Abstract

There are countless proven benefits of breastfeeding, and the demand for such a right in health for transfeminine people is rarely addressed in the literature, reinforcing inequities in health. The article aims to conduct a scoping review of lactation induction for transfeminine people in the health care context. Systematic literature review in six selected databases, looking for articles with terms related to lactation and transfeminine people. Data were extracted and analyzed, summarizing the main results in tables. Three hundred ninety articles were found. After the exclusion of the duplicates there was a selection by title/abstract and a following selection by the full reading of the remaining articles, considering the pre-determined exclusion and inclusion criteria. Twenty-one articles were included, published between 2018 and 2023. Among them, six are case reports with unprecedented information on the topic, and the others are publications in various formats. Lactation induction was achieved in all the case reports. There is a fragile and recent body of evidence affirming the success of lactation induction in transgender women. There is a necessity to support this demand by health professionals and robust studies to optimize necessary interventions.

Key words:
Lactation; Breastfeeding; Transgender; Transexual; Systematic review

Resumo

São inúmeros os benefícios comprovados do aleitamento materno, e a demanda por tal direito em saúde para as pessoas transfemininas é pouco abordada na literatura, reforçando as iniquidades em saúde. O artigo objetiva realizar uma revisão de escopo sobre a indução da lactação para pessoas transfemininas no contexto de assistência à saúde. Revisão sistemática da literatura em seis bases de dados selecionadas, buscando artigos com termos relacionados à lactação e pessoas transfemininas. Os dados foram extraídos e analisados, resumindo os principais resultados em tabelas. Foram encontrados 390 artigos. Após a exclusão dos duplicados, procedeu-se à seleção por título/resumo e posterior seleção pela leitura na íntegra, considerando os critérios de exclusão e inclusão. Foram incluídos 21 artigos, publicados entre 2018 e 2023. Entre eles, seis são relatos de casos com informações inéditas sobre o tema, e os demais são publicações em diversos formatos. A indução da lactação foi alcançada em todos os relatos de casos. Existe um corpo de evidências frágil e recente que afirma o sucesso da indução da lactação em mulheres trans. Há necessidade de respaldar essa demanda por parte dos profissionais e estudos robustos para otimizar as intervenções necessárias.

Palavras-chave:
Lactação; Aleitamento; Transgênero; Transexual; Revisão sistemática

Introduction

A person’s gender identity is self-referenced, not necessarily corresponding to the gender assigned at birth. People who do not identify with their assigned sex at birth may be considered transgender (or “trans”), a term currently used in the scientific literature as an “umbrella” term, which encompasses transgender/transsexual, non-binary, agender, other transmale or transfeminine people, etc.¹1 Ferri RL, Rosen-Carole CB, Jackson J, Carreno-Rijo E, Greenberg KB. ABM Clinical Protocol #33: Lactation Care for Lesbian, Gay, Bisexual, Transgender, Queer, Questioning, Plus Patients. Breastfeed Med 2020; 15(5):284-293.

The LGBTIA+ population suffers discrimination in numerous contexts, which, unfortunately, is not different in health care. In particular, transgender individuals suffer from various types of violence that stem, among other reasons, from the lack of training and preparation of professionals and health services to welcome them²2 Grant J, Mottet LA, Tanis J, Harrison J, Herman JL, Keisling M. Injustice at every turn: a report of the National Transgender Discrimination Survey. Washington: National Center for Transgender Equality and National Gay and Lesbian Task Force; 2011.^,33 Trautner E, McCool-Myers M, Joyner AB. Knowledge and practice of induction of lactation in trans women among professionals working in trans health. Int Breastfeed J 2020; 15(1):63..

There is a scarcity of scientific evidence and care protocols that are specific to the needs of this population, such as the lactation induction in transgender women¹1 Ferri RL, Rosen-Carole CB, Jackson J, Carreno-Rijo E, Greenberg KB. ABM Clinical Protocol #33: Lactation Care for Lesbian, Gay, Bisexual, Transgender, Queer, Questioning, Plus Patients. Breastfeed Med 2020; 15(5):284-293..

The benefits of breastfeeding for a newborn are widely known, especially those related to nutrition, development, immunity and reduction of mortality rates, in addition to other biopsychosocial issues such as closer bonding and neuropsychic development of the baby⁴4 Lyons KE, Ryan CA, Dempsey EM, Ross RP, Stanton C. Breast milk, a source of beneficial microbes and associated benefits for infant health. Nutrients 2020; 12(4):1039.^,55 Peñacoba C, Catala P. Associations between breastfeeding and mother-infant relationships: a systematic review. Breastfeed Med 2019; 14(9):616-629..

The reasons that lead a family to want to breastfeed their baby are notable, especially transgender women, who add to these many benefits of breastfeeding the possibility of gender affirmation⁶6 MacDonald TK. Lactation care for transgender and non-binary patients: empowering clients and avoiding aversives. J Hum Lact 2019; 35(2):223-226.. However, the current literature does not have materials with good scientific evidence to support these people’s desire to breastfeed⁷7 Wamboldt R, Shuster S, Sidhu BS. Lactation induction in a transgender woman wanting to breastfeed: case report. J Clin Endocrinol Metab 2021; 106(5):e2047-e2052..

Thus, the present study aims to conduct a scoping review of lactation induction in transgender women in the health care context.

Materials and methods

A scoping review was carried out, aiming at a broad look at the body of evidence related to the subject, allowing to summarize what already exists in the literature, and to point out gaps and directions for future research⁸8 Pham MT, Rajic A, Greig JD, Sargeant JM, Papadopoulos A, McEwen SA. A scoping review of scoping reviews: advancing the approach and enhancing the consistency. Res Synth Methods 2014; 5(4):371-385.

9 Arksey H, O'Malley L. Scoping studies: towards a methodological framework. Int J Soc Res Methodol 2005; 8(1):19-32.

10 Colquhoun HL, Levac D, O'Brien KK, Straus S, Tricco AC, Perrier L, Kastner M, Moher D. Scoping reviews: time for clarity in definition, methods, and reporting. J Clin Epidemiol 2014; 67(12):1291-1294.^-1111 Levac D, Colquhoun H, O'Brien KK. Scoping studies: advancing the methodology. Implementation Sci 2010; 5:69..

The present study followed the 5 steps suggested by Pham et al.⁸8 Pham MT, Rajic A, Greig JD, Sargeant JM, Papadopoulos A, McEwen SA. A scoping review of scoping reviews: advancing the approach and enhancing the consistency. Res Synth Methods 2014; 5(4):371-385. which was based on the framework proposed by Arksey et al.⁹9 Arksey H, O'Malley L. Scoping studies: towards a methodological framework. Int J Soc Res Methodol 2005; 8(1):19-32.: identifying the research question; identifying relevant studies; selecting the studies; extracting the data; summarizing and analyzing the results.

The bibliographic search was carried out in broad databases, some more specific to the medical area and some directed to other areas of healthcare: Biblioteca Virtual em Saúde (BVS)/ PubMed/Scopus/Web of Science/Embase/PsycInfo/CINAHL/Dimensions. The Cochrane Database of Systematic Reviews was not included as there was no published Cochrane systematic review/meta-analysis on the subject.

A search strategy was structured with DECS/MeSH descriptors and all listed synonyms, based on the defined population and concept. Additional terms that the authors deemed synonymous or relevant equivalents were also included. The search strategy can be found in Chart 1.

The database’s initial search was carried out on 4/19/2021. The initial step of selecting articles by title/abstract was carried out independently by the authors and disagreements were resolved by consensus. Inclusion criteria was: articles that addressed lactation in LGBTIQA+ people. Exclusion criteria was: articles that exclusively addressed lactation in transmasculine people. One article was excluded due to impossibility of access, despite contact by sending an e-mail to the authors¹²12 Griggs KM, Waddill CB, Bice A, Ward N. Care during pregnancy, childbirth, postpartum, and human milk feeding for individuals who identify as LGBTQ+. MCN Am J Matern Child Nurs 2021; 46(1):43-53..

Afterwards, the reviewers read all the full articles and disagreements were resolved by consensus. The inclusion criteria was: articles that addressed, even if not as their focus, the lactation process in trans women. The exclusion criteria was: articles that did not address, in any way, the lactation process in trans women.

The search in the databases was repeated on 11/19/21. No new articles were included in the review.

A new database search was held on 8/6/2023 and repeated on 9/11/2023, keeping the same indexes and descriptors defined in the first search. Thirteen articles were included at this time and submitted following the same inclusion and exclusion criteria previously used.

Two articles from this new research, Bower-Brown¹³13 Bower-Brown S. Trans and/or non-binary (TNB) parents' experiences during the perinatal period. Hum Reprod 2022; 37(1):502. and Achong¹⁴14 Achong N. Obstetric endocrinology in transgender people. Aust N Z J Obstet Gynaecol 2022; 62(S1):74-91., the latest one being a series of four case reports, were excluded due to the impossibility of access, despite the attempt to contact both authors by email and through magazines where these articles were published.

A data extraction worksheet was prepared, which underwent dynamic changes due to scarcity of information. Thus, many fields initially thought were modified to allow a compatible analysis with the available material. Data extraction was done independently and a final extraction spreadsheet was assembled together.

The extracted data were: title, journal of publication and impact factor, year of publication, country of origin of the researchers, type of study, theoretical definition of the population of interest, characteristics of the studied population (age, previous hormone therapy), offered or demanded intervention, health environment and by which health professional the intervention was conducted, intervention characteristics (use of hormones/galactogogues/mechanical stimulation), lactation support interventions, outcomes, challenges and difficulties of the process and criticisms and observations related to the article.

Two new spreadsheets were created for summarizing and analyzing the data: one containing the main characteristics and contributions of each article (Chart 2) and another with greater detail of the four case reports (Chart 3).

There was an attempt to contact the authors of the case reports to request information that might not have been included in the articles, when found to be necessary. We had no response to the requested information.

Results

Twenty one studies were included in the review (Figure 1). The extracted data and their main contributions to the review are shown in Chart 2.

A notable point about the set of studies included is that most of them originate from North American countries, with ten being from the USA and four from Canada. All articles were published from 2018 onwards.

Among the selected articles, five were case reports and one was a conference abstract, whose data are organized in Chart 3 and better analyzed in the text below, subdivided by topics that supported the data extraction.

Characteristics of the studied population

In the six reported cases, the participants were already in hormone therapy before the lactation induction. Spironolactone, estradiol and progesterone were among the drugs used priorly, but some of them with few or no details about dosages and duration of usage reported. Especially regarding the use of progesterone, there is no clarification on its purpose, whether with the aim of breast development for body modification (although there is no scientific proof of its effect on breast size), or for lactation induction.

The participants of the six reported cases identified themselves as transgender women, with a desire to breastfeed. At the time of the reports, the participants had an age range between 30 and 46, and in one of the cases this data was not revealed.

Hormonal interventions

Estrogen

The cases used different strategies regarding the use of estrogen. In the case of Reisman and Goldstein¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26., there was an increase in the estradiol dose from 4mg/day to 8mg/day and then 12mg, with an abrupt drop to 0.025mg/day two weeks before the expected date of delivery, maintaining this dose until the submission of the case report. In the case of Moravek and Pasque¹⁶16 Moravek MB, Pasque KB. Lactation can be successfully induced in transgender women while maintaining gender-congruent serum hormone levels. Reprod Sci 2019; 26(S1):136A., there was a decrease in the dose previously used of 6mg/day to 2mg/day five weeks before the expected date of delivery, with an increase to 3mg/day when the baby was two months old, due to maternal complaint of increase of facial hair. In the case of Wamboldt et al.⁷7 Wamboldt R, Shuster S, Sidhu BS. Lactation induction in a transgender woman wanting to breastfeed: case report. J Clin Endocrinol Metab 2021; 106(5):e2047-e2052., there is mention that the patient abruptly decreased the use of estrogens on her own to increase milk production, not specifying the doses and for how long they were maintained. In the case of Weimer¹⁷17 Weimer AK. Lactation induction in a transgender woman: macronutrient analysis and patient perspectives. J Hum Lact 2023; 39(3):488-494., the estradiol dose was increased from 4mg/day to 8mg/day, with an abrupt drop to 0.025mg/day 34 days before the delivery and it was kept constant in 0.025mg/day until 128 days after the delivery. For Elkin¹⁸18 Elkin B, Duran A, Rauwerdink K, Goldsmith ES. Inducing lactation in a transgender woman without galactogogues: a case report. J Gen Intern Med 2023; 38(2):S628-S629., the protocol was initiated 98 days prior to the partner’s pregnancy and 377 days before the due date. It started with a non specified increase in the prior estradiol dose to 4mg/day, in order to get close to physiological levels during pregnancy, and an abrupt decrease of the dosage right after the birth, even though the variation and period of time that each dosage was used was not specified.

Progesterone

The use of progestogen was quite different between the interventions. In the case of Moravek and Pasque¹⁶16 Moravek MB, Pasque KB. Lactation can be successfully induced in transgender women while maintaining gender-congruent serum hormone levels. Reprod Sci 2019; 26(S1):136A., medroxyprogesterone 1.25mg/day was introduced during the child’s prenatal period, without specifying the exact starting date, until five weeks before delivery. In the case of Reisman and Goldstein¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26., there was an increase in the progesterone dose in previous use from 200mg/day to 400mg/day, with a reduction to 100mg/day two weeks before the child’s birth. In the case of Wamboldt et al.⁷7 Wamboldt R, Shuster S, Sidhu BS. Lactation induction in a transgender woman wanting to breastfeed: case report. J Clin Endocrinol Metab 2021; 106(5):e2047-e2052., the patient had recently been using progesterone at a dose of 100mg/day, without specification of time length of this usage. The dose was increased to 200mg/day at the first visit, and then, at some unclear point, reduced again to 100mg/day as there were no changes in serum progesterone levels with this intervention. In the case of Weimer¹⁷17 Weimer AK. Lactation induction in a transgender woman: macronutrient analysis and patient perspectives. J Hum Lact 2023; 39(3):488-494., dose of 100mg/day was introduced at an unspecified point, which was increased to 200mg/day after two weeks and suspended 34 days before the delivery. In the case of Elkin¹⁸18 Elkin B, Duran A, Rauwerdink K, Goldsmith ES. Inducing lactation in a transgender woman without galactogogues: a case report. J Gen Intern Med 2023; 38(2):S628-S629., progesterone was introduced at the start of the protocol, since it wasn’t a part of the previous hormone therapy that the participant was on, and right before the birth, it was abruptly decreased, without any description of the timing of the interventions and the dosages in this case.

Antiandrogen

Spironolactone was cited as an antiandrogen used in three reports (Moravek and Pasque¹⁶16 Moravek MB, Pasque KB. Lactation can be successfully induced in transgender women while maintaining gender-congruent serum hormone levels. Reprod Sci 2019; 26(S1):136A.; Reisman and Goldstein¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26.; Wamboldt et al.⁷7 Wamboldt R, Shuster S, Sidhu BS. Lactation induction in a transgender woman wanting to breastfeed: case report. J Clin Endocrinol Metab 2021; 106(5):e2047-e2052.), but with different doses, ranging from 100 to 200 mg per day. In one of the case reports (Moravek and Pasque¹⁶16 Moravek MB, Pasque KB. Lactation can be successfully induced in transgender women while maintaining gender-congruent serum hormone levels. Reprod Sci 2019; 26(S1):136A.), spironolactone was reduced to 100mg/day right before the child was born, but after two months, it returned to the previous regimen (200mg/day) due to the growth of facial hair. This did not cause a change in the milk production already established at the time. In the other two cases, there was no change in the previous dose during the entire process. For Weimer¹⁷17 Weimer AK. Lactation induction in a transgender woman: macronutrient analysis and patient perspectives. J Hum Lact 2023; 39(3):488-494. and Elkin¹⁸18 Elkin B, Duran A, Rauwerdink K, Goldsmith ES. Inducing lactation in a transgender woman without galactogogues: a case report. J Gen Intern Med 2023; 38(2):S628-S629., the participants had already gone through orchiectomy years before, therefore, they had previously suspended the use of spironolactone as an antiandrogen at some point years previously to the case reports.

Hormonal dosages

Hormonal serum measurements of estradiol, progesterone, testosterone, and prolactin were performed in three of the case reports (Moravek and Pasque¹⁶16 Moravek MB, Pasque KB. Lactation can be successfully induced in transgender women while maintaining gender-congruent serum hormone levels. Reprod Sci 2019; 26(S1):136A.; Reisman and Goldstein¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26.; Wamboldt et al.⁷7 Wamboldt R, Shuster S, Sidhu BS. Lactation induction in a transgender woman wanting to breastfeed: case report. J Clin Endocrinol Metab 2021; 106(5):e2047-e2052.). In the case reported by Weimer¹⁷17 Weimer AK. Lactation induction in a transgender woman: macronutrient analysis and patient perspectives. J Hum Lact 2023; 39(3):488-494., besides these measurements, serum levels of estrone, estriol, and QTc on electrocardiogram in four different moments of the process were also analyzed. In the case reported by Elkin¹⁸18 Elkin B, Duran A, Rauwerdink K, Goldsmith ES. Inducing lactation in a transgender woman without galactogogues: a case report. J Gen Intern Med 2023; 38(2):S628-S629., it was only reported the sequential dosage of 17-beta estradiol, although the intervals of dosing weren’t specified.

Mechanical interventions

Mechanical interventions included manual or pump stimulation, generally performed for five minutes on each breast with variation in frequency and start date of interventions among reported cases. Moravek and Pasque¹⁶16 Moravek MB, Pasque KB. Lactation can be successfully induced in transgender women while maintaining gender-congruent serum hormone levels. Reprod Sci 2019; 26(S1):136A. does not provide details on the frequency and duration of pumping, and also does not define whether it was done manually or with the assistance of a pump, starting five weeks before the child’s birth. Reisman and Goldstein¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26. describe initial use of the pump three times a day for five minutes, increasing the frequency to 6 times a day after one month, with no details on the rest of the process. Wamboldt et al⁷7 Wamboldt R, Shuster S, Sidhu BS. Lactation induction in a transgender woman wanting to breastfeed: case report. J Clin Endocrinol Metab 2021; 106(5):e2047-e2052. reports initiation of manual stimulation prior to case follow-up, three to four times a day for five minutes in each breast. Afterwards, she was instructed to use an electric pump, which irritated the nipple, and then began to perform manual stimulation three times a day and once a night for five minutes on each breast. Weimer¹⁷17 Weimer AK. Lactation induction in a transgender woman: macronutrient analysis and patient perspectives. J Hum Lact 2023; 39(3):488-494. reports that the participant started pumping six weeks before the delivery, with a goal of six 15-min sessions per day. The protocol used in the case of Elkin¹⁸18 Elkin B, Duran A, Rauwerdink K, Goldsmith ES. Inducing lactation in a transgender woman without galactogogues: a case report. J Gen Intern Med 2023; 38(2):S628-S629. involved nipple stimulation with the use of a breast pump, without specifying frequency, duration or the starting date of the sessions.

Interventions by galactogogues

Domperidone, an antiemetic medication commonly used off-label as a galactagogue internationally, was prescribed in four of the reports found (Moravek and Pasque¹⁶16 Moravek MB, Pasque KB. Lactation can be successfully induced in transgender women while maintaining gender-congruent serum hormone levels. Reprod Sci 2019; 26(S1):136A.; Reisman and Goldstein¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26.; Wamboldt et al.⁷7 Wamboldt R, Shuster S, Sidhu BS. Lactation induction in a transgender woman wanting to breastfeed: case report. J Clin Endocrinol Metab 2021; 106(5):e2047-e2052.; Weimer¹⁷17 Weimer AK. Lactation induction in a transgender woman: macronutrient analysis and patient perspectives. J Hum Lact 2023; 39(3):488-494.), with doses ranging from 20 to 90 mg daily, divided into three to four daily doses. This medication is not cleared for use in the US due to FDA concern about its association with cardiac dysfunction when used intravenously. In addition, they do not recommend use as a galactagogue due to unknown risks in breastfeeding¹⁹19 The U.S. Food and Drug Administration. FDA warns against women using unapproved drug, domperidone, to increase milk production [Internet]. 2004. [cited 2023 oct 13]. Available from: https://www.fda.gov/drugs/information-drug-class/fda-talk-paper-fda-warns-against-women-using-unapproved-drug-domperidone-increase-milk-production
https://www.fda.gov/drugs/information-dr... . In the abstract from Elkin¹⁸18 Elkin B, Duran A, Rauwerdink K, Goldsmith ES. Inducing lactation in a transgender woman without galactogogues: a case report. J Gen Intern Med 2023; 38(2):S628-S629., domperidone was not used due to FDA recommendations against it. Other galactogogues were also not used due to the participant’s concerns about possible collateral effects.

The use of other galactogogues has not been described in any of the reports. No side effects have been reported with the use of domperidone in any of the cases that included it in the protocol used.

Outcomes

There was production of human milk achieved in all reported cases with variation between the amounts of milk produced and the waiting time between the start of lactation induction and first drops of milk reported. After initiation of breastfeeding, the quantification of production was poorly described, since it wasn’t quantified how much each baby ingested in each breastfeeding session. In the Canadian report by Wamboldt et al.⁷7 Wamboldt R, Shuster S, Sidhu BS. Lactation induction in a transgender woman wanting to breastfeed: case report. J Clin Endocrinol Metab 2021; 106(5):e2047-e2052., it was possible to quantify the maintenance of milk production of one teaspoon per day even six months after the beginning of the interventions, however the form of quantification was not described. Elkin¹⁸18 Elkin B, Duran A, Rauwerdink K, Goldsmith ES. Inducing lactation in a transgender woman without galactogogues: a case report. J Gen Intern Med 2023; 38(2):S628-S629. described an increase in the amount of milk produced to about two milliliters of breast milk extracted in each pumping session, one week after decreasing the estradiol and progesterone dosage.

Only in the case of Reisman and Goldstein¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26. it was possible to observe that exclusive breastfeeding was obtained (for six weeks). In the others, variables such as both mothers breastfeeding and formula introduction already installed made it difficult to observe this data.

In the case of Weimer¹⁷17 Weimer AK. Lactation induction in a transgender woman: macronutrient analysis and patient perspectives. J Hum Lact 2023; 39(3):488-494., the participant started breastfeeding 14 days after the delivery, once to twice daily, after the gestational parent’s breastfeeding was well established. The participant decreased the domperidone to 20mg three times daily but noticed that further dose reductions resulted in a decrease of milk supply. The dose was continued during the duration of her breastfeeding and once per month a sample of 40mL was analyzed. The participant’s milk showed values of protein, fat, lactose, and calorie content at or above those of standard term milk.

The authors of the case reports did not respond to emails sent in an attempt to clarify doubts.

The other articles in this review are opinion articles, narrative review, systematic review, news, congress poster, book chapter, drug review, clinical protocol and cross-sectional studies and in its majority, refer to the case of Reisman and Goldstein¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26.. The texts contributed to the discussion about difficulties and limitations of access to health care for the trans population and other LGBTIA+ groups.

The cross-sectional study by Trautner et al.³3 Trautner E, McCool-Myers M, Joyner AB. Knowledge and practice of induction of lactation in trans women among professionals working in trans health. Int Breastfeed J 2020; 15(1):63. shows that, despite being answered by professionals with specific practice in the care of the transgender population and 34% had contact with a transfeminine person who had expressed a desire to induce lactation, only 21% knew of places to help this demand, and only 9% participated directly in this care. Furthermore, although 91% believed that protocols were needed to help induce lactation in transfeminine people, only 27% were familiar with an existing protocol, citing mostly the Mount Sinai/Zil Goldstein case study¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26. and the Newman-Goldfarb protocol²⁰20 Newman J, Goldfarb L. Newman-Goldfarb Protocols for Induced Lactation: Decision Tool [Internet]. 2007. [cited 2023 oct 13]. Available from: https://asklenore.info/breastfeeding/induced_lactation/ilca2007decision_tool.pdf
https://asklenore.info/breastfeeding/ind... .

Some of the opinions and new articles on this topic included in the review²¹21 Hamzelou J. Trans woman breastfeeds baby. New Sci 2018; 237(3166):13.

22 Madu AE. Breastfeeding in the transgender; recent advances. Obstet Gynecol Int J 2018; 9(5):368.^-2323 Paynter MJ. Medication and facilitation of transgender women's lactation. J Hum Lact 2019; 35(2):239-243. criticize the applicability of the proposed article by Reisman and Goldstein¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26.. Some consider lactation in transfeminine people a subject that has not yet been studied and question the practice of induced breast milk regarding its quality and presence of medications, in addition to the impact on the child’s development. Some of these articles point out that questioning the support for this demand from the transfeminine population based on these arguments would be questionable and would reinforce inequities and barriers to health care.

The research of Weimer¹⁷17 Weimer AK. Lactation induction in a transgender woman: macronutrient analysis and patient perspectives. J Hum Lact 2023; 39(3):488-494. objectified analyzing the characteristics of macronutrients and calories of the milk produced and concluded that transgender women or nonbinary people with breast development from exogenous hormone therapy, when in lactation induction, can produce human milk with adequate caloric content for infant growth and development, and that supplementation may be necessary depending mainly on the volume of milk produced. It reinforces that in the future, further analysis of the human milk produced is recommended for a more detailed assessment of macronutrients as well as the analysis of micronutrients and bioactive factors.

The reviews, clinical protocol, and other opinion articles included⁶6 MacDonald TK. Lactation care for transgender and non-binary patients: empowering clients and avoiding aversives. J Hum Lact 2019; 35(2):223-226.^,2424 Reisman T, Goldstein Z, Safer JD. A review of breast development in cisgender women and implications for transgender women. Endocr Pract 2019; 25(12):1338-1345.

25 García-Acosta JM, San Juan-Valdivia RM, Fernández-Martínez AD, Lorenzo-Rocha ND, Castro-Peraza ME. Trans* pregnancy and lactation: a literature review from a nursing perspective. Int J Environ Res Public Health 2019; 17(1):44.

26 Patel S, Sweeney LB. Maternal Health in the Transgender Population. J Womens Health 2021; 30(2):253-259.

27 Lee R. Queering lactation: contributions of queer theory to lactation support for LGBTQIA2S+ individuals and families. J Hum Lact 2019; 35(2):233-238.

28 Rodriguez-Wallberg K, Obedin-Maliver J, Taylor B, Van Mello N, Tilleman K, Nahata L. Reproductive health in transgender and gender diverse individuals: a narrative review to guide clinical care and international guidelines. Int J Transgend Health 2022; 24(1):7-25.^-2929 González Mariño MA. La mama en la mujer transgénero. Revisión sistemática. Rev Obstet Ginecol Venez 2022; 82(3):373-382. have broader themes and provide brief descriptions of the possibility of inducing lactation in transfeminine people.

Finally, some systematically extracted data were not included in the final tables presented, as most articles did not provide information or the information was not very relevant. Some points to be discussed:

Discussion

The literature about lactation induction in transgender women provides little evidence-based material to support this demand. The only scientific productions that bring unprecedented data on the subject are case reports.

There is no protocol in the literature with robust scientific evidence to support the process of inducing lactation in women outside the pregnancy-puerperal period¹1 Ferri RL, Rosen-Carole CB, Jackson J, Carreno-Rijo E, Greenberg KB. ABM Clinical Protocol #33: Lactation Care for Lesbian, Gay, Bisexual, Transgender, Queer, Questioning, Plus Patients. Breastfeed Med 2020; 15(5):284-293.. What exists follows a physiological rationale of lactation¹1 Ferri RL, Rosen-Carole CB, Jackson J, Carreno-Rijo E, Greenberg KB. ABM Clinical Protocol #33: Lactation Care for Lesbian, Gay, Bisexual, Transgender, Queer, Questioning, Plus Patients. Breastfeed Med 2020; 15(5):284-293., as well as the references for the interventions in the case reports found. These studies are referenced indirectly and grouped by Reisman and Goldstein¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26. and Wamboldt et al.⁷7 Wamboldt R, Shuster S, Sidhu BS. Lactation induction in a transgender woman wanting to breastfeed: case report. J Clin Endocrinol Metab 2021; 106(5):e2047-e2052., which do not make clear the correlation between references and interventions, nor whether these were created or modified from base references. Moravek and Pasque¹⁶16 Moravek MB, Pasque KB. Lactation can be successfully induced in transgender women while maintaining gender-congruent serum hormone levels. Reprod Sci 2019; 26(S1):136A. directly mentions that their interventions were adapted from the Newman-Goldfarb protocol for adoptive mothers, but also does not make it clear what the proposed adaptations are. Sperling and Robinson³⁰30 Sperling D, Robinson L. Induced lactation in a transgendered female partner. J Obstet Gynecol Neonatal Nurs 2018; 47(3):S61. does not provide any reference on interventions.

Reisman and Goldstein¹⁵15 Reisman T, Goldstein Z. Case report: induced lactation in a transgender woman. Transgend Health 2018; 3(1):24-26. problematizes that perhaps not all interventions were necessary, and questions whether medication doses were adjusted based on laboratory results or the outcome of interest. It also states that prolactin levels would likely increase with breast pumping regardless of domperidone use.

It is understood that case reports have limitations due to their methodology. Despite this, the four reports included have numerous gaps that make data interpretation and reproducibility difficult. The authors’ main considerations are the following:

Some of the references in the present study questioned the composition of induced milk in transfeminine people compared to that of cisgender women and the impact on child development²¹21 Hamzelou J. Trans woman breastfeeds baby. New Sci 2018; 237(3166):13.^,2222 Madu AE. Breastfeeding in the transgender; recent advances. Obstet Gynecol Int J 2018; 9(5):368.. Based on this, these articles recommend that the practice should not be reproduced without further studies. The article by Reisman et al²⁴24 Reisman T, Goldstein Z, Safer JD. A review of breast development in cisgender women and implications for transgender women. Endocr Pract 2019; 25(12):1338-1345. mentions two references³¹31 Sonnenblick EB, Shah AD, Goldstein Z, Reisman T. Breast imaging of transgender individuals: a review. Curr Radiol Rep 2018; 6(1):1.^,3232 Kanhai RCJ, Hage JJ, van Diest PJ, Bloemena E, Mulder JW. Short-term and long-term histologic effects of castration and estrogen treatment on breast tissue of 14 male-to-female transsexuals in comparison with two chemically castrated men. Am J Surg Pathol 2000; 24(1):74. that showed that the breast tissue of trans women after hormone therapy was radiologically and histologically indistinguishable from that of cis women. Paynter²³23 Paynter MJ. Medication and facilitation of transgender women's lactation. J Hum Lact 2019; 35(2):239-243. discusses possible interferences of hormones and galactogogue on outcomes related to breastfeeding and child health and finds no evidence to support a concern about the use of these medications. Even though Weimer¹⁷17 Weimer AK. Lactation induction in a transgender woman: macronutrient analysis and patient perspectives. J Hum Lact 2023; 39(3):488-494. found higher values for all macronutrients and calories compared to a standard term milk, micronutrients and bioactive factors were not analyzed. Future research is necessary to confirm the data and analyze other components.

Breastfeeding is increasingly recognized as a health right, however, mostly linked to cis women, specifically those in the puerperal period²⁷27 Lee R. Queering lactation: contributions of queer theory to lactation support for LGBTQIA2S+ individuals and families. J Hum Lact 2019; 35(2):233-238.. This fact is one of the topics discussed by several of the references found in this review, which highlight the urgency of not only advancing in studies, but also starting the implementation of basic and inclusive practices in the health care of trans people¹1 Ferri RL, Rosen-Carole CB, Jackson J, Carreno-Rijo E, Greenberg KB. ABM Clinical Protocol #33: Lactation Care for Lesbian, Gay, Bisexual, Transgender, Queer, Questioning, Plus Patients. Breastfeed Med 2020; 15(5):284-293..

The general lack of knowledge by health professionals about the particularities of the trans population and the scarcity of specific guidelines for the care of this group corroborate for the existence of inequities³3 Trautner E, McCool-Myers M, Joyner AB. Knowledge and practice of induction of lactation in trans women among professionals working in trans health. Int Breastfeed J 2020; 15(1):63.^,2525 García-Acosta JM, San Juan-Valdivia RM, Fernández-Martínez AD, Lorenzo-Rocha ND, Castro-Peraza ME. Trans* pregnancy and lactation: a literature review from a nursing perspective. Int J Environ Res Public Health 2019; 17(1):44..

Conclusion

Evidence on lactation induction for transfeminine people is scarce, fragile, and recent. There is also no evidence to support a position contrary to embracing this demand. The non-recommendation of the practice, therefore, can reinforce inequities and barriers to health access for this population, since the same questions and concerns are not applied to the milk and breastfeeding of cis women outside the puerperal period, whose lactation induction protocols are also not based on robust evidence. Further academic debate and studies on the subject should be encouraged, seeking stronger evidence to offer this care in the best possible way, aiming to understand which are the necessary interventions. Searching for the best protocol for lactation induction for the transfeminine people will also be challenging due to the confounding factors with the possible hormonal therapy in use, ideally requiring adequate randomized controlled clinical trials.

There are some limitations on this review: non-inclusion of gray literature, impossibility of accessing three of the articles that should be read in full and a low number of articles found.

References

Publication Dates

History