Week 12 of pregnancy
Week 12 is early days: much of what happens now is too small to see, and you may be the only one who knows.
About the size of a lime
| Size | About a lime |
|---|---|
| Length | 5.4 cm (2.1 in), measured from the top of the head to the bottom (crown to rump), the way early scans measure |
| Weight | 14 g (0.5 oz) |
| Trimester | First trimester |
| Weeks to go | About 28 to your due date |
These are averages. Every baby grows at their own pace.
What is forming this week
Reflexes are developing, and the baby can open and close their fingers.
How you may feel
You might have a little more energy as the first trimester comes to an end.
Everyone's pregnancy is different. If something worries you, call your midwife or doctor.
One thing to do this week
Take your questions to the scan on paper. They are easy to forget in the room.
Questions you could bring to your next appointment
- When is my dating scan, and what will it check?
- Which medicines and supplements are fine to keep taking?
- Who do I call if I'm worried between appointments?
- NHS: Your pregnancy week by week
- ACOG: How your fetus grows during pregnancy
- Hadlock FP et al. In utero analysis of fetal growth: a sonographic weight standard. Radiology 1991 (weights from week 10)
- Robinson HP, Fleming JE. A critical evaluation of sonar crown-rump length measurements. Br J Obstet Gynaecol 1975 (early lengths)
Questions
When is the first scan?
In England the NHS offers a dating scan between 10 and 14 weeks. In the US the timing of the first ultrasound depends on your care team, so ask at your first appointment.
Why is pregnancy counted from my last period?
Weeks are counted from the first day of your last period, about two weeks before conception. That is why week 4 is only around two weeks after conception.
Is my baby exactly this size?
No one is. The size, length and weight here are averages from published growth charts. Your scan results are the ones that count, and your midwife or doctor is the person to ask about them.
Start with today
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