First trimester, week 11
11 weeks pregnant: Hands open, hands close
- Size of a
- Fig

- Length
- 4.1 cm crown to rump
- Weight
- 7 g approximate
- Heart rate
- 140–170 bpm typical range
- Due date
- 203 days away 28% of the way
At 11 weeks pregnant, your baby is about the size of a fig: roughly 4.1 cm from crown to rump, weighing about 7 g. You’re in your first trimester, with about 29 weeks to go until your due date.
Your baby this week
- The head is still about half of the baby’s length, but the body is starting to catch up.
- Hands can open and close. Hiccup-like movements and stretches can be seen on ultrasound.
- Tooth buds are forming under the gums, and the diaphragm is developing.
Your body this week
- Some people notice nausea easing. For others it continues for a few more weeks.
- Increased blood flow can cause nosebleeds, bleeding gums and a stuffy nose (pregnancy rhinitis).
- Fingernails and hair may seem to grow faster.
- Typical weight gain so far
- 0.4–1.7 kg
- Your uterus
- About the size of an orange
Weight gain range is for a pre-pregnancy BMI of 18.5–24.9 (IOM guideline). Your provider may advise differently.
Scans, tests and checkups
-
This weekNIPT (cell-free DNA blood test) Blood test
A blood test that screens for Down syndrome (trisomy 21), trisomies 18 and 13, and can report sex chromosomes. It is a screening test. A high-chance result is confirmed with CVS or amniocentesis.
Baby’s sex: Sex from ~10 weeks, typically >98–99% accurate
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This weekCVS (chorionic villus sampling) Diagnostic
Diagnostic test on a tiny placenta sample, offered after a high-chance screening result or known family condition. The NHS gives the miscarriage risk as less than 1 in 200 for most pregnancies. The UK usually does it at 11–14 weeks.
Baby’s sex: Diagnostic, only done for medical reasons
-
This weekNT scan / 12-week scan Ultrasound
Measures the fluid at the back of the baby’s neck (nuchal translucency). Combined with blood hormones, it estimates the chance of chromosomal conditions. The window is about 11 weeks to 13 weeks 6 days.
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From week 15Second-trimester (quad) screening Blood test
A blood test (AFP, hCG, estriol, inhibin-A) for chromosomal conditions and neural tube defects, if you didn’t have first-trimester screening or NIPT. The NHS offers it at 14–20 weeks.
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From week 15Amniocentesis Diagnostic
Diagnostic test on a small sample of amniotic fluid. Offered after a high-chance screening result. The NHS gives the miscarriage risk as about 1 in 200. A 2019 review estimated the added risk at about 0.3%.
Baby’s sex: Diagnostic, only done for medical reasons
Real size, next to an adult hand
Growth curve
When to call your midwife or doctor at 11 weeks
Call your midwife, doctor or maternity unit straight away, day or night, if you have any of these:
- Vaginal bleeding, with or without cramps.
- Strong pain low on one side of your belly, pain at the tip of your shoulder, or feeling faint. These can be signs of an ectopic pregnancy, which needs urgent care.
- Being sick so often that you can’t keep fluids down for a day.
- Fever of 38 °C (100.4 °F) or higher, or pain or burning when you pee.
- Pain or swelling in one leg, chest pain, or sudden shortness of breath. These can be signs of a blood clot.
- Feeling very low, hopeless or anxious most days. If you feel you might harm yourself, get emergency help.
Based on NHS and ACOG guidance. This list isn’t complete. If something feels wrong, call anyway. In an emergency, call your local emergency number.
Tip for this week
The nuchal translucency (NT) scan window opens now, running from about 11 weeks to 13 weeks 6 days.
Myth or fact?
Is the nub theory accurate at 12 or 13 weeks?
Partly trueIt can be fairly accurate at 12–13 weeks in experienced hands, but it is an educated guess, not a diagnosis.
Read the evidenceCommon questions at this stage
Questions people ask about week 11
Can the nub theory tell the gender at 11 weeks?
Not reliably. The genital “nub” is harder to read at 11 weeks. Studies report accuracy around 70% at 11 weeks, rising towards 90% or more at 13 weeks with experienced sonographers.
What is an NT scan?
An ultrasound that measures the fluid at the back of the baby’s neck. Combined with a blood test, it estimates the chance of Down syndrome and some other conditions. It is done between about 11 and 14 weeks.
References
- NHS Best Start in Life: 11 weeks pregnant
- NHS: Your antenatal appointments
- NHS: Ectopic pregnancy
- NHS: Miscarriage
- NHS: Vomiting and morning sickness
- Mayo Clinic: Fetal development, the first trimester
- MedlinePlus (US National Library of Medicine): Fetal development
Advice differs between countries, so follow your own care team’s plan. Weights from week 20 are the WHO median, and earlier weights are approximate. How we check this.
All 40 weeks
First trimester Weeks 1–13
From conception to a fully formed, tiny fetus. The most rapid change of the whole pregnancy.
Second trimester Weeks 14–27
Growth, movement and senses. Often the most comfortable stretch for parents.
Third trimester Weeks 28–40
Weight gain, brain and lung maturation, and getting into position for birth.