Someone asked us:
My girlfriend is trans and has been doing hormone replacement therapy for about a year. About how likely is it that she can still get me pregnant?
The short and simple answer is: anytime your girlfriend’s semen° (cum) gets into your vagina° or onto your vulva°, you’re at risk for pregnancy.
The fertility of a trans woman or trans* feminine person depends on how they’ve decided to transition. Some trans women lose their ability to create a pregnancy, and some have no change in their fertility at all. Many end up falling somewhere in between.
So how does Hormone Replacement Therapy (HRT) affect this?
Each person’s body responds differently to HRT. It usually lowers the ability to get or keep an erection, and could also reduce sperm count. But don’t rely on HRT as a form of birth control by itself. If you want to avoid pregnancy, you and your girlfriend should explore all your birth control options. Luckily, there are lots out there!
You can use one of many types of hormonal birth control (such as the pill, shot, implant, Mirena IUD), or the non-hormonal (ParaGard) IUD.
Barriers, like condoms, are another option (and the only way to prevent STDs as well as pregnancy).
Since people taking HRT can have trouble getting erections, condoms that go onto the penis° may slip off. A good alternative is an internal condom (also known by its brand name, the FC2 Female Condom®). These condoms are worn inside a vagina° or anus, so you’ll still be protected from pregnancy and STDs even if your partner’s erection comes and goes.
-Mylanie at PPFA
°These may not be the terms that you use to describe your own bodies, but we hope that the information in this answer is still clear enough to help you and your girlfriend make a well-informed decision.