16th week: Every type of movement is now present

Weeks and days
15+0 to 15+6
Month
4
Trimester
2

This week, the fetus grows from about 101 to 116 millimeters and weighs around 144 grams by the end. On ultrasound, it now shows all the movement patterns that exist until birth. You usually cannot feel them yet.

A single grapefruit lies in an open palm on beige linen
Grapefruit100 to 119 mm, the size of your baby at the end of the week

Week 16 of 40

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How big is the fetus?

020406080100120140 mm14th week74 to 8715th week87 to 10116th week101 to 11617th week116 to 130Grapefruit at the same scale

101 to 116 mm

By the end of the week, the fetus is about the size of a grapefruit. The fine down of hair, called lanugo, gradually covers the whole body.

Crown-rump length according to the UNSW Embryology table; the NHS gives the same values. Weight according to the WHO growth charts. A grapefruit usually measures 100 to 119 mm.

This week

Your baby

  • From 15+0, all 16 movement patterns could be seen in one study, including hiccups, yawning, and breathing movements.
  • Thumb sucking was observed from 15 weeks, mostly of the right thumb.
  • Until the 16th week, the fetus usually lies on its back, and after that more often on its side.

Your body

  • The median hCG level is 28,962 mIU/ml; 12,039 to 70,971 is normal. More in the hCG levels chart.
  • By the end of the week, the top of the uterus is about halfway between the pubic bone and the navel.
  • The first baby movements feel like a light fluttering. With your first child, you often only feel them after the 20th week.

What matters now

  • Amniocentesis (an amniotic fluid test) is possible from 15+0. The procedure leads to a miscarriage in about 1 to 4 in 1,000 women.
  • If you are not reliably protected against rubella, the antibody test is repeated in Germany in the 16th to 17th week of pregnancy.
  • In Austria, the first Parent-Child Pass (Eltern-Kind-Pass) examination with lab tests and the first ultrasound are scheduled by the end of this week.

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. 15+0

    Amniocentesis is performed from this point under ultrasound guidance, if it is needed.

  2. 15+0

    Movements: All movement patterns can now be observed.

  3. 15+0

    Thumb sucking can be seen on ultrasound from about this point.

Even if you cannot feel anything yet: on ultrasound, your baby now moves with all the movement patterns it shows until birth.

Frequently asked questions about the 16th week of pregnancy

Can you feel movements in the 16th week of pregnancy?

Most cannot yet. In one study, first-time mothers felt the first movements at 15 weeks at the earliest, on average at 19 weeks. The NHS gives the 16th to 24th week.

From when is amniocentesis possible?

From 15+0, that is, from the 16th week of pregnancy. It is not recommended earlier. In Germany, health insurance pays for it if there is a medical reason.

What is the risk of miscarriage in the 16th week of pregnancy?

Low. In an analysis of several studies, from the 14th week, it was less than 10 in 1,000 pregnant women per week and fell further after that.

Which month is the 16th week of pregnancy?

The last week of the 4th month of pregnancy. The 5th month begins with the 17th week of pregnancy, that is, at 16+0.

Sources

Updated on 30 October 2026 · Fertilio Editorial Team