Week 20 of pregnancy
Updated 25 Oct 2026
Your baby this week
About the size of a banana
Source: Vinmec – Bảng cân nặng và chiều dài thai nhi theo tiêu chuẩn của WHO
Your baby's development
Your baby is about 26 cm long and weighs about 300 grams, about the size of a banana. The whole body is covered with a smooth white waxy layer, also called vernix, which protects your baby better in the amniotic fluid.
Your baby's skin now has 4 layers; the fat under the skin is getting thicker, and the skin is no longer see-through as it was a few weeks ago. Your baby's reproductive organs have developed remarkably. If it is a girl, the ovaries may reach their peak of about 7 million eggs. If it is a boy, the testes are still inside the abdomen at this point.
Your body
So you are halfway through your pregnancy. From here your uterus grows quickly, pushing your organs out of their usual positions. Your centre of gravity shifts forward. Muscle strain also increases, causing aches in your lower tummy, back or pelvic area. You may find your hair grows faster and your nails are stronger, though they may become drier and more brittle.
From week 20 you may feel your baby's movements quite clearly, such as turning over or gently nudging your tummy. At first the movements are usually irregular. But later on they become more regular. This is one way your baby communicates with the outside world.
Advice for you
You can use a maternity support belt to support your uterus and reduce discomfort when moving around. However, a maternity support belt should not be worn for more than 2-3 hours.
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Signs that need a doctor now
If you notice any of the signs below, please go to the nearest health facility to be checked by a doctor.
Vaginal bleeding in pregnancy
This sign needs to be checked by a doctor. Please go to the nearest health facility now. If the bleeding is heavy or comes with severe pain or faintness, call the emergency number 115.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Convulsions (fits)
A convulsion in pregnancy is an emergency. Family members should call 115 at once, lay the mother on her side in a safe place and get her to the nearest hospital.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Fever in pregnancy
A temperature above 38°C counts as a fever. Please go to a health facility so a doctor can find the cause and advise on safe ways to bring it down; do not take medicine on your own.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Leaking fluid or waters breaking
Fluid leaking from the vagina may mean the waters are leaking or have broken and needs to be checked by a doctor. Please go to a health facility soon, lying with your head low while travelling.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Severe headache, blurred vision, sudden swelling
Headache with blurred vision, or sudden swelling of the face, hands or eyelids, can be a sign of high blood pressure in pregnancy or pre-eclampsia. This sign needs to be checked by a doctor. Please go to the nearest health facility now.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Reduced or no fetal movement
A clear drop in the baby's movements, or no movement, needs to be checked by a doctor. Please go to the nearest health facility now rather than waiting until tomorrow.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Severe or worsening abdominal pain
Abdominal pain that keeps getting worse, does not ease, or is severe needs to be checked by a doctor. Please go to the nearest health facility now. If the pain is severe with sweating, faintness or bleeding, call 115.
Source: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
Sources
Content advised by our doctors.
- NHS (accessed 22 Oct 2026)
- NHS (accessed 22 Oct 2026)
- Vinmec (accessed 22 Oct 2026)
- Source for fetal size: Vinmec – Bảng cân nặng và chiều dài thai nhi theo tiêu chuẩn của WHO
- Source for the signs that need a doctor: Bệnh viện Đa khoa Tâm Anh – Các dấu hiệu nguy hiểm trong thai kỳ
This article helps you understand and prepare. It does not replace a check-up. For an answer about your own situation, please ask the doctor who is caring for you.