Trimester
Pregnancy is divided into three trimesters of about three months each. Doctors use them to describe where you are, and each has its own typical check-ups and changes.
In our calculator the second trimester starts at week 14 and the third at week 28. Some sources use slightly different boundaries, so small differences are normal.
The first trimester
This is when the baby's organs begin to form. Many women feel very tired and some have nausea. It is also the time to book your first check-up, which the World Health Organization advises before week 12, and to ask about folic acid.
The second trimester
Many women feel better in this part of pregnancy, and the bump starts to show. Many first notice the baby moving during these months. Routine visits continue, for example at weeks 20 and 26 in the WHO schedule.
The third trimester
The baby grows and gets ready for birth, and visits become more frequent: weeks 30, 34, 36, 38 and 40 in the WHO schedule. This is the time to pack your hospital bag, learn the warning signs and ask your doctor when to come in.
What to keep in mind each stage
Every pregnancy is different, so use these stages as a guide and follow the schedule your doctor gives you.
- Take your prenatal vitamins as your doctor advised
- Go to every scheduled visit and bring your questions
- Contact your doctor at once for any warning sign, in any trimester
This is general information, not a substitute for a doctor's advice.
Sources
- Methods for Estimating the Due DateACOG (American College of Obstetricians and Gynecologists)
- How Your Fetus Grows During PregnancyACOG (American College of Obstetricians and Gynecologists)
- New guidelines on antenatal care for a positive pregnancy experience (2016)WHO (World Health Organization)