And The Winner Is...

Monozygotic! 

DNA testing confirms that Evan and Owen are identical twins. Crazy. All this time, the doctors have told us they're fraternal, but from all the research I did during my three months on bedrest, I knew it was completely possible for them to be identical. Separate sacks and placentas do NOT always mean fraternal. Curiosity got the best of us, and we ordered the DNA test. We're so glad to know the truth. It's mindboggling to Nate and me that they're identical, because they look like totally different kids to us. Owen looks just like Nate, and Evan looks a lot like my Grandpa Boettcher. But I guess it's normal for the parents to be able to diferentiate each twin. Most people can't - even their grandpas! (The grandmas are the only other people who've got them down pat.)

So what does knowing their zygosity mean for us? Other than giving us a difinitive answer when people ask, it also means Evan and Owen are exact matches for each other in the unlikely event one of them needs some sort of transplant, transfusion, etc. It means they're destined to be almost exactly the same build and height, so maybe they'll have similar physical abilities. It also means they'll probably trick their teachers. Above all, it means they're extremely lucky. Identical twins are very rare, and they share the most unique bond known to man.

Here are some fun facts I dug up:

• Male identical twins are the least-common form of twins. About three in 1,000 deliveries worldwide result in identical twins.
• Identical twins are not considered to be hereditary.
• When one egg is fertilized by one sperm cell, and then divides and separates, two identical cells will result. If the zygote splits very early (in the first 2 days after fertilization) they may develop separate placentas (chorion) and separate sacs (amnion). These are called dichorionic, diamniotic (or "di/di") twins, which occurs 20-30% of the time.
• Genetically speaking, the children of identical twins are half-siblings rather than cousins. If each member of one set of identical twins marries one member of another set of identical twins then the resulting children would be genetic full siblings.
• It is estimated that there are around 10 million identical twins and triplets in the world.