Do Multiples Run In YOUR Family?

I'm sure you've all heard by now that Angelina Jolie finally gave birth to her twins. People Magazine reports that "multiples do run in the Pitt family: Brad's sister Julie has twin girls." I should have known better than to expect People Magazine to make a clear, relevant comment.

You see, Brad Pitt's sister having twins has absolutely NOTHING to do with Angelina having twins. Nothing. How could it?

Do multiples run in your family? is a question I'm asked ALL the time. No. Identical multiples are a random act of nature. They usually occur in younger mothers or older mothers, both of which are more likely to have weaker eggs. A weak egg splits to create identical twins, triplets, etc.

Multiples running in the family is a completely maternal factor. It means that genetically speaking, you are predisposed to release more than one egg during ovulation, resulting in fraternal multiples.

Now those are two extremes: all identical or all fraternal. There are women who have spontaneous triplets, which consist of a pair of identical twins and fraternal triplet. And there are women who have weak eggs no matter what their age.

I've never heard of multiples being a paternal factor. But we are talking about Brad Pitt...