Track your pregnancy week-by-week

Pregnancy week by week

13 Weeks Pregnant

Length of baby: 7.4cm (74mm)
Weight of baby: 23g (0.023kg)
At week 13, your baby’s body is growing faster than the head and the head is now about one third of its entire height.


Congratulations for making it through the first trimester! And this means, you are one third of your way into your pregnancy! 

Today you officially begin the second trimester, which would take you through week 13 to week 27 of pregnancy.

It is also around this time that you can start sharing the happy news of your pregnancy, or you could choose to keep it a secret for just a while longer (though not for much longer as your baby bump is set to grow).

The good news about starting your second trimester is that pregnancy symptoms such as morning sickness and fatigue is set to subside. Many women also notice an increase in their sex drive once the symptoms go away (wink).



How big is baby at 13 weeks? Your baby is the size of a lemon, which is about 74mm (7.4cm).

The current weight of your baby is about 23grams (0.023kg).

Fun fact: The baby’s head is now 1/3 of the body.



This is the weight gain that you must achieve this week.

Underweight(BMI <18.5)  0.44kg to 0.58kg
Normal weight(BMI 18.5 to 24.9)0.39kg to 0.50kg
Overweight(BMI 25 to 29.9) 0.23kg to 0.33kg
Obese(BMI ≥ 30) 0.16kg to 0.25kg

During the second trimester, you will need to eat an extra 340 calories a day.



At 13 weeks, your pregnancy symptoms will change. As your placenta takes over the production of pregnancy hormones, you can now get through the day without the nausea or needing the nap.

Being 13 weeks pregnant, here are some signs and symptom that your body might be experiencing:

  • Increased energy. It is in the 2nd trimester that you will feel the most energetic, out of the three trimesters. Time to also get back to your exercise routine as exercising helps tremendously in your labour later on. So start exercising and your body will thank you later!
  • Increased sex drive. You might feel the urge to get funky under the sheets. Do note that slight spotting after the deed is normal because your cervix is more sensitive. If you spot any unusual bleeding, call your doctor.
  • Visible veins. During pregnancy your blood volume will increase by fifty percent. Your veins play the important role of bringing the blood to your growing baby.


If you are having a baby girl, she will already have more than 2 million eggs in her body at this stage.



So you may see your baby bump this week as your uterus has officially outgrown the pelvis. You can only expect to look more pregnant in the days ahead as your baby grows bigger in your womb.

Good news is, you might be given the reserved seat on the MRT! Start wearing loose fitting clothing to make yourself feel comfortable.

Even though birth is still some time away, your breast is starting to make colostrum, a nutrient rich fluid that will feed your baby the first few days after birth, before your milk starts to flow.

Remember to eat healthily, get your sufficient dose of protein, iron and calcium daily because your baby will need these nutrients to grow. Your prenatal vitamins will help fill up any nutritional gap in your diet, but it is still important to eat plenty of fresh fruits and vegetables for fibre which helps with digesting and to avoid constipation.



Your baby’s body is starting to grow faster than the head, as the head has now decreased to one third of the body size. Fingerprints are forming, and veins and organs are visible through the skin.

If you are having a baby girl, she would have more than two million eggs in her ovaries.

Still the ultrasound at this stage would not be able to tell the gender of the baby, and your doctor could wait till mid pregnancy to confirm the gender.

If you have chosen to undergo a non invasive prenatal testing (NIPT) to screen for chromosomal abnormalities, in addition to the results, you will also be able to find out the gender of the baby.



Reminders for the week:

  • Start looking for infant/child care places around where you stay
  • If you are having a confinement lady, start looking for one
  • Prepare your company, boss and colleagues that you will soon go on maternity leave
  • Exercise