All weeks

Second Trimester

Week 18 of pregnancy

Your baby is the size of a sweet potato.

Length: 14.2 cm / 5.6 in · Weight: 190 g / 6.7 oz

Baby at 18 weeks

  • Baby can yawn + hiccup.
  • Gender visible on ultrasound.
  • Inner ear bones harden — baby hears more clearly.

What you may feel

  • Round ligament pain (sharp groin twinges).
  • Visible movements (some women).
  • Bigger appetite.
  • Lower back ache.

This week’s checklist

  • Anomaly scan booking (18-22 weeks).
  • Start sleeping on left side consistently.
  • Consider pregnancy support belt for back.

Key milestone

Anomaly scan window opens (18-22 weeks).

Doctor / midwife visits

Anomaly scan + sex reveal (18-22 weeks).

Top foods this week

Educational only — not medical advice. Always consult your midwife or GP. Sources: NICE NG201 antenatal care, NICE NG207 inducing labour, NHS, RCOG. Read the full medical disclaimer.