Genetically and physically, male babies born with a condition called "micropenis" are more likely to achieve psychological and sexual well-being in adulthood if raised male, according to a new study by researchers at Johns Hopkins and three other centers. Their report in this month's Hormone Research is the first comprehensive, long-term study examining psychological and sexual outcomes for both men and women.

People born with a micropenis and raised as girls said they identified solidly with their female gender, but only 20 percent of the women said they were satisfied with their genitalia. In contrast, 50 percent of men, some of whom had attained normal penis length with the help of testosterone replacement, said they were satisfied with their genitalia. Like the women, men said they identified with their male gender.

"Raising the baby either male or female presents parents with challenges," says Johns Hopkins Children's Center psychologist Amy Wisniewski, Ph.D., lead author of the study. "But we were pleased with the successful outcome of some of the males. All men who were compliant with their testosterone replacement attained a final penile length within the normal range."

The research team collected birth and adult genitalia measurements from 13 men and 5 women, all born with a micropenis. The researchers surveyed the individuals, all adults between 21 and 54 years of age at the time of the study, for self-assessments of gender identity, sexual function and satisfaction with their genitalia. The researchers also asked the participants questions regarding sexual orientation, marriage and satisfaction with their sex of rearing.

Of the 12 men who responded, 10 reported a male heterosexual orientation, six were married, and 11 said they were satisfied with their sex of rearing. Among the women, three (of four responding) reported a female heterosexual orientation, none was married, and all were satisfied with the sex of their rearing, although men were more often satisfied with the appearance of their genitalia.

While the researchers do not necessarily recommend that parents raise a baby with a micropenis as male, their study suggests that a child raised female would require extensive feminizing treatments to achieve satisfactory cosmetic and functional outcome for her genitalia.

"Patients reared male considered themselves to be masculine and those raised female considered themselves to be feminine," Wisniewski says. "Our recommendation that babies be raised male is based not on problems with gender identity but on the difficulties associated with the surgical construction of a vagina and subsequent hormone treatment."

Micropenis occurs when the penis elongates properly during the first trimester of a genetically male embryo's development but fails to grow normally during the second and third trimesters. Micropenises are typically 1.9 cm (0.75 inches) or less at birth when stretched. Micropenis may also be accompanied by small testes and lower testosterone production, which often leads to enlarged breasts and sparse body hair as the child grows older.

Because the micropenis birth defect can, in some cases, result in inadequate male sexual function later in life, some parents have chosen to raise their child female with the hope that genital reconstruction is more likely to result in a strong sexual identity, positive body image and pleasurable sex life.

Johns Hopkins Children's Center endocrinologists Claude Migeon, M.D., and Leslie Plotnick, M.D., urologist John P. Gearhart, M.D., John Money, Ph.D., and researchers at the Johns Hopkins School of Medicine, Emory University School of Medicine, the University of Miami School of Medicine, and the Columbia University College of Physicians and Surgeons also contributed to the study. It was funded by grants from the Genentech Foundation for Growth and Development, the National Institutes of Health, the National Center for Research Resources, and the Johns Hopkins School of Medicine.

"Congenital Micropenis: Long-Term Medical, Surgical, and Psychosexual Follow-Up of Individuals Raised Male or Female" Hormone Research 2001; v.56, pp.3-11

---Johns Hopkins Medical Institution

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