# Day 190: Off your back

> Twenty-seven weeks and one day. Sleeping on your back can bring backache, constipation and piles. Three nights on your side, with pillows, starts tonight.

- Series: Your sixth month of pregnancy, day by day (https://chorevia.com/learn/pregnancy-month-6), day 190 of 280, 27 weeks + 1 day
- Your baby this week: about the size of a head of cauliflower; around 36.6 cm from head to heel
- Canonical URL: https://chorevia.com/learn/pregnancy-month-6/day-190
- Last reviewed: 2026-10-22
- Publisher: Chorevia (https://chorevia.com)
- Cite as: Chorevia. "Day 190: Off your back." Last reviewed October 22, 2026. https://chorevia.com/learn/pregnancy-month-6/day-190

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-seven weeks and one day. Tonight's job happens in bed, and it's mostly about pillows.

## Your baby

Around 36.6cm from head to heel, about the size of a head of cauliflower ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-27/)). "A few weeks ago, your baby looked a bit like a wrinkled prune," the NHS says; now fat is filling out the folds of skin ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-27/)). The face you'll meet is being padded out, a little more each week.

## Your body

Sleeping on your back around now can cause backache, constipation and piles ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-27/)). MedlinePlus explains the other reason: lying on your side with your knees bent keeps the baby from pressing on the large vein that carries blood from your legs back to your heart ([MedlinePlus](https://medlineplus.gov/ency/patientinstructions/000559.htm)). Many providers recommend the left side, which improves blood flow to the heart, the baby, the uterus and the kidneys, and MedlinePlus puts it plainly: "It is best not to sleep flat on your back" ([MedlinePlus](https://medlineplus.gov/ency/patientinstructions/000559.htm)).

The NHS gives the timing. Sleeping on your stomach is fine early on, but after 28 weeks, sleeping on your side is safest ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-14/)). That's next week, so this week is for practice. The same applies when you're awake and moving: the Office on Women's Health advises against exercising on your back after the first trimester ([OWH](https://womenshealth.gov/pregnancy/youre-pregnant-now-what/staying-healthy-and-safe)).

## Try today

### The side-sleep trial

- **Time:** 5 minutes at bedtime, three nights

1. Gather three pillows: one under your bump, one between your knees, and one rolled at the small of your back ([MedlinePlus](https://medlineplus.gov/ency/patientinstructions/000559.htm)).
2. Lie down on your side with your knees bent, the left if it's comfortable ([MedlinePlus](https://medlineplus.gov/ency/patientinstructions/000559.htm)).
3. Move the pillows until nothing pulls. The NHS describes the same setup: pillows supporting the bump and between your legs ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/3rd-trimester/week-29/)).
4. In the morning, write one line: how you slept, and how your back feels.
5. After three nights, keep what worked and change one thing that didn't.

**Make it work:** If you wake up on your back, roll onto your side again and resettle the pillows. The trial is about where you start the night.

## Watch for

- **Normal:** backache, on the NHS's list for this week ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-27/)); lying down, resting and heat may help ([OWH](https://womenshealth.gov/pregnancy/youre-pregnant-now-what/body-changes-and-discomforts)). **Call your provider** if the pain does not get better ([OWH](https://womenshealth.gov/pregnancy/youre-pregnant-now-what/body-changes-and-discomforts)).
- **Normal:** an achy back after a long day on your feet. **Call your provider** or go to the hospital to be checked for a low, dull backache, pressure in your pelvis, or cramps like period cramps; the NICHD lists each as a possible symptom of preterm labor ([NICHD](https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms)).
- **Normal:** tiredness, which the NHS lists as common around now ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-27/)). **Call your provider** for overwhelming tiredness; the CDC counts it among the urgent warning signs ([CDC](https://www.cdc.gov/hearher/maternal-warning-signs/index.html)).

## For you

Bad nights are part of this stretch. MedlinePlus's list for sleeping better is practical: limit caffeinated drinks, avoid large meals or lots of fluid within a few hours of bedtime, and make up lost sleep with short naps ([MedlinePlus](https://medlineplus.gov/ency/patientinstructions/000559.htm)). It is just as clear about sleep aids: don't take any, including over-the-counter medicines and herbal products, without talking to your provider first ([MedlinePlus](https://medlineplus.gov/ency/patientinstructions/000559.htm)).

If you're the partner: the bed is about to get crowded with pillows. Make room without comment, and if she needs a hand turning over at night, give it without waking all the way up.

## Sources

- NHS. "Week 27." 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-27/
- MedlinePlus. "Problems sleeping during pregnancy." National Library of Medicine. https://medlineplus.gov/ency/patientinstructions/000559.htm
- NHS. "Week 14." 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-14/
- Office on Women's Health. "Staying healthy and safe." U.S. Department of Health and Human Services. https://womenshealth.gov/pregnancy/youre-pregnant-now-what/staying-healthy-and-safe
- NHS. "Week 29." 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/3rd-trimester/week-29/
- Office on Women's Health. "Body changes and discomforts." U.S. Department of Health and Human Services. https://womenshealth.gov/pregnancy/youre-pregnant-now-what/body-changes-and-discomforts
- National Institute of Child Health and Human Development. "What are the symptoms of preterm labor?" NIH, 2023. https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/symptoms
- Centers for Disease Control and Prevention. "Urgent Maternal Warning Signs and Symptoms." HEAR HER campaign, 2024. https://www.cdc.gov/hearher/maternal-warning-signs/index.html