The fourth trimester: the very term sounds counterintuitive. "Tri" means three. A tricycle has three wheels. King Triton's trident has three prongs. A school year is divided into three trimesters. You're pregnant for nine months (give or take), and that gestation period is conveniently divided into three, three-month trimesters. So what's this about a fourth? I'm not keeping that baby in there any longer than I have to! Well, no. The fourth trimester refers to your baby's first three months of life outside the womb. Turns out, there are many reasons you should absolutely call it the fourth trimester.
It's strange. There's so much information about pregnancy out there on the internet and online forums and books and soon-to-be mom groups. If you're anything like me, you were reading about what was happening in your body, checking your "what size fruit is baby" chart, and referring to your pregnancy app every week. However, there's not a ton of information on the fourth trimester. In fact, I only knew the "fourth trimester" was a thing after reading The Happiest Baby on the Block, by Dr. Harvey Karp. Dr. Karp's "5 S's" of soothing and colic philosophy are based on the idea that the fourth trimester isn't only real, but that newborns need a fourth trimester.
It might sound silly, but I found that thinking of the months that followed my baby's birth to be part of an "extended pregnancy" helped me better understand my daughter and meet her needs more effectively. It also helped me forgive myself and my still-healing body, as well as my squalling baby, to know that what we were going through was completely and physiologically normal.