20 Weeks Pregnant — Baby Is the Size of a Banana
At 20 weeks you are 140 days into the 40-week count, with 140 days to go and 50% of the pregnancy behind you. Baby is about the size of a banana and weighs about 8.4 g. This page fixes week 20 in place: what is developing, which appointments are still ahead, and how the week maps onto months.
50% of 280 days. The due date itself is a midpoint, not a deadline: full-term births spread across roughly weeks 37 to 42.
This week
This is the midpoint. The twenty-week anatomy scan checks the heart, limbs and organs — and possibly the sex.
Measured in months, week 20 sits in month 5: Halfway: the anatomy scan happens now, and the first flutters usually become unmistakable kicks.
Appointments still ahead
| Window | Appointment | What it checks |
|---|---|---|
| 24–28 wks | Glucose tolerance test | Screens for gestational diabetes. |
| 28–34 wks | Routine growth checks | Regular midwife visits, bump measurements and blood pressure. |
| 34–36 wks | Group B strep swab | A simple swab that protects the baby during delivery. |
| 37–40 wks | Weekly checkups | Position checks, growth checks and the birth plan in earnest. |
Around week 20
| Week | Size | Weight |
|---|---|---|
| 19 | a mango | about 7 g |
| 20 | a banana | about 8.4 g |
| 21 | a carrot | about 10 g |
Frequently asked
What does 20 weeks pregnant mean in days and months?
20 weeks is 140 days since the first day of your last period, which is about 5 months pregnant on the four-week-per-month convention. 140 days remain in the 40-week count from here — that is 50% of the way through.
How big is a baby at 20 weeks?
Around the size of a banana, at about 8.4 g. These are population averages: a scan measurement that differs by a few days is normal and does not by itself mean anything is wrong.
Which trimester is week 20?
The 2nd trimester. The split used here is the same one the calculator applies: the first trimester covers days 1–90, the second 91–195, and the third from day 196 onward. Other sources draw the boundary a week either side, which is why week 13 and week 14 can both be described as "end of the first trimester".
What appointments happen after week 20?
Next up: Glucose tolerance test at 24–28 weeks, Routine growth checks at 28–34 weeks, Group B strep swab at 34–36 weeks. The full schedule is in the table above; exact timing varies by country and by your care team.