21 Weeks Pregnant: Baby Development, Symptoms and Tips

Short Answer: At 21 week pregnancy, your baby is about 27 cm from head to heel, roughly the size of a carrot, and weighs around 360 grams. The bone marrow is starting to make blood cells, the baby is swallowing and absorbing nutrients from amniotic fluid, the movements are stronger and the first rapid eye movements begin around now. The top of your womb sits about 1 cm above your navel. You may notice kicks, hiccups, Braxton Hicks tightenings, swelling in your feet and more vaginal discharge. Watch for urinary infections, severe headaches with blurred vision and fluid leaking, and prepare for the glucose test at 24 to 28 weeks.

Pregnancy weeks are counted from the first day of your last period, not from conception. Twenty-one weeks pregnant means about nineteen weeks since conception. You are in your fifth month with about 19 weeks to go. For the week before, read our guide to 20 weeks pregnant, for the next, 22 weeks pregnant, and to follow the whole journey see our pregnancy guidelines week by week.

Your baby at 21 weeks

Growth. Your baby gains weight faster than length from now. Weight will rise from about 360 grams this week to around 1 kg by week 27.

Blood and bones. Until now, the liver and spleen made most of your baby’s blood cells. From about this week, the bone marrow begins to take over, and it will become the main source of blood cells for life. The skeleton keeps hardening, and you help by getting enough calcium, vitamin D and iron.

Digestion. Your baby swallows amniotic fluid, and the gut now absorbs some water and sugars from it. The waste material, called meconium, builds up in the bowel and is usually passed after birth.

Taste. Taste buds are working. The flavour of the amniotic fluid changes a little with what you eat, so your baby may be tasting the foods of your family.

Sleep and eyes. Your baby sleeps and wakes in cycles, often busy when you rest in the evening. Rapid eye movements, a sign of a more active, dream-like sleep, begin around now, even though the eyelids are closed. The eyebrows and eyelids are well defined.

Movement. Movements are stronger and more coordinated, including kicks, rolls, punches, stretches, hiccups and the startle reflex when there is a loud noise. Your baby may respond to your voice, music or a touch on your belly. You might notice a pattern, such as more movement after meals or at night.

Skin. The skin is thin and see-through, with fat building up under it. Vernix protects it, and fine lanugo hair covers the body. Fingerprints and toe prints have formed.

Lungs. The airways keep branching, and the air sacs are not ready yet. Your baby practises breathing movements with the chest, but the lungs are filled with fluid. This practice helps them develop for birth.

Genitals. In girls, the womb and fallopian tubes are in place, and the ovaries hold millions of egg cells. In boys, the testes begin to move toward the scrotum.

Your body at 21 weeks

Womb. The top of your womb is about 1 cm above your navel. A tape measure from the pubic bone to the top of the womb reads about 21 cm. Your doctor may measure this at each visit as a quick check of growth. A difference of up to 2 cm either way is normal.

Bump. Most people have a clear bump now. If it is your first baby, it may still be small, and your height, build and muscle tone affect how you show. Your navel may flatten or pop out and returns to normal after the birth.

Weight. A person of normal weight usually gains about 0.4 to 0.5 kg a week. By now most people have gained about 5 to 7 kg in total, though it varies.

Blood volume and heart. Your blood volume has risen by up to 40 percent and your heart works harder. You may feel warmer, sweat more and notice your pulse is faster.

Braxton Hicks. These practice tightenings can start now, when the belly goes hard for 30 to 60 seconds and then relaxes. They are usually painless and irregular. Water, rest and a change of position help. If they become regular or painful, see below.

Skin. A glow is common, but so are acne, dry skin, dark patches on the face (melasma) and a dark line down the belly (linea nigra). Stretch marks can show on the belly, breasts and thighs. Genetics matters more than any cream.

Hair and nails. Hair often looks thicker, and nails grow faster. Some nails split.

Breasts. They are larger and heavier, and a few drops of thick yellow fluid, called colostrum, may leak.

Vision. Some people notice dry eyes or slight blurring from hormones. Sudden vision changes need a doctor, because they can be a sign of pre-eclampsia.

Common symptoms and what helps

Do not take any medicine, including painkillers and herbal products, without asking a doctor or pharmacist. Paracetamol at the recommended dose is generally considered safe. Avoid ibuprofen, aspirin and diclofenac unless your doctor prescribes them.

Urinary infections in pregnancy

Urinary tract infections are common in pregnancy because hormones relax the urinary tract and the growing womb presses on the bladder. Some infections cause no symptoms, which is why your urine is tested at prenatal visits. Untreated, an infection can spread to the kidneys and raise the risk of early labour.

Symptoms: burning or pain when passing urine, a strong urge to go, passing small amounts often, cloudy or strong-smelling urine, lower belly pain, blood in the urine, fever, chills or pain in the back or sides.

What to do: see a doctor the same day for any of these symptoms. A urine test will confirm it, and your doctor will prescribe an antibiotic that is safe in pregnancy. Finish the full course. Do not take antibiotics from a pharmacy without a prescription.

How to lower the risk: drink plenty of water, pass urine when you need to and do not hold it, pass urine after sex, wipe from front to back, wear cotton underwear and avoid scented soaps and douches.

A fever with back pain or shaking chills may mean a kidney infection and needs urgent care.

Swelling, varicose veins and piles

Swelling. Mild swelling of the feet and ankles late in the day is common, especially in heat. Raise your feet, avoid long standing, wear comfortable shoes and drink water. Sudden swelling of the face and hands, or swelling in one leg only, needs a doctor.

Varicose veins. Extra blood volume and pressure from the womb can make veins in the legs and vulva swell. Avoid standing or sitting for long periods, raise your legs when you rest, walk daily and ask about compression stockings. They usually improve after the birth. Pain, redness and heat in one calf can be a blood clot and needs urgent care.

Piles (haemorrhoids). Constipation and pressure can cause swollen veins around the anus, with itching, pain or a little bright blood after passing stools. Eat fibre, drink water, do not strain or sit for long on the toilet and ask your doctor about safe creams. Heavy bleeding needs a check.

When to call a doctor

Pre-eclampsia. A serious blood pressure condition that can develop after 20 weeks. Signs include a severe headache that will not go away, blurred vision or flashing lights, sudden swelling of the face and hands, pain under the ribs on the right side, vomiting and rapid weight gain. It needs urgent care.

Preterm labour. Call straight away if you have regular tightenings, a steady low backache, pelvic pressure, a change in vaginal discharge or fluid leaking before 37 weeks.

Fever. In Bangladesh a fever can also mean dengue, so do not treat it at home. See a doctor straight away.

If you feel sad, anxious or hopeless for more than two weeks, tell your doctor. If you ever have thoughts of harming yourself, seek help right away.

Preparing for the glucose test

Gestational diabetes is common and usually has no symptoms. It is screened for at 24 to 28 weeks, or earlier if you have risk factors such as a family history of diabetes, a previous large baby, obesity, polycystic ovaries or gestational diabetes in an earlier pregnancy. South Asian women have a higher risk, so do not skip it.

Clinics use different methods. A common one is the oral glucose tolerance test, where you have a blood test while fasting, drink a measured sugar solution and have more blood tests after one and two hours. The test takes up to three hours. Others use a shorter test without fasting. Ask your clinic exactly how to prepare, and follow its instructions.

General tips:

• Eat normally and do not cut carbohydrates in the days before the test
• Fast for the number of hours your clinic tells you, usually 8 to 10, and drink only water
• Take a book and a snack for afterwards
• Do not smoke or exercise hard before the test
• Ask whether you should take your usual medicines

If you have gestational diabetes, it is manageable. Most people control it with food choices, walking and checking blood sugar, and some need tablets or insulin. Ask your doctor about a dietitian.

Other tests and visits ahead:

Food, calcium and iron

Calcium. Calcium supplements are usually advised from about 20 weeks where diets are low in calcium. They help your baby’s bones and teeth and lower the risk of high blood pressure in pregnancy. Take calcium at a different time from iron.

Iron. Keep taking iron-folic acid tablets as prescribed. Take iron away from tea, coffee and milk, and with something sour such as lemon, to help absorption. Dark stools are normal on iron.

Eat more of:

• Protein: eggs, well-cooked fish, chicken, lentils (dal), beans and milk
• Iron-rich foods: leafy greens (shak), lean meat and lentils, with lemon or guava for vitamin C
• Calcium-rich foods: milk, yogurt, and small fish such as mola eaten with the bones
• Fruit and vegetables: a variety of colours every day
• Whole grains and fibre: brown rice, whole wheat roti and oats
• Healthy fats: well-cooked oily fish, nuts and seeds
• Water: about 8 to 10 glasses across the day

Limit: caffeine to about 200 mg a day, which is one or two cups of tea or a single small coffee. Limit sweets, sugary drinks, juice and fried snacks. Large portions of white rice, bread and sweets push blood sugar up, so pair carbohydrates with protein and vegetables.

Avoid: alcohol, all tobacco (including zarda and jorda), raw or undercooked meat, fish and eggs, unpasteurized milk and cheese, unwashed produce, large predatory fish such as shark and swordfish, high-dose vitamin A supplements, unripe papaya and herbal tonics your doctor has not approved.

Weight gain. Total gain over the whole pregnancy depends on your weight before pregnancy, and Asian-specific BMI ranges may apply, so ask your doctor.

Sleep and exercise

Sleep. Sleep on your side, ideally the left, with a pillow between your knees and another under your belly. Doctors advise against sleeping flat on your back from about 20 weeks. If you wake on your back, simply turn over. A long body pillow helps. Keep a regular bedtime and avoid screens at night. Vivid dreams and waking to pass urine are common.

Exercise. The standard advice for healthy pregnancies is about 150 minutes of moderate activity a week, such as 30 minutes of brisk walking on most days. Swimming, prenatal yoga, stationary cycling and pelvic floor exercises are good choices. You should be able to talk while you exercise. Avoid lying flat on your back during exercise, contact sports, heavy lifting and anything with a risk of falls. Stop and call your doctor if you have pain, bleeding, dizziness or trouble breathing.

Pelvic floor. Squeeze and lift the muscles you use to stop urine flow, hold for a few seconds and release. Do a few sets a day. Strong pelvic floor muscles help with bladder control during and after pregnancy.

Posture and back. Stand tall, keep your shoulders back, avoid high heels and lift by bending your knees. Warm baths and gentle stretching ease backache.

Feelings and relationships

Excitement, worry and mixed feelings are all normal. Many people feel closer to the baby now that movements are stronger. Others feel anxious about the birth, money or changes in their relationship. Talk about your hopes and fears with your partner or someone you trust.

Partners can help by coming to appointments, sharing chores, feeling the baby move and listening without trying to fix everything. Sex is safe for most healthy pregnancies unless your doctor advises otherwise, and it is fine to say when you are not in the mood.

If sadness, anxiety or worry lasts for two weeks or more, or affects your sleep and eating, tell your doctor. Depression and anxiety in pregnancy are common and treatable, and mental health care is part of prenatal care.

If you feel unsafe at home, tell your doctor or a trusted person. In Bangladesh you can call the national helpline 109 for support with violence against women and children. It is free.

Myths about pregnancy

If you hear advice from family, it is polite to listen, and wise to check with your doctor before you act on it.

Planning ahead

• Maternity leave. Under Bangladesh’s labour law, working mothers in the private sector are entitled to 16 weeks of paid maternity leave, eight before and eight after the birth. Government employees receive six months. Check your own contract and plan when to tell your employer.
• Place of birth. Choose a hospital or clinic with a qualified doctor or midwife, a way to handle emergencies and a blood supply. Ask what the delivery package covers and what an emergency would cost.
• Mode of delivery. Many births in Bangladesh are by C-section, and some are not medically needed. Ask your doctor when a C-section is recommended and what a vaginal birth involves.
• Money. Start a simple budget for prenatal care, delivery and baby costs.
• Classes. Ask about classes on labour, breathing, newborn care and breastfeeding.
• Dental care. Dental treatment is safe in pregnancy, and gum disease is linked to early birth.
• Baby shopping. You do not need to buy anything yet. Make a list, and wait for sales, hand-me-downs and advice from other parents.

Checklist for this week

• Confirm your anomaly scan if you have not had it, and keep any follow-up appointments
• Ask about the glucose test and how to prepare
• Take iron-folic acid and calcium as prescribed, at different times
• Ask about the tetanus-diphtheria, flu and whooping cough vaccines
• Learn the signs of urinary infection, pre-eclampsia and preterm labour
• Drink plenty of water and do not hold urine
• Check your home for standing water and use mosquito protection
• Sleep on your side and keep up daily walks and pelvic floor exercises
• Book a dental check
• Save your doctor’s number and the nearest hospital’s emergency number

FAQ

How big is the baby at 21 weeks?
About 27 cm from head to heel and 360 grams, roughly the size of a carrot. Sizes vary a little between babies.

Can I feel the baby move at 21 weeks?
Most people do. First-time mothers usually feel the first movement between 18 and 22 weeks. Tell your doctor if you have felt nothing by about 24 weeks.

Where is my womb at 21 weeks?
The top of your womb is about 1 cm above your navel, and your doctor may measure about 21 cm from your pubic bone.

Are Braxton Hicks contractions normal at 21 weeks?
Yes. They are irregular, usually painless tightenings that stop with rest. Call your doctor if they become regular, painful or come with fluid leaking or bleeding.

Why do I have so much discharge?
Hormones increase milky white discharge. A strong smell, itching or a green or yellow colour needs a check.

Is it normal to get urinary infections in pregnancy?
Yes, they are common. See a doctor the same day for burning, frequent urination or fever, because untreated infections can reach the kidneys.

Can I find out the baby’s sex at 21 weeks?
Often yes, if the baby is in a good position at the scan. It is not always possible. Tell the sonographer if you do not want to know.

When is the glucose test?
Usually at 24 to 28 weeks, or earlier if you have risk factors such as a family history of diabetes, obesity or gestational diabetes before.

Is it safe to exercise at 21 weeks?
Yes for most healthy pregnancies. Walking, swimming, gentle yoga and pelvic floor exercises are good. Avoid contact sports, heavy lifting and lying flat on your back during exercise.

Note: This article gives general information and does not replace advice from your doctor or midwife. Every pregnancy is different. Call your doctor or go to a hospital if you have bleeding, severe pain, fever, fainting or any symptom that worries you.