Did you know that fraternal twins are the most common kind of multiple pregnancies? This happens when two separate eggs are fertilized by two different sperm. Each twin therefore has sac and placenta to develop inside. By being fraternal they can be two girls, two boys, or if you’re lucky one of each. By purely genetics these type of twins no more alike than any other siblings you might have. Of course they still share that tight connection of always being together. The other kinds of twins that are less common are identical twins. Identical twins happen when a single egg is fertilized and then splits. Typically in this scenario they will share a placenta but have separate sacs. So unlike the fraternal twins these babies are genetically identical. The options of having one boy and one girl does not exist in this type of twin as they will have to be the same sex either boy girls or both boys. There is one more type of twins that are the rarest of all, and that is conjoined twins. Conjoined twins happen when the egg fails to split completely apart forming the two babies versus one conjoined. There is always the option of having even more babies than just twins. Triplets, quads etc. exist and in those cases you can see several options from the babies being fraternal, identical or even a combination of both.
Our twins we found out too late because we didn’t know we were going to have twins and the sacs were pressed together so we couldn’t find out whether they were fraternal or identical. The only way now would be to do a DNA test. Being both boys, they do look alike but we don’t care enough to find out whether they are identical or fraternal. Maybe one day.