What pregnancy week 20 means
Halfway point. “20 weeks pregnant” means 20 weeks have passed since the first day of the last menstrual period — the standard way pregnancy is dated. Conception usually happened about two weeks after that date, so the baby’s own age (fetal age) is roughly 18 weeks. Week 20 runs from 20 weeks 0 days to 20 weeks 6 days; on the following day the pregnancy is 21 weeks.
Your baby at 20 weeks
From around now, the baby is usually measured from head to heel rather than head to bottom. The baby is swallowing amniotic fluid, which is good practice for the digestive system, and is producing meconium, the first stool.
A common way to picture it: the baby is now about the size of a banana — roughly about 25 cm (head to heel) and about 300 g. These are averages; babies grow at different rates, and ultrasound measurements vary.
Your body at 20 weeks
You have reached the halfway point of a 40-week pregnancy. The top of the uterus is roughly level with the belly button. Movements are becoming easier to feel for many people.
Care and appointments around week 20
The anatomy scan is often done around 20 weeks. It is also a good time to think about antenatal classes, which can book up early.
The timing of tests and appointments differs between countries and care providers. If anything worries you — such as bleeding, severe pain, fluid leaking, fever — contact your midwife, doctor or maternity unit straight away rather than waiting for your next appointment.
Week 20 in your pregnancy timeline
Week 20 is in the second trimester (weeks 14–27) and in pregnancy month 5, which covers roughly weeks 18–22. The third trimester begins in 8 weeks.
| Pregnancy start (first day of last period) | |
|---|---|
| Estimated conception | |
| Third trimester begins (28 weeks) | |
| Full term (39 weeks) | |
| Estimated due date (40 weeks) |
Dates assume you are exactly 20 weeks 0 days today. For dates based on your own last period, use the calculator above or the main Pregnancy Calculator.
20 weeks pregnant in days and months
20 weeks is 140 days of pregnancy — 50% of a 40-week pregnancy. Counted in calendar months, 20 weeks is about 4.6 months, which is usually described as month 5 of pregnancy. Months are only a rough grouping; healthcare professionals almost always talk in weeks and days because they are more precise. See Pregnancy Month Calculator for how weeks map to months.