Chestfeeding and breastfeeding describe the same physical process: feeding an infant milk produced by the body’s mammary tissue. The difference is purely in language. “Chestfeeding” is a term used primarily by transgender men, nonbinary people, and some other parents who don’t identify with the word “breast” or the gendered associations of “breastfeeding.” The milk, the mechanics, and the nutritional value are identical.
Why a Different Term Exists
For many trans and nonbinary parents, words like “breasts,” “breastfeeding,” and “mother” don’t match their gender identity. Being described with those terms during something as intimate as feeding a baby can trigger significant distress, known as gender dysphoria. In qualitative research with transmasculine parents, all participants referred to their upper front torso as their chest and avoided the word “breasts” entirely. Two participants only used the word “breasts” when recalling feeding their babies years earlier, before they had come out as transgender.
The term “chestfeeding” gives these parents a way to describe infant feeding that aligns with how they see themselves. It’s not a medical distinction or a different technique. It’s language that reduces a real psychological barrier to feeding.
The Milk Is the Same
Whether someone calls it breastfeeding or chestfeeding, the milk their body produces has the same composition: fats, proteins, sugars, antibodies, and immune cells that protect the infant. Mammary tissue functions the same way regardless of how a person identifies. The hormone prolactin drives milk production, and oxytocin triggers the let-down reflex that moves milk to the nipple. These processes don’t change based on terminology.
For trans men and nonbinary people who carried a pregnancy, lactation typically begins the same way it does for any postpartum parent. Transfeminine parents who did not carry a pregnancy can sometimes induce lactation using a protocol originally developed for adoptive mothers, which involves hormonal preparation and breast stimulation over several weeks. Testosterone, however, interferes with prolactin and can significantly reduce milk supply, which becomes an important consideration for transmasculine parents thinking about resuming hormone therapy while still feeding.
How Medical Organizations Use the Term
The Academy of Breastfeeding Medicine (ABM) formally recognizes that not all people who give birth and lactate identify as female, and that some identify as neither female nor male. Their position statement recommends using gender-inclusive language, such as “lactating person” or “chestfeeding,” in clinical materials intended for healthcare professionals in countries where transgender and nonbinary people openly give birth and feed their babies.
The ABM frames this as consistent with United Nations and World Health Organization goals around ending discrimination against LGBTQI+ people. The recommendation is context-dependent: inclusive language is meant to supplement, not replace, sex-specific terms. A hospital policy in the U.S. or U.K. might use “chestfeeding/breastfeeding,” while a global public health document might stick with “breastfeeding” for clarity across different cultural contexts.
The NHS in the United Kingdom also uses “chestfeeding” in its guidance for trans and nonbinary parents, treating it as a standard term alongside breastfeeding.
Challenges Trans and Nonbinary Parents Face
Finding supportive lactation care can be difficult. In interviews with trans and nonbinary parents in the U.K., a recurring theme was being misgendered by healthcare providers who defaulted to calling everyone “mum.” One nonbinary parent described the experience of entering lactation support spaces as hitting “a very big wall of mummies.” Even providers who used a parent’s correct pronouns in conversation would slip into gendered language when speaking broadly, referring to “breasts” in ways that felt regressive for someone who had worked through dysphoria during their transition.
Educational materials present another gap. One trans father recounted being shown a book of exclusively feminine, cisgender women nursing in various positions, with husbands visible in the background. The lactation consultant apologized and said they needed to update it, but no alternative existed. Representation in feeding resources remains rare.
Some parents also experience a condition called dysphoric milk ejection reflex (D-MER), where the hormonal shift during let-down triggers sudden feelings of nausea or sadness. This affects parents of all gender identities, but for trans and nonbinary parents it can be especially confusing. One parent described months of distress while pumping before a lactation consultant identified D-MER as the cause. Knowing the name and that it was a hormonal response, not an emotional rejection of feeding, made it far more manageable.
Binding While Feeding
Some transmasculine parents bind their chest to reduce the visible appearance of breast tissue, and this creates specific risks during lactation. Binding compresses the tissue where milk is produced and stored, which can block milk ducts. Blocked ducts raise the chance of mastitis, a painful infection. Binding can also reduce overall milk supply by restricting the tissue’s ability to fill and drain properly.
Parents who want to continue binding while feeding their baby should talk with a midwife or lactation consultant who understands their situation. There are ways to manage the balance between gender-affirming choices and milk production, but it requires individualized guidance.
Testosterone and Milk Supply
For trans men who paused testosterone therapy to become pregnant and give birth, the question of when to resume it while still feeding is medically complex. Testosterone suppresses prolactin, the hormone that drives milk production, so restarting it will likely reduce supply. One parent described being told by a gender clinic specialist that she wouldn’t prescribe testosterone while he was still chestfeeding, even though he had read that testosterone molecules may be too large to pass into milk in significant amounts. The limited research on this question has been conducted on cisgender women taking oral testosterone at different doses, not on trans men using injectable or topical forms at masculinizing levels.
This gap in research leaves parents and their providers making decisions with incomplete information. It’s one of the more pressing practical questions for transmasculine parents who want to feed their baby and also return to hormone therapy for their own well-being.