Week 23 is when the ribcage starts expanding to make room, which is felt as rib pain and breathlessness. Movement is becoming regular enough that a rhythm starts to show. That rhythm is about to become the single most useful thing you track.
Your body this week
Rib pain comes from the ribcage widening as the bump grows upward, and breathlessness comes from the same pressure on the lungs. Neither is dangerous by itself. Both are eased more by sitting back with your feet up than by anything else.
Breasts may start leaking colostrum, the early milk that arrives long before a birth. It is not a sign that anything is starting.
The one thing to separate out: breathlessness that comes on suddenly, or with chest pain, is not this. That needs emergency care, and the red-flag box below says so.
What you may notice
Tiredness and sleep problems, stretch marks, sore gums, round ligament pains, piles, headaches, backache, nosebleeds, indigestion and heartburn, bloating and constipation, leg cramps, feeling hot, dizziness, swollen hands and feet, urine infections, vaginal infections, and skin and hair changes.
The NHS's line this week is the one to remember for the rest of the pregnancy: get to know your baby's rhythms, and talk to a midwife if the movements slow down.
Your baby this week
Around week 23, the length given is about 28.9cm from head to heel — the NHS compares it to a large mango. It is a population average, and a scan measuring differently is a conversation with a clinician rather than a verdict.
Limbs are now in proportion. Over the coming weeks movements become strong enough to see from the outside, and the bump visibly changes shape. Breathing practice and sleep-wake cycles continue.
What care usually happens around now
Nothing is routinely scheduled in the UK this week. If the whooping cough vaccination has not happened, the window is open until week 32.
The next fixed appointment for most women in the UK is around 24 or 25 weeks, and the pattern differs depending on whether this is a first pregnancy. Antenatal schedules also differ between countries, so use your own notes rather than a general timeline.
This week's tip
Start noticing when movements usually happen — after meals, in the evening, when you lie down. Not counting, noticing. From around 24 weeks, the thing that matters is a change from your own usual pattern, and you cannot notice a change from a pattern you never learned.
When to see a doctor
Contact your maternity service straight away if movements slow down or change. Report bleeding, severe pain, a fever, or a headache with vision changes. Pregnancy warning signs has the full list.
Seek care now: Contact your local emergency services or go to your nearest emergency department if you have heavy bleeding, severe or one-sided tummy pain, a severe headache with vision changes, sudden swelling of the face or hands, a fever, fluid leaking from the vagina, chest pain, trouble breathing, fainting, or a seizure. Contact your maternity service the same day for any reduction in your baby's usual pattern of movement. Femio cannot assess a pregnancy.
Frequently asked questions
How many movements should I be feeling?
There is no number, and any app or leaflet that gives you one is wrong. What clinicians ask about is a change from your own usual pattern.
Why do my ribs hurt?
The ribcage widens to make room, and later in pregnancy feet also press against it. Week 24 covers the next appointment, and week 22 covers the week before. Severe pain under the ribs is different and needs care today.