Key takeaways
- In the fourth month, your baby is about About 12 cm — the size of a avocado.
- Bones strengthen is a key milestone this month.
- Common symptoms include more energy and a baby bump appears.
- This month's key check: quadruple.
The fourth month (weeks 13–16) begins the second trimester — often the most comfortable phase. Energy returns, nausea settles, and a small baby bump appears. Your baby is now about the size of an avocado (12 cm).
How big is the baby in the fourth month?
Your baby is about About 12 cm, roughly the size of a avocado.
What is developing this month?
Key milestones in the fourth month include:
- Bones strengthen
- Facial muscles develop
- Baby swallows
- Fine hair (lanugo) appears
What symptoms can you expect in the fourth month?
Every pregnancy is different, but common symptoms this month include:
- More energy
- A baby bump appears
- Reduced nausea
- Mild backache
What should you do this month?
- Continue vitamins, and iron and calcium if advised
- Mind your posture and do gentle stretches for backache
- Keep up moderate exercise or prenatal yoga
- Eat a balanced, protein-rich diet
Which tests or scans are done in the fourth month?
Screening and routine monitoring continue this month.
- The quadruple (quad) or triple marker blood test (around 15–16 weeks) if combined screening wasn't done earlier
- Routine blood pressure, weight and urine checks
- A review of your growth and wellbeing