Trimester 1
Week 5
Your baby is about the size of an apple seed.
Length: 0.4 cm · Weight: <1 g
Common this week: Nausea, Smell sensitivity, Breast tenderness, Fatigue, Mood swings, Frequent urination.
Baby development
- The neural tube is forming — this becomes the brain and spinal cord.
- A tiny heart is beginning to form and will start beating this week.
- The foundations of the eyes and ears are developing.
- The embryo curves slightly, taking on a C-shape.
Changes for you
- Morning sickness may begin — nausea is common at any time of day.
- Smell sensitivity often increases dramatically.
- Breasts may feel heavier and more tender.
- Fatigue is often intense; rest as much as you can.
Tips
- Eat small, frequent meals to manage nausea — an empty stomach can worsen it.
- Ginger tea or ginger biscuits may help with morning sickness.
- Stay hydrated; sip water throughout the day.
- If nausea is severe or you cannot keep fluids down, see your GP promptly.
Appointments
- First GP visit this week or next to confirm pregnancy and begin antenatal care planning.
Warning signs
- Unable to keep any fluids down (hyperemesis gravidarum)
- Bleeding with severe pain
Australian notes
- Hyperemesis gravidarum affects about 1–3% of pregnancies in Australia. If vomiting is severe, your GP can prescribe safe anti-nausea medication.
- Pregnancy, Birth and Baby helpline: 1800 882 436 — free, 24/7, staffed by midwives.