Week 13 of 40 ยท first trimester

Week 13 of pregnancy

Week 13 is early days: much of what happens now is too small to see, and you may be the only one who knows.

Medical review: not yet reviewed. How we review content

Illustration of a peach, the average size of a baby at 13 weeks
Your baby this week

About the size of a peach

SizeAbout a peach
Length7.4 cm (2.9 in), measured from the top of the head to the bottom (crown to rump), the way early scans measure
Weight23 g (0.8 oz)
TrimesterFirst trimester
Weeks to goAbout 27 to your due date

These are averages. Every baby grows at their own pace.

What is forming this week

Vocal cords are forming, and the intestines are moving into the belly.

How you may feel

Many people feel a lift in energy as the second trimester begins.

Everyone's pregnancy is different. If something worries you, call your midwife or doctor.

One thing to do this week

If you'd like a bump diary, start now: same spot, same light, once a week.

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?
Sources

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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