13 Weeks Pregnant: Symptoms & Baby Development - Babylist
13 Weeks Pregnant
April 6, 2021

13 Weeks Pregnant

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13 Weeks Pregnant.
13 Weeks Pregnant

How Big is Your Baby at 13 Weeks?

Your baby is about 2.9 inches and weighs 0.81 ounce this week. In cuter terms, that’s the size of a Tamagotchi virtual pet.

Here’s what else to know when you’re 13 weeks pregnant:

Your Baby’s Development at 13 Weeks

At 13 weeks—and continuing into the second trimester—your baby is starting to develop those personal touches that will make them them. Think fingerprints and cries. Here’s what to expect with baby’s growth this week.

  • Vocal cords: Your baby at 13 weeks is developing vocal cords, readying for those first cries.
  • Fingerprints form: Baby’s already showing their individuality. Their tiny little fingers are getting their unique fingerprints.
  • Working kidneys: With their kidneys developed, they’re starting to pee into the amniotic fluid. For the rest of your pregnancy, baby will actually swallow their amniotic fluid and urine too. (Gross but fascinating.)

13 Weeks Pregnant Ultrasound


Your Body: 13 Weeks Pregnant Symptoms

As those less-than-fun first trimester pregnancy symptoms begin to abate, here’s what you can expect to feel this week and in the weeks to come.

  • Increased sex drive: Feeling amorous? A boosted sex drive during pregnancy is completely normal, and to be expected in the second trimester. Sex during pregnancy is completely safe too (as long as you don’t have a condition that’s caused your doctor to advise against sex). Your babe is cocooned with amniotic fluid, and there’s a mucus plug to keep everything out. So have some fun if you feel like it!
  • Nausea: Morning sickness is known as one of the early pregnancy symptom, but it can stick around in the second trimester. If you’re still feeling ill, you’re likely heading down the home stretch by 13 weeks pregnant. If you don’t get noticeably better in the next few weeks, tell your healthcare provider.
  • Heartburn: Have you traded nausea and fatigue for heartburn? More than half of pregnant women develop heartburn, especially in the second trimester. If you’re suffering, try eating six small meals rather than three big ones. Also, eat more slowly (yep that’s a real tip), and avoid rich or spicy foods if they aggravate you.
  • Stretch marks: These reddish streaks may start sprouting up on your hips and breasts. Basically, your skin is stretching like crazy, creating tiny tears. Lotions may help prevent stretch marks (more on that below), so feel free to try those, and stay hydrated too. Still, you might just be prone to them because of genetics. The good news is, often times, stretch marks fade a bit after you give birth.
  • Baby movement? You may start to feel your baby move around soon! Those first flutters appear at different times for people, but some experience them as early as 13 weeks to 16 weeks pregnant. Others may not be able to tell the difference between gas and baby kicks until about 17 weeks to 22 weeks pregnant.

13 Weeks Pregnant With Twins

If you’re 13 weeks pregnant with twins, those prenatal vitamins are really important. Both babies need plenty of folic acid throughout pregnancy for optimal development. So don’t stop taking them just because the first trimester is over.

Top Tip for 13 Weeks Pregnant

You need an extra 340 calories a day during the second trimester, which is basically a second breakfast.

Your Life at 13 Weeks Pregnant

So long, first trimester. Start the second trimester with a celebration and some practical advice.

  • Chow down: Growing a baby takes extra calories, but there’s no need to count them. Once your appetite comes back, aim for small but frequent meals of nutritious foods, including fruits, vegetables, lean protein and nourishing fats, like olive oil, nuts, and avocado. Want more tips for a healthy, balanced pregnancy diet? We have you covered.
  • Recipes to try: A second breakfast is one healthy way to incorporate those additional calories into your diet, and overnight oats are an ideal option. Make ahead? Check! Easy to eat on the go? Check! Delicious and versatile. Check, check! Start with a basic recipe like this one and add in whatever flavorings and/or toppings suit your fancy. We like nut butter, chia seeds, and berries.
  • Belly treat: Hard truth alert: If you’re naturally prone to stretch marks, you might not be able to avoid them. But regularly applying a good moisturizing balm may keep them at bay longer and help them fade more quickly if they do appear. Even better, it gives you an excuse for a little TLC at the end of the day or after a shower. Lather up with Burt’s Bees Mama Bee Belly Butter, Glow Organic’s Belly Butter, or for an extra boost, Bio-Oil.
  • Plan ahead: You’re a third of the way through your pregnancy, which means it’s no longer too early to talk babymoons. Go forth and brainstorm destinations—staycations count, btw!—and make your travel plans. Just remember that if you decide to go during your third trimester your doctor may recommend you not fly. And you don’t want to plan a trip too close to your due date should your little one decide to come early.

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Your 13 Weeks Pregnant Belly

Recommended weight gain for the first trimester is around 1.1 to 4.4 pounds. If you haven’t gained much (or even lost) weight because of morning sickness or lack of appetite, it’s totally OK. But you should try to gain about a pound per week from here on out. (The recommendation could be slightly more or less, depending on your BMI, so get a personalized rec from your doc.)

13 Weeks Baby Bumps from Real Moms








@mrs mckennaelston


Fun Fact

More boys are born than girls.

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13 Weeks Pregnant Checklist

  • With your 12-week ultrasound behind you, now’s the time to book your anatomy scan, which usually happens around 20 weeks.
  • Decide how and when you’ll share your good news with your boss, coworkers and any friends or family who don’t know yet.
  • Thinking about a babymoon? Talk locations and start booking travel with your partner in crime.
  • If you haven’t already, think about starting a pregnancy journal to record this unique time in your life. Dedicate a blank-page journal to it, or if you want some structure, check out The Belly Book or Expecting You.
This information is provided for educational and entertainment purposes only. We do not accept any responsibility for any liability, loss or risk, personal or otherwise, incurred as a consequence, directly or indirectly, from any information or advice contained here. Babylist may earn compensation from affiliate links in this content. Learn more about how we write Babylist content and the Babylist Health Advisory Board.