When Does The Fourth Trimester Start?

If you've been pregnant, are pregnant, or are thinking about getting pregnant, there's a good chance you've heard of this thing called the "fourth trimester." Traditionally (and technically), pregnancy has been divided into three trimesters, all consisting of about 12 weeks. So when does the fourth trimester start? It actually isn't part of the pregnancy at all, so how does it fit in?

According to Belly Belly, the fourth trimester is simply a term to mean the period of time after your baby is born until they're no longer a newborn. It's a convenient name that forces health care providers and mothers alike to focus on life after the baby is born—the period that, oddly enough, gets most neglected in birthing classes, pregnancy books, and doctor visits — not just on having a healthy pregnancy and delivery.

Since the fourth trimester lasts from the moment your baby is born until they're about three months old, according to Baby Center, your baby experiences a lot of physical and mental growth during this period. Furthermore, your recovery, and all the changes you'll deal with postpartum, happen during this "trimester" as well, making it a pivotal time for both you and your baby. Things like postpartum depression, infection, anxiety, or problems with breastfeeding are the most common hurdles new moms in the fourth trimester may face as they recover. Your recovery time will last anywhere from four weeks to a few months depending on the type of delivery you had and how well it went, according to Parents.


It's not all negative, though, you'll also experience the "love hormone" according to Baby Center, which helps your body heal and the bond strengthen between you and your baby. Plus, you'll no longer be pregnant, which, after 40 weeks, is a great benefit.

While your baby is learning how to eat, and sleeping for most of the day, your body will be recovering from pregnancy and delivery, your breasts will be producing milk, and your emotions will be all over the place. But despite all of the craziness, this period is arguably the best one, because you have your brand new little one to share it all with.