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Pregnancy Week By Week

13 Weeks Pregnant

Congrats! You’ve made it through the first trimester! We’re not just talking about getting through those work meetings without falling asleep (or puking!), we’re talking about how you’re now 1/3rd of the way through your pregnancy! At 13 weeks pregnant, you’ve grown a fetus that has vocal cords, teeth, and even fingerprints (wow!) and you’ve probably kept this incredible news (mostly) secret while wishing you could shout it from the rooftops—or, at the very least, use it as an excuse for getting to work late.

Around week 13 of pregnancy, many parents-to-be start spreading the word that there’s a baby on the way. But know that there are no hard-and-fast rules about when you should divulge your secret. It could be after your next prenatal appointment, once you start showing, or at a big family event where everyone will be gathered. Or maybe everyone already knows! That’s totally your call.

How Big Is Baby at 13 Weeks?

At 13 weeks pregnant, baby is as big as a lemon. Your 13-week fetus is about 2.9 inches long and weighs about .81 ounces, and proportion-wise, his or her head is now about 1/3 the size of the body instead of ½.

13 Weeks Pregnant Is How Many Months?

13 weeks pregnant is 3 months pregnant. This is the last week of the first trimester. (We can’t say it enough because it’s so great to be here!)

13 Weeks Pregnant Symptoms

You might notice that around 13 weeks pregnant, your symptoms change a bit. You might actually be able to get through the day without nausea (if not now, soon) or feeling the need for a nap. But you may be experiencing a few of these too:

  • Visible veins. You can see all those blue streaks under your skin because you have increased blood flow.
  • Increase in energy. The second trimester is known as the least symptomatic—and the most energetic. As you start to feel more like yourself and get that energy surge, you’re going to want to knock a bunch of to-dos off your list. Also, if you’ve found yourself too sick and tired to exercise lately, now’s the time to get back to a fitness routine. Exercise will only benefit you and baby and can even make labor easier. Worth it!
  • Increased sex drive. If you’re one of those lucky pregnant women who feels up for a roll in the hay at 13 weeks, well… enjoy! You may notice a bit of post-coital spotting during pregnancy at 13 weeks. A little spotting is normal simply because your cervix is more sensitive. But heavy bleeding (like a period) isn’t, so call your doctor if it’s more like a flow.

Sorry, twin moms-to-be. If you’re 13 weeks pregnant with twins, you might still be experiencing some morning sickness and fatigue. That’s because twin moms can have more of the pregnancy hormone hCG in their systems. If your nausea and vomiting is super severe, definitely bring it up to your OB. If you’re able to hold down food and liquids, but you’re still feeling ill, just wait it out a little longer.

13 Weeks Pregnant Belly

Your uterus is now big enough that it’s growing up and out of your pelvis. That means you’re starting to actually look pregnant. Finally, right? You’re a third of the way through and you finally get to demand a seat on a crowded train!

Expect to look more and more pregnant from here on out because pregnancy at 13 weeks calls for a weight gain increase. OBs recommend you gain weight in the healthiest way possible—that means slowly and steadily throughout your pregnancy. Here are the weight gain guidelines outlined by the American College of Obstetricians and Gynecologists (ACOG):

If you’re underweight (BMI under 18.5):

  • Your recommended total pregnancy weight gain is 28 to 40 pounds.
  • In the second and third trimesters, aim to gain about a pound (1 to 1.3 pounds to be exact) per week.

If you’re average weight (BMI of 18.5 to 24.9):

  • Your recommended total pregnancy weight gain is 25 to 35 pounds.
  • In the second and third trimesters, aim to gain about a pound or a little less (0.8 to 1 pound to be exact) per week.

If you’re overweight (BMI of 25 to 29.9):

  • Your recommended total pregnancy weight gain is 15 to 25 pounds.
  • In the second and third trimesters, aim to gain a little over a half pound (0.5 to 0.7 pounds to be exact) per week.

If you’re obese (BMI of 30 and above):

  • Your recommended total pregnancy weight gain is 11 to 20 pounds.
  • In the second and third trimesters, aim to gain about a half pound (0.4 to 0.6 pounds to be exact) per week.

If you’re 13 weeks pregnant with twins:

  • Your recommended total pregnancy weight gain is 37 to 54 pounds.
  • In the first half of your pregnancy, aim to gain about a pound per week. In the second half, aim to gain a little over a pound per week.

Of course, you don’t want to stress yourself out about these numbers. What’s important is that you’re eating a healthy diet full of a variety of different foods, eating about 300 extra (nutritious) calories per day more than you did pre-pregnancy and getting plenty of exercise.

13 Weeks Pregnant Ultrasound

A 13-week ultrasound could detect baby’s gender, but since it can be pretty tough to make out little boy or girl parts, your doctor will probably wait until the mid-pregnancy ultrasound (around 18 to 22 weeks), when it will be much more obvious, to look and see whether you’re having a girl or a boy.

If you’ve chosen to have prenatal cell-free DNA testing, also known as non-invasive prenatal testing (NIPT), to screen for chromosomal abnormalities, you’ll be able to find out the gender when you get your results. Hey, at 13 weeks, you may already know! Oh boy! (Or girl!)

Pregnancy Checklist at 13 Weeks Pregnant

Reminders for the week: