All 40 weeks·Trimester 2 weeks·Dashboard

Trimester 2 · Week 20 of 40

Week 20 of pregnancy: Halfway There

The halfway point: travelling safely in mid-pregnancy, and the pre-eclampsia warning signs that matter from 20 weeks onwards.

Last updated 28 September 2026

What's happening this week?

You have reached the middle of a full-term pregnancy. Your uterus has usually reached your navel and your baby is wrapped in waxy vernix. Two things become important from this week. First, mid-pregnancy is often the most comfortable time to travel, so if you have a trip in mind, plan it carefully now. Second, pre-eclampsia, a serious blood pressure condition of pregnancy, can appear from 20 weeks, so this is the time to learn its warning signs and keep them in mind until after the birth.

Baby's development

Vernix now covers your baby's skin, protecting it from the fluid it floats in. Fingernails are growing, and movements are frequent enough that many people, including first-time mothers, begin to notice them around now. Fine lanugo hair still covers much of the body, and the skin remains thin.

Inside the lungs, special cells start to form lamellar bodies from about 20 weeks. These are storage packages for surfactant, the substance that will one day stop the tiny air sacs collapsing. Surfactant is not released in useful amounts yet, and the lungs have a long way to go.

The cochlea, the snail-shaped hearing organ of the inner ear, is almost complete in structure. Being built is not the same as working fully: responses to sound are still limited and become more consistent later in the second trimester.

Your baby continues to swallow amniotic fluid and pass urine back into it, and meconium, the first stool, is slowly collecting in the gut. It is not normally passed before birth. From here on, your baby's main task is to grow and mature: the organs are formed, and the second half of pregnancy is about size, strength and readiness.

Your baby's size

About the size of a banana

16.4 cm

6.5 in · Length

300 g

Weight

Week 20

Gestational age

Two different numbers describe your baby this week. The 16.4 cm figure is crown–rump length, head to bottom. From about 20 weeks many guides switch to crown–heel length, head to heel, which is roughly 25 cm now. Neither means your baby suddenly grew. A typical estimated weight is around 300–330 g, with a wide normal range.

Your body this week

The top of your uterus usually reaches your navel at about 20–22 weeks. From around 24 weeks many doctors measure the distance from the pubic bone to the top of the uterus in centimetres, which roughly matches the number of weeks. Your blood volume keeps rising and you may notice breathlessness when climbing stairs.

Pre-eclampsia is a condition of pregnancy linked with high blood pressure. It usually appears after 20 weeks, sometimes without any symptoms at first, which is why your blood pressure and urine protein are checked at every visit. It can become serious for both mother and baby, but careful monitoring and early treatment help. Some people with a higher risk are prescribed low-dose aspirin; if you have been, keep taking it as instructed.

Emotionally, halfway can feel like a turning point. Many people start thinking about preparations, leave from work or where they will give birth. It is fine to take things one step at a time.

Symptoms you may notice

Every pregnancy is different - you may have some, all or none of these.

Headaches: Mild headaches can happen with tiredness or dehydration; rest, fluids and paracetamol if needed usually help. A severe headache that does not go away, especially with vision changes, is a pre-eclampsia warning sign.
Mild ankle swelling: Gradual puffiness of the feet by evening, better overnight, is common. Sudden swelling of the face, hands or feet is different and needs checking the same day.
Breathless on exertion: Hormones and a larger uterus change your breathing. Slow down on stairs. Sudden breathlessness, or breathlessness with chest pain, is an emergency.
Heartburn: Often ongoing from earlier weeks. Smaller meals and not lying down straight after eating help. Pain under the ribs on the right is not heartburn and should be checked urgently.
Fatigue on long days: Travel, work and a growing bump can be tiring. Plan rest breaks and do not push through exhaustion.

Medical care and tests

Blood pressure and urine checks
Routine
Every antenatal visit
These simple checks are the main way pre-eclampsia is found early. In India, blood pressure, weight and urine for protein and sugar are recommended at every visit. A raised reading may lead to repeat checks, blood tests or closer monitoring.
Anomaly scan, if not yet done
Commonly offered
UK by 20+6 weeks; India commonly up to 22 weeks
If your detailed scan has not happened, contact your doctor this week so it is not missed.
Whooping cough vaccine
Varies by provider
UK usually around 20 weeks; US 27 to 36 weeks
The UK offers it from 16 weeks, usually around 20. In India the government schedule gives the Td vaccine; Tdap is recommended by FOGSI at 27–36 weeks and offered mainly in private care. Ask your doctor what they advise.
Low-dose aspirin
Only if needed
Started early in pregnancy if prescribed
Prescribed for some women at higher risk of pre-eclampsia. It is different from using aspirin or ibuprofen as a painkiller. Do not stop or start it without your doctor's advice.

WHO's antenatal model includes a contact at 20 weeks. In India, government facilities offer free check-ups on the 9th of each month for women in the second and third trimesters.

Nutrition this week

Eating while travelling is this week's focus. Choose freshly cooked food served piping hot, such as dal-rice, khichdi, idli or a hot paratha, over food that has been standing around.
Drink boiled, filtered or sealed bottled water, and skip ice of unknown origin, pre-cut fruit, open chutneys and pani-puri water from stalls.
Carry snacks that travel well: roasted chana, makhana, peanuts, homemade theplas or khakhra, and fruit you can peel yourself such as bananas or oranges.
Keep sipping on long trips, aiming for more than 2 litres of fluid a day, and do not skip meals to avoid toilet stops.

Movement and exercise

Keep up regular walking or swimming. Mid-pregnancy is often when exercise feels easiest, so it is a good time to build a routine.
On flights, trains or car rides of four hours or more, walk around regularly and do simple calf exercises in your seat, circling your ankles and pointing and flexing your feet.
Stop and seek advice if you get a headache, calf pain, dizziness, bleeding or a fluid leak while exercising or travelling.

Things to keep in mind

Travel: the second trimester is often the most comfortable time. Air travel is not harmful in itself in an uncomplicated pregnancy, but airline rules vary, and many need a doctor's fit-to-fly letter later in pregnancy, so check before booking.
Wear a seat belt on every car or taxi ride, with the lap strap under your bump across your hips and the diagonal strap between your breasts. Bumpy two-wheeler rides carry a risk of falls.
Carry your antenatal card and reports, and know where the nearest hospital with maternity care is at your destination.
Do not travel to areas with an ongoing Zika outbreak, and use insect repellent as labelled to avoid mosquito bites wherever you are.
Painkillers: avoid ibuprofen, diclofenac and similar medicines from 20 weeks unless a doctor advises them. Many cold and pain combination products contain them.

When to contact your doctor

Call your doctor or midwife the same day if you have

Sudden swelling of your face, hands or feet.
A headache that will not go away.
Any vaginal bleeding from now on, even if light.
Pain, swelling or redness in one calf, especially after long travel.
Burning when passing urine, or a temperature of 38°C or more.
Any fall or knock to your bump, even if you feel fine.

Get emergency care now if you have

Severe headache with blurred vision, flashing lights or spots.
Pain just below the ribs, especially on the right, or vomiting with these signs.
A fit (seizure).
Heavy bleeding, severe abdominal pain or a gush of fluid.
Chest pain, sudden breathlessness or coughing up blood.

In India, call 108 for an ambulance, 102 for free transport for pregnant women in many states, or 112 for any emergency - or go straight to your nearest hospital with a maternity unit.

If something feels wrong, trust that feeling and call - you never need to wait for your next appointment.

Questions to ask your doctor

Is my blood pressure normal, and am I at higher risk of pre-eclampsia?
Is it safe for me to travel, and do I need a fit-to-fly letter?
Do I need compression stockings for a long flight or train ride?
Which painkillers can I take if I get a headache?
Which vaccines do you recommend for me in this pregnancy, and when?

Week 20 checklist

Pre-eclampsia warning signs saved on your phone
Blood pressure recorded at your latest visit
Travel plans checked with your doctor
Antenatal records packed for any trip
Ibuprofen and combination cold remedies moved out of reach

Frequently asked questions

Is it safe to fly at 20 weeks?

For most people with an uncomplicated pregnancy, flying is not harmful in itself, and mid-pregnancy is often the most comfortable time to do it. On flights of about four hours or more, walk around, do calf exercises, drink water and consider well-fitted compression stockings. Check the airline's rules before booking and ask your doctor whether anything in your pregnancy changes the advice.

What is pre-eclampsia and how would I know I have it?

Pre-eclampsia is a pregnancy condition involving high blood pressure, usually after 20 weeks. It may cause no symptoms early on, which is why blood pressure and urine are checked at every visit. Warning signs include a severe headache, vision problems, pain below the ribs, vomiting and sudden swelling of the face, hands or feet. If you notice these, seek help immediately.

My bump measured smaller than my friend's at 20 weeks. Should I worry?

Bump size varies with your height, build, muscle tone, the baby's position and whether this is your first pregnancy. Your doctor or midwife checks growth using scans and, from about 24 weeks, fundal height measurements. If there is any concern, they will arrange a scan. Comparing bumps is natural but tells you very little.

This page is general information, not a diagnosis or a substitute for care from your own doctor or midwife. Pregnancies differ, and timings here are typical ranges rather than deadlines. Read our medical disclaimer and editorial policy.