fourth trimester

noun

: the three month period immediately following giving birth in which the mother typically recovers from childbirth and adjusts to caring for her infant

The "fourth trimester" is a catchphrase used to describe the postpartum period, defined as the first 12 weeks after delivery.

—Meera Varma Simões

Women and their families experience substantial physiological, social, and emotional changes. … Most women would benefit from much closer follow-up during the fourth trimester.

—Ilona T. Goldfarb

especially : the first three months of an infant's life

The concept of the fourth trimester—the three-month period of adjustment for babies to life outside of the womb—was introduced in the late 1970s and then popularized by pediatrician Harvey Karp … in 2002.

—Maggie Overfelt

Examples of fourth trimester in a Sentence

Recent Examples on the Web

Having everything together in one place makes the early days of your fourth trimester a little bit easier. —Katrina Cossey, Parents, 18 Apr. 2024

But the early weeks and months after baby’s arrival, often known as the fourth trimester, can be an even more critical time in a family’s reproductive health. —Rivea Ruff, Essence, 16 Apr. 2024

Bump Boxes Bump Boxes are packed with goodies for expecting moms at any stage of pregnancy and beyond, including the fourth trimester. —Maya Polton, Parents, 27 Mar. 2024

The slight compression offers the body plenty of support during the fourth trimester. —Nikita Charuza, Peoplemag, 20 Feb. 2024

Coupled with the tie-front adjustable waist, this is a coat designed to see you through your fourth trimester. —Dorian Smith-Garcia, Parents, 23 Feb. 2024

However, these would accommodate a pad, so they can be used for many stages of the fourth trimester. —Nikita Charuza, Peoplemag, 20 Feb. 2024

What a Doula or Midwife Costs Some parents of multiples might find that a birth doula and/or a postpartum doula can be helpful as an additional source of knowledge and support through their pregnancies and into their fourth trimesters. —Madison Medeiros, Parents, 3 Dec. 2023

An unplanned C-section and ongoing struggles with breastfeeding meant my fourth trimester (the 12 weeks after giving birth, which many experts now believe is as crucial to a mother’s health as their first three trimesters) was filled with unexpected challenges. —Liz Hammond, Vogue, 26 Oct. 2023

Word History

First Known Use

1970, in the meaning defined above