Three at once

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Week

Week 13

Each baby is about the size of a lemon this week

Weight each
23 g · 1 oz
Length each
7.4 cm · 2.9 in

What's happening this week

Fingerprints are forming now — three completely unique sets, already different from one another before anyone's even met them. Their voice boxes are being built, and their little limbs are stretching out fast.

There's still plenty of room in there for now. Each has their own pocket of fluid to tumble about in, and they're making the very most of it while the space lasts.

Three little wonders this week

  • Even babies who look identical will have their own fingerprints — shaped by how each one explores the walls around them.
  • Heads and bodies are settling into more newborn-like proportions, even if the head is still leading the way.
  • Tiny spleens and pancreases are quietly getting to work.

The triplet twist

You'll likely be encouraged to gain weight more steadily and generously than someone carrying one baby — it's simply what feeds three growing bodies well, and getting ahead of it early tends to pay off nicely later on.

Something to look forward to

  • Second trimester begins next week — often a little burst of energy arrives before your size really catches up with you.
  • You're about 3 weeks from when those first flutters might become noticeable.

To Mom:

As fingerprints begin to form on thirty tiny fingers, your body is successfully managing a beautiful, busy crowd of lemons. You are entering a new chapter now, and you're doing it with such grace and strength.