Hey, DrG here in the frozen wasteland of our Nation's Capitol. Funny that when the weather turns nasty here in the Metro DC area the government shuts down, the schools close, the supermarkets run out of toilet paper and milk...but our patients make it to the office without any problem whatsoever....
This past week has been a week of identical twins for me....officially termed monozygotic twins (scientific talk meaning one egg/embryo). The best thing about MZ twins is that I can confidently look the patient in the eye and say categorically that this is not my fault. Apparently God or the universe or whatever you believe controls our fate wanted you to have twins because I cannot put back fewer than one embryo. I am even more innocent in cases where patients have MZ twins after an IUI as opposed to IVF as there is an increased rate of MZ twins in IVF compared with conceiving au naturel (yes, sometimes patients are rude and conceive without our help) or with IUI.
Twins that share a placenta can either be in their own little amniotic sac (diamniotic twins) or share a single sac with their sibling (monoamniotic twins). Identical twins do represent a higher risk pregnancy than fraternal (dizigotic) twins and can experience twin-twin transfusion syndrome which is life-threatening and can require advanced intervention prior to delivery (such as laser ablation of communicating blood vessels).
Last week one of my patients stopped by to visit with her beautiful identical twin girls that were from IVF. She told me that her doctor had said that the girls were probably identical but that no twins are really identical. Technically correct I suppose since twins have different fingerprints but at a genetic level they are identical since they came from a single embryo that split. Since these two were in a single sac (mono amniotic) there is no doubt that they were identical. The best news is that they were healthy and happy....plus I didn't have to do any babysitting!