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    BABY

    What Is the Fourth Trimester?

    Babies are born too soon!

    Dr. Harvey Karp

    Written by

    Dr. Harvey Karp

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    what is the fourth trimester

    ON THIS PAGE

    • What is the Fourth Trimester? 
    • What Does Your Baby Want in the Fourth Trimester?
    • What Can I Expect in the 4th Trimester?
    • How to Soothe a Baby During the 4th Trimester?

    What is the Fourth Trimester? 

    The fourth trimester is a period I coined as the first 3 months of a baby’s life after birth. Babies are born too soon! Yes, you read that right. If given the choice, babies would definitely have voted for a few extra months inside the womb. So, for the first three months post-birth—the Fourth Trimester—you should think of babies as foetuses outside the womb. 

    What Does Your Baby Want in the Fourth Trimester?

    A fourth trimester (the first 3 months of a baby's life) of cuddling is the birthday present your baby really wants! You may think your peaceful nursery offers your new baby the perfect environment, but from her point of view, your home feels like it is part wild Las Vegas casino...and part dark closet!

    I always tell my patients that babies are born too soon. I know what you are thinking: Are you kidding? Too short?! For many mums, the last month of pregnancy seemed interminable. Heartburn, puffy ankles, stretch marks, and peeing every 2 hours can take all the shine off that pregnancy glow.

    But while you could not wait to finally hold your baby in your arms, your baby would definitely have voted for a few extra months inside if you had given her the choice. 

    Remember—your baby’s brain was so big that you had to 'evict' her after 9 months, even though she was still smushy, mushy, and very immature. As a result, she is not quite ready for the big, bad outside world.

    So, for the first months, it can help to think of her like a foetus…outside the womb.

    In fact, grandmas, nurses, and nannies who are gifted baby calmers all have one talent in common: they are really good at mimicking a baby’s life in the womb.

    To be a good womb impersonator, you first need to know: 'What was it like in there?' Warm? Sure. Dark? Actually, foetuses see soft red light as the rays of the sun pass through your outer skin and muscle. Quiet and still? No way!

    What Can I Expect in the 4th Trimester?

    During the fourth trimester, you can expect fussiness and crying from your baby and very likely exhaustion for you. Newborn babies are learning to adjust to life outside the womb where it was warm and squishy! They will push their new vocal cords to the limits with screams, naps might feel few and far between and only happen on you, and you will find yourself on an erratic sleep schedule. 

    Turns out, though, reality can be a big slap in the face. The fourth trimester is nothing short of stressful, frustrating, and exhausting. You see, some parents breed fussy babies. The kind who are only happy if being held, and even then, not always content. They have a voice and are not afraid to use it. Swings, bouncers, or anything else that is not mums' arms? A waste of money. Naps are few and far between, and the eat, wake, sleep cycle consumes their every moment.

    How to Soothe a Baby During the 4th Trimester?

    Before birth, foetuses are lavished with rhythmic sensations: the caress of velvet-soft walls, lots of jiggly motion, and loud whooshing from blood pulsing through the uterine arteries (BTW, they do not hear your heartbeat). To give your little one "fourth trimester" care, you will want to give her plenty of snug wrapping/swaddling, shushing, swaying motion, holding in the side/stomach position and opportunities to suck. These techniques are what I call the 5 S's. They will make your baby feel back at home and trigger her calming reflex. 

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