Second trimester · Week 18 of pregnancy

18 weeks pregnant: body, feeding, and care

Ears move into final position and hearing structures mature. Many people have the mid-pregnancy anatomy ultrasound around weeks 18-20.

Body and care — week 18

Ears move into final position and hearing structures mature. Many people have the mid-pregnancy anatomy ultrasound around weeks 18-20. Development notes on this page are general education summarized from ACOG patient-education material; they describe typical development, not your pregnancy specifically. Anatomy and growth are confirmed by your own provider and ultrasounds.

This week's checklist

Week 18 questions

What is happening at 18 weeks pregnant?

Ears move into final position and hearing structures mature. Many people have the mid-pregnancy anatomy ultrasound around weeks 18-20.

Which trimester is week 18?

Week 18 falls in the second trimester (weeks 14–27). See the second trimester hub.

How is a due date calculated?

A due date is typically estimated as 280 days (40 weeks) from the first day of the last menstrual period. It is an estimate — try the client-side due-date calculator; your provider's dating outranks it.

Educational information only — not medical advice. Every pregnancy and every baby develops on their own timeline. If you have any concern, talk to your obstetric provider or your baby's pediatrician.