The Playbook

20 Weeks Pregnant: Halfway There and the Anatomy Scan

By the Guide to Fatherhood editorial team. Last reviewed . 2 min read.

Checked against guidance from organizations like the AAP, CDC, ACOG and NHS (linked below). This is general information, not medical advice. Read our medical disclaimer.

Trimester2
Sizea banana
Length / weightabout 10 in (25.6 cm) from head to heel, about 10.6 oz (300 g)

Halfway. From here, the baby is measured head to heel instead of head to bottom. The baby is swallowing more, and meconium, the first poop, is forming in the bowel.

Your to-do list this week

  • Be at the anatomy scan if it's this week. Ask what was checked and what, if anything, needs follow-up.
  • Celebrate halfway. Dinner, a card, a weekend plan; mark it.
  • Start a baby registry with the essentials first. The need-vs-skip list keeps it sane.
  • Open the name explorer and each build a shortlist of five. Then compare.
A conversation to have this week

"What names are you drawn to, and which ones are off the table for you?" Agree that either of you can veto any name, no explanation needed.

Halfway

Twenty weeks down, about twenty to go. The baby is roughly the length of a banana, and from now on is usually measured from head to heel rather than head to bottom. The baby is swallowing more amniotic fluid, and meconium, the dark, sticky first poop you’ll meet in the first diapers, is forming in the bowel (Mayo Clinic; NHS).

How she may be feeling

The top of her uterus has reached about the level of her belly button. Movements are often regular now. Heartburn, swollen feet, and backache are common. She might also have a new appreciation for elastic waistbands.

The anatomy scan

If it hasn’t happened yet, the detailed anatomy scan is usually around now. According to ACOG, it checks the baby’s growth and the structure of the brain, face, spine, heart, stomach, kidneys and limbs, plus the placenta and fluid.

Before you leave, ask two questions: “Was everything you needed to see visible?” and “Is there anything that needs a follow-up?” A repeat scan is common, often just because the baby was lying the wrong way.

Celebrate the halfway mark

Seriously. The first half had a lot of nausea, worry and waiting. Mark it: a nice dinner, a weekend away, a letter to the baby, a photo. These moments go fast.

Registry and names

Two fun projects for the second half:

  • The registry. Start with essentials: a car seat, a safe sleep space, a stroller that fits your life, diapers, bottles. Our gear checklist sorts what you need on day one, what can wait, and what to skip.
  • Names. Try this: you each build a shortlist of five in the name explorer, then compare. Names you both picked go straight to the final round. Either of you can veto anything, no justification required.

Frequently asked questions

Why does the baby's length jump at 20 weeks?

Until about 20 weeks, babies are measured from crown to rump because the legs are curled up. From around 20 weeks, length is usually given from head to heel, so the number looks like it jumped.

What if the anatomy scan finds something?

Many findings are minor or resolve on their own, like a low-lying placenta that often moves up as the uterus grows. If something needs follow-up, her provider will explain the next steps, which may include another ultrasound or a specialist referral.

Sources

  1. Ultrasound Exams, American College of Obstetricians and Gynecologists
  2. Week 20: Your baby and your body, NHS
  3. Fetal development: The 2nd trimester, Mayo Clinic

We link to the original source for every medical and safety claim. Guidance changes; if a source has been updated since our last review, the source wins. How we research.