27th week: The first kilogram

Weeks and days
26+0 to 26+6
Month
7
Trimester
2

This week, the fetus grows from about 232 to 242 millimeters and, on average, passes one kilogram. Around the 27th and 28th week of pregnancy, the eyelids begin to open. The 2nd trimester ends with next week.

A whole cauliflower with green outer leaves lies on an open hand on beige linen
Caulifloweraround 1 kg, the weight of your baby at the end of the week

Week 27 of 40

Calculate your week
1st trimester2nd trimester3rd trimester

How big and how heavy is the fetus?

050100150200250 mm25th week213 to 22326th week223 to 23227th week232 to 24228th week242 to 250

232 to 242 mm

By the end of the week, the fetus weighs about as much as a large cauliflower. From head to heel, it measures about 34 centimeters.

Crown-rump length according to the values from Archie et al. 2006, weight according to the WHO growth charts. From this week on, we compare by weight: a cauliflower without its outer leaves weighs 300 to 1,200 g.

This week

Your baby

  • By the end of the week, in one study, almost all unborn babies responded to low-pitched sounds, but none yet to high-pitched ones.
  • The first cells that produce surfactant form in the lungs. After birth, this substance keeps the air sacs in the lungs open.
  • Fat pads begin to form under the skin, but the skin is still wrinkled.

Your body

  • Heartburn becomes more common: in one study, 72 out of 100 pregnant women had it in the 3rd trimester.
  • Calf cramps occur mainly at night. Gently moving your feet and legs can help prevent them.
  • Restless legs in the evening are common. In the 3rd trimester, this affects about 22 out of 100 pregnant women.

What matters now

  • In Germany, it is the last week for the antibody screening test (until 26+6). The glucose test is still possible until 27+6.
  • The German Standing Committee on Vaccination (STIKO) recommends the whooping cough vaccination at the beginning of the 3rd trimester. Plan the appointment now.
  • From the 28th week, it is better to sleep on your side. According to the NHS, sleeping on your back from then on can double the risk of stillbirth.

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

Gestational sacPlacentaFetus with heartbeat

On ultrasound

  1. 26+0

    Head circumference is on average about 244 mm.

  2. 26+0

    Abdominal circumference measures on average about 219 mm.

  3. 28+0

    Third screening is scheduled in Germany from this day.

At the third basic ultrasound between 28+0 and 31+6, the head, abdomen, and thigh bone are measured, along with the baby's position and heartbeat. In Austria, the third ultrasound follows between the 30th and 34th week of pregnancy.

Frequently asked questions about the 27th week of pregnancy

Which month is the 27th week of pregnancy?

The 7th month of pregnancy, in the 2nd trimester. The 28th week of pregnancy is the last week of the 2nd trimester; the 3rd trimester begins at 28+0, that is, with the 29th week of pregnancy.

Can a baby survive in the 27th week of pregnancy?

Yes, a good one. In Sweden, 85 out of 100 babies born alive in this week survived their first year of life. However, many still have problems with their lungs afterward.

Is it normal for the baby to move less in the 27th week of pregnancy?

No, you should pay attention to this. If it moves less or differently than usual, call your midwife or the labor ward right away and do not wait until the next day.

Can the baby open its eyes in the 27th week of pregnancy?

Around the 27th and 28th week of pregnancy, the eyelids begin to open. They are usually only fully open a few weeks later.

Sources

Updated on 30 October 2026 · Fertilio Editorial Team