18 Weeks Pregnant
You’re 18 weeks pregnant — in the second trimester, and 22 weeks to go until your due date. Your baby is about the size of a bell pepper this week.
How big is your baby at 18 weeks?
Size of a
bell pepper
Length
~14.2 cm
Weight
~190 g
Last week your baby was about the size of a pomegranate; this week it's grown to roughly a bell pepper.
Sizes are averages from standard fetal-growth references. Every baby grows at its own pace — your provider tracks yours at scans.
Baby development at week 18
The ears are now in their final position and the fetus may start to hear muffled sounds, including your heartbeat and voice. A protective coating called myelin begins forming around the nerves. In female fetuses, the uterus and fallopian tubes are forming; in males, the genitals are now distinct. About the size of a bell pepper.
Your body at 18 weeks
Common symptoms many people notice around week 18 include:
- Noticeable baby movements for many
- Backache and round-ligament pain
- Leg cramps, especially at night
- Increased appetite
Symptoms vary enormously from person to person and pregnancy to pregnancy. Not having a symptom on this list is just as normal as having it.
Tips for week 18
- The mid-pregnancy anatomy scan often happens around weeks 18–22
- Talking or playing music to your bump is a lovely habit to start
- Stretch before bed to reduce leg cramps
What trimester is 18 weeks?
Week 18 falls in the second trimester. As a quick map: the first trimester runs weeks 1–13, the second covers weeks 14–27, and the third is week 28 through birth (a due date is set at 40 weeks). Want your own dates? Our Pregnancy Due Date Calculator shows your due date and exactly how far along you are today.
The second trimester (weeks 14–27) is the stretch many people find most comfortable: early nausea usually fades, energy returns, and the bump becomes visible. The big checkpoint is the mid-pregnancy anatomy scan around week 20, and you'll likely feel the first movements during these weeks.
Frequently asked questions
- How many months is 18 weeks pregnant?
- 18 weeks pregnant is about 5 months. Pregnancy months don't divide evenly into 4-week blocks, so week-to-month conversions are approximate — most providers track pregnancy by week, not month.
- How big is the baby at 18 weeks?
- At 18 weeks, the baby is about the size of a bell pepper, roughly 14.2 cm and around 190 g. These are averages — healthy babies vary, and your provider tracks your baby's own growth curve at scans.
- What trimester is 18 weeks?
- Week 18 is in the second trimester. The first trimester is weeks 1–13, the second is weeks 14–27, and the third is weeks 28 to birth (around week 40).