Amniotic fluid leakage and rupture of membranes are common complications of fetoscopy. We describe a plug technique for leakproof removal of endoscopic cannulas. Thirty gelatin sponge plugs were introduced in 5 pregnant ewes and 5 pregnant rhesus monkeys. In the primate model no evidence of amniorrhexis was noted on postoperative ultrasonography. Myometrium and membranes at the port sites were intact at term. A gelatin sponge plug technique may facilitate leakproof port removal after fetoscopy.