambiguous genitalia. The most common cause of female ambiguous genitalia is congenital enlarged adrenal hyperplasia, or enlarged adrenal glands, which produce excess male hormones, according to Merck. The clitoris grows larger than normal, resembling a penis. Surgery can help create more female appearing genitalia.
Epispadias
Epispadias is a rare genital defect, occurring in 1 in 30,000 births, according to the March of Dimes, that affects males slightly more often than females. Epispadias, a split in the urethra on the upper side of the penis in boys and in the clitoris in girls, causes bladder control problems in 50 percent of children, the March of Dimes reports. Bladder exstrophy, where the bladder turns inside out and forms outside the abdomen, often occurs in conjunction with epispadias. Surgeons usually perform exstrophy repair within the first 48 hours of a baby's life, with genital defects corrected around 6 to 12 months.
Hypospadias
Hypospadias affects as many as 1 in 300 male infants, the Merck Manuals states. In hypospadias, the urethra, the opening of the penis, doesn't reach the tip of the penis. The opening occurs instead on the underside of the penis. Circumcision is deferred because the foreskin may be needed for surgical repair of the defect, which usually occurs between the ages of 3 and 18 months.
