36 weeks pregnant: group B strep testing and breech position
36 weeks pregnant is a stage at which, the NHS says, the baby is around 47.4 cm long from head to heel, about the size of a romaine lettuce, and the lungs are probably mature enough to breathe outside the womb without help (NHS, 2026). This page sets out what the NHS, NICE, ACOG and the Office on Women’s Health say about week 36.
Last updated
Medically reviewed by Dr Mary Davidson, Reproductive endocrinologist, checked on
Seek help now if you have any of these symptoms
Bleeding and cramping are common in early pregnancy and often do not mean miscarriage. The symptoms below, however, need to be assessed straight away.
- Soaking two or more sanitary pads per hour, or passing large clots
- Severe lower abdominal pain, especially on one side
- Pain at the tip of the shoulder
- Dizziness, fainting, or collapse
- Signs of shock — pale, clammy, rapid heartbeat, breathlessness
- Pain on opening bowels, or bladder or bowel changes
- Feeling very unwell, or feverish
Showing routes for United States.
How the sources describe development around 36 weeks
- Size and shape, NHS
- The NHS week 36 page in its week-by-week guide (NHS, 2026) gives the baby as around 47.4 cm long from head to heel and compares it to a romaine lettuce. It says the lungs are probably mature enough to breathe outside the womb without any help, and that the baby will be able to suck and digest breast milk.
- Size and development, Office on Women’s Health
- The Office on Women’s Health page on the stages of pregnancy (2025) says that at 36 weeks the protective waxy coating called vernix gets thicker, body fat increases, movements are less forceful but you will still feel stretches and wiggles, and the baby is about 16 to 19 inches long and weighs about 6 to 6½ pounds. The NHS and the Office on Women’s Health each give their own size, and this page does not convert one into the other.
- Development, ACOG
- ACOG’s list for weeks 33 to 36 includes bones that harden while the skull remains soft and flexible, limbs that begin to look chubby, and a fetus that may turn into a head-down position for birth (ACOG, How Your Fetus Grows During Pregnancy, 2024).
Weeks are counted from the first day of the last menstrual period, so about two weeks of the count come before conception (ACOG, How Your Fetus Grows During Pregnancy, 2024). This page covers 36 weeks 0 days to 36 weeks 6 days.
A normal pregnancy lasts about 40 weeks from the first day of the last menstrual period, so at 36 weeks about 4 weeks remain to the estimated due date (ACOG, How Your Fetus Grows During Pregnancy, 2024). Your own due date depends on your last period or a scan, not on the week alone.
The 36-week appointment and the baby’s position
The NHS says you will have an antenatal appointment around now, which checks your blood pressure, urine and the size of your bump, and its appointments page says the midwife asks to feel your bump to check the position of the baby and discusses preparing for the birth (NHS, "Week 36 of pregnancy", 2026; NHS, "Antenatal (pregnancy) care and appointments", 2026). The NHS says that if the baby is not head down you may be offered external cephalic version, in which your doctor or midwife gently applies a hand to your bump to encourage the baby to turn, and that it is successful around half the time (NHS, "Week 36 of pregnancy", 2026).
NICE guideline NG201 says care teams should offer abdominal palpation at all appointments after 36 weeks 0 days to identify possible breech presentation, and offer an ultrasound if breech is suspected. For a confirmed breech presentation after 36 weeks 0 days it recommends discussing external cephalic version, breech vaginal birth and elective caesarean birth (NICE, 2021).
Group B strep testing: the windows differ
ACOG says the test for group B strep is a swab of the vagina and rectum, done between 36 and 38 weeks (ACOG, Routine Tests During Pregnancy, 2024). The Office on Women’s Health describes the test at 36 to 37 weeks (Office on Women’s Health, Prenatal care and tests, undated). ACOG says that if GBS is present, antibiotics should be given through a drip once labour has started (ACOG, "Routine Tests During Pregnancy", 2024).
How babies are born in England, as the NHS gives it
The NHS says around 6 out of 10 births in England are vaginal births, nearly 3 out of 10 babies are delivered by caesarean, and just over 1 in 10 births are assisted with a ventouse or forceps (NHS, "Week 36 of pregnancy", 2026).
Work out which week you are in
The Pregnancy week calculator takes your last period, conception date, scan or IVF transfer and shows how many weeks and days pregnant you are today.
Sources
- NHS Best Start in Life. Week 36 of pregnancy (week-by-week guide to pregnancy). nhs.uk, 2026.
- NHS. Antenatal (pregnancy) care and appointments. nhs.uk, 2026.
- National Institute for Health and Care Excellence. Antenatal care (NG201). NICE, 2021.
- American College of Obstetricians and Gynecologists. How Your Fetus Grows During Pregnancy (FAQ156). ACOG, 2024.
- American College of Obstetricians and Gynecologists. Routine Tests During Pregnancy (FAQ133). ACOG, 2024.
- Office on Women's Health, US Department of Health and Human Services. Stages of pregnancy. womenshealth.gov, 2025.
- Office on Women's Health, US Department of Health and Human Services. Prenatal care and tests. womenshealth.gov.
Frequently asked questions
When is the group B strep test?
ACOG says between 36 and 38 weeks (ACOG, 2024), and the Office on Women’s Health says 36 to 37 weeks (Office on Women’s Health, Prenatal care and tests, undated). Your care team tells you if and when you are offered it.
What if the baby is breech at 36 weeks?
The NHS says you may be offered external cephalic version to turn the baby, which is successful around half the time (NHS, 2026). NICE guideline NG201 recommends discussing external cephalic version, breech vaginal birth and elective caesarean birth for a confirmed breech presentation after 36 weeks 0 days (NICE, 2021).