A transgender woman has breastfed her partner's baby after stimulating milk production with a regimen of domperidone, estradiol, progesterone, and breast pumping, providing the sole source of nourishment for the baby's first 6 weeks.

This is believed to be the first formal report of induced lactation in a transgender woman, lending weight to the argument that in some circumstances, modest but functional lactation can be induced in men who have transitioned to become women, say the authors, led by Tamar Reisman, MD, Center for Transgender Medicine and Surgery and Icahn School of Medicine at Mount Sinai, New York.

Their short report was published in the January issue of Transgender Health.

The 30-year-old woman sought help to breastfeed the baby she was having with her partner, who was personally not interested in breastfeeding the infant.

Prior to seeking help from Reisman and coauthor Zil Goldstein, NP, also from Mount Sinai, the patient had received feminizing hormone therapy for the preceding 6 years: oral spironolactone 50 mg twice daily, estradiol 2 mg twice daily, and micronized progesterone 100 mg twice daily.

The woman had not had any gender-affirming surgeries such as breast augmentation, orchiectomy, or vaginoplasty. On initial examination the patient was a pleasant, well-nourished, well-developed woman who appeared her stated age. Her breasts were noted to be Tanner stage V.

Domperidone Used to Induce Milk Production, But Is it Needed?

Domperidone, an antiemetic used off-label internationally as a galactagogic, was sourced from Canada. (It is unavailable in the United States because the US Food and Drug Administration has warned against off-label use for this purpose, stating the risks for breastfeeding are unknown.) The patient was started on oral domperidone 10 mg three-times daily just over 3 months before the baby was due.

The patient was also advised to use the breast pump for 5 minutes per breast three-times daily, in the hope that this would increase prolactin and oxytocin levels. After 1 month, she started to produce droplets of milk.

Her drug doses were then increased — domperidone to 20 mg four-times daily, micronized progesterone to 200 mg daily, and estradiol to 8 mg daily — and her breast pump use was increased to six-times daily.

After another month, progesterone was increased to 400 mg daily and estradiol to 12 mg daily, to mimic hormone increases during pregnancy.

Three months after starting treatment and 2 weeks before the baby was due, the patient was making 8 oz of breast milk per day. At this point, her estradiol regimen was changed to a low-dose patch (0.025 mg daily) and her progesterone dose was lowered to 100 mg daily. The reduction in estradiol and progesterone was intended to mimic hormone levels at delivery.

After the baby was born, weighing 6 lbs 13 oz, the pediatrician reported developmentally normal growth, feeding, and bowel habits. At 6 weeks, breastfeeding was supplemented with 4 to 8 oz of formula to ensure sufficient milk volume.

The role of the domperidone in prolactin production is uncertain, say the researchers.

"Although there is significant literature indicating that domperidone increases prolactin levels and milk volume, it is uncertain whether this intervention was necessary to induce lactation. The patient used a breast pump, which likely increased her prolactin levels independently of domperidone."

The benefits of breastfeeding are well known, including immunological, metabolic, and psychosocial benefits for both mother and baby. It also facilitates mother–child bonding, which explains the interest in inducing lactation in adoptive parents, note Reisman and Goldstein.

However, they point out that a major difference between the induction of lactation in cis and transgender women is the need for androgen blockade in the latter group. "Our patient continued to take spironolactone while breastfeeding for androgen blockade."

Although canrenone, a metabolite of spironolactone, is excreted in human milk, it is considered to be present at a clinically insignificant level, and despite reports of tumorigenicity in rats, it is considered compatible with breastfeeding by the American Academy of Pediatrics, they add.

At the time of paper submission, the baby was 6 months old and the patient was continuing to breastfeed as a supplement to formula feeding.

The authors have reported no relevant financial relationships.

Transgend Health. 2018;3:24-26. Article

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