Your second trimester: What to expect!

During week 13, your little one will start developing bones in her arms and legs and her intestines, which up until now have been growing inside the umbilical cord, will move to their permanent address in your baby’s abdomen.
Your baby's vocal chords begin to develop and your baby is beginning to make urine and release it into the amniotic sac, making amniotic fluid.

Your baby’s skin is now covered in hair that keeps them warm until they build more fat in the [third trimester.]{href='https://www.motherandbaby.com/pregnancy-and-birth/pregnancy/your-third-trimester' }Eyelids, eyebrows, eyelashes, nails, and hair are formed. Your baby will start to use her facial muscles to smile and grimace and will have fully developed genitals.

By 15 weeks, they will have ears on either side of their head and their eyes are moving from the side of her head to the front of her face. The eyes will start to become sensitive to light, even though they remain closed, they can now register bright light. Your baby's scalp hair pattern also is forming.

Your baby can suck their thumb, yawn, stretch, and make faces, though they don't really have much control over this. At the moment, they've not got any baby fat yet and their skin is still translucent.

Baby's heart is now regulated by the brain, which means it’s not beating so randomly any more, but will still be beating about twice as fast as yours. Your little one will also get fingerprints during this week!

 Your baby’s hearing is now getting more acute, which means now is a good time to start talking and signing to your growing bump!

This week, fat is starting to develop on your baby’s body, although she’ll still look pretty skinny.
She’ll also be covered in a waxy substance, medically referred to as vernix caseosa. This is greasy and white and made up of hair, oil and dead skin cells. It might not sound too appealing, but it does an important job protecting your baby’s soft and sensitive skin from the amniotic fluid she’s living in. 

For girls, the uterus and vaginal canal are forming.

If you’re carrying a little girl, she’ll already have seven million primitive eggs in her ovaries, this will be down to two million when she’s born. If you’re carrying a boy, his testicles will start moving from his abdomen this week. You baby is regularly sleeping and waking and can be awakened by loud noises/your movements.

Baby's arms and legs will now be in proportion, the neutrons between the brain and muscles are connected, and the cartilage in your baby’s body will be turning to bone, all of which gives your baby more control over the movement of her limbs - meaning you're much more likely to feel your baby kick.

Your baby is starting to look more like a newborn than ever, with distinct lips, eyelids and eyebrows, and even tiny tooth buds. Their hair is becoming visible and thier eyebrows have developed.

Your baby might begin hiccupping, causing jerking movements. Her lung’s blood vessels are developing to prepare for breathing in the outside world, and she’s also becoming acclimatised to familiar noises, such as the roar of cars outside or the sound of your dog barking.

Your baby’s hands will develop creases in the palms this week (cute!), and soon sweat glands will form in her skin. Your baby is spending most of their sleep time in REM sleep and can recognise the sound of your voice.

Your baby’s heart rate will have slowed down considerably by this week too, from 180 beats per minute to 140 to 150 beats per minute.

Your baby’s brain is really active these days, as more brain tissue is developing. She’s an active foetus, sleeping and waking up regularly, opening and closing their eyes and sucking their fingers too. She’s about the size of a head of broccoli!