Second trimester
23 weeks pregnant
A meaningful threshold. Around this week a fetus reaches the edge of viability, meaning survival outside the womb becomes possible with specialist neonatal care, though outcomes at this stage remain difficult.
Size of
large mango
Length
29 cm
Weight
500 g
Your baby at 23 weeks
The lungs are developing the structures needed for gas exchange, but are not yet producing enough surfactant — the substance that keeps air sacs from collapsing — to work unaided.
The skin is still wrinkled and reddish because fat is accumulating more slowly than skin is growing. That balance shifts over the coming weeks.
Hearing is good enough now that loud noises may provoke a startle, and the fetus is increasingly responsive to familiar voices.
How you may be feeling
The uterus is well above the navel, and pressure on the diaphragm can make breathing feel less easy. Swelling in the feet and ankles is common by the end of the day.
Many people find this the week they start thinking seriously about birth, which can bring both excitement and anxiety. Both are entirely reasonable responses.
Common symptoms around week 23
- Swollen feet and ankles
- Shortness of breath
- Braxton Hicks contractions
- Backache
- Strong, regular fetal movement
Appointments and tests around now
Glucose tolerance testing for gestational diabetes is typically offered between weeks 24 and 28, so arrangements are often made around now.
What is normal, and what varies
Gradual swelling that develops during the day and improves overnight is usually positional and normal. Sudden swelling, particularly of the face and hands, is the version that needs same-day attention.
Worth doing this week
Know the difference in swelling
Gradual and positional is normal. Sudden, facial, or paired with headache and visual changes needs assessing the same day.
Elevate and move
Both help with fluid retention. Long periods standing or sitting still make it worse.
Start thinking about birth preferences
Not a rigid plan, but knowing what matters to you makes conversations with your care team more productive.
Looking ahead
Next week lung development accelerates and glucose screening is typically offered.
Nearby weeks
Not sure which week you are in? The week tracker works it out from the first day of your last period, and the due date calculator gives you an estimated due date.