A collagen plug with shape memory to seal iatrogenic fetal membrane defects after fetoscopic surgery

Iatrogenic preterm premature rupture of fetal membranes(iPPROM)after fetal surgery remains a strong trigger for premature birth.As fetal membrane defects do not heal spontaneously and amniotic fluid leakage and chorioamniotic membrane separation may occur,we developed a biocompatible,fetoscopically-applicable collagen plug with shape memory to prevent leakage.This plug expands directly upon employment and seals fetal membranes,hence preventing amniotic fluid leakage and potentially iPPROM.Lyophilized typeⅠcollagen plugs were given shape memory and crimped to fit through a fetoscopic cannula(Ø3 mm).Expansion of the plug was examined in phosphate buffered saline(PBS).Its sealing capacity was studied ex vivo using human fetal membranes,and in situ in a porcine bladder model.The crimped plug with shape memory expanded and tripled in diameter within 1 min when placed into PBS,whereas a crimped plug without shape memory did not.In both human fetal membranes and porcine bladder,the plug expanded in the defect,secured itself and sealed the defect without membrane rupture.In conclusion,collagen plugs with shape memory are promising as medical device for rapid sealing of fetoscopic defects in fetal membranes at the endoscopic entry point.

Selective Fetal Growth Restriction in Monochorionic Diamniotic Twins: Diagnosis and Management

Selective fetal growth restriction (sFGR) is a severe condition that complicates 10% to 15% of all monochorionic diamniotic (MCDA) twin pregnancies. Pregnancies complicated with sFGR are at high risk of intrauterine demise or adverse perinatal outcome for the twins. Three clinical types have been described according to the umbilical artery (UA) Doppler pattern observed in the smaller twin: type I, when the UA Doppler is normal;type II, when there is persistent absent or reversed end-diastolic blood flow in the UA Doppler;and type III, when there is intermittent absent and/or reversed end-diastolic blood flow in the UA Doppler. Clinical evolution and management options mainly depend on the type of sFGR. Type I is usually associated with a good prognosis and is managed conservatively. There is no consensus on the management of types II and III, but in earlier and more severe presentations, fetal interventions such as selective laser photocoagulation of placental anastomoses or selective fetal cord occlusion of the smaller twin may be considered. This review aims to provide updated information about the diagnosis, evaluation, follow-up, and management of sFGR in MCDA twin pregnancies.

Twin Reversed Arterial Perfusion Sequence:Prenatal Diagnosis and Treatment

Twin reversed arterial perfusion sequence,a severe and unique complication of monochorionic multiple pregnancy,is characterized by vascular anastomosis and abnormal or absent cardiac development in the twins.This article reviewed its pathogenesis,prenatal ultrasound diagnosis,and management.The pump twin’s chances for survival can be maximized by proper management.The optimal timing of the interventions remains a debate,although the latest studies encourage early intervention,i.e.,in the first trimester.The most preferred approach is to interrupt the vascular supply to the acardius,such as through ultrasound-guided laser coagulation and radiofrequency ablation of the intrafetal vessels.