pregnancy week 18
18 weeks pregnant.
The baby is twisting, stretching, and yawning. The reproductive system is fully formed and detectable on ultrasound.
Updated 29 July 2026 · Sources: NHS and ACOG
Your baby this week
Limbs are graceful and elongated. Skin is still wrinkly because there's no fat yet, but eyebrows and head hair are filling in.
- Yawning and stretching
- Reproductive system formed
- Myelin coats nerves
- Ear bones harden
What may be changing in your body
Many feel quickening now — distinct little flutters or kicks. Round-ligament twinges and lower-back ache are common as the bump grows.
Distinct movements
Flutters are graduating into recognisable pokes and rolls for many people this week. Movements are still irregular — a quiet day at this stage is not yet something to track.
Dizziness when lying flat
The uterus is now heavy enough that lying on your back can compress a major vein and make you light-headed. Roll onto your side and it passes within moments — and take it as your cue to favour side-lying.
Lower back ache
The bump's forward pull is now real, and back ache becomes one of the most common mid-pregnancy complaints. Heat, posture work and pregnancy-safe massage all earn their keep.
Leg cramps at night
Sharp calf cramps that wake you are common from mid-pregnancy. Stretch the calf hard (toes toward your shin) to break the cramp, and stretch before bed to prevent it.
Increased vaginal discharge
Discharge keeps increasing as pregnancy progresses — thin and milky is normal. Any bleeding, or fluid that seems watery and continuous, needs a same-day call to your midwife.
Faster-growing bump
The uterus now reaches roughly halfway to your navel and growth becomes visible week to week. Strangers may begin to notice — with all the commentary that entails.
Your week 18 checklist
- Attend the anomaly scan if scheduled this week — allow plenty of time, it is a long appointment
- Formally notify your employer in writing if required for maternity leave (deadlines are typically around week 25)
- Book antenatal classes now if you have not — the 30-to-36-week courses fill up
- Start a kick-awareness habit: notice when the baby tends to be active, without formal counting yet
A useful partner move this week
The anomaly scan is the longest and most detailed look at your baby — around 30 to 45 minutes of measurements and, usually, the option to learn the sex. Be there, and block out the whole morning or afternoon, since scans often run late or need a second attempt if the baby is awkwardly positioned. Around now you may also feel a kick from the outside for the first time if you are patient with your hand on the bump in the evening.
What comes next
The anatomy scan is usually scheduled now or just after. You may also start feeling stronger kicks each day.
Common questions
What does the 20-week anomaly scan look for?
The sonographer examines the baby's anatomy in detail — brain, face, spine, heart, stomach, kidneys, bladder, arms, legs, hands and feet — plus the placenta's position and the amniotic fluid level. It screens for 11 specific conditions, including spina bifida and serious heart defects. Most scans are entirely reassuring, and it is usually when you can find out the sex if you wish.
Should I be feeling kicks every day at 18 weeks?
Not yet — at 18 weeks movements are still inconsistent, and gaps of a day or more are common and normal. The baby is small enough to move without you feeling it, especially with an anterior placenta. A regular daily pattern typically establishes between 24 and 28 weeks, which is when movement awareness starts to matter clinically.
What is a low-lying placenta and should I worry?
At the anomaly scan, some placentas are found sitting low in the uterus, near or over the cervix. In the large majority of cases, the placenta effectively moves up as the uterus grows, and a follow-up scan around 32 weeks confirms it has cleared. Only if it remains over the cervix (placenta praevia) does it change birth planning — your team will explain exactly what it means for you.
How many months is 18 weeks pregnant?
Pregnancy months do not divide evenly into weeks, so clinicians date pregnancy in weeks. At 18 weeks, you are in trimester two.