A full-term pregnancy has three trimesters and lasts around 40 weeks — starting from the first day of the last menstrual period. In each trimester, the fetus meets specific developmental milestones.
While 40 weeks is the usual time frame, a full-term baby can be born as early as 37 weeks and as late as 42 weeks.
The Office on Women’s HealthTrusted Source defines the three trimesters as follows, though the timing can vary:
first trimester: 1–12 weeks
second trimester: 13–28 weeks
third trimester: 29–40 weeks
Some people also talk about a fourth trimester, which is the 3-month transitional period after delivery.
Read on for more information about what to expect during each pregnancy trimester.
The first trimester is weeks 1-14. During the first trimester, both your and your baby’s body will be changing rapidly. It can be an overwhelming time emotionally and physically, especially for first-time moms and parents. This is also when many expecting moms experience symptoms such as fatigue, nausea, morning sickness and more.
Weeks 10-14: Congratulations! You are in the third month of pregnancy and almost done with your first trimester! During these last few weeks of the first trimester, you can expect your baby to be able to bend its limbs, make and release urine and develop genitals and fingernails.
You’ve made it to your second trimester! The second trimester is considered to be weeks 14-28. During this trimester is when expecting moms find that they feel less nauseated and their energy levels have returned.
When it comes to the arrival of babies, nothing is guaranteed. During this trimester is typically when you should start planning and considering where and how you want to give birth. There are five common delivery methods that should be explored so you can begin creating a birth plan with your partner.
We understand that life can get busy and it can be hard to plan for the day you welcome your bundle of joy into this world. The Mother Baby Center has made it easy for you to take a virtual tour of our three convenient locations in the Twin Cities metro area.
Now that you’ve crossed off the two most important to-do items, check out what else is recommended in a second trimester to-do list for expecting parents.
Weeks 14-15: During weeks 14-15, you should be working your way through your third month of pregnancy. In these coming weeks, your baby will develop their scalp or hair patterns and stronger bones.
Weeks 16-18: Welcome to one of the most exciting weeks of pregnancy! Weeks 16-18 means that you have started your fourth month of pregnancy. During these weeks, you can expect your baby to be able to move their eyes, develop toenails and hear sounds. Starting week 18 is also when mid-pregnancy ultrasounds are scheduled and if you choose to know, you can find out the gender of your baby!
Weeks 19-21: Congratulations! You are a little over halfway pregnant, or five months, by the end of week 20. During this period, you can expect your baby to move more.
Weeks 37-40: You’re at the home stretch! At this point, you should be working through your ninth month of pregnancy and your baby could come any day.