Week 21 starts the second half of the pregnancy, and the most noticeable change is balance. Your centre of gravity has moved and your joints are looser, which is a combination that catches people out on stairs. Hearing is sharp enough now for voices from outside to register.
Your body this week
Feeling unsteady is expected at this stage, and it is worth adjusting for rather than pushing through. Hold handrails, slow down on wet floors, and think about a seat on public transport.
If you do fall, the NHS is clear on both halves of the answer: try not to panic, because a pregnancy at this stage is well protected — and tell your midwife as soon as possible anyway. Being checked after a fall is routine, not an over-reaction.
Sleep-wake patterns are forming, and they will rarely be yours. Naps when you can get them are the practical answer.
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.
Backache often becomes a regular feature from around now, as posture changes to carry the bump.
Your baby this week
Around week 21, the length quoted is about 26.7cm from head to heel, which the NHS compares to a carrot. These are averages across a population, not a measurement of a particular pregnancy.
The lanugo — a fine, downy layer of hair — is developing, along with hair and eyebrows. Noises and voices from outside can now be heard. The NHS notes that at this point the placenta is outweighed for the first time, which is a good measure of how much has changed since week 12.
What care usually happens around now
Nothing is routinely scheduled in the UK. If the whooping cough vaccination has not happened, this is a catch-up week: the window runs from week 16 to week 32, and it is usually offered around week 20.
If the anomaly scan raised something unexpected, this is often the week further appointments are arranged. Support organisations exist specifically for that situation, and a midwife can point you to them. Schedules and services differ between countries.
This week's tip
Take the stairs one at a time and hold the rail — every time, not only when you feel wobbly. Falls in pregnancy usually happen on ordinary stairs on an ordinary day, and the habit has to be automatic before it is useful.
When to see a doctor
Tell your midwife about any fall, even a minor one. 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. Femio cannot assess a pregnancy.
Frequently asked questions
I fell over. Do I need to be checked?
Tell your midwife or maternity unit even if you feel fine. It is a routine call and they would rather have it than not.
Can the baby hear me?
Voices from outside are audible around now, along with your heartbeat and digestion. Week 22 covers what develops next, and week 20 covers the halfway point.