11th week: The embryo becomes a fetus

Weeks and days
10+0 to 10+6
Month
3
Trimester
1

Between 10+0 and 10+4, the embryonic period ends, and from now on your baby is called a fetus. This week, it grows from about 33 to 42 millimeters, and all organs are in place.

A single round plum lies in an open palm on beige linen
Plum35 to 50 mm, the size of your baby at the end of the week

Week 11 of 40

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How big is the fetus?

0102030405060 mm9th week16 to 2310th week24 to 3211th week33 to 4212th week44 to 54Plum at the same scale

33 to 42 mm

By the end of the week, the fetus is about the size of a round plum. The head, trunk, and limbs are now clearly formed, the eyelids close, and the toes are separate.

Crown-rump length on ultrasound according to Robinson and Fleming. A round plum such as a greengage usually measures 35 to 50 mm.

This week

Your baby

  • With the end of the embryonic period, all organs are in place; from now on, they grow and mature.
  • The intestine begins to move from the umbilical cord back into the abdomen.
  • The heart slowly becomes calmer; at a length of 35 mm, it beats on average 170 times per minute.

Your body

  • The median hCG level is 85,172 mIU/ml; 46,509 to 186,977 is normal. More in the hCG levels chart.
  • The growing uterus presses on the bladder, so you need to go to the toilet more often. If it burns when you urinate, this may be a bladder infection.
  • For many, tiredness and nausea ease in the coming weeks.

What matters now

  • In Germany, the basic ultrasound is scheduled until 11+6 at the latest.
  • In Switzerland, basic health insurance pays for an ultrasound and the first-trimester test in the 12th to 14th week.
  • Whether you tell your employer yet is up to you. In Germany, however, protection against dismissal only applies once your employer knows about the pregnancy.

Get checked right away: heavy bleeding, severe or persistent abdominal pain, fever, pain when urinating, or vomiting where you cannot keep anything down.

Gestational sacYolk sacFetus with heartbeat

On ultrasound

  1. 10+0

    Fetus: The embryonic period ends by about 10+4; the head, trunk, and limbs are clearly distinguishable.

  2. 10+3

    Physiological umbilical hernia was visible in all fetuses until about this point; after that, the intestine withdraws.

  3. 10+6

    Stomach was visible as a dark spot in all fetuses by this point.

Nuchal translucency is only measured from 11+0 and from a crown-rump length of 45 mm. An image from this week does not yet tell you anything about it.

Frequently asked questions about the 11th week of pregnancy

Is the baby an embryo or a fetus in the 11th week of pregnancy?

A fetus. The embryonic period ends between 10+0 and 10+4, that is, at the beginning of the 11th week of pregnancy.

Can nuchal translucency be measured in the 11th week of pregnancy?

Not yet. It is measured between 11+0 and 13+6 at a crown-rump length of 45 to 84 mm. 11+0 is already the 12th week of pregnancy.

What is the risk of miscarriage in the 11th week of pregnancy?

In a study of women without symptoms in whom the heartbeat was visible, it was 0.7 in 100 at 10 completed weeks. The case numbers were small.

Which month is the 11th week of pregnancy?

The 3rd month of pregnancy, in the 1st trimester. Figures such as 10+5 weeks also belong to the 11th week of pregnancy.

Sources

Updated on 27 October 2026 · Fertilio Editorial Team