All weeks

First Trimester

Week 13 of pregnancy

Your baby is the size of a peach.

Length: 7.4 cm / 2.9 in · Weight: 23 g / 0.8 oz

Baby at 13 weeks

  • Last week of first trimester (or first of second, depending on system).
  • Baby can pee — amniotic fluid recycling.
  • Bones in arms + legs lengthening.

What you may feel

  • Energy + mood lifting.
  • Reduced miscarriage risk.
  • Mild constipation.
  • Visible 'pregnancy glow' (some).

This week’s checklist

  • Start pelvic floor exercises (Kegels).
  • Plan how to share pregnancy news.
  • Look into pregnancy classes (NCT, antenatal yoga).

Key milestone

Miscarriage risk drops significantly — first-trimester milestone.

Doctor / midwife visits

Combined screening results received this week if not already.

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.