An Ultrasound-Induced Self-Clearance Hydrogel for Male Reversible Contraception.

Nearly half of pregnancies worldwide are unintended mainly due to failure of contraception, resulting in negative effects on women's health. Male contraception techniques, primarily condoms and vasectomy, play a crucial role in birth control, but cannot be both highly effective and reversible at the same time. Herein, an ultrasound (US)-induced self-clearance hydrogel capable of real-time monitoring is utilized for injection into the vas deferens, enabling effective contraception and noninvasive recanalization whenever needed.