Second trimester · 25 weeks to go
| Fact | Week 15 |
|---|---|
| Days of pregnancy | 99–105 since LMP |
| Gestational age span | 14w0d to 14w6d |
| Trimester | Second trimester (weeks 14–27) |
| Pregnancy month | Month 2 (weeks 5–8) |
| Average length | 4.1 in (crown to rump) |
| Average weight | 2.5 oz |
| Size comparison | an apple |
| Weeks remaining | 25 (40-week due date) |
Week 15 brings the first evidence of a senses upgrade: the baby senses light through still-fused eyelids. Bones are dense enough to show on an X-ray, and the baby practices breathing amniotic fluid.
Legs now outmeasure arms, and the skeleton keeps hardening from cartilage. Skin is still paper-thin and translucent, with blood vessels visible. Some providers offer the quad screen or NIPT blood draw around now.
Gestationally, week 15 means you are 14 weeks and 0 to 6 days pregnant, day 99 to day 105 counted from the first day of your last period. This is week 2 of the second trimester (weeks 14–27). Prenatal appointments run about every four weeks in this stretch. Week 20 brings the anatomy scan window (weeks 18–22). Across this trimester the baby more than triples in weight, so expect your bump, your appetite, and eventually your waddle to keep pace with the calendar. Every number on this page is an average across pregnancies; your own scan dates and your baby's measurements are what actually describe your week 15.
Sleep on your side from now on; it improves blood flow to the placenta. A pillow under the bump and between the knees helps.
Weeks of pregnancy don't map cleanly to calendar months, but the common division puts week 15 falls in month 2 of pregnancy (weeks 5–8). Week 15 is part of the second trimester, which runs from week 14 to week 27. Gestationally, week 15 means you are 14 weeks and 0 to 6 days pregnant.
At week 15 the baby averages 4.1 in long and weighs about 2.5 oz, roughly the size of an apple. Sizes come from fetal growth charts (crown-rump length before week 20), and normal variation week to week is wide; your ultrasound measurements always outrank a chart.