Week 16 · Second trimester
16 weeks pregnant
For you
Constipation, bloating, or other digestive changes may be present as hormones and the growing uterus affect the body; some people notice little change.
For baby or babies
Across the broad weeks 13–16 range, hearing and lung tissue begin further development; this is not an individual assessment.
Source: American College of Obstetricians and Gynecologists — How Your Fetus Grows During Pregnancy ↗
Development stage · Growth and early sensory development
Across weeks 13–16, bones harden, lower limbs develop, hearing starts to develop, and lung tissue continues forming.
Source: American College of Obstetricians and Gynecologists — How Your Fetus Grows During Pregnancy ↗
Week numbers are estimates, counted from the first day of the last period.
In the app this week
- Words you can show or say to your care team
- One clear ask for your supporter
- A prompt for the two of you
Part of Pace Premium from week 16; weeks 4–15 are free.
About these sources
NHS — Week-by-week guide to pregnancy ↗
General education · United Kingdom public health source. The public guide supplies weekly pages from week 4 through week 41. UK care schedules and advice do not automatically apply elsewhere.
American College of Obstetricians and Gynecologists — How Your Fetus Grows During Pregnancy ↗
General development reference · United States professional organization. The source describes broad four-week development bands. Pace does not turn them into an individual assessment or claim that development follows an exact weekly schedule.
Source receipts reviewed 27 August 2026. General information that Pace, Please has summarised from the public sources named on this page. It is not medical advice, does not assess your pregnancy, and every pregnancy differs. Your care team and your own care plan come first.
If something feels wrong, contact your maternity team now. In an emergency, call your local emergency number.