Mr Trump reinstated the so-called global gag rule on Monday, affecting American non-governmental organisations working abroad, to signal his opposition to abortion, which is difficult to access legally in many developing countries due to restrictive laws, stigma and poverty.
Kenyan campaigner Rosemary Olale, who teaches teenage girls in Nairobi slums about reproductive health, said women would go back to getting unsafe abortions.
"You will increase the deaths."