Welcome to the second trimester, known as the best time of pregnancy for many. One-third of the way through, week 13 of pregnancy is the start of a new (hopefully) improved chapter. Why not catch up on trimester one articles if you’re behind?

You might feel great over the coming weeks or somewhat improved. And as your uterus rises, you may also have a visible, if small, bump!

What can you expect from this new stage? The fading of old symptoms and incredible transformations as your body accommodates your fast-growing child.

Join us for weekly updates about the second trimester. We’ll answer your questions about your growing baby and body. We also provide tips to help you all through pregnancy and into early motherhood.

At A Glance: Week Thirteen of Pregnancy

• Entering the second trimester, which lasts until week 27 of pregnancy, you may feel renewed and energised.
• Your baby is roughly the size of a lemon at seven centimetres and learning to swallow, suck and urinate.
• You might have hints at a bump and observe other noticeable differences, like stretch marks.
• Some physical changes, like oral health issues, require treatment.
• Add these items to your checklist for a smooth and health pregnancy – research antenatal classes and prioritise your dental health. In the UK, don’t forget you get free dental treatment while pregnant and until your baby is one year old! 

Week Thirteen of Pregnancy Overview

As you ring in the second trimester, a lot could be happening inside your womb and throughout your body. 

One of the most interesting developments pertains to the uterus, which will soon spring from the pelvis, ascending upwards and outwards to accommodate your rapidly developing baby.  The shift brings some relief to the bladder. But expect this to be a temporary easement before your expanding uterus falls down onto the hard-pressed organ later.

You might hope for a reduction of symptoms by the thirteenth week of pregnancy, but experiences can vary. For mothers expecting twins, unpleasant symptoms may endure due to higher levels of pregnancy hormones coursing through the body. 

Pregnancy is still no picnic, even if you feel strong or invincible. The second trimester is generally less hectic, but your pregnant body undergoes wonderful, painful and mysterious changes .

And what’s your little fetus up to? Learning to suck their thumb and urinate – scroll down for more updates and developments.  

Baby Size and Latest Developments for Week Thirteen of Pregnancy

Your tiny, approximately seven-centimetre-tall fetus has sped through varying fruits and veggies during their short life. 

Let’s delve into their growth and progress for this week.

• The second and third trimesters are crucial times for brain development, performance and maturation. The 13-week-old fetus’s brain comprises some billion neurons or cells that transmit essential information throughout the brain. At birth, your newborn has generated an impressive 100 billion neurons!
• Your baby’s tiny, jerky and random movements grow more complex and coordinated. Around this time, your baby starts thumb-sucking and making up-and-down motions with their mouth. This activity helps them develop the reflexes they’ll need to breastfeed.
• Besides sucking, your little one is also swallowing amniotic fluids. These fluids are vital as they provide essential nutrients supporting the digestive system and antibodies for a healthy immune system. Read about all their benefits here. 
• With a functioning kidney, your baby produces and releases urine into the amniotic fluid, which the placenta removes as waste. An interesting aside: while the kidneys are crucial for the unborn fetus, they take a couple of weeks to function correctly after birth.
•  Lanugo, fetal hair covering your baby’s body during pregnancy, starts to appear. These downy hairs prevent infections and keep your lean baby warm, cosy and protected. After your baby grows fatty and insulating layers of skin, most of it will disappear. 
• Distinct patterns also emerge on the skin of the fingertips. Over the second trimester, these become fingerprints unique to your little one.

Because every pregnancy is unique, the above description generalises fetal development. Variations in the timing of milestones can occur.

Body Changes for Week Thirteen of Pregnancy

As you advance another week into your pregnancy, you may notice some of your symptoms are diminishing. Yet what other changes should you expect? From bigger boobs to stretchmarks and achy joints, here’s a rundown of everything you could experience during the second trimester.

It’s important to note that all pregnancies are unique.  The timing and experiences of pregnancy symptoms may vary. 

1. Looking More and More Pregnant

Is that a baby bump? It might be, but there’s no reason to worry if you don’t see much change in the shape and size of your belly.

2. Increased Libido

The increased blood volume travelling toward your pelvic area could positively impact your sex drive. You might also have more energy for intimacy.

3. Stretchmarks

Pregnancy is an expected time for stretch marks. They appear as red or purple lines spreading across your belly, breasts and thighs, which should reduce to pale indentations after pregnancy.

While stretchmarks are a natural mark of pregnancy, you’re not alone in feeling self-conscious about them. We’ve included some hot tips to help with stretchmarks in our pregnancy tips and tricks section.

4. Aches and Pains

Aches and pains are continuous pregnancy symptoms. During the second trimester, you could be struck down by ligament pain. This discomfort, felt on one or both sides of the belly, occurs when the ligaments that support the expanding womb are stretched and pulled.

Described as a sharp or dull ache, ligament pain or round ligament pain is commonly experienced during the early second trimester and can last for weeks.

Feeling sore and achy is also caused by the hormone progesterone smoothing your joints, muscles and ligaments. Although unpleasant, this occurrence plays a supportive role for your body when it’s time to squeeze out a baby.

Fortunately, you can treat and manage ligament pains. Spider tape could help.

5. Dizziness

Progesterone is one culprit of dizziness, widening blood vessels to accommodate the increased blood supply in your body.

While beneficial for the baby, dilated blood vessels cause low blood pressure and other adverse symptoms.

Hormonal changes contribute to feelings of dizziness, but dehydration and low blood sugar might also be responsible. Ensure you’re eating and drinking enough to avoid dizzy spells and possible fainting.

6. Pregnancy Glow

The pregnancy glow is a harmless side-effect that is said to leave the skin healthy, dewy and beautiful.

Unfortunately, the pregnancy glow doesn’t impact people equally or at all. Are you experiencing rapidly deteriorating skin? Unfortunately, skin complications like acne breakouts and greasy skin can be observed as much as that much-desired skin glow.

7. Boobs

Many women notice their bust size increasing during pregnancy.

Contributing factors like pre-pregnancy size, weight gain, and genetics influence the appearance of breasts. And while you might need to buy larger bras, please note that the physical changes of pregnancy affect women differently. You might experience a significant difference in your chest or very little change at all.

Sporting larger boobs isn’t a healthy indicator of pregnancy, so don’t be anxious if yours remain small or unchanged.

This week, your boobs begin producing colostrum, referred to as the “first milk”. Colostrum strengthens your newborn’s immune system during the first few days of life before your breast milk comes in.

8. Still Feeling Sick and Tired?

Completely normal – pregnancy symptoms don’t abruptly stop, so it won’t help to compare your pregnancy to others.

While some people experience never-ending symptoms, many experience relief from the second trimester.

9. Weight Gain

Steady weight gain is essential for fetal health during the second and third trimesters, especially if you’re currently underweight.

Recommended weight gain varies depending on your body type, pre-pregnancy weight and other factors. Curious to know more? Click here for an accurate weight gain guideline for expecting mamas.

10. Teeth

Pregnancy may impact your dental health, thanks to hormonal changes that may trigger conditions like gingivitis – early-stage gum disease that leads to quick deterioration.

Visit your dentist for treatment if you have the following. 

• Swollen and discoloured gums
• Gums that bleed during brushing or flossing 
• Bad breath 
• Gum tenderness

Week Thirteen of Pregnancy Tips and Tricks

With most of your symptoms easing, the second trimester could be productive and busy.

However, as you transition from trimester one to two, remember you’re carrying precious cargo and must take care of yourself. Don’t try to do everything all at once – you still have many months to cross things off your to-do list.

Overwhelmed and not sure where to start with baby preparation? We have some ideas for you.

1. Work on Your Diet

Upgrade from eating crackers only for an improved diet packed with protein, veggies, fruit, dairy and healthy fats. Beyond the first trimester, you can continue taking prenatal vitamins to support a healthy pregnancy. Additionally, many doctors recommend prenatal vitamins throughout pregnancy and breastfeeding, especially if your diet lacks specific vitamins and minerals.

2. Look After Your Teeth

Many pregnant women suffer from gingivitis, a common gum condition, and other dental health issues.

To keep your teeth and gums healthy over this period, consider the following.

• Visit your nearest dentist for a teeth cleaning and other treatments.
• Follow at-home practices – brush twice daily for two-to-three minutes, and don’t forget to floss.
• Follow a healthy diet to optimise your oral hygiene.

3. Research Antenatal Classes

Whether you’re a first-time parent or have other children, antenatal classes provide valuable pregnancy and parenthood insights.

A popular way of learning what to expect, antenatal classes teach you how to prepare for birth and look after a newborn thereafter. Be sure to book early to avoid missing out on these essential pregnancy, birth and baby lessons.

 4. Maternity Wear Ideas

Adjusting your pregnancy clothes might become necessary, even if you’re not a fan of maternity clothes or don’t want to spend money on new outfits. If you’re not prepared to buy a whole set of pregnancy clothes, why not borrow stretchy pregnancy jeans and other items from family members or friends? Otherwise, invest in a few statement pieces you know will serve you well – you don’t need to replace everything you own.

5. Preparing Older Siblings for a New Baby

Welcoming a new family member is a considerable adjustment for existing siblings. Carefully and gently break the news of the new baby to your other child or children.

Consider these tips to prepare them for the arrival of their new sibling

• Involve them in the process to make them feel important and needed. Ask for their help with baby clothes and toys.
• Use picture books that describe what’s going on and what it means to be a big brother or sister.
• Avoid making other significant changes that may leave your other offspring anxious and uncertain about the future.

Do you have four-legged children? Here’s how to introduce your cats and dogs to their new, fur-less sibling.

6. Reducing Stretch Marks

While stretch marks are typically unavoidable, you can use moisturiser to minimise their appearance. Drinking water, limiting your coffee and being healthy also helps to keep your skin soft and less prone to developing stretch marks.

7. Coping with Pain

Round ligament pain can cause intense, temporary discomfort. Here’s how to treat it.

• Don’t make sudden movements, especially transitioning from sitting to standing.
• Coughing, laughing, and sneezing can cause pain – flex your hips to ease soreness. 
• Consider stretching or prenatal yoga to strengthen your core muscles.
• Take over-the-counter pain medications, acetaminophen. 
• Try Spider Tape for a medication-free option.

Do I need an Ultrasound for Week 13 of Pregnancy?

Week thirteen is within the time frame of when you should book your first ultrasound. In previous weeks, we’ve covered what to expect from this procedure and why it’s done. Don’t delay – book your week 13 pregnancy ultrasound soon! This not-to-be-missed scan not only confirms your pregnancy, but also assesses development, determining gestational age, fetal health and more.

Around this time, your doctor may also recommend optional genetic screenings. These tests look for chromosomal abnormalities like Down syndrome, trisomy 13, Edward’s Syndrome and more.  Even if your doctor hasn’t mentioned this, if you want peace of mind about your child’s health, enquire about them anyway. For detailed information, skip ahead to Week 15 for a crash course on the different types of tests available.

Fun Facts for Pregnancy Week Thirteen

• Have you ever watched movie scenes where the pregnant woman’s water breaks dramatically in a Hollywood-style gush? With just 15 to 20 per cent of women experiencing their waters breaking, this hardly reflects real life. Normally, the person in labour experiences contractions before the waters break, and sometimes, the doctor has to rupture the membrane artificially.

Week Thirteen of Pregnancy Checklist

• Have you had your ultrasound yet?
• Are you taking advantage of having fewer symptoms?
• Are you eating well and looking after your dental health?
• Is your checklist growing?
• Are you anticipating our week 14 article? Don’t go anywhere.