20 Weeks Pregnant

Baby’s Development

Your baby is now about 16.4 centimeters long — around the size of a banana — and weighs roughly 300 grams [1]. You’ve reached the halfway point! Measured crown-to-heel, your baby is about 10 inches long. Sleep-wake cycles run about 20 to 30 minutes, and your baby can now suck their thumb. Movements are coordinated, with specific responses to sound, light, and touch. The sensory areas of the brain are becoming specialized. The reproductive system continues to develop: if you’re having a girl, her ovaries already contain a lifetime egg supply (around 6 to 7 million, which will decrease to 1 to 2 million by birth), and if a boy, his testes are still in the abdomen and will descend later. The vernix is at its thickest, and lanugo covers the body. Kicks, punches, rolls, and hiccups are all distinct now. The age of viability is still around 24 weeks, so babies born at 20 weeks have very low survival odds [2].

Body Changes

Your uterus has reached your navel and is about the size of a small watermelon. A weight gain of 12 to 17 pounds by week 20 is typical, and your bump is obvious. You might see stretch marks, the linea nigra, melasma, visible veins, or varicose veins. Your breasts may be up 1 to 2 cup sizes with possible colostrum, your hair is likely thicker and growing faster, and your nails are growing faster too. Skin tags can appear, and heartburn may worsen as your uterus pushes your stomach upward [2].

Tips for Week 20

• The anatomy scan window closes at week 22 — if you haven’t had yours, schedule it this week. Take your time, ask questions, and get the full report.
• Celebrate the halfway point — mark the milestone with a photo, a dinner, a journal entry, or a gratitude practice. Reflect on how far you’ve come and plan for what’s ahead.
• Plan for glucose screening — at 24 to 28 weeks you’ll drink a 50g glucose solution (Glucola) and have blood drawn an hour later. A result under 140 mg/dL is normal; a positive screen leads to a 3-hour GTT to diagnose gestational diabetes.
• Strengthen your pelvic floor and core — daily Kegels (three times a day), gentle core work like pelvic tilts, bird-dog, and modified side planks, plus glute bridges, all help prevent back pain and prepare your body for birth.

Things To Do (Checklist)

• Complete anatomy scan this week
• Mark halfway point — photo, journal, dinner
• Add daily Kegels + core exercises
• Plan glucose screening for 24-28 weeks
• Schedule childbirth class (book 20-24 weeks)

Frequently Asked Questions

Q: Can I feel my baby hiccup? A: Yes, and it’s common from week 20 on. Hiccups feel rhythmic, light, and repeated — different from the sharp jab of a kick. They’re completely normal, as your baby is simply practicing breathing motions [2].

Q: I have sciatica. Help? A: It’s common. Your baby may press on your sciatic nerve, causing shooting pain down your buttock or leg. Stretching, prenatal yoga, warm baths, side-sleeping, and physical therapy all help, and it usually resolves after birth [1].

Q: Can I drink coffee? A: Yes, up to 200 mg per day (about 12 ounces of brewed coffee). Studies show no harm at that level, though some people switch to half-caf. Cold brew has a bit less caffeine. As always, discuss it with your OB [3].

Sources

1. ACOG — How Your Fetus Grows During Pregnancy
2. Mayo Clinic — 20 Weeks Pregnant
3. Expecting Better — Emily Oster (Chapter 11: Pregnancy Diet & Exercise)