The Playbook

28 Weeks Pregnant: Third Trimester, Baby Movements and Side Sleeping

By the Guide to Fatherhood editorial team. Last reviewed . 2 min read.

Checked against guidance from organizations like the AAP, CDC, ACOG and NHS (linked below). This is general information, not medical advice. Read our medical disclaimer.

Trimester3
Sizean eggplant
Length / weightabout 14.8 in (37.6 cm), about 2.2 lb (1 kg)

The third trimester begins. The baby can blink, has eyelashes, and is practicing breathing movements. Brain growth is accelerating.

Your to-do list this week

  • Learn her baby's normal movement pattern with her. If movements slow down or change, she should call her provider the same day; don't wait until tomorrow.
  • Pre-register at the hospital if you haven't, so paperwork isn't happening during labor.
  • Start drafting birth preferences together (one page, plain language).
  • Buy or build a better side-sleeping setup: body pillow, wedge, whatever works.
A conversation to have this week

"What's on your birth preferences page, and what would you want me to say if things change?" You're her advocate; you need to know what she'd want.

Welcome to the third trimester

The baby, about the weight of an eggplant, can now blink and has eyelashes. Breathing movements are practice for life outside, and the brain is growing fast (Mayo Clinic; NHS). If born now, a baby would need intensive care, but survival chances are much higher than just a few weeks ago.

How she may be feeling

Big, tired, achy, and often hot. Prenatal visits usually become every two weeks from about now. Some people feel a burst of nesting energy; others feel like they’re carrying a bowling ball up a hill. Both are normal.

Baby movements: learn the pattern

This is one of the most important things to understand in the third trimester. The NHS advises getting to know the baby’s usual pattern of movements and contacting the maternity unit or provider immediately if movements slow down, stop, or change. Key points:

  • There’s no set number of kicks that’s “normal.” What matters is a change from her baby’s pattern.
  • Babies do not move less toward the end of pregnancy; movements may feel different as space gets tight, but should continue.
  • Don’t use a home Doppler to reassure yourselves. Call.

Some U.S. providers recommend formal kick counts; follow whatever her provider advises. Your role: if she mentions the baby seems quiet, don’t say “I’m sure it’s fine.” Say “Let’s call.”

Side sleeping

Many providers advise side sleeping in late pregnancy. The NHS recommends going to sleep on her side from 28 weeks, because lying on her back can compress major blood vessels. If she wakes up on her back, she just rolls over; it’s not cause for alarm. A long body pillow helps keep her there.

Start the birth preferences page

Not a rigid “birth plan,” just a one-page list of preferences you can hand to nurses: pain relief thoughts, who’s in the room, skin-to-skin, feeding, and what matters if a C-section happens. See being a great birth partner for a template.

Frequently asked questions

What should we do if the baby is moving less?

Call her provider or the maternity unit right away, the same day. Don't wait until the next appointment, and don't rely on home heartbeat monitors. Reduced movement can be a sign the baby needs checking.

Why do doctors recommend sleeping on her side?

In later pregnancy, lying flat on the back can compress major blood vessels. NHS guidance advises going to sleep on her side from 28 weeks. If she wakes on her back, she can simply turn over.

Sources

  1. Fetal development: The 3rd trimester, Mayo Clinic
  2. Week 28: Your baby and your body, NHS
  3. Your baby's movements, NHS

We link to the original source for every medical and safety claim. Guidance changes; if a source has been updated since our last review, the source wins. How we research.