1st trimester · Week 6
6 weeks pregnant
A heartbeat may flicker
Cardiac activity is often first seen around this week on ultrasound, though not always on the first scan. Limb buds appear. This is still a fragile embryonic stage, not a miniature newborn.
How big is your baby at 6 weeks?
- Length
- 0.5 cm
- Weight
- 0 g
- Size
- Pea
On average about 0.5 cm long and 0 g. Size comparison: Pea.
These are averages; every baby grows at their own pace.
How is your baby developing at 6 weeks?
A heart tube may beat (rates often start near 100–120 beats per minute and later rise). The neural tube should be closed. Arm and leg buds, optic pits, and a curving C-shape appear. Length is often about 4–7 mm — similar to a pea as a size cue, not a weight.
What changes in your body at 6 weeks?
Morning sickness can arrive any time of day. Smell sensitivity, bloating, and needing more sleep are common. Breast changes continue. Some people have little nausea; that can also be normal.
Tips for this week
Sip fluids and try bland, frequent snacks if you are nauseated. Call if you cannot keep liquids down for a day, you lose weight, or you feel faint. Do not use anti-nausea medicines unless a clinician agrees. Avoid alcohol, smoking, and high-dose vitamin A supplements.
