Fetal Perspective

Month 5

Month 5 is an exciting time as both the baby and the mother experience significant changes. The fetus grows rapidly, begins to develop senses, and its movements become more noticeable. For many mothers, this is when they can first feel the baby's movements, known as quickening.

Weeks 17 to 20: Key Developments

Week 17:

Development:

The baby's skeleton, initially soft cartilage, continues to harden into bone.

Fat begins to form under the skin, helping regulate body temperature after birth.

The sweat glands start developing.

The umbilical cord grows thicker and stronger, ensuring the baby receives nutrients efficiently.

The circulatory and urinary systems are fully operational.

Size: About 5 inches long, comparable to a pomegranate.

Weight: Around 5 ounces.

Week 18:

Development:

The baby's ears stand out from the head and can now detect sounds, such as the mother's heartbeat or muffled external noises.

Eyes are developing a sensitivity to light, even though the eyelids remain closed.

The baby starts practicing swallowing, a skill crucial for feeding after birth.

The nervous system connects muscles to the brain, enabling coordinated movements.

Fingerprints begin forming.

Size: About 5.5 inches long, similar to a sweet potato.

Weight: Around 6.7 ounces.

Week 19:

Development:

A protective coating called vernix caseosa, a white, cheesy substance, begins to cover the skin. This protects the skin from amniotic fluid exposure.

Brown fat accumulates under the skin to help with energy storage and temperature regulation.

The baby's senses of taste, smell, touch, and hearing develop further.

The reproductive system is more defined; in females, the uterus and ovaries are in place, while in males, the testes begin to descend.

Size: About 6 inches long, similar to a mango.

Weight: Around 8.5 ounces.

Week 20:

Development:

This is the halfway point of pregnancy. The baby's growth slows slightly, but development continues.

The baby can suck its thumb, yawn, and stretch.

Hair, eyelashes, and eyebrows are now clearly visible.

Movement becomes more deliberate and strong enough for the mother to feel (if she hasn't already).

The digestive system produces meconium, the first bowel movement substance, which will be expelled after birth.

Size: About 6.5 inches long (from crown to rump), comparable to a banana.

When measured head-to-toe (common from this week forward), the baby is about 10 inches long.

Weight: Around 10.5 ounces.

Physical Milestones in Month 5

Increased Movement:

Movements are more purposeful, including kicking, rolling, and somersaulting.

These may feel like flutters, bubbles, or light taps to the mother.

Development of Senses:

The baby begins responding to external stimuli, such as loud sounds or bright lights.

Complex Brain Growth:

The brain continues to form millions of neurons, crucial for reflexes and memory.

Skin and Hair:

The skin is still thin and translucent, but layers of fat and vernix provide protection.

Heartbeat:

The baby's heart is strong and pumping blood, with a rate of 120–160 beats per minute.

Symptoms for the Mother in Month 5

Quickening: Most women feel their baby move for the first time during this month.

Weight Gain: The second trimester is when most weight gain occurs, typically 1–2 pounds per week.

Stretch Marks: As the belly grows, stretch marks may appear on the abdomen, breasts, or thighs.

Increased Appetite: With the baby growing rapidly, the mother may feel hungrier.

Breathlessness: The growing uterus may push against the diaphragm, causing mild shortness of breath.

Skin Changes:

The "pregnancy glow" often becomes more pronounced.

Linea nigra, a dark line running from the belly button to the pubic area, may appear.

What to Expect at the End of Month 5

By the end of this month:

Size: The baby is about 6.5 inches long from crown to rump or around 10 inches head-to-toe, similar to a small cantaloupe.

Weight: Around 10.5–12 ounces.

The baby is active and growing stronger, with more developed senses. Movements will become more noticeable and frequent. Both the mother and baby are now entering a critical phase of preparation for the rapid growth and changes in the third trimester.