22 weeks pregnant

How big is your baby at 22 weeks?

About the size of a sweet potato — around 27.8 cm (10.9 in) long head to heel, according to the NHS, weighing roughly 476 g (1 lb 1 oz).

Your baby has more than doubled in weight since the anomaly scan window opened.

A note on the numbers: from week 20 the NHS measures head to heel, not head to bottom. That is why the length jumps from 15.3 cm at 19 weeks to 25.6 cm at 20 — no baby grew 10 cm in a week, the tape measure moved. Weights here are the WHO fetal growth chart median; half of babies weigh more, half less.

What's developing this week

The lungs are developing and your baby is doing breathing practice, drawing amniotic fluid in and out. There is no air and no need for it yet — oxygen comes through the placenta — but the muscles and the reflex are being rehearsed. Swallowed fluid mostly stays in the bowel and emerges after birth as meconium, the dark sticky first poo.

The NHS is most pointed about smoking here: cigarettes starve your baby of oxygen and raise the risk of miscarriage, stillbirth and cot death, and it is these lungs at stake.

What you might feel

Stretch marks often become noticeable now, as lines or streaks on the tummy, upper thighs or breasts. They are harmless and usually fade after birth. Piles are common too, and treatable.

The NHS adds a line worth repeating: aches and pains are common, but sometimes it is hard to know what is serious, so raise any concerns. In severe pain, or bleeding, call immediately.

Is 22 weeks pregnant 4 months or 5 months?

Week 22 is the last week of month 5. Month 6 begins at week 23.

There is no official weeks-to-months map. A calendar month averages about 4.3 weeks, not 4, so 40 weeks is a little over nine months — and two apps can disagree about which month you are in. The most widely used mapping:

• Month 1 — weeks 1 to 4
• Month 2 — weeks 5 to 8
• Month 3 — weeks 9 to 13
• Month 4 — weeks 14 to 17
• Month 5 — weeks 18 to 22
• Month 6 — weeks 23 to 27
• Month 7 — weeks 28 to 31
• Month 8 — weeks 32 to 35
• Month 9 — weeks 36 to 40

Your maternity team will not use months. Everything is booked by week and day — "19 weeks and 3 days" — because a few days change what is offered. The anomaly scan window is 18+0 to 20+6 weeks, not "about five months".

What's happening at your appointments around now

Still the quiet stretch in the UK: the next routine appointment is 25 weeks for a first baby, 28 otherwise. One deadline does bite. If your anomaly scan has not happened, the NHS backstop is 23 weeks — tell your midwife or GP now.

What viability means at 22 weeks

This is the week search engines start suggesting the word. There is no single global threshold, and anyone giving you one number is giving you their country's. Three things get muddled.

A registration line. The NHS calls a UK loss before 24 weeks a miscarriage and after that a stillbirth — paperwork, not biology.

A clinical decision framework. The BAPM framework used across the UK, updated in February 2026, is explicit that decisions for babies born between 22+0 and 26+6 weeks should not rest on gestational age alone, but on that baby's risk profile. Survival-focused care is not offered before 22+0. Babies are stratified as extremely high, high or moderate risk, and where the risk of dying or of severe disability is extremely high, comfort-focused care is recommended instead. In the US, ACOG and the SMFM define the periviable period as 20+0 to 25+6 weeks and note wide variation between hospitals in resuscitation practice at 22 and 23 weeks.

Numbers, which depend entirely on the denominator. BAPM's UK figures at 22 weeks: survival to neonatal discharge is around 8 per cent of babies alive at the onset of labour, 10 per cent of live births, 20 per cent of those given survival-focused care and 30 per cent of those admitted to a neonatal unit. Four different-sounding numbers, same babies. Recent international cohorts put survival among live births at 22 weeks at 24 per cent in the US, 39 in Sweden and 46 in Japan, driven largely by how actively care is offered. Among survivors, BAPM estimates around 1 in 3 has severe impairment, on data thin enough that the figure is imprecise.

Your unit's threshold is real and it varies. If there is reason to think you might give birth early, ask what it is and expect joint counselling from the obstetric and neonatal teams.

Is it safe to fly at 22 weeks pregnant?

Yes, in a straightforward pregnancy — and you are inside the window everyone recommends. The RCOG is unambiguous: occasional air travel is not harmful in an uncomplicated pregnancy. There is no evidence that cabin pressure or humidity harm you or the baby, and none that flying causes miscarriage, early labour or your waters to break. ACOG names 14 to 28 weeks as the best time to travel; the NHS names mid-pregnancy.

One thing to check before booking. The RCOG lists an increased chance of early labour among reasons you may be advised not to fly, with severe anaemia, recent bleeding and serious heart or lung conditions.

The risk that is real: blood clots

Pregnancy raises deep vein thrombosis (DVT) risk, and that does not ease in the second trimester. ACOG puts it plainly: any travel of four hours or more doubles DVT risk, and pregnancy adds to that. Under four hours the RCOG says you are unlikely to need special measures. Over four hours:

• Loose clothing, comfortable shoes, an aisle seat, regular walks about the cabin
• In-seat exercises roughly every 30 minutes
• Water steadily; cut down on caffeine
• Graduated compression stockings — not ordinary flight socks, and sized for you by a midwife or doctor

With other clot risk factors you may be advised to have heparin injections around the flight.

Practical points

• Airline cut-offs are usually 37 weeks for one baby, 32 for twins, so nothing restricts you yet — but from 28 weeks most airlines want a letter from your midwife or doctor, which the NHS warns can cost money and take weeks.
• Check what maternity and emergency care exists at your destination, and tell your insurer you are pregnant so that cover includes pregnancy-related care.
• Some travel vaccines and anti-malarial tablets are unsuitable in pregnancy; travel to Zika areas is not recommended.

When to call your midwife or doctor

The second trimester is the quietest stretch of pregnancy for most people, which is exactly why it is worth knowing what is not ordinary. Maternity units are staffed around the clock.

Get emergency help now

Call your local emergency number (999 in the UK and Ireland, 911 in the US and Canada, 000 in Australia, 111 in New Zealand) or go to an emergency department if you have:

• Heavy vaginal bleeding, or any bleeding with severe abdominal pain
• Abdominal pain you cannot concentrate through
• Fainting or collapse, chest pain, or sudden breathlessness
• A severe headache painkillers do not touch, blurred vision or flashing lights, pain below your ribs, or sudden swelling of your face, hands or feet — the NHS lists these as pre-eclampsia symptoms, most likely from 20 weeks, needing immediate assessment

Call your midwife or maternity unit today, whatever the hour

• Any vaginal bleeding, however light
• A gush or a steady trickle of fluid from your vagina
• Regular tightenings, or persistent low backache and pelvic pressure
• Discharge that changes colour or texture, smells strongly, or brings itching or soreness
• Itching without a rash, especially at night or on your palms and soles — the NHS asks for this to be checked, because it can be intrahepatic cholestasis of pregnancy
• A temperature, feeling generally unwell, or burning when you pee
• Any reduction, weakening or change in your baby's usual pattern of movements — the NHS says call immediately, even at night, and not to use a home doppler, because hearing a heartbeat does not mean your baby is well
• If you have felt no movement at all by 24 weeks, tell your midwife

You do not need to be certain something is wrong. That is what the number is for.