NOTE: This is a chapter from my book ‘Born in the Right Body‘, which is based on my 2018 critique of “male lactation” experiments.

This updated analysis comprehensively addresses all studies I could find at the time of publication (November 2022). At the end of this article, you can also see additional comments addressing one study that was published since (March 2023) and one from January 2021 that I missed, but which has the same issues.

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In 2018, media outlets all over the world reported on a case study where a doctor, and a nurse, at a clinic in the United States used a cocktail of drugs to enable a male patient, who identified as a woman, to breastfeed a newborn baby (Reisman & Goldstein, 2018).

A UK expert commented that this was “exciting” research which could lead to more cases of “transgender women” breastfeeding (Therrien, 2018). According to Reisman & Goldstein, the male patient (who is referred to as a “she” throughout the study) claimed that his partner – the baby’s mother – was pregnant but not interested in breastfeeding, and that he was hoping to take on the role of being “the primary food source” for this infant. However, reading the paper, I could not find any evidence that the authors interviewed the mother to verify their patient’s claims, or that they obtained informed consent from the mother by discussing the risks that male drug-induced galactorrhoea (nipple discharge unrelated to milk production during pregnancy and breastfeeding) could pose to the baby.

They did report that their patient had a history of “gender incongruence” but had had no gender reassignment surgeries, which means he was a fully sexed male at the time of the study. His “gender-affirming regimen” included spironolactone (a heart medication used in this case as an androgen blocker), estradiol and micronised progesterone. He was also taking occasional clonazepam and zolpidem for a panic disorder and insomnia.

At the initial appointment the patient had gynaecomastia (an abnormal enlargement of a man’s breasts usually due to a hormonal imbalance or the result of hormone therapy), which was likely a side effect of the spironolactone and cross-sex hormones he was taking.

His serum testosterone level on initial examination is unclear because two markedly different values were given: 256 ng/dL in the body of text and 20.52 ng/dL in the results table 1. The authors reported no further testosterone data, which indicates that they did not measure the patient’s testosterone level at any other point in the study.

In order to make sense of this glaring inconsistency, I took into account the evidence that three-quarters of trans-identified men on spironolactone and estradiol fail to reach testosterone levels within the female range (Liang 2018). I concluded that the higher figure is likely to be correct, and that this patient’s testosterone was not adequately suppressed despite the authors emphasising that androgen blockade was an important part of the prescribed regimen.

While the testosterone level of 256 ng/dL might be slightly low for a man (normal male range is 265 – 923 ng/dL), it still far exceeds the normal female testosterone range of 15-70 ng/dL. In cases of Polycystic Ovarian Syndrome (PCOS) the female testosterone levels are increased, but still lower than 150 ng/dL, whereas female testosterone levels that exceed 200 ng/dL are suggestive of an ovarian or adrenal tumour (Sheehan, 2004).

There’s a paucity of research into the effects of elevated testosterone on breast milk and breastfed infants. In one case report, a post-partum woman with depressive symptoms was given testosterone, both orally and vaginally (doses unknown), as well as subcutaneously via a 100 mg testosterone pellet, to improve her mood. The study concluded that “testosterone was very low in infant blood at baseline and during testosterone therapy by pellet implant. There were no adverse clinical effects in the infant after seven months of continuous testosterone therapy to the mother by subcutaneous pellet implant. Testosterone delivered by sublingual drops, vaginal cream, and pellet implant was absorbed but not measurably excreted into breast milk” (Glaser et al, 2009). However, crucial details are missing from this study – such as the age and sex of the infant, as well as the extent of breastfeeding.

Another case study concerns a trans-identified female patient (described as a “transgender man”) resuming weekly testosterone injections at 13 months post partum, as a part of her “gender affirming therapy”. This study showed that “milk testosterone concentrations also increased with a maximum concentration of 35.9 ng/dl when the lactating parent was on a dose of 80 mg subcutaneous testosterone cypionate weekly. The calculated milk/plasma ratio remained under 1.0 and the calculated relative infant dose remained under 1%. The infant had no observable side effects, and his serum testosterone concentrations remained undetectable throughout the study period.” (Oberhelman-Eaton, et al., 2022)

This study likewise did not report the extent of the breastfeeding, and significantly, the infant in this study was male and 13 months old.

We already know that elevated testosterone in pregnant women inhibits breastfeeding, and it exposes foetuses to an hyperandrogenic environment in the womb (Barry, 2010). This can cause a variety of medical complications in girls, such as polycystic ovaries, insulin resistance and Congenital Adrenal Hyperplasia, as well as increase likelihood of gender non-conforming behaviour in childhood (Phillipson, 2013).

Considering that, currently, gender non-conformance increases the likelihood of a child being diagnosed as “transgender”, that this frequently results in paediatric gender reassignment, and that the effects of elevated breast milk testosterone on newborns of both sexes are not known, there are serious ethical issues here. Including with the decision, by clinicians, to enable a man whose testosterone suppression isn’t adequately demonstrated to breastfeed a potentially female infant.

This brings me to another glaring omission in this report. While the authors consistently refer to their trans-identified male patient as “she”, they never state the sex of the infant involved in this experiment.

In addition to my concerns about high levels of testosterone in breast milk, this male patient is also reported to have used domperidone to stimulate galactorrhoea. Domperidone is banned in the US (FDA, 2004), and is only used off-label internationally to induce lactation in women. Domperidone is sometimes used to treat reflux but it has been discontinued for use in children under the age of 12, due to potential cardiac side-effects (MHRA, 2014). When domperidone is given off-licence to stimulate lactation, it requires ensuring that the mother and infant don’t have any contraindications to this treatment (Nottinghamshire Area Prescribing Committee, 2021).

There’s no evidence, here, that the authors attempted to ascertain this.

There’s also no evidence that the patient stopped using clonazepam, a drug that can cause sedation in infants, or zolpidem (also known as Ambien), which could exacerbate the effects of clonazepam, prior to commencement of “breastfeeding”.

When we talk about the safety of medicines in breastfeeding, we weigh the benefits of mother’s milk to the health of the child, and of bonding between the mother and baby, against the risks of discontinuing the medication. If it is at all possible and medically justified, mothers who take medicines that could be passed to their babies via breast milk often decide, or are advised, not to breastfeed in order to avoid adversely affecting their baby’s health.

Contrast this with a man taking unnecessary medications to induce galactorrhoea, just so he can fulfil his desire to breastfeed.

A word on a male’s desire to breastfeed.

Psychosexual disorders such as autogynaephilia are present in a proportion of men who identify as women, and a breastfeeding fetish can be a feature of this condition, as this excerpt from a news article written by one such man illustrates:

“Breastfeeding is freaky. Not the sucking bit. You’re reading The Stranger, so odds are you’ve had a titty sucked at some point in your life. No, it’s because when my baby attached to my breast, there was an incredible chemical cascade that ran through my entire body like lightning. Imagine the most electric thing a partner has ever done to you, then multiply it by 10. I could feel my brain rewiring, creating pathways that would permanently connect me to my child. (And yeah, I kind of got off on it. Don’t judge.)” (Fried, 2017)

It should be said that there is some historical evidence of men occasionally breastfeeding babies in situations where breast milk or other adequate nourishment was not available, such as on long sea voyages after the death of a baby’s mother (Swaminathan, 2007). These men would have had medical conditions that abnormally elevated their prolactin levels and caused galactorrhea – such as pituitary tumours – and would have resorted to it in a desperate attempt to keep the baby alive, not because it was their “desire” to do so despite an availability of appropriate food sources for the infant. It is thought that this helped infants survive mainly by maintaining hydration, not because it was an adequate substitute for the breast milk of lactating women.

In the wake of this study, numerous attempts were made to equate drug-induced galactorrhoea in men with the natural breast milk a mother produces after giving birth. This ideological narrative has gone so far that we have witnessed systematic replacement of the words “breast milk” and “breastfeeding” with phrases such as “chest milk” and “chest feeding”, in an attempt to normalise this practice.

However, the research on the composition of male nipple discharge is very scarce, and the research into the effects of this type of fluid on infants is non-existent.

In one case study from 1981, the researchers collected monthly nipple discharge samples for 3 months, from a 27 year old man with hyperprolactinaemia and likely pituitary adenoma. They then compared these samples to colostrum (collected during the last trimester of pregnancy and 1 day post partum) and breast milk (collected between 1-12 months post partum) from normal lactating mothers. They concluded that “the concentrations of lactose, proteins, and electrolytes in the breast secretion of this man are within the range of colostrum and milk obtained from normal lactating women” (Kulski, Hartmann & Gutteridge, 1981). Looking at the results in detail, however, the lactose level in the male patient’s nipple discharge was nearly double that of colostrum (between 4.1 and 6.3 versus 2.34 +- 0.65 g/100ml) and sodium was just below the lower end of the normal range (39.0 +- 14.0 versus 61.9 +- 16.0 nm).

More importantly, unlike mother’s milk, male nipple discharge hasn’t occurred as a consequence of growing a baby inside his body, and it is in no way tailored to an individual child – or any child for that matter.

Breast milk is the unique nourishment lactating mothers produce in order to sustain their own babies and protect them from disease in the weeks and months after birth, when the infant immune system is still not fully developed. First milk is called colostrum (birth – 4 days), which is a thick, yellowish fluid full of fat, vitamins and particularly rich in antibodies. Colostrum changes to a more calorific transitional milk (4 days – 2 weeks), which is high in fat and vitamins, and after that it becomes mature milk which is 90% water.

Maternal antibodies are first passed via the placenta to the baby during the last three months of pregnancy, and after the baby is born, he or she continues to receive antibodies through breast milk. As mother and baby share both the genetics and the environment, these antibodies are customised by the mother’s body to offer an individually tailored passive immunity and protection from the pathogens the baby is most likely to encounter.

Therefore, I found it strange that Reisman & Goldstein made no attempt to analyse the composition of their male patient’s drug-induced nipple discharge, considering that they talked at length about the benefits of breastfeeding on mother and baby, none of which were applicable to their male patient or indeed the infant he, allegedly, fed.

Be that as it may, as a consequence of a cocktail of drugs and a breast pump, this patient started to “lactate”, eventually producing 8 oz of nipple discharge daily, two weeks prior to the birth of the baby.

Although we have no further details about the volume, the study claims that whatever fluid was produced, it was the sole source of this baby’s nourishment for 6 weeks. After this time, the patient reportedly started to supplement with 4–8 oz of Similac brand formula daily.

The authors gave no indication that they observed this alleged “breastfeeding”, or that they met the mother or the infant. They did state that “the child’s pediatrician reported that the child’s growth, feeding, and bowel habits were developmentally appropriate”, but offered no corroborating evidence.

Considering that a 5 lb baby needs about 12 oz of breast milk or formula a day, and more as the baby’s weight increases, it is extremely unlikely that any infant would survive for 6 weeks on 8 oz alone. Furthermore, mothers who are unable to breastfeed know only too well how important it is to use adequate amounts of baby formula. Failing to do so can result in serious harm to the baby.

I have no evidence that the baby who was allegedly subject to this experiment was harmed in any way. However, there are so many omissions, unknowns and missing data that I cannot help but ask, why was a trans-identified man held to a drastically different standard of infant care than actual mothers?

That this experiment was conducted by a Transgender Clinic, which neither had licence, nor expertise, to oversee the breastfeeding of a newborn, only adds to my concerns regarding ethics, safety and bias in this study.

It is my opinion that, rather than constituting “exciting” new research, this study is fraught with incomplete and misleading information, disingenuous analysis and undeclared conflicts of interest. That it was also reported as fact in the media, without any meaningful challenge from the mainstream medical community, makes me wonder if transgender research has lost sight of the bigger picture and has come to prioritise the emotional needs of trans-identified males over the welfare of women and children.

References

Reisman, T. & Goldstein, Z. (2018). Case Report: Induced Lactation in a Transgender Woman. Transgender health, 3(1), 24–26. https://doi.org/10.1089/trgh.2017.0044. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5779241/

Therrien, A. (2018). Transgender woman breastfeeds baby in first recorded case, study says. BBC. https://www.bbc.co.uk/news/health-43071901 Liang, J. J. Jolly, D. Chan, K. J. & Safer, J. D. (2018).

Testosterone levels achieved by medically treated transgender women in a United States endocrinology clinic cohort. Endocrine practice: official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists, 24(2), 135–142. https://doi.org/10.4158/EP-2017-0116 Sheehan, M. T. (2004).

Polycystic ovarian syndrome: diagnosis and management. Clin Med Res. 2004 Feb;2(1):13-27. doi: 10.3121/cmr.2.1.13. PMID: 15931331; PMCID: PMC1069067. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1069067/

Glaser, R. L. Newman, M. Parsons, M. Zava, D. Glaser-Garbrick, D. (2009). Safety of maternal testosterone therapy during breast feeding. Int J Pharm Compd. 2009 Jul-Aug;13(4):314-7. PMID: 23966521. https://pubmed.ncbi.nlm.nih.gov/23966521/

Oberhelman-Eaton, S. Chang, A. Gonzalez, C. Braith, A. Singh, R. J. Lteif, A. (2022). Initiation of Gender-Affirming Testosterone Therapy in a Lactating Transgender Man. J Hum Lact. 2022 May;38(2):339-343. doi: 10.1177/08903344211037646. Epub 2021 Sep 7. PMID: 34490813. https://pubmed.ncbi.nlm.nih.gov/34490813/

Barry, J. A. Kay, A. R. Navaratnarajah, R. Iqbal, S. Bamfo, J. E. David, A. L. Hines, M. & Hardiman, P. J. (2010). Umbilical vein testosterone in female infants born to mothers with polycystic ovary syndrome is elevated to male levels. Journal of obstetrics and gynaecology : the journal of the Institute of Obstetrics and Gynaecology, 30(5), 444–446. https://doi.org/10.3109/01443615.2010.485254

Phillipson, A. (2013). Girls exposed to high testosterone levels ‘destined to be tomboys’. The Telegraph. https://www.telegraph.co.uk/news/science/science-news/10102686/Girls-exposed-to-high-testosterone-levels-destined-to-be-tomboys.html FDA. (2004).

FDA Talk Paper: FDA Warns Against Women Using Unapproved Drug, Domperidone, to Increase Milk Production | FDA. U.S. Food and Drug Administration. https://www.fda.gov/drugs/information-drug-class/fda-talk-paper-fda-warns-against-women-using-unapproved-drug-domperidone-increase-milk-production MHRA. (2014).

Domperidone: risks of cardiac side effects. GOV.UK. https://www.gov.uk/drug-safety-update/domperidone-risks-of-cardiac-side-effects Nottinghamshire Area Prescribing Committee. (2021).

Domperidone for Lactation Stimulation – Prescribing Information. https://www.nottsapc.nhs.uk/media/1729/domperidone-info-sheet.pdf Fried, D. (2017). My First Time Breastfeeding My Daughter. The Stranger. https://www.thestranger.com/queer-issue-2017/2017/06/21/25225867/my-first-time-breastfeeding-my-daughter

Swaminathan, N. (2007). Strange but True: Males Can Lactate. Scientific American. https://www.scientificamerican.com/article/strange-but-true-males-can-lactate/ Kulski, J. Hartmann, P. Gutteridge, D. (1981).

Composition of Breast Fluid of a Man with Galactorrhea and Hyperprolactinaemia*. The Journal of clinical endocrinology and metabolism. 52. 581-2. 10.1210/jcem-52-3-581. https://www.researchgate.net/publication/15737507_Composition_of_Breast_Fluid_of_a_Man_with_Galactorrhea_and_Hyperprolactinaemia

Comments on two other studies

A new study titled ‘Lactation Induction in a Transgender Woman: Macronutrient Analysis and Patient Perspectives’ was authored by Amy K. Weimer, MD and published in March 2023.

All the criticisms from my article apply, with the following exception: the male participant had orchiectomy at 41 (5 years prior to this experiment) and therefore high testosterone level and related concerns are not likely to be a factor.

Otherwise, the following problems persist:

1. No evidence of maternal consent.
2. No mention of the sex of the baby.
3. Referring to the male participant as “she” and mother as “gestational carrier”.
4. Pathological male nipple discharge which resulted from a severe hormone imbalance and medications which cause galactorrhoea, is equated with normal, physiological mother’s milk.
5. No observance of alleged “male breastfeeding”.
6. Incomplete analysis of male nipple discharge: the presence of medications including Domperidone, cross-sex hormones or antibodies in the male breast fluid was NOT measured; sodium NOT measured (it was low-ish in another study); other nutrients “at the same level or HIGHER” (not necessarily a good thing); comparison was with mature mother’s milk (70-94 days after delivery) not with colostrum or transitional milk appropriate for a newborn.
7. Uniqueness of mother’s milk to the baby and its fundamental difference from male nipple discharge wasn’t explored.
8. Inadequate volume (just 150ml per day) was mitigated by the fact that mother was breastfeeding this baby the entire time.
9. If the infant had access to adequate nutrition, immune support and bonding via breastfeeding from their own mother, and developmentally appropriate formula was available should anything go wrong, the only reason this experiment was conducted was to satisfy the desire of the man, not to benefit the baby.
10. In this male patient’s own words, it “would be a wonderful, personal experience, and it would be a great help for my partner.” Since men can feed the baby with expressed mother’s milk in order to help their partners, there was no practical or medical need whatsoever to conduct this experiment.

Another study titled ‘Lactation Induction in a Transgender Woman Wanting to Breastfeed: Case Report’ authored by Rachel Wamboldt et al in January 2021 has very similar issues as Weimer et al 2023 and Reisman & Goldstein 2018:

1. This was another case of gynaecomastia and minimal volume (3-5 ounces) of male galactorrhea secondary to iatrogenic (clinician-induced) hormone imbalance, and side-effects of multiple medications (including domperidone, cross-sex hormones and androgen blockers).
2. No study of composition of this fluid that was fed to an infant.
3. No corroborating evidence; No evidence of informed consent given by the mother; No exploration of ethics of involving an infant in an experiment that is chiefly designed to satisfy the desire of a man to “breastfeed”.
4. Study states (when talking about the male patient) “Although this was not enough to meet the nutritional needs of her [sic] child, she [sic] felt encouraged that she [sic] was potentially contributing to the immunological health of her [sic] child.”
5. There is no evidence in existence that abnormal, drug-induced male nipple discharge contributes to immunological health of babies who ingest it.

Crucially, none of the usual scientific protocols that are used to ascertain whether medications and food given to infants are safe have been followed in any of the studies in this area, and there is no long-term follow up of the infants who were experimented on in these studies.