Your baby's bones are turning to stone

What's happening with your baby this week

Your baby's skeleton is hardening. Those ultrasound-approved bones are transitioning from rubbery cartilage to calcium-packed strength. Tiny ribs, spine, even tooth buds under the gums are taking shape.

They're practicing breathing. Well, not air, but amniotic fluid moves in and out of developing lungs. The diaphragm twitches in hiccups you might feel later. Eyebrows and eyelashes are sprouting too (time to debate whose widow's peak they'll inherit).

• Circulation's fully online. Blood vessels are visible through thin skin that's still translucent. The heart pumps about 25 quarts daily.
• Sucking reflex develops. Babies often find thumbs or fingers to mouth in the womb now.
• Tiny movements get coordinated. Limbs bend at joints, hands clasp, and feet push off the uterine wall (hello, first soccer player kicks).

You're hitting the sweet spot for many. Past the first trimester exhaustion, not yet into third-trimester bulk. Energy returns, hair gets thick (thanks, hormones), and that pregnancy glow isn't just hype, increased blood flow plumps everything nicely.

What's happening to your body this week

You're likely feeling those first flutters. At 16 weeks, some people describe it like bubbles popping or a goldfish swimming inside. Others mistake it for gas at first. Where you carry your placenta affects when you'll feel movement (anterior placentas muffle kicks longer).

Round ligament pain can really ramp up now. As your uterus grows, those thick bands holding it in place stretch. A sharp tug low in your belly when you cough or roll over? Classic. Warm baths and slow position changes help.

• Headaches. Hormones + increased blood volume can trigger them. Stay hydrated and ask about pregnancy-safe pain relief if needed.
• Nasal congestion. Pregnancy rhinitis is real. Saline sprays and humidifiers are your friends.
• New moles or skin changes. Surge in melanocyte-stimulating hormone can darken nipples, freckles, or the linea nigra (that faint belly line).

What might happen soon

The anatomy scan is coming up soon.

Most providers schedule it between 18–22 weeks. That detailed ultrasound checks your baby's organs, limbs, and growth. You'll likely get a grainy printout (feet are always oddly adorable). Some clinics offer early gender reveals now, but accuracy improves if you wait.

You might have a prenatal visit this week. The doppler finds baby's heartbeat easily now (sounds like galloping horses). Expect talk of genetic screening results if you did them.

• Ponder the anatomy scan's optional findings
• Note any movement patterns you're feeling