What pregnancy week 23 means
Steady growth. “23 weeks pregnant” means 23 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 21 weeks. Week 23 runs from 23 weeks 0 days to 23 weeks 6 days; on the following day the pregnancy is 24 weeks.
Your baby at 23 weeks
The lungs are developing branches and the cells that will later make surfactant, a substance needed for breathing after birth. The skin is still wrinkled and somewhat translucent.
A common way to picture it: the baby is now about the size of a grapefruit — roughly about 29 cm and about 500 g. These are averages; babies grow at different rates, and ultrasound measurements vary.
Your body at 23 weeks
Some people notice painless, irregular tightening of the bump. These Braxton Hicks contractions are practice contractions and usually ease with rest or a change of position.
Care and appointments around week 23
If tightening becomes regular, painful or comes with other symptoms, contact your maternity unit rather than waiting for your next appointment.
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 23 in your pregnancy timeline
Week 23 is in the second trimester (weeks 14–27) and in pregnancy month 6, which covers roughly weeks 23–27. The third trimester begins in 5 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 23 weeks 0 days today. For dates based on your own last period, use the calculator above or the main Pregnancy Calculator.
23 weeks pregnant in days and months
23 weeks is 161 days of pregnancy — 57% of a 40-week pregnancy. Counted in calendar months, 23 weeks is about 5.3 months, which is usually described as month 6 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.