18 Weeks Pregnant: Baby Development, Symptoms and Tips
Short Answer: At 18 week pregnancy, your baby is about 14 cm long, roughly the size of a sweet potato or a bell pepper, and weighs around 190 grams. Your baby can yawn, hiccup and hear sounds, the nerves are getting a protective coating and the baby is very active. You may feel the first flutters this week if it is your first pregnancy. The anomaly scan window opens now and runs to about 22 weeks. Keep taking iron and calcium as prescribed, sleep on your side, check your blood pressure and hemoglobin at each visit and call a doctor for heavy bleeding, severe pain, fever, fluid leaking or a severe headache with blurred vision.
Pregnancy weeks are counted from the first day of your last period, not from conception. Eighteen weeks pregnant means about sixteen weeks since conception. You are in your fifth month, with about 22 weeks to go, and you are almost halfway. For the week before, read our guide to 17 weeks pregnant, for the next, 19 weeks pregnant, and to follow the whole journey see our pregnancy guidelines week by week.
Week 18 at a glance
| Detail | At 18 weeks |
|---|---|
| Trimester | Second |
| Months | About 4.5 |
| Baby’s length | About 14 cm (5.5 inches) |
| Baby’s weight | About 190 grams |
| Heart rate | About 120 to 160 beats per minute |
| Weeks to go | About 22 |
| Size comparison | A sweet potato or a bell pepper |
Your baby at 18 weeks
Growth. Your baby is growing steadily, with weight rising faster than length. The legs are now longer than the arms, and the body looks well proportioned, though the head is still large.
Nerves. The nerves are being wrapped in a fatty coating called myelin. Myelin helps signals travel quickly between the brain and the body. The process continues after birth and through childhood.
Hearing. The ears are in their final position and the inner ear is developing. Your baby may start to hear your heartbeat, your voice, your digestion and loud sounds from outside. A sudden loud noise may make your baby jump. Talking, reading and singing to your baby is a nice habit, even if the long-term effect is not proven.
Reflexes and movement. Your baby yawns, stretches, hiccups, sucks a thumb, kicks, rolls and grasps the umbilical cord. The muscles are strong, and the movements are more coordinated. Your baby also sleeps and wakes in short cycles, though not on a schedule that matches yours.
Skin. The skin is still thin and see-through. Fine hair called lanugo covers it, and a white coating called vernix protects it. Fat is building up underneath. Fingerprints and toe prints have formed.
Genitals. In girls, the womb and fallopian tubes are formed and in position. In boys, the genitals are visible. A good scan this week can often show the sex, if your baby’s position allows it.
Organs. The lungs are developing, with airways branching like a tree. The kidneys make urine. The liver and pancreas are working. The digestive tract is practising by swallowing amniotic fluid. The heart is strong, and a sonographer can see all four chambers.
Bones. The bones continue to harden. Teeth are forming under the gums, including the buds for the permanent teeth.
Your body at 18 weeks
Womb. Your womb is about the size of a large melon, and the top sits about 1 to 2 cm below your navel. By around week 20 it reaches the navel. A bump is visible for most people. If it is your first pregnancy, the bump may be smaller, and your height, build and muscle tone make a difference.
Weight. A person of normal weight usually gains about 0.4 to 0.5 kg a week now. Gain is not perfectly steady, and your doctor tracks yours at each visit.
Blood pressure. It often dips a little in the second trimester, which can cause dizziness when you stand up quickly. After about 20 weeks it may start to rise, so every visit includes a blood pressure check.
Energy. Most people feel well, with good energy and appetite. Some feel tired again as the belly grows.
Appetite. You need about 300 extra calories a day. You do not need to eat for two.
Skin and hair. A glow is common, but so are acne, dry skin and dark patches on the face (melasma). A dark line down the belly (linea nigra) may appear, and stretch marks can show. Hair often looks thicker. These changes usually fade after the birth.
Breasts. They are larger and heavier. A few drops of thick yellow fluid, called colostrum, may leak from the nipples. This is normal.
Mind. Vivid dreams, forgetfulness and mood swings are common. Lists and reminders help.
Feeling the baby move
The first movement is called quickening. It often feels like bubbles, flutters, a gentle tap or a swimming fish. You may not be sure what it is at first.
- People who have been pregnant before often feel it between 14 and 18 weeks.
- First-time mothers usually feel it between 18 and 22 weeks.
- An anterior placenta, which sits at the front of the womb, or a larger body size can delay it.
- Movement is irregular at this stage, so do not worry if you feel it one day and not the next.
You do not need to count kicks yet. Doctors usually advise paying attention to your baby’s pattern from about 28 weeks. If you notice a clear drop in movement later in pregnancy, call your doctor the same day. Do not wait until the next day, and do not rely on a home Doppler.
The anomaly scan: what to expect
The anomaly scan, also called the mid-pregnancy or 20-week scan, is the most detailed scan of your pregnancy. The usual window is 18 to 22 weeks. Book it now, since slots fill up.
What it checks:
- The head and brain
- The face, including the lips
- The spine
- The four chambers of the heart and the major vessels
- The stomach, kidneys, bladder and bowel
- The abdominal wall
- The arms, legs, hands and feet
- The umbilical cord, which should have three vessels
- The placenta position, to rule out a low-lying placenta
- The amount of amniotic fluid
- The size of the baby, using head, abdomen and thigh bone measurements
How it works. You lie on a couch, a sonographer puts gel on your belly and moves a probe over it. The scan takes 20 to 40 minutes. A full bladder is not usually needed at this stage, but check with your clinic. Wear a two-piece outfit so your belly is easy to reach. Your partner can usually come.
The sex of the baby. The sonographer can often see it, but not always. If the baby is curled up or facing the wrong way, it can be hard. If you do not want to know, tell the sonographer before the scan starts. Some clinics have their own policy about telling parents the sex, so ask in advance.
What the results mean. Most scans are normal. The scan cannot find every problem, and no scan is perfect. Some things only show later in pregnancy or after birth. If the sonographer sees something unclear, you may be asked to return in a week or two for another look. That is common and not always a sign of a serious problem. If a problem is found, your doctor will explain what it means, what tests are available and what the options are. Ask questions, and ask for a written report.
Cost. Prices vary a lot between clinics. Ask what is included, whether the report and images are provided and whether a doctor will explain the results.
Common symptoms and what helps
| Symptom | Why it happens | What helps |
|---|---|---|
| Backache | Growing womb, loosening joints, posture | Flat supportive shoes, good posture, side-sleeping with a pillow, gentle stretches |
| Round ligament pain, a sharp pull in the lower belly or groin | Ligaments stretch as the womb grows | Move slowly, rest, warm bath |
| Stuffy nose, nosebleeds | More blood flow to the nose lining | Saline spray, a humidifier, lean forward and pinch the nose for a bleed |
| Bleeding gums | More blood flow to the gums | Soft brush, gentle flossing, dental check |
| Headaches | Hormones, tiredness, dehydration | Rest, fluids, ask your doctor before taking medicine |
| Dizziness | Blood pressure changes, low blood sugar | Eat regularly, stand up slowly |
| Heartburn | Relaxed valve at the top of the stomach | Smaller meals, avoid spicy and oily food, stay upright after eating |
| Constipation | Slow gut, iron tablets | Fibre, water, daily movement |
| Leg cramps, mostly at night | Circulation and mineral changes | Calf stretches before bed, drink water, ask about calcium |
| Increased vaginal discharge | Hormones | Cotton underwear, no douching |
| Itchy, stretching belly skin | Skin stretching | Moisturiser, loose cotton clothes |
| Swollen feet and ankles | Fluid retention | Raise your feet, avoid long standing |
| Mild breathlessness | Growing womb, hormones | Rest, good posture |
| Hip pain | Loosening joints, sleeping position | Pillow between knees, change position often |
| Leaking colostrum | Breasts getting ready for feeding | Breast pads, a supportive bra |
When to call a doctor
| Usually normal | Call a doctor soon |
|---|---|
| Short, sharp pulls in the lower belly | Severe or constant abdominal pain |
| Mild cramps after activity that settle with rest | Bleeding that soaks a pad in an hour, or with clots |
| Milky white discharge | Watery fluid leaking, or foul, itchy or coloured discharge |
| Occasional headache | Severe headache with blurred vision, flashing lights or upper belly pain |
| Tiredness, mood swings | Fainting, chest pain or sudden breathlessness |
| Mild swelling of feet late in the day | Sudden swelling of the face and hands |
| Occasional nosebleed | Any fever, burning urination or pain in one calf |
From about 20 weeks, a severe headache, vision changes, sudden swelling and pain under the ribs can be signs of pre-eclampsia, a serious blood pressure condition that needs urgent care. Call straight away for fluid leaking from the vagina, regular tightening of the belly that does not stop or any fever. 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.
Medicines in pregnancy
Always ask a doctor or pharmacist before taking any medicine, including herbal and over-the-counter products. General guidance for common problems:
| Problem | Usually considered safe | Avoid or ask first |
|---|---|---|
| Pain or fever | Paracetamol at the recommended dose | Ibuprofen, aspirin and diclofenac, unless your doctor prescribes them |
| Heartburn | Antacids as your doctor advises | Antacids with high sodium, unless advised |
| Constipation | Fibre, water, lactulose if prescribed | Strong laxatives |
| Colds and blocked nose | Saline spray, steam, rest | Decongestant tablets, unless advised |
| Allergies | Some antihistamines, ask your doctor | Many cold and cough mixtures |
| Infections | Antibiotics your doctor prescribes | Antibiotics from a pharmacy without a prescription |
Never stop prescribed medicine for a long-term condition, such as thyroid, blood pressure, diabetes or epilepsy, without talking to your doctor. A fever of 38°C or more needs a doctor’s visit. In Bangladesh, fever can also mean dengue or another infection, so do not self-treat.
Food and weight
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
- Fruit and vegetables: a variety of colours every day
- Whole grains and fibre: brown rice, whole wheat roti and oats
- Calcium: milk, yogurt and small fish such as mola eaten with the bones
- Healthy fats: well-cooked oily fish, nuts and seeds
- Water: about 8 to 10 glasses across the day
Take as advised: iron-folic acid tablets, calcium and vitamin D as your doctor prescribes. Many doctors advise calcium from about 20 weeks. Do not add extra supplements on your own. Take iron away from tea and milk, and with something sour such as lemon.
Limit: caffeine to about 200 mg a day, which is one or two cups of tea or a single small coffee, and sugary and fried snacks.
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.
| Weight before pregnancy | Recommended total gain |
|---|---|
| Underweight | 12.5 to 18 kg |
| Normal weight | 11.5 to 16 kg |
| Overweight | 7 to 11.5 kg |
| Obese | 5 to 9 kg |
Sleep, exercise and posture
Sleep. Sleep on your side, ideally your left, with a pillow between your knees and another under your belly. After about 20 weeks, doctors advise against sleeping flat on your back, because the womb can press on the large blood vessels. A long body pillow helps. Keep a regular bedtime and avoid screens at night.
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. After 20 weeks, avoid lying flat on your back during exercise. Avoid contact sports, heavy lifting and activities 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. As your belly grows, your centre of gravity shifts forward. Stand tall, keep your shoulders back and avoid high heels. Use a chair that supports your lower back, and lift by bending your knees. A support belt can ease back pain, so ask your doctor.
Seat belts. Wear the lap strap below the belly and the shoulder strap across the chest.
Free and low-cost care in Bangladesh
You do not need an expensive private clinic to get good prenatal care. Government community clinics and upazila health complexes offer prenatal checks, iron-folic acid tablets and tetanus vaccination at no cost or low cost. District and medical college hospitals provide ultrasound, delivery and emergency care. Ask your local health worker or the nearest clinic about services and schedules. If you are using a private hospital, ask for a written estimate that includes tests, delivery and complications before you commit.
The World Health Organization recommends at least eight contacts with a health professional during pregnancy. Keep your appointments, and bring your prenatal card or records to each visit.
Feelings, relationships and safety
Excitement, worry and mixed feelings are all normal. Many people feel closer to the baby once they feel movement or see the anomaly scan. Talk to your partner about your hopes, fears and plans. Partners can help by coming to appointments, sharing chores and listening.
If sadness, anxiety or worry lasts for two weeks or more, or affects your sleep and eating, tell your doctor. Mental health care is part of prenatal care.
Pregnancy can be a time of increased risk of violence at home. If you feel unsafe, tell your doctor, a trusted relative or friend. In Bangladesh you can call the national helpline 109 for support with violence against women and children. It is free.
Checklist for this week
- Book your anomaly scan for 18 to 22 weeks, and decide whether you want to know the sex
- Ask for a hemoglobin test and blood pressure check, and take iron-folic acid as prescribed
- Ask about calcium, and the tetanus-diphtheria, flu and whooping cough vaccines
- Learn the signs of pre-eclampsia and know who to call
- Keep a list of your medicines and share it with your doctor
- Cut caffeine, alcohol and tobacco
- Switch to side-sleeping and buy a long body pillow
- Start a daily walk 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 18 weeks?
About 14 cm long and 190 grams, roughly the size of a sweet potato or a bell pepper. Sizes vary a little between babies.
Can I feel the baby move at 18 weeks?
Many people do, especially if they have been pregnant before. First-time mothers usually feel the first movement between 18 and 22 weeks. Do not worry if you feel nothing yet.
Can I find out the baby’s sex at 18 weeks?
Often yes, at the anomaly scan, if the baby is in a good position. It is not always possible, and the sonographer may not be able to tell.
What is the anomaly scan?
A detailed ultrasound at 18 to 22 weeks that checks your baby’s organs, spine, limbs, face, heart, the placenta and the amniotic fluid. It cannot find every problem, but it finds many.
Do I need a full bladder for the anomaly scan?
Usually not at this stage. Check with your clinic, since practices differ.
Can the baby hear at 18 weeks?
The ears are developing and your baby may start to hear your heartbeat, your voice and loud sounds. Hearing keeps improving over the coming weeks.
Is it okay to sleep on my back at 18 weeks?
Occasional back-sleeping is usually fine now. Doctors advise side-sleeping from about 20 weeks, so build the habit early.
Can I take paracetamol in pregnancy?
Paracetamol at the recommended dose is generally considered safe. Avoid ibuprofen, aspirin and diclofenac unless your doctor prescribes them. A fever needs a doctor’s visit.
Is it safe to exercise at 18 weeks?
Yes for most healthy pregnancies. Walking, swimming, gentle yoga and pelvic floor exercises are good. Avoid contact sports and heavy lifting.
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.
