Conception to Birth: The Stages of Fetal Development During Pregnancy

Pregnancy is a beautiful experience full of joy and wonder. From the moment you know of the tiny life inside you, it becomes your mission to help them to grow, flourish and thrive. It’s an urge that runs deep and strong, staying with you throughout your life.

If you have recently become pregnant, while the excitement and anticipation sprints around your mind, so may the questions. What’s going on in there? What does your baby look like, and how are they developing? At the end of nine months you’ll have a brand new, beautiful bub to take home – but how does your baby develop throughout those 9 months?

The first stage of fetal development occurs during the first month of your pregnancy when your newly fertilised egg begins to grow, forming a water-tight amniotic sack. This then fills with fluid, serving to cushion the growing life inside you.

During this time, your placenta develops so it may fulfil its role of supplying your baby with the nutrients they need to develop, as well as transferring waste away from the baby.

In this first month of pregnancy, your baby’s face begins to take form.

Dark circles emerge as the early development of eyes, and other areas of the head such as the mouth and jaw start to form. Blood cells also begin to take shape and circulation starts.

At this stage, your little one is smaller than a grain of rice!

As the weeks turn into months, your baby’s face continues to develop. In this fetal development stage, the ears begin to form, as do arms, legs, fingers, toes and eyes.

Your baby’s neural tube, including the brain and spinal cord, is established, while the digestive tract and sensory organs begin to develop. Bone also starts to replace cartilage at this stage.

Most exciting of all, it is during this period, after six weeks, where you may hear your baby’s heartbeat for the first time!

Approaching the three-month mark, your little one’s limbs, fingers and toes are fully formed. At this stage of fetal development, your baby can open and close their fists, and the beginnings of the outer ears, finger and toenails start to appear.

After three months have passed, your baby is fully formed. All of their organs and limbs are established, and you might be able to spot their sex during an ultrasound.

Almost mid-way through your pregnancy, your little baby’s adorable fingers and toes are now well-established. During this fetal development period, their eyelids, eyelashes, eyebrows, hair and nails begin to take form.

Your baby’s nervous system begins to function, and your doctor may be able to spot whether you’re having a boy or girl!

At the same time, your baby’s bones and teeth become denser, and your little one will become far more animated – capable of yawning, making faces and sucking on their thumb.

Top tip: Before you discover the sex of your baby, you may want to discuss whether you’d like to find out or keep it a surprise with your partner. There are so many fantastic and creative ways to announce the news – have fun with it!

Five months in, your bump may go bump! Now that your baby is busily developing muscles you may feel them start to move around – how exciting!

While their muscles are developing, so is the hair on your baby’s head and body. Your baby forms a soft, fine hair known as “lanugo” all over their body, however, this is usually shed during your baby’s first couple of weeks of life after birth. Their gorgeously soft skin is protected from the amniotic fluid inside your womb by a cheesy, white coating called “vernix caseosa”. When you give birth, some of this coating may still be present.

While your bump is growing with every passing day, the veins in your baby’s skin start to show through their semi-translucent skin. Their eyes start to open and close – finger and toe prints are also visible.

After six months of fetal development, you may find that your baby becomes far more active.

They may respond to sound by moving around, and can even experience hiccups.

At this time, your baby is around 30 centimetres long!

Shifting and moving about, your baby now changes position regularly and responds to stimuli such as sound and light. They begin to store reserves of body fat, and how have fully developed hearing. As your little one is now not-so-little, your amniotic fluid will now begin to diminish to accommodate the growing baby.

Time to start talking about exercises and methods to help relieve back pain with your healthcare professional, because you’re about to enter into the homeward stretch!

With only two months to go, your baby’s brain develops rapidly and now has the ability to see and hear. They continue to develop fat reserves and increase their body weight, and you may feel your baby kicking more often. Most of your baby’s internal organs are now well established, but their lungs still have a way to go.

Now that your baby is almost fully grown (and a little wiggle pot inside you), you may experience some difficulty sleeping.

If you do experience difficulty sleeping due to an aching back, you may find some gentle, relaxing yoga helpful. If it’s causing you more than the odd restless night, we recommend talking to your healthcare professional about your best options.

With nearly fully developed lungs and coordinated reflexes, your baby can now blink, turn their head, grasp with their hands and respond to stimuli.

If you haven’t gotten your nursery together or have been putting off shopping for prams, get going because your baby’s almost ready to meet you!

Every pregnancy is unique and special. But if you have any concerns along the way, talk them over with a healthcare professional. And remember, you’re eating for two – ensuring you are getting enough of the right vitamins and minerals during your pregnancy is a must.

If you’re not sure what you need to be eating more or less of, your healthcare professional will gladly talk you through the optimal nutritional intake for your pregnancy.

Have you found this information useful? If so, you may enjoy the following:

Having A Baby: The Conception And Pregnancy Fundamentals

What Is The Nesting Instinct And Why Is It Important?

1. Cleveland Clinic 2014, Fetal Development: Stages of Growth, https://my.clevelandclinic.org/health/articles/7247-fetal-development-stages-of-growth 
2. Office on Women’s Health 2018, Stages of Pregnancy, https://www.womenshealth.gov/pregnancy/youre-pregnant-now-what/stages-pregnancy