How long is a trimester

Q: How long are each of the trimesters?

A normal,” full-term pregnancy is 40 weeks and can range from 37 to 42 weeks. Its divided into three trimesters. Each trimester lasts between 12 and 14 weeks, or about 3 months. As you may be experiencing now, each trimester comes with its own specific hormonal and physiological changes.

If you’ve tried searching the web to find out when each trimester begins and ends, you’ve probably noticed that there are many answers to this question. Different practitioners may use different markers to determine the start and end dates of each trimester. Some just break it up into three chunks of 13 weeks, but most add on an extra week for a grand total of 40 weeks of pregnancy. Here’s the most common breakdown, along with official weeks from the American Congress of Obstetricians and Gynecologists:

Índice Show

Is 7 months 2nd or 3rd trimester?
What are the trimester months?
How long are each of the trimesters?
Is first trimester 12 or 13 weeks?

First Trimester: 0 weeks–13 and 6/7 weeks (Months 1–3)
Starts with the first day of your last menstrual period (LMP) and ends with the last day of the 13th week thereafter. During your last period (which will be your last for a while), your uterus is preparing for ovulation and your body is gearing up for pregnancy, so technically, you can start counting from this point.

Second Trimester: 14 and 0/7 weeks–27 and 6/7 weeks (Months 4 –7)
Starts at the beginning of the 14th week after your LMP and lasts through the 27th week of pregnancy.

Third Trimester: 28 and 0/7 weeks– 40 and 6/7 weeks (Months 7–9)
Starts at the beginning of the 28th week after your LMP and ends with labor.

Still confused? Use our Due Date Calculator tool help pinpoint which trimester you’re in based on your estimated due date.

Please note: The Bump and the materials and information it contains are not intended to, and do not constitute, medical or other health advice or diagnosis and should not be used as such. You should always consult with a qualified physician or health professional about your specific circumstances.

Is 7 months 2nd or 3rd trimester?

When does the third trimester start? The third trimester begins around week 28 of pregnancy and lasts until you give birth, which may be around week 40 of pregnancy. In other words, your third trimester lasts from around week 28 to week 40, or months 7 to 9 of pregnancy.

What are the trimester months?

How many trimesters are in a pregnancy? There are three trimesters in a pregnancy: the first trimester, which lasts from weeks 1 to 13, the second trimester, which lasts from week 14 to week 27, and the third trimester, which lasts from week 28 to week 40 (and up).

How long are each of the trimesters?

A “normal,” full-term pregnancy is 40 weeks and can range from 37 to 42 weeks. It's divided into three trimesters. Each trimester lasts between 12 and 14 weeks, or about 3 months. As you may be experiencing now, each trimester comes with its own specific hormonal and physiological changes.

Is first trimester 12 or 13 weeks?

A pregnancy is divided into trimesters: the first trimester is from week 1 to the end of week 12. the second trimester is from week 13 to the end of week 26. the third trimester is from week 27 to the end of the pregnancy.