At 22 weeks of pregnancy, a fetus measures about 7.5 inches (19 centimeters) from crown to rump and roughly 11.5 inches from head to heel. Weight is around 1 pound (460 grams), comparable in size to a sweet potato. That’s big enough to have distinctly human features, and the body is developing rapidly in ways you can both see on an ultrasound and feel from the outside.
Length, Weight, and How Size Is Measured
Fetal measurements at this stage use two reference points. Crown-to-rump length, measured from the top of the head to the bottom of the tailbone, is about 7.5 inches. Crown-to-heel length, which includes the legs, brings the total closer to 11.5 inches. Earlier in pregnancy, only crown-to-rump is used because the legs are curled tightly. By 22 weeks the legs are stretching out more, so crown-to-heel becomes a more practical way to picture overall size.
Weight gain accelerates from here. At 1 pound, the fetus still has very little body fat, which is why the skin appears wrinkled and somewhat translucent. Over the coming weeks, fat deposits will fill in rapidly, and weight can more than double by the end of the second trimester.
What Your Baby Looks Like Now
By 22 weeks, the face is starting to look like a miniature newborn. Lips, eyelids, and eyebrows are becoming more distinct. Fine, soft hair called lanugo covers much of the body. This hair develops between weeks 16 and 20 and serves an important purpose: it helps a waxy coating called vernix stick to the skin. Vernix protects delicate skin from the amniotic fluid, which could otherwise cause irritation or damage over months of constant exposure. Lanugo also helps regulate body temperature until enough fat builds up to do that job on its own.
Fingernails and toenails are forming, though they’re still soft and thin. The skin is reddish because blood vessels are visible beneath it, and it won’t take on a more opaque appearance until additional fat layers develop in the third trimester.
What’s Developing on the Inside
The lungs are in a critical growth phase. Specialized cells that will eventually produce surfactant, the substance that keeps the lungs’ tiny air sacs from collapsing, begin maturing around week 20. Between weeks 20 and 24, structures called lamellar bodies first appear inside these cells. This is the earliest stage of lung preparation for breathing air, but the lungs are far from ready. Surfactant production increases gradually and won’t reach functional levels for several more weeks.
The inner ear is one of the most advanced organs at this point. It reaches adult size and structural maturity by mid-pregnancy, making it the first sense organ to fully develop. The hearing apparatus itself is anatomically complete as early as 18 weeks, and physiological function comparable to an adult cochlea is in place by around week 20. That said, consistent behavioral responses to sound (like a startle reflex) don’t reliably appear until closer to 24 or 25 weeks. So while the hardware is essentially built, the fetus is still developing the neural connections needed to process what it hears.
Movement You Can Feel
Most pregnant people start feeling fetal movement between 16 and 24 weeks. If this is your first pregnancy, you might not notice anything until after 20 weeks. At 22 weeks, movements often feel like gentle fluttering or swirling sensations, though some people describe light taps or rolls. As the fetus grows larger in the weeks ahead, those subtle flutters will shift into more recognizable kicks and jerky movements.
There’s no set number of movements to expect each day at this stage. Every fetus has its own activity pattern. What matters is getting familiar with what’s typical for your pregnancy so you can notice if something changes later on.
How Your Body Reflects the Growth
Starting around week 20, your healthcare provider may measure fundal height, the distance from the top of the pubic bone to the top of the uterus. At 22 weeks, this measurement should be roughly 22 centimeters, give or take 2 centimeters. It’s a quick way to check that growth is tracking as expected. This correlation between weeks and centimeters holds fairly well from about week 20 through week 36, after which the baby drops lower into the pelvis in preparation for labor.
Viability at 22 Weeks
Twenty-two weeks sits right at the earliest edge of what medicine considers potentially viable. Survival at this gestational age has improved over time but remains challenging. A large Swedish study tracking outcomes across three time periods found that survival among live-born infants at 22 weeks rose from about 10% in 2004 to 2007 to roughly 39% in more recent years (2014 to 2019). That improvement reflects advances in neonatal intensive care, but the numbers also underscore how difficult outcomes remain. Among survivors born at 22 weeks, only about 1 in 5 avoided major complications such as serious brain bleeding, chronic lung disease, or severe eye problems.
These statistics vary significantly by hospital. Facilities with specialized neonatal units and active resuscitation policies at 22 weeks report better outcomes than those without such resources. Geography, hospital philosophy, and individual circumstances all play a role in what happens if a baby arrives this early.