Week 17 · 2nd trimester

Pregnancy Week 17: What to Expect

Baby's development, your body's changes, common symptoms, what to eat, and what to do this week.

Baby's size this week: Pomegranate or pear (~13 cm)

Baby's development at week 17

Baby starts gaining fat under the skin, which will help with temperature regulation after birth. The umbilical cord becomes thicker and stronger. Eyebrows and eyelashes appear (still tiny). Baby's heart is fully functional and pumping about 25 quarts of blood per day. Baby can hear better — your voice, your partner's voice, music, traffic noise. The placenta is now about the same size as baby.

What's happening in your body

Your uterus is now palpable just below the belly button. Possible mild backache as your center of gravity shifts. Heartburn may ramp up as the uterus pushes the stomach upward. The bump is unmistakable. Linea nigra more visible. Skin on the abdomen may itch as it stretches.

Common symptoms at week 17

Definitive bump. Possible back pain as posture shifts. Heartburn. Round ligament pain. Possible mild constipation. Stronger fetal kicks (for those who can feel them). Possible itchy belly. Mild leg cramps at night. Possible nasal congestion.

When to call your provider

Severe back pain combined with bleeding, signs of preterm labor (contractions, watery discharge, pelvic pressure), or vision changes — call provider. Mild back pain alone is usually just the bump pulling your posture forward.

How to feel better this week

Start pelvic floor exercises (Kegels) if you have not. Strong pelvic floor muscles help during delivery, prevent incontinence, and speed postpartum recovery. Squeeze the muscles you would use to stop urinating mid-stream; hold 5 seconds, release; do 10-15 reps three times daily. Use a maternity belt if back pain is becoming an issue. Sleep on your side with a pillow between knees. Apply unscented lotion to the belly daily — itching is common.

Nutrition focus for week 17

Iron (still climbing), calcium, vitamin D, protein, omega-3s. Add foods rich in zinc and selenium (Brazil nuts) for baby's immune system and brain development. Avoid raw or undercooked anything. Keep caffeine below 200 mg.

For your partner

Daily Kegels are surprisingly worth it for both pelvic floor function and avoiding postpartum issues. Encourage and remind. Massage your partner's lower back at night — pregnancy back pain is real.

This week's to-do

Start daily Kegels. Apply lotion to the belly to manage itching.

Is this normal?

The 20-week anatomy scan is structural — it checks for major issues like spina bifida, heart defects, and other malformations. Most scans show everything is normal. If something does come up, follow-up testing is usually needed before any conclusions.

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Medical disclaimer: This content is for general educational purposes only and is not a substitute for medical advice. Always talk to your healthcare provider about your specific pregnancy. If you have concerning symptoms, do not wait — call your provider or go to the emergency department.