Week 4of 40
Trimester 1
from 3 full weeks + 0 days to 3 full weeks + 6 days
The fetus
0.1 cm
Size of a poppy seed
- The blastocyst has now attached to the uterine wall — implantation is complete.
- The embryo is about 1 mm and has begun forming three cell layers that will develop into all organs.
- The placenta and umbilical cord are beginning to form to supply the embryo with nutrients.
Your body
Physical changes
- hCG levels are rising and may now show up on a pregnancy test.
- Your period is missed — often the first clear sign of pregnancy.
Common symptoms
- Tender breasts and a feeling of heaviness in the lower abdomen.
- Mild fatigue and possible nausea may begin.
- Mood swings due to hormonal changes.
Emotional changes
- Many feel a mix of joy, anticipation and worry — all feelings are completely normal.
Good to know
- Take a pregnancy test if your period is late.
- Contact the midwife clinic to book a first appointment.
- Continue with folic acid and healthy habits.
Food & nutrition
Good to eat
- Folic acid-rich vegetables such as asparagus, avocado and broccoli.
- Whole grain products and nuts.
Be aware of
- Be careful with liver products that contain high amounts of vitamin A.
Avoid
- Alcohol — there is no known safe level during pregnancy.
- Tobacco in all forms.
Supplements
- Folic acid 400 micrograms daily.
- Vitamin D may be needed, especially during the winter months.
Exercise
Continue exercising as usual. Regular exercise reduces the risk of complications during pregnancy.
Suggested activities
- Walking and light jogging
- Cycling
- Strength training with moderate loads
Sources
The content on this website is based on information from 1177.se and the Swedish Food Agency. It does not replace professional medical advice. Always contact your midwife or doctor with questions about your pregnancy.