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 A 30-year-old transgender woman has become the first officially recorded to breastfeed her baby. An experimental three-and-a-half-month treatment regimen, which included hormones, a nausea drug and breast stimulation, enabled the woman to produce 227 grams of milk a day. 
 
 “This is a very big deal,” says Joshua Safer of Boston Medical Center, who was not involved with the treatment. “Many transgender women are looking to have as many of the experiences of non-transgender women as they can, so I can see this will be extremely popular.” 
 
 The transgender woman had been receiving feminising hormonal treatments for several years before she started the lactation treatment. These included spironolactone, which is thought to block the effects of testosterone, and progesterone and a type of oestrogen. 
 
 This regimen enabled her to develop breasts that looked fully grown, according to a medical scale that assesses breast development based on appearance. She had not had any breast augmentation surgery. 
 
 When her partner was five-and-a-half-months pregnant, the woman sought medical treatment from Tamar Reisman and Zil Goldstein at Mount Sinai’s Center for Transgender Medicine and Surgery in New York City. Her partner had no interest in breastfeeding, she explained, so she would like to take on that role instead. 
 
 Enough for six weeks 
 
 A hormone called prolactin usually stimulates the production of breastmilk in women who have just given birth, but this chemical isn’t available as a lab-made drug. Instead, the woman decided to try using a nausea drug called domperidone to trigger breastmilk. 
 
 There’s anecdotal evidence that this drug may boost milk production, although the US Food and Drug Administration has previously warned that it shouldn’t be used for this purpose. 
 
 She took it with increasing doses of the hormones oestrogen, progesterone and spironolactone. At the same time, she began to use a breast pump to stimulate her breasts. 
 
 Within a month, the woman was able to express milk droplets. After three months of treatment, this increased to 227 grams of breast milk per day. Once the baby was born, she was able to exclusively breastfeed the infant for six weeks – during which time a paediatrician confirmed the baby was growing and developing normally and healthily. 
 
 Although significant, this is below the average of around 500 grams that a baby consumes by the time the it is 5 days old. After six weeks, the woman supplemented her breastfeeding with formula. 
 
 Unknown effects 
 
 This is the first case of breastfeeding by a trans woman to be reported in the medical literature, say Reisman and Goldstein. Safer agrees. “It’s out there on internet forums, but there’s a lot on the internet that’s true or untrue to varying degrees,” he says. “It’s a very big deal to have this recorded in a reliable document.” 
 
 But Safer isn’t surprised that it’s possible. “When I treat transgender women, we see good breast development” he says. There’s no reason why the cells in these breasts wouldn’t make milk the same way that those of non-transgender women do, he says, although he notes that it is unclear to what extent the drugs and hormones helped. “For all we know, breast stimulation alone might be sufficient.” 
 
 If the treatment is proven safe and effective, it could benefit the babies of other transgender women, as well as women who adopt or those who have difficulty breastfeeding, says Safer. 
 
 However, the woman’s breastmilk has not been assessed yet, so we don’t know if it has the same mix of components as in milk from new gestational mothers. This means the practice cannot yet be recommended, says Madeline Deutsch at the University of California, San Francisco. She says she can see the potential benefits of breastfeeding, but that the long-term impact of this milk on the baby – including on subtle measures like IQ – is unknown. 
 
 Deutsch herself is a transgender woman with a six-month-old baby who is currently being breastfed by Deutsch’s wife, who was the gestational mother. “I am very sad not to be able to breastfeed her and at the same time I did not consider doing this for the above reasons,” she says. 
 
 Nevertheless, Safer thinks there is likely to be demand for treatments like this. “This is very special,” he says. “It will be very important for the many transgender women who want to breastfeed but do not feel they have the opportunity to do so.” 
 
 Journal reference: Transgender Health, DOI: 10.1089/trgh.2017.0044 
 
 Read more: Why overzealous breastfeeding advice can be bad for babies 

 Medical research Transgender woman able to breastfeed in first documented case Doctors hail breakthrough and say case shows ‘modest but functional lactation can be induced in transgender women’ The report was published in the journal Transgender Health. Photograph: Yui Mok/PA 
 
 A 30-year-old transgender woman has been able to breastfeed her child, the first ever case of induced lactation in a transgender woman to be documented in academic literature. 
 
 Doctors said the case shows “modest but functional lactation can be induced in transgender women”. The account was published in Transgender Health. 
 
 I’m breastfeeding everywhere – and guess what? People are great about it | Nell Frizzell Read more 
 
 Tamar Reisman of Mount Sinai hospital in New York, one of the doctors who reported the case, said: “Transgender medicine is becoming part of mainstream medicine. We’re getting more evidence-based data, we’re getting more standardized care, we’re getting more reproductive options.” 
 
 The transgender woman went to doctors when her partner was five months pregnant. She said her partner did not want to breastfeed the couple’s child, so she hoped to take on the responsibility. 
 
 Reisman and Zil Goldstein wrote that the woman was being treated for insomnia and anxiety, but otherwise appeared to be a “pleasant, well-nourished, well-developed woman”. 
 
 The patient had taken hormone therapy for six years, but had not had gender reassignment or breast augmentation before she approached doctors. Reisman and Goldstein used a framework known to induce lactation in cisgender women who had not experienced a pregnancy to promote the patient’s lactation. 
 
 The patient took a gradually increasing regimen of the female hormones progesterone and estradiol, stimulated her chest with a breast milk pump, and took domperidone, a nausea medication known to increase milk production. 
 
 Domperidone is used internationally but it is not approved in the US, because in some intravenous instances it produced cardiac arrhythmias, cardiac arrest and sudden death. It is licensed to treat nausea in the UK. The patient obtained the drug from Canada. 
 
 Reisman said that with an optimized hormone regimen it may be possible to induce lactation without domperidone, because chest stimulation naturally increases the breast milk-producing hormone prolactin. 
 
 “There have been self-reported cases online of transgender woman trying DIY regiments to induce breastfeeding, but this is the first case of induced functional lactation in the academic literature,” Reisman said. There are also cases of transgender men carrying pregnancies and breastfeeding, she said. 
 
 However, Reisman said the case has also attracted questions about whether men could now breastfeed. “That, implicitly, is saying that you see transgender women as cisgender men, which is transphobic,” she said. 
 
 Joshua Safer, an endocrinologist at Boston Medical Center not involved in the case, told the New Scientist the report is “a very big deal”. 
 
 “Many transgender women are looking to have as many of the experiences of non-transgender women as they can, so I can see this will be extremely popular,” Safer said.
– Though online forums suggest she's not the first to manage the feat, doctors are celebrating the case of a breastfeeding transgender woman, the first to be recorded in medical literature. The 30-year-old went to doctors at New York's Mount Sinai hospital with the intention of breastfeeding when her partner—who did not want to breastfeed—was five months pregnant, per the study in Transgender Health. Though she hadn't undergone gender reassignment or breast augmentation surgery, she'd been taking hormone therapy for six years and was what doctors called a "well-developed woman," per the Guardian. Following a plan to induce lactation in non-trans women, she used a breast pump to stimulate milk production while taking domperidone—a nausea medication linked to increased production—and increasing doses of progesterone, estradiol, and spironolactone, reports New Scientist. Progesterone and estradiol are female hormones, while spironolactone acts as an inhibitor to testosterone. Harder to come by was domperidone (the patient got it from Canada) as it's banned in the US. According to the FDA, it may boost the milk-producing hormone prolactin—doctors say chest stimulation does the same thing—but it has caused heart problems and death, though in those cases it was being administered intravenously. After three months, the woman could produce 8 ounces of milk per day, enough to keep her baby healthy and developing normally for six weeks, though the average baby consumes more than twice that daily. The woman afterwards supplemented with formula. Referring to the study as "a very big deal," an endocrinologist who did not treat the woman predicts the practice "will be extremely popular" in the future, per New Scientist, though doctors aren't recommending it at this time.