Before the First Dose: Fertility and the Conversation That Can’t Wait — Anatomy of Good Care (6/7)

The door you have to point out before it closes

Most of what hormone therapy does can be revisited. Doses are adjusted, routes are switched, effects accrue and can often be slowed or shifted. Fertility is the part where the timing is least forgiving — because the single most reliable way to preserve it is to act before treatment starts, while the gonads are still doing what they were doing.

That makes fertility counselling unlike most of the monitoring and titration this series has described. It is not something you can return to later and optimise. It is a door the patient walks past on the way in, and the clinician’s job is to make sure they see it clearly, and have the chance to use it, before they pass it. Done late, the most dependable options are simply gone. Which is why every major guideline frames this as a conversation to have, and preservation to offer, before the first prescription.

What the hormones actually do — feminizing therapy

Estrogen combined with an anti-androgen suppresses the hypothalamic-pituitary-gonadal axis, and with it sperm production. In practice, most trans women on established hormone therapy have markedly impaired sperm production — frequently absent altogether by the time of any gonadal surgery — alongside described changes in testicular tissue [1][2]. That much is well evidenced.

What is not settled is whether this is permanent, and here the honest answer matters more than a tidy one. The most reliable preservation method is sperm cryopreservation before starting therapy [2][3]. But the assumption that feminizing therapy causes irreversible sterility is not as solid as it is often stated: a 2022 case series followed nine trans women who stopped therapy and saw sperm production return — viable sperm in some within about three months, longer in others — with four going on to conceive naturally [4]. The authors are careful, and so should we be: it is a small series, larger studies are needed, and they still recommend banking sperm beforehand for anyone who might want to be a genetic parent [4]. The defensible position is therefore neither slogan. Feminizing therapy impairs fertility, often profoundly; whether it does so permanently is genuinely uncertain and appears at least partly reversible, at least for some people — and because it is uncertain, the person deserves the chance to preserve before they start.

What the hormones actually do — masculinizing therapy

Testosterone typically produces amenorrhea and is generally assumed to suppress ovulation, and its long-term effect on ovarian function is not well characterised [3]. But one widely-missed point belongs in any honest version of this conversation: amenorrhea is not the same as infertility. In one study, roughly a third of trans men who were amenorrheic on testosterone showed signs of recent ovulatory activity at the time of surgery [5] — which means pregnancy remains possible for some, and contraception stays a live consideration where relevant, rather than something testosterone can be assumed to have taken care of. Conversely, the suppression is generally reversible — menstruation and ovulation typically resume after stopping testosterone, and pregnancies have been reported in trans men following prolonged use [3].

Preservation options exist and are effective: oocyte (egg) or embryo cryopreservation, and in some cases fertility can be pursued without prolonged interruption of testosterone [6]. As with the feminizing side, the through-line is honesty about uncertainty: testosterone affects fertility in ways that are real but incompletely mapped, which is precisely why the conversation, and the offer, should come early.

Why this is consent, not a gate

It would be easy to slide from “fertility should be discussed” into “fertility must be preserved,” and that slide is a mistake. The duty is to inform and to offer — to make sure the person understands the possible, partly-irreversible reproductive consequences and has genuine access to preservation if they want it. It is not to require preservation, and it is emphatically not to use fertility as a hurdle that gates access to care. Current standards are explicit on this: fertility preservation should be discussed and offered, and gender-affirming care should not be withheld from someone who, properly counselled, declines it [7].

This is, in other words, the consent principle from earlier in this series applied to its hardest case. Material information about a possibly-irreversible effect is exactly the kind a person needs in order to decide — and the only way to honour their autonomy is to give it to them early enough, and honestly enough, that the choice is actually theirs. Offering the information is the clinician’s job. Making the decision is the patient’s.

The point

The clinician’s obligation here is narrow and absolute: make the door visible before the patient walks past it, tell the truth about what lies behind it — including the parts we are still unsure of — and make sure the means to use it are genuinely available. Not to choose for them. Not to make it a test they have to pass.

Fertility counselling done well is simply consent done in time. The measure of it is whether the person stepped through the door — in whichever direction they chose — knowing what they were choosing, while choosing was still possible.

Sources

1. Marins LR, Rosito TE, Kliemann LM, Capp E, Corleta HE. Gender affirming hormone therapy and transgender women fertility: histologic predictors of germ cell presence. Rev Bras Ginecol Obstet, 2024; 46:e-rbgo33; doi:10.61622/rbgo/2024rbgo33 (PMC11075381). — Feminizing therapy suppresses spermatogenesis; duration of hormone treatment is associated with testicular atrophy and spermatogenesis arrest, and trans women on GAHT frequently have abnormal semen parameters and may be azoospermic, with described testicular histologic changes. (Trans-specific; adults.)
2. Yau M, Safer JD. The return of spermatogenesis in transgender women ceasing gender-affirming hormone therapy (commentary). Cell Reports Medicine, 2023; 4(1):100835; doi:10.1016/j.xcrm.2022.100835 (PMID 36652904; PMC9873818). — Estrogen-based GAHT suppresses spermatogenesis; the accompanying de Nie series suggests gonadal suppression may be transient; clinical guidelines encourage sperm cryopreservation before starting GAHT. (Trans-specific; adults.)
3. UCSF Gender Affirming Health Program, Fertility options for transgender persons. — Sperm cryopreservation prior to initiation is the most successful preservation option for trans women; restoration of spermatogenesis after extended estrogen exposure is not well studied; testosterone usually produces an anovulatory state and amenorrhea (usually reversible on discontinuation, with pregnancies reported after prolonged testosterone use), with prolonged effects on ovarian function unclear. (Trans-specific; adults.)
4. de Nie I et al. Successful restoration of spermatogenesis following gender-affirming hormone therapy in transgender women. Cell Reports Medicine, 2022; 3:100858; doi:10.1016/j.xcrm.2022.100858. — Case series of nine trans women who ceased GAHT; renewed sperm production observed (viable sperm as early as ~3 months, longer in others — one requiring testicular biopsy at 17 months), four conceived naturally; suggests GAHT-induced suppression may be at least partly reversible and casts doubt on inevitable permanent infertility — while still recommending sperm cryopreservation beforehand. Small series; larger studies needed. (Trans-specific; adults.)
5. Asseler JD et al. One-third of amenorrhoeic transmasculine people on testosterone ovulate. Cell Reports Medicine, 2024; doi:10.1016/j.xcrm.2024.101440 (PMC10982961). — Histologic signs of recent ovulatory activity in 17/52 (33%) of amenorrheic trans men on testosterone at gender-affirming oophorectomy, not correlated with duration, serum level, or type of testosterone; amenorrhea does not reliably equal anovulation, with implications for contraception. (Trans-specific; adults.)
6. Fertility preservation in transmasculine individuals (oocyte/embryo cryopreservation), including reports without prolonged testosterone discontinuation: Fertility preservation in a transgender man without prolonged discontinuation of testosterone: a case report and literature review (F&S Reports, 2021; PMID 34223211; PMC8244337; testosterone held for only three doses through stimulation); and Fertility preservation in transgender men without discontinuation of testosterone (2022; PMID 35789719; PMC9250124; two cases continued testosterone through controlled ovarian stimulation, 35 oocytes / 23 MII in case 1). — Effective oocyte and embryo cryopreservation is available; in selected cases preservation has proceeded without an extended androgen-free interval, though some centres still advise pausing testosterone beforehand. (Trans-specific; adults.)
7. World Professional Association for Transgender Health, Standards of Care version 8 (Coleman E et al., Int J Transgend Health 2022; doi:10.1080/26895269.2022.2100644); and Endocrine Society clinical practice guideline (Hembree WC et al., JCEM 2017). — Known and uncertain fertility impacts and preservation options (established and experimental) should be discussed and offered before gender-affirming treatment; in the appropriately counselled patient it is reasonable to proceed without fertility preservation, so care is not gated on it. (Trans-specific; adults.)