Helmig R, Oxlund H, Petersen L K, Uldbjerg N
Department of Obstetrics and Gynaecology, Aarhus Kommunehospital, Denmark.
Eur J Obstet Gynecol Reprod Biol. 1993 Mar;48(3):183-9. doi: 10.1016/0028-2243(93)90086-r.
The aim of this study was to elucidate whether the mechanical properties of fetal membranes change during late pregnancy and labour. Membranes delivered by elective caesarean section in week 38 showed different load-strain curves to membranes obtained after spontaneous vaginal delivery at term. A major change in mechanical properties was a decrease in strength of the intact chorioamniotic membrane from 1.39 N to 0.98 N (width of biopsy 4 mm), mainly due to loss of strength of the amniotic component, from 1.27 N to 0.72 N. Moreover, the extensibility of the chorionic component (epsilon Fmax) increased after vaginal delivery from 0.42 to 0.54, resulting in a two-component behaviour of the intact chorioamniotic membrane and further decrease of strength. Based on these observations it is suggested that the amnion is attached to the chorion, act biomechanically in parallel and possess relatively high mechanical strength during pregnancy. After vaginal delivery the two membranes are separated, and pronounced changes are induced in their mechanical properties.
本研究的目的是阐明妊娠晚期和分娩期间胎膜的力学性能是否发生变化。在第38周通过择期剖宫产娩出的胎膜与足月自然阴道分娩后获得的胎膜显示出不同的载荷-应变曲线。力学性能的一个主要变化是完整的羊膜绒毛膜的强度从1.39 N降至0.98 N（活检宽度4 mm），这主要是由于羊膜成分的强度从1.27 N降至0.72 N。此外，绒毛膜成分的伸展性（εFmax）在阴道分娩后从0.42增加到0.54，导致完整的羊膜绒毛膜呈现双成分行为并进一步降低强度。基于这些观察结果，提示羊膜附着于绒毛膜，在妊娠期间以平行方式发挥生物力学作用并具有相对较高的机械强度。阴道分娩后，两层膜分离，其力学性能发生显著变化。
