A normal pregnancy, measured from the first day of the last menstrual period, lasts about 40 weeks (three trimesters). The fetus reaches certain developmental milestones at the end of each trimester of pregnancy.
A full-term baby can be born between 37 and 42 weeks, with 40 weeks being the average.
Although exact timing may vary, the following describes the three trimesters as defined by the Office on Women’s Health Reliable Sources:
- 1-12 weeks is the first trimester.
- 13-28 weeks into the second trimester
- 29-40 weeks the third trimester
First Trimester (1-12 weeks)
Your baby will develop the most in the first three months of pregnancy. Your baby undergoes significant physical and physiological development during this time. Many pregnancies end in miscarriage, and many more are affected by birth defects, during this time.
During the first trimester of pregnancy, you’ll also see significant changes in your body. A wide range of symptoms, from nausea and fatigue to breast tenderness and frequent urination, can result from these shifts. These are all fairly typical signs of pregnancy, but every woman has a unique experience. Some people may feel energized during this time, while others may struggle with exhaustion and mood swings.
Second Trimester (13-28 weeks)
Pregnancy’s second trimester is often referred to as the “golden period” because it’s when most women report feeling “back to normal” after the initial discomforts of pregnancy have subsided. Pregnancy’s second trimester is when most women feel the most like themselves, with fewer morning sicknesses, improved sleep, and boundless reserves of energy. On the other hand, you might start experiencing brand new symptoms, such as backache, tummy ache, leg cramps, constipation, and heartburn.
It’s possible to feel your baby’s first kicks anywhere from 16 weeks to 20 weeks.
Third Trimester (29-40 weeks)
You’re probably feeling a mix of excitement and anxiety as you enter the final weeks of your pregnancy. Physical symptoms such as shortness of breath, hemorrhoids, urinary incontinence, varicose veins, and trouble sleeping are all possible during this time. Many of these changes occur as your uterus grows from its original size of about 2 ounces to about 1.4 kg by the time of birth.
When it comes to your baby’s development, the first trimester is crucial. The major body organs and systems of your unborn child are forming even if you don’t look much different from when you were pregnant. This is also when the effects of alcohol, drugs, and some medications, as well as the effects of certain diseases, can be seen most clearly in the developing baby. That’s why it’s so important to take all the precautions you can to ensure your baby’s health at this time.
There are many women who find the first three months of pregnancy to be the most challenging. You need to give your body some time to adapt to the many changes it’s experiencing during this time. The first trimester of pregnancy is the most difficult because of the hormonal changes and the accompanying extreme fatigue, nausea, vomiting, tender breasts, and frequent need to urinate.
In some ways, the last three months of pregnancy are the most painful. Now that your baby is growing rapidly, you may be experiencing increased discomfort as a result of the strain being placed on your body. Braxton Hicks contractions are common among pregnant women because they occur as the body prepares for labor. There may be some discomfort, but it shouldn’t be too bad in the stomach. You and your unborn child depend on the prenatal care you receive because it increases the odds of smooth and trouble-free delivery. It’s helpful to have an idea of what to expect on the day of delivery, so enrolling in a prenatal class is a great idea.