A 35-year-old woman, pregnant for the first time, received pre-eclampsia prophylaxis starting from the 12th week of pregnancy due to her high-risk status. Genetic screening at Tam Anh General Hospital in Ho Chi Minh City identified that the pregnant woman carried a heterozygous gene mutation for 5-alpha reductase deficiency, indicating she carried a gene associated with abnormal sexual development but was not affected by the condition herself.

Doctor Nguyen Thi Mong Nghi, a level 1 specialist at the Fetal Medicine Center, explained that 5-alpha reductase deficiency primarily affects males. This enzyme deficiency disrupts the synthesis of dihydrotestosterone (DHT), which is crucial for external genitalia formation. During fetal development, this can result in ambiguous genitalia and defects such as undescended testes, a small or curved penis, bifid scrotum, and hypospadias. In puberty, DHT is important for prostate development and male hair growth.

This condition is inherited in an autosomal recessive pattern, meaning a child develops it if they inherit two mutated genes, one from each parent. A 20-week ultrasound confirmed the fetus had a ventrally curved penis and hypospadias, with the urethral opening positioned lower than normal.

Hypospadias is a congenital defect of the external genitalia in boys, often an isolated anomaly. However, some cases are associated with other genitourinary abnormalities, such as ectopic or horseshoe kidneys, or ureteropelvic junction obstruction. This condition can also be linked to various genetic anomalies, including: Klinefelter syndrome, Smith-Lemli-Opitz syndrome, Wolf-Hirschhorn syndrome, 5-alpha reductase deficiency, hand-foot-genital syndrome, androgen insensitivity, and adrenal hyperplasia.

"The hypospadias and penile curvature in this fetus could be related to 5-alpha reductase deficiency," Dr. Nghi stated. However, the father had previously refused genetic testing, preventing doctors from conclusively determining if the fetal anomaly was genetic. The pregnant woman declined amniocentesis for a precise diagnosis. Doctors closely monitored the pregnancy via ultrasound, noting no other abnormalities and anticipating the fetal anomaly would not be complex.

At 39 weeks of gestation, the baby boy was born weighing 3.2 kg and was in stable health. Doctors confirmed penile curvature, mild hypospadias, phimosis, and bilateral descended testes. A follow-up appointment is scheduled for one month later to assess the condition and plan treatment.

The obstetrics and gynecology team performed a C-section for the pregnant woman. *Photo: Tam Anh General Hospital*

According to Dr. Nghi, children with untreated hypospadias face a future risk of infertility, particularly if the urethral opening is located in the middle of the penile shaft or at the scrotal base. Treatment primarily involves surgical correction of urethral narrowing, penile curvature, or urethral reconstruction, typically performed between 6 and 18 months of age. In some cases, patients may require hormone therapy, such as testosterone derivatives.

Fetal morphology ultrasound, combined with Doppler ultrasound, can detect hypospadias prenatally through detailed assessment of external genitalia. Therefore, Dr. Nghi recommends that pregnant women undergo regular prenatal check-ups and specialized genetic screening to detect abnormalities early, ensuring optimal treatment for both mother and baby.

Ngoc Chau