Fetal Development In 22 Weeks | Baby Growth And Milestones

Around 22 weeks of pregnancy, many parents start to picture the baby as a small person with clear features, rhythms, and habits. Understanding what is happening with growth at this stage can make checkups feel less mysterious and make each kick feel even more personally meaningful.

Fetal Development In 22 Weeks: Growth Snapshot

By 22 weeks of pregnancy, the baby is roughly the length of a small sweet potato or coconut. Many medical sources describe an average length of about 27–28 centimetres from head to heel and a weight in the 430–500 gram range, though every pregnancy has its own pattern.

The skeleton now contains more calcium, so bones show up more clearly on ultrasound. Muscles have more strength, which is why kicks and rolls can feel sharper than they did a few weeks ago. Soft fine hair, called lanugo, covers the body and helps the delicate skin hold on to protective waxy coating.

Baby Size And Body Proportions

Head growth has slowed compared with the first trimester, so the body is starting to catch up. Arms and legs look much more in balance with the head. Fingers and toes are well formed, complete with tiny nails. Many babies can now grasp the umbilical cord briefly or touch their own face.

Organ Development At 22 Weeks

The lungs are one of the busiest organs at this point. Air sacs are forming and the baby practices tiny breathing motions using amniotic fluid instead of air. An NHS week 22 overview notes that this ongoing practice lays the groundwork for breathing after birth, while the lungs still need many more weeks to be ready for life outside the womb.

The digestive system keeps rehearsing too. The baby swallows small amounts of amniotic fluid, which travel through the stomach and intestines. Parts of this fluid stay behind in the bowel as meconium, the dark sticky first stool seen after birth.

Brain, Nerves, And Sleep Patterns

The brain now contains many more nerve connections than earlier in pregnancy. Nerve endings spread through the skin, lips, and fingertips, which helps the baby sense touch inside the womb. A Mayo Clinic review of second trimester fetal development describes how eyebrows and scalp hair become visible around this time, hinting at the growing role of the nervous system in facial expression and movement.

Parents often notice patterns in movement by 22 weeks. Some babies kick more in the evening, others in the morning. These rhythms reflect cycles of light sleep and active phases rather than firm day and night habits, but they still give a sense of the baby’s personality.

Core Measurements And Milestones At 22 Weeks

Health professionals track several features on growth charts and ultrasound reports for this stage. The ranges below are broad guides, not strict targets, and individual reports may use slightly different units or ranges.

Feature	Typical Range At 22 Weeks	What It Usually Tells You
Crown–Heel Length	About 27–28 cm	Shows overall body growth and limb length.
Estimated Weight	Roughly 430–500 g	Used with past scans to check steady weight gain.
Head Circumference	Average on mid-pregnancy charts	Monitored to follow brain and skull growth.
Abdominal Circumference	In line with head size and length	Helps assess fat stores and organ size.
Femur Length	Several centimetres long	Reflects long-bone growth in the legs.
Placenta Location	Front, back, high, or low in the uterus	Guides monitoring later for placenta previa risks.
Amniotic Fluid Volume	Within normal index range for gestation	Shows how well the baby and placenta balance fluid.

Fetal Development At 22 Weeks Of Pregnancy: Senses And Brain

One of the most striking shifts around this time is the baby’s growing ability to sense the world inside the womb. Hearing, touch, and early visual routes all gain more structure in the brain.

Hearing And Sound Response

The tiny bones in the middle ear harden through the second trimester, which lets sound travel more clearly. By about 22 weeks, the baby can likely pick up muffled versions of voices, heartbeat, and blood flow. An overview from Cleveland Clinic notes that movement and sensory response continue to grow throughout the fetal stage as nerve circuits mature.

Sense Of Touch And Body Awareness

With more nerve endings in the skin, lips, and tongue, the baby can feel contact with the uterine wall, umbilical cord, and their own body. You may see thumb sucking, hand-to-face strokes, or stretching movements during an ultrasound. These actions help shape body awareness and coordination.

Brown fat begins to build under the skin. This special fat helps newborns keep warm after birth. The baby’s skin is still thin and has a reddish tint because blood vessels lie close to the surface, but layers of fat and stronger skin will follow in the coming weeks.

Vision And Light Sensitivity

The eyelids remain closed at 22 weeks, though the eyes move behind them. Eyebrows and fine lashes may be visible on ultrasound. A guide from the American College of Obstetricians and Gynecologists (ACOG) explains that the second trimester marks a phase of quick growth in organs and senses, including the eyes.

Even through the uterine wall, fluid, and skin, strong light shone on the abdomen may reach the baby as a dim glow. Some babies respond with a shift in movement when the belly is lit or shaded, though not every baby shows this on cue.

Placenta, Umbilical Cord, And Amniotic Fluid At 22 Weeks

The placenta, cord, and fluid work together to deliver oxygen and nutrients and to carry away waste. Their health is just as central as the baby’s own organs.

Placental Function

The placenta grows thicker through the second trimester. Tiny blood vessels from the uterus and from the baby sit close together in this organ without mixing directly. Oxygen and nutrients cross this thin barrier, while waste products move out toward your bloodstream for removal.

Umbilical Cord And Blood Flow

The umbilical cord usually contains two arteries and one vein, wrapped in protective jelly-like tissue. At 22 weeks, blood flows swiftly along this cord between placenta and baby. Doppler ultrasound can show this flow pattern when doctors need to review it in detail.

Amniotic Fluid Balance

Amniotic fluid cushions the baby, allows free movement, and helps muscles and bones grow straight and strong. By 22 weeks the baby both swallows fluid and releases urine back into the sac, which helps keep the volume in balance.

Too much fluid (polyhydramnios) or too little fluid (oligohydramnios) can signal health issues for the baby or placenta. In those cases, care teams may arrange extra scans, blood tests, or closer monitoring.

What A 22-Week Ultrasound Often Shows

A scan around this time may be part of a routine mid-pregnancy review or a follow-up after earlier tests. Parents often look forward to this visit because the baby already has a recognisable face, limbs, and movements.

Ultrasound Feature	What You Might See	What Clinicians Check
Facial Profile	Nose, lips, and chin in clear outline	Looks for cleft lip or other visible facial changes.
Heart Chambers	Four chambers beating in rhythm	Checks structure, rhythm, and blood flow paths.
Spine	Line of vertebrae from neck to lower back	Reviews spine alignment and skin coverage.
Limbs And Hands	Arms, legs, fingers, and toes moving	Counts limbs and checks joint movement.
Organs In The Abdomen	Stomach bubble and bladder filling and emptying	Assesses organ position and basic function.
Placenta And Cord	Placenta position and cord insertion site	Looks for low-lying placenta or unusual cord patterns.
Amniotic Fluid Index	Fluid around the baby	Measures pockets of fluid to judge the range.

Fetal Growth Around 22 Weeks And Future Milestones

By this point, the baby has many body systems in place, yet still needs time in the uterus to refine them. Over the next few weeks, lungs produce more surfactant to keep air sacs open, skin thickens, and fat layers grow. These shifts help the body cope with life outside the womb later in pregnancy.

Medical groups stress that the ability to feel pain and survive outside the uterus comes later than 22 weeks in most cases. An ACOG factsheet on gestational development and pain notes that current evidence points to pain awareness after about 24–25 weeks, once the brain and nerve routes link more fully.

When To Contact A Health Professional At 22 Weeks

Every pregnancy has its own rhythm, yet certain patterns call for prompt advice. Contact your midwife, obstetrician, or local maternity unit straight away if you notice any of the following at 22 weeks or later:

• Bleeding from the vagina, with or without pain.
• Fluid leaking from the vagina that feels like your waters have broken.
• Severe abdominal pain, cramps, or tightening that comes and goes in a pattern.
• A sudden drop in the baby’s movements after you have been feeling regular kicks.
• Fever, strong headache, visual changes, or swelling in the face and hands.

If you are unsure about symptoms, your care team would usually rather hear from you than have you stay at home worrying. Quick contact makes it easier to arrange review, treatment, or reassurance when needed.

Looking After Yourself While Baby Grows At 22 Weeks

As fetal development continues at 22 weeks, daily habits still shape both your comfort and the baby’s growth. Eating a varied diet with enough protein, iron, calcium, and folate helps meet the needs of pregnancy. National guidelines such as the NHS advice on diet in pregnancy outline which foods to include and which to avoid.

Regular antenatal checkups allow your team to measure fundal height, review blood pressure and urine, and keep an eye on growth. Sources like the Mayo Clinic guidance on the second trimester point out that many body changes, such as backache and mild swelling, are common yet still worth mentioning so that more serious problems are not missed.

Taken together, these changes show how quickly the baby’s body and senses move from early structures toward newborn patterns. Staying aware of fetal development at 22 weeks can make each appointment feel less overwhelming and help you notice when something feels reassuring or needs attention during this week. Local health services and prenatal education resources can offer extra context that fits your region and needs.