New data reveal transmasculine men run the risk of pregnancy even when taking testosterone therapy.
Results from a small study of transgender men and gender-diverse people recently published in Cell Reports Medicine revealed that one-third of the participants still ovulated despite taking testosterone and could therefore potentially become pregnant.
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Even if their periods had stopped because of gender-affirming hormone therapy, the trans men could still ovulate, the study showed.
Trans men routinely take testosterone to initiate secondary male sex characteristics, like a thicker body, facial hair, and a deeper voice. The therapy also typically halts menstruation within three to six months.
It’s often assumed that when a person taking testosterone stops menstruating, they no longer ovulate, meaning no eggs are released from the ovaries, the study’s authors explain. That assumption seems to be false in some cases.
All of the participants had taken testosterone and none had experienced a period for at least a year before they received an oophorectomy, a gender-affirming surgery to remove the ovaries. Scientists analyzed those ovaries in search of signs of ovulation.
In a large percentage of the ovaries, scientists found the fluid-filled sacs where an unfertilized egg develops, called the corpus luteum, a group of cells that forms following ovulation and produces hormones that support pregnancy.
Approximately 33% percent of the participants’ ovaries showed signs that they were ovulating, no matter how long they’d been taking testosterone, no matter how much testosterone was in their blood, or whether they’d taken the hormone by gel or injection.
The 52 transmasculine men in the study had taken testosterone by various delivery methods, indicating there was no change in the incidence of ovulation based on how participants received the hormone therapy.
Previous research has indicated trans men taking testosterone could still get pregnant. A study published in 2020 revealed that seven of 20 transgender men taking testosterone showed temporary upticks in their urine of a byproduct of the sex hormone progesterone, which supports menstruation. Progesterone levels peak after ovulation and indicate ovulation when present.
“The physical and mental consequences of an unplanned and unwanted pregnancy are enormous,” co-senior study author Joyce Asseler, a doctoral candidate at Amsterdam University Medical Centers, said in a statement. “It is important that transmasculine people and their healthcare providers are aware of this risk and act accordingly.”
Transmasculine people who wish to become pregnant can stop testosterone therapy to do so.
