2nd trimester · Week 18
18 weeks pregnant
Nerves gain myelin and ears stand out
Myelin begins to insulate some nerves. The ears stand away from the head. Quickening becomes more likely, especially in a second pregnancy.
How big is your baby at 18 weeks?
- Length
- 14.2 cm
- Weight
- 190 g
- Size
- Passion fruit
On average about 14.2 cm long and 190 g. Size comparison: Passion fruit.
These are averages; every baby grows at their own pace.
How is your baby developing at 18 weeks?
The fetus can yawn and may hiccup. The uterus has more room for rolls and stretches. Average length is about 14 cm; weight often near 190 g. Genitalia are often clearer on ultrasound now, if you choose to look.
What changes in your body at 18 weeks?
You may feel pops, bubbles, or muscle twitches that are hard to name. Dizziness in warm rooms can increase. Stretch marks may appear on hips or breasts — genetics matter more than oils.
Tips for this week
If movement is new, do not start formal kick counts yet unless your clinician asked. Note the pattern over days. Hydrate if you feel faint. Mention reduced movement once you have a regular pattern — later this trimester that becomes more important.
