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The first trimester of pregnancy: The good, the bad, and the OMG

The first trimester of pregnancy is an exciting time but it can also be an uncomfortable time as your body adapts to the life growing inside. It can also be confusing. Your body is changing and becoming unfamiliar.

What is the first trimester?

The first trimester begins on the last day of your period and continues until the 13th week of pregnancy. You may not even realize you’re pregnant until well into your first trimester when symptoms become obvious, especially if you have a history of abnormal menstrual cycles.

During the first trimester, your baby develops rapidly, going from a bundle of cells to having arms, legs, and even tiny little toes. The brain and spinal cord develop, as well as the circulatory and digestive systems. By the end of your first trimester, your baby is around three inches long and weighs in at about an ounce.

First Trimester: The Good

Lots of good things are happening both internally and externally. Your body is prepping for the long haul and you may notice your breast size increase as mammary tissue develops and your hips may gain a little extra curve as your body adds fat to fuel the enormous task ahead. There’s a chance your skin will clear up and develop that tell-tale pregnancy glow and your hair and nails will likely grow thicker, longer, and stronger.

During the first trimester, you will also have the opportunity to see your growing baby for the first time. At your first prenatal doctor’s appointment, you will most likely have an ultrasound to confirm that you are indeed pregnant and to make sure everything is developing normally. While it won’t look much like a baby on the screen, your ultrasound tech should be able to point out any vital parts and also let you listen to your baby’s heartbeat on a fetal doppler.

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First Trimester: The Bad

For many women, the first trimester isn’t all butterflies and rainbows, however. The flood of hormones your body puts out to nurture your baby can wreak havoc on your body. Morning sickness (which can really happen any time during the day or night), fatigue, heartburn, and constipation are just a few of the maladies that some people experience during those first 13 weeks.

The first trimester is also when the risk of miscarriage is the highest. Some bleeding or spotting is perfectly normal within the first 13 weeks, but if it’s accompanied by clots or cramping, you should see your health care provider immediately.


First Trimester: The OMG

With all these changes you can expect some weird stuff to happen during the first trimester as well. Those hormones that are working hard to make a safe environment for your developing baby can increase your need to urinate and increase your body temperature so that you feel warmer than usual. Hormones also cause your digestive system to slow down a bit, which can cause constipation and larger than normal bowel movements.

Hormones during early pregnancy can make your hair longer and thicker but can also cause hair to grow in places it normally doesn’t. Finding a rogue stray hair on your face, chin, chest, or breasts is common during pregnancy, so don’t be surprised if you need to pluck more frequently during your first trimester.

And because more your blood is being shunted to your uterus, you might experience dizzy spells or lightheadedness.

There’s no denying that the first trimester is a time of major change for your body. Some of these changes are good, some of them aren’t so good, and some of them are just plain weird. The important thing is to listen to your body and pay attention to your instincts. If you’re concerned about any of the changes or if something just doesn’t feel right, contact your health care provider. Even if it’s perfectly normal, at least you’ll have peace of mind, which is important during pregnancy.

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Kristi Pahr
Former Digital Trends Contributor
Kristi is a professional writer and mother of two. When she's not writing or playing chauffeur to her kids, she enjoys…
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