The second trimester, weeks 14 to 27
Often the most comfortable stretch of pregnancy: the bump shows, energy returns, and you meet your baby on screen.
Updated October 13, 2026 · sources checked October 13, 2026
In short
The second trimester runs from 14 weeks to 27 weeks and 6 days. Your baby grows fast, hearing develops and you usually feel the first movements between 16 and 24 weeks. The big appointments are the anatomy scan, around 18 to 21 weeks in England, and the glucose screening test for gestational diabetes between 24 and 28 weeks.
The dates
ACOG defines the second trimester as 14 weeks and 0 days to 27 weeks and 6 days. It is the time of rapid growth and development. Check where you are today with our pregnancy week calculator.
Your baby's development
| Weeks | What ACOG describes |
|---|---|
| 13 to 16 | Bones harden; toenails form; hearing starts to develop; lungs begin forming the tissue for breathing |
| 17 to 20 | The motor area of the brain is fully formed; the digestive system is working; ears, nose and lips are recognisable on ultrasound |
| 21 to 24 | Kicks and turns are stronger; the sucking reflex develops; fat forms under the skin; fingerprint ridges form |
| 25 to 28 | Lungs are fully formed but not ready to work; eyelids open and close; the lungs begin to make surfactant |
Feeling your baby move
The NHS says you should start to feel movements between 16 and 24 weeks, often as a gentle swirling or fluttering at first. If this is your first baby, it may be after 20 weeks. From then on, get to know your baby's usual pattern. You do not need to count kicks. What matters is any change.
If your baby is moving less than usual, or the pattern changes, call your midwife or maternity unit immediately, even in the middle of the night. Do not wait until the next day.
The anatomy scan (18 to 21 weeks)
The NHS 20-week scan, also called the anomaly scan, looks for 11 conditions and checks your baby's growth and placenta. It usually takes around 30 minutes and is done between 18 and 21 weeks, sometimes up to 23 weeks. It is your choice whether to have it. The sonographer may be quiet while checking the bones, heart, brain, spine, face, kidneys and tummy: that is concentration, not bad news.
In the US, an ultrasound in the second trimester is also standard, with timing set by your provider. Our guide to prenatal appointments compares both schedules.
The glucose test (24 to 28 weeks)
ACOG explains the usual US screening: you drink a sugar solution and a blood sample is taken an hour later; if the level is high, a second, longer test confirms or rules out gestational diabetes. In England, an oral glucose tolerance test is offered at 24 to 28 weeks to people with risk factors.
Why it matters: the HAPO study of 25,505 pregnant women in nine countries found continuous associations between the mother's blood sugar, even below the threshold for diabetes, and higher birth weight. Read our full guide to gestational diabetes.
Vaccines to plan
The NHS recommends the whooping cough vaccine during pregnancy, usually at 20 weeks and possible from 16 weeks, ideally before 32 weeks so that antibodies pass to your baby. The flu vaccine is also recommended in pregnancy during flu season. In the US, ask your OB-GYN or midwife which vaccines they recommend and when.
Body changes you may notice
| Change | What helps |
|---|---|
| Growing bump, clothes feel tight | Our maternity clothes sizing guide |
| Heartburn (the NHS says it is more common from 12 weeks) | Smaller meals and sleeping propped up: see heartburn in pregnancy |
| Back ache | Posture and movement: see back pain and sciatica |
| Sharp pain low on one side | Often ligament pain; rest and change position |
| More energy | A good moment to start exercise in pregnancy or prenatal yoga |
Printable checklist: this trimester
For your partner
This is the trimester when you can feel the baby kick too, usually a few weeks after she does. Come to the anatomy scan if you can, and share the planning: classes, leave, budget and the nursery.
Is this normal? When to call
Mild aches, a sharp twinge low on one side when you move, heartburn, and fluttery movements you are not sure about yet are all common now. Call your maternity unit or OB-GYN for:
- Stomach pain that is severe, or does not ease after 30 to 60 minutes of rest.
- Any bleeding, or fluid leaking from the vagina.
- A severe headache, vision changes or sudden swelling of your face, hands or feet.
UK: call your maternity unit; 999 in an emergency, NHS 111 if unsure. US: call your OB-GYN or midwife, or 911 in an emergency.
Questions parents ask
When will I feel my baby move?
The NHS says between 16 and 24 weeks. In a first pregnancy you may not notice movements until after 20 weeks. If you have felt nothing by 24 weeks, tell your midwife.
Can I find out the sex at the anatomy scan?
Often, if the baby's position allows and the hospital's policy permits it. Ask at the start of the scan if you want to know, or tell the sonographer if you would rather keep it a surprise.
What is the sharp pain low on one side of my bump?
The NHS describes ligament pain, sometimes called growing pains, as a sharp cramp on one side of the lower tummy. Mild pain that eases with rest is usually nothing to worry about; severe pain, pain that lasts after 30 to 60 minutes of rest, or pain with bleeding needs a call to your maternity unit.
Sources
- ACOG — How Your Fetus Grows During Pregnancy checked October 13, 2026
- ACOG — Routine Tests During Pregnancy checked October 13, 2026
- NHS — 20-week scan checked October 13, 2026
- NHS — Your baby's movements checked October 13, 2026
- NHS — Vaccinations in pregnancy checked October 13, 2026
- NHS — Stomach pain in pregnancy checked October 13, 2026
- NHS — Gestational diabetes checked October 13, 2026
- NHS — Pregnancy symptoms you need to get help for checked October 13, 2026
- NHS — Indigestion and heartburn in pregnancy checked October 13, 2026
- HAPO Study Cooperative Research Group (2008), New England Journal of Medicine — Hyperglycemia and adverse pregnancy outcomes (PMID 18463375) checked October 13, 2026
Mamavela explains; it does not replace your midwife, doctor or pediatrician, who know your situation. If something worries you, call them. In an emergency, call 911 (US), 999 (UK) or 112.