Understanding Circumvallate Placenta: Symptoms, Diagnosis & What to Expect

Question
age 25 / 3 children / nov 9th 2005  
I went into the ER yesterday for lower abdominal pains.  They wound up doing an ultrasound and found a layer of tissue between my placenta and cirvix I'm 17 1/2 wks pregnant they said it was something called circumvallate placenta.  Thats all they told me they didn't say anything else about it and I recieved no information in my discharge papers.  All they did say is we will need to do another U.S. at 20wks to make sure its moved out of the way.  Because if I went into premature labhor the baby would'nt be able to come out.  And said nothing else no info. nothing. So can you please help me?  As to how or why its there? What will happen if it does'nt move out of the way?  

Answer
Acircumvallate placenta is usually seen AFTER delivery as a small central plate surrounded by a thick white ring that is composed of a double fold of amnion and chorion (fetal membranes)with fibrin and degenerated decidua between. It is diffcult to identify this at 17 weeks gestation. Ar you sure that the placenta was circumvallate? Could it have been a marginal placenta or placenta previa, which covers the cervix. Usually, this moves away from the cervix as the uterus grows. If it does not move awy, the baby can not be delivered vaginally due to the risk of bleeding and the blockage of the baby. Most of the time, it will move away from the opening of the cervix. If it does not move away, yuou will have to deliver by cesarean section.