Having adopted through the same agency, one Florida mother and I had occasion to often view photos of each other's children. As Sam grew, she and I came to the same conclusion: our sons look very much alike.

Hers is sixteen months older and was cared for in a another Cambodian orphanage on the outskirts of Phnom Penh. Neither family has any information whatsoever on birth families, so following back trails to see if there are shared roots is not possible.

What would be possible is DNA testing, although the results are usually unimpressive, at best, and the process that may very well end up with something inconclusive enough to make resemblance seem like science is not cheap.

At this point in time, we've mutually agreed that it's not worth the expense to have our boys genes checked against the other's. We live on opposite sides of the globe, but understand that there may be a relationship here, so we will keep in touch and hope that our sons will someday have a chance to meet. In the meantime, we occasionally share photos so both boys can marvel over seeing 'themselves' in unfamiliar surroundings wearing clothes they've never seen before.

Other international adoptive parents have taken a more aggressive approach, and with varying results.

Since without parental DNA identical twins are the most reliably identified as full sibs, the truly dramatic reunions have been of them. One case, the two Merediths, is remarkable to the point of miraculous, since upon the girls' two families meeting there was not only a mirror-image thing going on, but the fact that both had been given the same name by their adoptive parents.

Sister Far is a web group for parents of internationally adopted children who have found, or suspect, a bio sib or twin that is chock-full of information on the process of DNA testing. Their members, many who have successfully reunited their children with brothers and sisters, are knowledgeable and supportive.

Although information may not be forthcoming, inquiring of your children's carers about siblings in their birth country at the time of completion may be worth some time and effort. Depending on the country you're adopting from, there may be a possibility of finding someone to do the asking for you during your stay. Ask your agency if they have a policy for determining if related children have been or are available for adoption.

For more from me on this topic, see this post and this one.

Here's a list of famous people who were separated from sibs, and interesting stories about twins and triplets in history.