What Are the Stages of Pregnancy? Trimesters Explained
by Jess Wartinger
Jan 10, 2019
Welcome to pregnancy, where nine months means forty weeks and the clock starts well before conception actually occurs. Needless to say, determining pregnancy timing might just require an advanced degree.
Conventionally though, your pregnancy can be broken into three (almost) equal parts. Each pregnancy stage (or trimester) lasts about three months and comes with distinct changes for both baby and mom. Let’s take a look at what makes each trimester unique.
First Trimester (Weeks 0-13)
In order to be as consistent as possible, each pregnancy is dated from the first day of your last menstrual period. This means that your first trimester begins about two weeks before conceptions occurs.
By the time you find out you’re pregnant, you’re ⅓ to ½ way through this first stage or trimester (which lasts until pregnancy week 13). This first stage of pregnancy is crucial for your baby’s development. It includes the formation of all organ systems as well the outward change from an unrecognizable embryo to a fetus that resembles a newborn.
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Unfortunately, this potential for development means the likelihood of miscarriage or birth defects is highest in the first trimester. While there’s nothing specific women can do to avoid these setbacks, having a balanced diet, avoiding caffeine, and increasing your folic acid are all ways to support a healthy pregnancy.
Women may find that their pregnancy symptoms crop up early, even before they’ve missed a period. Others will feel normal throughout much of the first trimester. Symptoms can vary significantly from person to person but nausea, fatigue, breast tenderness, and frequent urination are the most common complaints in this first pregnancy stage.
Second Trimester (Weeks 14-26)
The second trimester of pregnancy is a welcome relief as these months are the most comfortable for many women. Following the first trimester, complete with tricky symptoms to manage, the second trimester brings a decrease in nausea, better nighttime sleep, and increased daytime energy.
Although there’s a good likelihood of a few new symptoms cropping up (backache, leg cramps, heartburn, and nasal congestion), most moms-to-be find these manageable. Exciting moments abound in this stage of pregnancy. Your baby bump will finally be really showing and you’ll feel your baby move for the first time (between weeks 16-20).
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As for that little one, your baby spends the second trimester growing. His body triples in size throughout this period, his eyes open, and he is able to hear sounds within the womb (and eventually your own voice). His fingerprints will fully form and digestive system will begin working.
The second trimester is a great time to really enjoy your pregnancy. It’s often when couples plan to take a babymoon and savor the time together before their family dynamics change.
Third Trimester (Weeks 27-40)
By the time you reach your third trimester, you’ll have well-meaning grocery employees asking if you need assistance. This third stage of pregnancy brings about a rather impressive baby belly.
Unfortunately, the increased girth can be difficult to manage. Many women find symptoms directly related to their size including shortness of breath, frequent urination, sleeping problems, and difficulty moving. Overall, a pervasive feeling of discomfort envelopes the third trimester.
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Fortunately, this is the home stretch of pregnancy. Babies are considered full term between pregnancy weeks 38-42. The frequency of doctor’s visits will increase as your baby’s birth gets closer.
The third trimester is a good time to plan your baby shower and take childbirth classes. You may want to tour your local hospital so you’ll know exactly what to expect on the big day.
Stage of Pregnancy: Next Steps
Are you pregnant? Would you like more in-depth details about your pregnancy each week? Join me (and my husband) as I detail our pregnancy journey with baby number six in weekly pregnancy guides.
Jess Wartinger
Jess Wartinger resides in rural New York with her husband and five children. Formerly an early elementary teacher, Jess currently spends her time loving her kids and holding down the fort at home.
