Third trimester

30 weeks pregnant: what is happening this week

Week 30 of 42worked example

39.9 cm

Measured: head to heelabout the size of a cabbage
This week runs: Thu, Jul 23, 2026 to Wed, Jul 29, 2026
Days to the estimated due date: 77
Term window (37-42 weeks): Thu, Sep 17, 2026 to Thu, Oct 22, 2026

The NHS publishes this figure for week 30, about the size of a cabbage. 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.

39.9 cm, roughly a cabbage, and the eyes can focus. Vision after birth is short range by design - the NHS puts the initial focal distance at around 20 to 25 centimetres, which is approximately the gap between a feeding baby's eyes and the face of whoever is holding them. That is a detail worth carrying with you, because it reframes the first fortnight after birth from an infant who cannot see much into an infant built to see exactly one thing. Stairs now produce breathlessness. Sleep is disrupted, and vivid, occasionally unpleasant dreams are commonly reported in the third trimester - a combination of hormones, broken sleep and a mind with a great deal to process. Round ligament pains continue on the sides of the bump. Ten weeks to the estimate. If the pushchair, the car seat and the cot have not been bought, this is a reasonable week for it: everything needs assembling, some of it needs fitting properly, and none of that is work you want to be doing at short notice with instructions in four languages.

Put your own dates on week 30

Your estimated due dateNothing you type here leaves your browser. Without a date the panel shows a worked example built from a last period of Thu, Jan 1, 2026.

Week 1 began: Thu, Jan 1, 2026
Week 30 begins: Thu, Jul 23, 2026
Week 30 ends: Wed, Jul 29, 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-30?s=d:2026-10-08

Everything you type here is computed in your browser. Nothing you enter is stored on a server, sent anywhere, or shared — there is no account and no health data to leak.

What the NHS describes this week

The NHS puts the foetus at around 39.9 cm from head to heel this week.
The eyes can now focus, and vision continues to develop.
After birth, the NHS describes focus as being on faces around 20 to 25 cm away.

What happens around now

Disturbed sleep and vivid dreams are widely reported in the third trimester. The whooping cough vaccination is given before week 33 and the RSV vaccination around week 28 if either has not happened.

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 30 comes from

NHS: week 30 of pregnancy
NHS, Week-by-week guide to pregnancy — the guide these weeks are built from

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