MHMW

Third trimester

28 weeks pregnant: what is happening this week

Week 28 of 42worked example

37.6 cm

Measured
head to heelabout the size of an aubergine
This week runs
Thu, Jul 9, 2026 to Wed, Jul 15, 2026
Days to the estimated due date
91
Term window (37-42 weeks)
Thu, Sep 17, 2026 to Thu, Oct 22, 2026

The NHS publishes this figure for week 28, about the size of an aubergine. It is an average from patient guidance rather than a measurement of any particular pregnancy, and the measurement basis changes at week 20 - see the note below the dates.

37.6 cm and the third trimester by the convention this site uses. The heart rate has settled to around 140 beats a minute, down from about 170 earlier on, which is a change worth noticing because a slowing heart rate here is maturation rather than anything to be concerned about. The face and body are recognisably those of a newborn. There is a substantial appointment this week. A blood test is taken, the bump is measured, labour and birth are discussed, and anti-D is offered where the blood group requires it. The RSV vaccination is recommended around week 28 and can be given up to labour; whooping cough is given now if it has not been already. Newborn screening tests get explained around this point too. Discomfort is genuinely increasing by now - heartburn, indigestion, back strain, swelling in the ankles and feet, and nosebleeds. That is a lot of separate small things at once, and the cumulative effect is more tiring than any of them individually. It is worth naming that rather than treating each one as a separate complaint to be solved.

Put your own dates on week 28

Week 1 began
Thu, Jan 1, 2026
Week 28 begins
Thu, Jul 9, 2026
Week 28 ends
Wed, Jul 15, 2026
Estimated due date
Thu, Oct 8, 2026

Dates run on ACOG's 280-day convention, the same arithmetic as the due date calculator. Share this week with your dates: /pregnancy/week-28?s=d:2026-10-08

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What the NHS describes this week

  • The NHS puts the foetus at around 37.6 cm from head to heel this week.
  • The heart rate has slowed to about 140 beats a minute, down from around 170 earlier in pregnancy.
  • The face and body are recognisably those of a newborn.

What happens around now

The 28-week antenatal appointment includes a blood test, a bump measurement and a discussion of labour and birth, with anti-D offered where the blood group requires it. The RSV vaccination is recommended around week 28, and whooping cough is given now if it was not given earlier.

  • 28-week antenatal appointment - blood test, bump measurement, labour and birth discussion, anti-D where needed (NHS)
  • RSV vaccination - recommended around week 28 (NHS)

On the measurement. The NHS publishes a length for each week from 4 to 40. Up to week 19 it is measured head to bottom (crown to rump, the measurement a scan takes while the legs are curled). From week 20 it is measured head to heel, which is why the figure jumps from 15.3 cm at week 19 to 25.6 cm at week 20 - the baby did not grow 10 cm in a week, the ruler changed. The NHS states the change on its week 20 page.

Where week 28 comes from

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