# Day 143: Preterm labor, from now

> Twenty weeks and three days. Some tightenings through the day are normal; six or more in an hour are not. Today the preterm labor signs go on your card.

- Series: Your fifth month of pregnancy, day by day (https://chorevia.com/learn/pregnancy-month-5), day 143 of 280, 20 weeks + 3 days
- Your baby this week: about the size of a banana; around 25.6 cm from head to heel
- Canonical URL: https://chorevia.com/learn/pregnancy-month-5/day-143
- Last reviewed: 2026-10-22
- Publisher: Chorevia (https://chorevia.com)
- Cite as: Chorevia. "Day 143: Preterm labor, from now." Last reviewed October 22, 2026. https://chorevia.com/learn/pregnancy-month-5/day-143

This guide is general education that summarizes published research and guidance from groups like the American Academy of Pediatrics, the CDC, and the WHO. It isn’t medical advice, and every child develops on their own timeline. Your pediatrician knows your child; if something feels wrong, call them. In an emergency, call 911.

Twenty weeks and three days. Yesterday was preeclampsia; today is the other thing that becomes possible from week 20. It gets named once here, plainly, and then it lives on a card.

## Your baby

Around 25.6cm long from head to heel, about the size of a banana ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-20/)). Your baby may be sucking their thumb, which develops the sucking reflex they'll need for feeding after birth ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-20/)). Practice, months early, for the first job they'll have.

## Your body

Preterm labor is labor that happens between 20 and 36 weeks of pregnancy ([NICHD](https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms)). Your uterus tightens now and then, and NICHD is clear that some contractions through the day are normal; six or more in one hour are not, because frequent contractions may cause the cervix to begin to open ([NICHD](https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms)). MedlinePlus draws the line in the same place: contact your provider immediately for more than 5 contractions an hour, or contractions that are regular and painful ([MedlinePlus](https://medlineplus.gov/ency/patientinstructions/000486.htm)).

In 2022, preterm birth affected about 1 in 10 babies born in the US ([CDC](https://www.cdc.gov/maternal-infant-health/preterm-birth/index.html)). In most women the cause is unknown ([MedlinePlus](https://medlineplus.gov/ency/patientinstructions/000486.htm)), which is why the signs matter more than any checklist of risks.

## Try today

### The six-in-an-hour rule

- **Time:** 5 minutes

1. On the call-line card, write the headline: contractions every 10 minutes or more often, or six or more in an hour ([NICHD](https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms)).
2. Under it, the rest of NICHD's list: leaking fluid or bleeding; pressure in the pelvis; a low, dull backache; cramps like a period; belly cramps, with or without diarrhea ([NICHD](https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms)).
3. Then the action, in NICHD's words: call your doctor or go to the hospital to be evaluated ([NICHD](https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms)).
4. Add how to count: note the clock time each tightening starts, for one hour.

**Make it work:** Call early rather than late; MedlinePlus says early treatment is the best way to prevent a preterm delivery ([MedlinePlus](https://medlineplus.gov/ency/patientinstructions/000486.htm)). A call that turns out to be nothing costs you ten minutes.

## Watch for

- **Normal:** a handful of tightenings spread across a day ([NICHD](https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms)). **Call your provider** or go to the hospital for tightenings that come every 10 minutes or closer ([NICHD](https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms)).
- **Normal:** a little more discharge than before. **Call your provider** for a change in discharge such as leaking fluid or bleeding ([NICHD](https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms)).
- **Normal:** backache as your ligaments loosen ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-19/)). **Call your provider** for a new low, dull backache or pressure in your pelvis ([NICHD](https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms)).
- **Normal:** a brief twinge on one side when you move, round ligament pain ([MedlinePlus](https://medlineplus.gov/ency/patientinstructions/000580.htm)). **Call your provider** for cramps like period cramps, or belly cramps with or without diarrhea ([NICHD](https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms)).

## For you

This is the page where preterm labor gets named in full. You don't need to reread it. The card holds it now.

If you've had a preterm baby before, tell your provider if they don't already know; the CDC lists that among the steps that lower risk, along with not smoking, avoiding alcohol and drugs, and keeping up with prenatal care ([CDC](https://www.cdc.gov/maternal-infant-health/preterm-birth/index.html)).

If you're the partner: you're the one with the clock. If she says "it's just tightening" and it's the fourth one this hour, you say what's on the card and pick up the phone.

## Sources

- NHS. "Week 20." Week-by-week guide to pregnancy, Best Start in Life. https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-20/
- National Institute of Child Health and Human Development. "What are the symptoms of preterm labor?" National Institutes of Health, 2023. https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms
- MedlinePlus. "Preterm labor." National Library of Medicine. https://medlineplus.gov/ency/patientinstructions/000486.htm
- Centers for Disease Control and Prevention. "Preterm Birth." https://www.cdc.gov/maternal-infant-health/preterm-birth/index.html
- NHS. "Week 19." Week-by-week guide to pregnancy, Best Start in Life. https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-19/
- MedlinePlus. "Aches and pains during pregnancy." National Library of Medicine. https://medlineplus.gov/ency/patientinstructions/000580.htm