What is happening in week 18
Doctors count pregnancy weeks from the first day of your last period, so week 18 sits in the second trimester (week 14 to week 27). That is about 22 weeks to go until week 40, and about 4.1 months by a rough conversion. In week 18 the baby is about 14.2cm long and may be moving in ways you can first feel.
Your baby
The NHS guide gives about 14.2cm, comparing it to a bell pepper. Hearing, feeling, swallowing and sucking reflexes are developing and the baby is wriggling its arms and legs. You may feel first movements now as bubbling or fluttering.
Your body
Your belly is growing so you may feel clumsier, and your blood pressure is probably slightly lower, so stand up slowly. A dark line down the stomach (linea nigra) is normal and usually fades some months after birth.
This week’s to-do
- Prepare for the anomaly scan; the NHS says it is offered at about 18 to 20 weeks (21 on its scan page) and checks the baby’s development in detail.
- Decide beforehand whether you want to know the baby’s sex and tell the sonographer.
- Stand up slowly from sitting or lying.
When to call
Call your doctor or hospital if you have any bleeding, or if everyday life is becoming hard to manage.
Chaitanya Hospital in Kadapa, near RTC Bus Stand, Simhapuri Colony, provides delivery and emergency care 24/7. Our antenatal check-ups team can answer questions about your own pregnancy.
Use the week-by-week guide to jump to your week, or the due date calculator to work out your dates. Timings for scans and tests come from NHS guidance in the UK and can differ from your doctor’s schedule, so always follow your own doctor’s advice. This page is educational and not a substitute for a doctor.
Sources
Text on this page is paraphrased from the sources above. Sizes are averages and vary between babies.