The Science Baby Podcast · Leila Battison

What to Expect in the Fourth Trimester

·50 min·3 clips

Up to 45% of women report some form of trauma during birth, and about 5% end up with PTSD.

1. The Science Baby Podcast episode “What to Expect in the Fourth Trimester” centers on how postpartum life does not fit a tidy three-month label. 2. The hosts are unnamed speakers discussing their own postpartum experiences, and they matter because both draw on birth, breastfeeding, and recovery firsthand. 3. The episode asks what the fourth trimester is for, and answers it by treating it as a period of hormonal, physical, and emotional adjustment for both mother and baby. 4. The conversation starts from the “newborn period,” which they describe as the first two months, and the fourth trimester, which extends that to a third month. 5. They compare pregnancy trimesters to postpartum change, saying the first trimester brings “a hell of a lot of morning sickness” and the second trimester can feel like relief after the 12-week mark. 6. The third trimester is described as the stage of major physical change, with one speaker naming hips that “just went” and stretch marks. 7. The hosts discuss 24 weeks as the point of viability, when a baby can have a good chance of survival with appropriate medical attention. 8. They also mention three levels of neonatal care, and one speaker jokes about tracking whether a baby would need the second level of emergency care. 9. A major theme is that the postpartum body and the baby both face a sudden switch from pregnancy physiology to separate life. 10. The baby is described as moving from a warm, dark, muffled uterus into a bright, cold, loud world that is overstimulating. 11. One repeated phrase is that babies are “not giving you a hard time” but “having a hard time.” 12. The hosts say the most helpful responses include skin-to-skin, babywearing in a sling, feeding on demand, and letting babies sleep on demand. 13. They contrast that approach with older advice about clock-based feeding and sleep schedules, and with fears about “spoiling” a child. 14. Another major section covers birth trauma, including the statistic that up to 45% of women report some form of trauma during birth. 15. The same section says about 5% end up with PTSD, and the hosts mention tears, prolapses, and a C-section as examples of difficult recovery. 16. The hormone discussion is detailed, with progesterone called “nature’s tranquilizer” and the placenta described as the source of hormones that stop suddenly after delivery. 17. The hosts say the resulting crash can bring tearfulness, anxiety, and the “sundown scaries,” especially when nights are long and the baby has no circadian rhythm. 18. Later they describe breastfeeding, weaning, prolactin, oxytocin, low estrogen, and the return of periods as part of a slow hormonal reset over months. 19. The episode sounds like a candid, conversational postpartum debrief with jokes, personal anecdotes, and practical reassurance. 20. People expecting honest postpartum physiology, breastfeeding detail, and a nonjudgmental tone would like it; listeners wanting a short, abstract baby-planning chat might skip it.

As heard by us

A plainspoken look at how the fourth trimester can be bodily, messy, and hard to predict.

The episode treats the fourth trimester as part of birth rather than a clean ending: the hormone crash, milk coming in, pain, and the low days of postpartum recovery all land in the same rough stretch, shaped by body, baby, and feeding.

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Why you'd press play

For when the first weeks after birth feel like body horror with a pram.

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