Understanding Each Trimester of Your Pregnancy

Learn how to navigate the first, second, and third trimesters.

You will encounter different experiences during each of your trimesters as your little miracle develops.

Stages of Pregnancy: First, Second and Third Trimester

A pregnancy is divided into three stages called trimesters: first trimester, second trimester, and third trimester. A trimester lasts between 12 and 14 weeks, while a full-term pregnancy lasts around 40 weeks from the first day of a woman’s last period. In each trimester, the fetus will meet specific developmental milestones.

The First Trimester (0-13 Weeks):

During this period, your baby’s body structure and organs develop. Your body will also undergo major changes, and you may feel nausea, fatigue, breast tenderness and frequent urination. These are all common symptoms, but every woman has her own unique experience.

The Second Trimester (14-26 Weeks):

Known as the “honeymoon period”, the second trimester is when many of the unpleasant symptoms of early pregnancy subside. You’re likely to have increased energy and sleep better. However, some women experience back or abdominal pain, leg cramps, constipation or heartburn.

An ultrasound can determine the gender of the baby as early as 14 weeks, although some doctors may perform your first ultrasound between 18 and 20 weeks. During the anatomy ultrasound, measurements of the baby are taken by an ultrasound technician.

Somewhere between 16-20 weeks, you may feel your baby’s first movements, this is known as “quickening”.

Third Trimester (27-40 Weeks):

You are now nearing the home stretch of your pregnancy and are probably very excited and anxious for the birth of your baby. Some of the physical symptoms you may experience during this period include shortness of breath, hemorrhoids, urinary incontinence, varicose veins, and sleeping problems. Many of these symptoms arise from the increase in the size of your uterus, which expands from approximately 2 ounces before pregnancy to 2.5 pounds at the time of birth.

During the final trimester, your baby’s bones are fully formed, its touch receptors will be fully developed, and the baby’s organs are capable of functioning on their own. As you near your due date, the baby’s body may turn southwards into a head-down position for birth.

Stages of Pregnancy: First, Second and Third Trimester

A pregnancy is divided into three stages called trimesters: first trimester, second trimester, and third trimester. A trimester lasts between 12 and 14 weeks, while a full-term pregnancy lasts around 40 weeks from the first day of a woman’s last period. In each trimester, the fetus will meet specific developmental milestones.

The First Trimester (0-13 Weeks):

During this period, your baby’s body structure and organs develop. Your body will also undergo major changes, and you may feel nausea, fatigue, breast tenderness and frequent urination. These are all common symptoms, but every woman has her own unique experience.

The Second Trimester (14-26 Weeks):

Known as the “honeymoon period”, the second trimester is when many of the unpleasant symptoms of early pregnancy subside. You’re likely to have increased energy and sleep better. However, some women experience back or abdominal pain, leg cramps, constipation or heartburn.

An ultrasound can determine the gender of the baby as early as 14 weeks, although some doctors may perform your first ultrasound between 18 and 20 weeks. During the anatomy ultrasound, measurements of the baby are taken by an ultrasound technician.

Somewhere between 16-20 weeks, you may feel your baby’s first movements, this is known as “quickening”.

Third Trimester (27-40 Weeks):

You are now nearing the home stretch of your pregnancy and are probably very excited and anxious for the birth of your baby. Some of the physical symptoms you may experience during this period include shortness of breath, hemorrhoids, urinary incontinence, varicose veins, and sleeping problems. Many of these symptoms arise from the increase in the size of your uterus, which expands from approximately 2 ounces before pregnancy to 2.5 pounds at the time of birth.

During the final trimester, your baby’s bones are fully formed, its touch receptors will be fully developed, and the baby’s organs are capable of functioning on their own. As you near your due date, the baby’s body may turn southwards into a head-down position for birth.

First, Second and Third Trimester Frequently Asked Questions

What pregnancy trimester is the most critical?

The first trimester is the most crucial to your baby’s development. While you may not be showing much on the outside yet, on the inside, your baby’s major body organs and systems are forming. It’s also during this time that the fetus is the most susceptible to damage from alcohol, drugs, certain medications, and illnesses. That’s why it is so important to ensure you’re doing what you can to help your baby stay healthy during this critical time.

What pregnancy trimester is the hardest?

For many women, the first trimester of pregnancy is often the hardest. During this period, your body is going through a major transformation and needs time to adjust to the changes. Pregnancy hormones, extreme fatigue, nausea and vomiting, tender breasts, and the frequent need to pee are common symptoms that make the first trimester the most challenging time for pregnant women.

Which pregnancy trimester is the most painful?

The third trimester is the final stage of pregnancy and can be considered to be the most painful. During this stage, your baby is getting bigger, which puts more stress on your body that causes aches and discomfort. As your body begins to prepare for labor, a woman may have irregular contractions known as Braxton Hicks. While these can cause some abdominal discomfort, they shouldn’t cause excessive amounts of pain. The prenatal care you receive throughout your pregnancy is essential to the health of both you and your baby, and can improve the likelihood of a safe and healthy delivery. Knowing what to expect the day of delivery helps, so make sure to take some prenatal classes to get you better prepared for your bundle of joy.

What pregnancy trimester is the longest?

The third trimester is considered to be the longest trimester of pregnancy. This trimester begins in week 28 of pregnancy and lasts until you give birth. Most women begin labor around week 40 of pregnancy, while some pregnancies may take longer. If your pregnancy lasts more than 42 weeks, it is called post-term (past due).

Next Milestone

Birth

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