Baby by Week
Week 16

Your week 16 guide

Stronger muscles and an active nervous system support more deliberate-looking movement.
Trimester

2

Month

4

Weeks left

24

Size at a glance

Comparison
Avocado
Length
12 cm
Weight
3.9 oz
Measurements are approximate. Healthy babies grow at different rates.

Baby development

The circulatory system is working continuously.
The spine and muscles can support the head more upright.
Eyes move behind closed lids, facial expressions appear, and the bowel begins making meconium.

Your body

You may feel the first faint flutters, though many people do not feel movement yet.
Backache, nasal congestion, constipation, and round-ligament pain can occur.
Morning sickness is often much better.

This week's checklist

Schedule the mid-pregnancy ultrasound if your care team recommends one.
Bring a list of questions about movement, screening, and symptoms.
Enjoy baby-name brainstorming without pressure to decide.

Call your care team

Call for bleeding, leaking fluid, fever, painful urination, or persistent pain.
Seek urgent help for severe headache with vision changes, chest pain, fainting, or significant trouble breathing.

Medical information, not medical advice

Every pregnancy is different. Use this guide for general education and follow the advice of your own maternity care team. Do not delay urgent care because of something you read here.