"Make sure that’s the right sperm!" is a comment we often hear when doing an IUI. While there is a tone of joking when it’s said, the anxiety behind that statement it is very real. The odds of a mix-up ever happening are extremely extremely extremely low. I used to think it was about the same as the odds of a baby mix-up at the hospital, but now I think the occurrence of a sperm/embryos mix-up is much less likely than that of a baby mix-up at the hospital. Baby mix-ups might even happen more than we realize. I would bet that there is at least one child out there in the world who was switched at birth, who grew up and lived an entire life without anybody knowing — not the child, not his parents, not the doctors, nobody.
The reason a sperm or embryo mix-up is even lower odds is because of the low volume. For example, we rarely do more than 4 IUI’s in one day, so we can pretty much focus individually on each prep. We have systems in place to double check and triple check. In addition, I have a small staff whom I trust 100% to be diligent and ultra-meticulous in avoiding any remote possibility of mix-up or contamination. Such is not true of a large government hospital. There, it is possible for thousands of babies to be born each year under disorganized hectic conditions, with a nursing staff of hundreds so that you will have the extremes of some excellent workers and some careless or clueless ones. If you have the bad luck of an overworked less-than-compulsive nurse being on shift at the time your baby delivery, you are at higher risk of something bad happening.
A recent story in the news tells of a woman in Spain (let’s call her Juana) who went shopping. By the way, their real names were never publicly revealed. The sales clerk, a stranger, ran up excitedly and tried to hug her, thinking it was her good friend. When Juana rebuffed the hug attempt, the puzzled sales clerk called the friend (let’s call her Amalia) who confirmed that she had not been in the store that day. A few days later, when Juana came back to the store, the sales clerk struck up a conversation and arranged a meeting between Juana and Amalia. When they saw each other, it was a cinematic moment of two long-lost identical twins being reunited. Juana apparently became very shaken and went into a depression. Years later, she eventually agreed to a DNA test, which confirmed they were twins. Piecing together the story, it appears that Amalia and Juana’s mother had given birth to her at a hospital in a part of Spain, known as the Canary Islands. Incidentally, if you are ever playing Trivial Pursuit and are asked what animal the Canary Islands are named after, the answer is not that obvious. They are named after dogs! Think canary as having the same root as the word canine.
Somehow, Juana was taken out of the bed next to Amalia and switched with another girl (let’s call her Maria). There is no evidence that this was intentional. In fact, similar stories like this have been reported, and often it’s when nurses are overworked, doing double shifts. So Maria and Amalia grew up as happy loving sisters, while Juana grew up by herself, oblivious to the existence of Amalia until the fateful day in the clothing store. Juana’s attorney is suing the government of Spain for mucho dinero, of which, some of it will go to Juana herself.
The emotional damage has been done. Will taking money out of the public health funds and giving it to Juana and her lawyer make things better or make this less likely to happen in the future? I have an opinion. You are entitled to yours.
It just goes to show what we’ve all heard time and time again, "If you’ve seen Juana, you’ve seen Amalia". 
