Second trimester · 20 weeks to go
| Fact | Week 20 |
|---|---|
| Days of pregnancy | 134–140 since LMP |
| Gestational age span | 19w0d to 19w6d |
| Trimester | Second trimester (weeks 14–27) |
| Pregnancy month | Month 2 (weeks 5–8) |
| Average length | ~10 in (crown to heel) |
| Average weight | 10.6 oz |
| Size comparison | a banana |
| Weeks remaining | 20 (40-week due date) |
Week 20 is the halfway mark, measured head to heel now instead of crown to rump, which is why length seems to jump. The baby swallows small amounts of amniotic fluid, and meconium, the first stool, is accumulating in the bowels.
The anatomy scan happens around now: a detailed ultrasound checking heart chambers, brain structures, kidneys, limbs, and, if you want, sex. The baby's taste buds are working, and the sweet tooth starts here; amniotic fluid carries flavors.
Gestationally, week 20 means you are 19 weeks and 0 to 6 days pregnant, day 134 to day 140 counted from the first day of your last period. This is week 7 of the second trimester (weeks 14–27). Prenatal appointments run about every four weeks in this stretch. Week 24 brings viability and the opening of the glucose-test window (weeks 24–28). 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 20.
Eat varied flavors now; babies taste what you eat through amniotic fluid. Put your feet up above heart level for swollen ankles.
Weeks of pregnancy don't map cleanly to calendar months, but the common division puts week 20 falls in month 2 of pregnancy (weeks 5–8). Week 20 is part of the second trimester, which runs from week 14 to week 27. Gestationally, week 20 means you are 19 weeks and 0 to 6 days pregnant.
At week 20 the baby averages ~10 in long and weighs about 10.6 oz, roughly the size of a banana. Sizes come from fetal growth charts (crown-to-heel length from week 20), and normal variation week to week is wide; your ultrasound measurements always outrank a chart.