Stages of Pregnancy: How your baby is developing month by month

A typical pregnancy lasts between 37 and 42 weeks, learn more about your little one's development at each stage of your pregnancy.  

The First Trimester

First Month of Pregnancy

Around three weeks after the first day of your last period, your fertilised egg will travel down the fallopian tube towards your uterus, and at four weeks, the embryo will implant in the side of your uterus. At this stage, your little one measures about two millimetres. 

Second Month of Pregnancy

Your little one is now just under an inch long and is developing into a tiny human being. They are now living inside a fully formed amniotic sac that cushions them. At this stage, their heart is beating, their brain is developing, and their legs are growing longer.

Third Month of Pregnancy

Your little one is now fully formed and is between two and four inches long. By the end of the first trimester, all organs, muscles and bones are in place, and even their fingernails are developing. Your little one is also moving their arms and legs, though you won’t be able to feel it yet. You will have your first ultrasound scan between eight and fourteen weeks, where you will be able to see your baby and hear their heartbeat.

The Second Trimester

Fourth Month of Pregnancy

Your baby is five to six inches long and weighs up to four ounces. Baby’s facial muscles can move, and their heart is fully formed at this point, though the lungs are still developing. Your baby’s eyes aren’t open yet, but they will be sensitive to light, and they are starting to hear sounds such as your heartbeat and voice for the first time. By the end of this month, you may feel the first flutters of your baby’s movement.

Fifth Month of Pregnancy

Your baby now weighs around ten ounces and is six to nine inches long. At this stage, your baby will start to move more, and you will experience stronger kicks. They also begin to develop sleep cycles, so they will have pauses in their movement. It’s a good idea to keep a note of their movement, so you begin to recognise their activity patterns.

Sixth Month of Pregnancy

Your baby is now about ten inches long and weighs over a pound. You’ll be aware of your baby’s movements as they kick and somersault, and you may have also felt your baby move in response to loud noises. Your baby’s eyes are now opening for the first time, and they are developing their blinking reflex. Your baby’s vocal cords are functioning, and their eyebrows have formed.

The Third Trimester

Seventh Month of Pregnancy

Your baby is starting to put on weight and now weighs between two and four pounds and is up to fifteen inches in length. Your baby can now see and focus their eyes, hear and taste. Your baby’s sucking reflex is now active, so you may see your baby sucking their thumb when you have your scan. Your baby’s brain and nervous system are growing rapidly.

Eighth Month of Pregnancy

Your baby is almost ready to be born. They will weigh around six or seven pounds and will be about eighteen inches in length by the end of the month. Their lungs are almost fully developed, and other body systems, such as the digestive system, are getting ready for living outside the womb. Your baby will continue to be active but is now filling up more of the uterus and has less room to stretch. By the end of the month, most babies are head down and descending into the pelvic area.

Ninth Month of Pregnancy

Your baby measures about eighteen to twenty-one inches long and weighs between six to nine pounds. Your baby’s lungs are now fully developed, and they are ready to take their first breath.

With each passing day, the countdown to your baby’s birthday begins!

Once your baby is born into the world we will be here to help with our baby socks that keep babies feet warm and stay on babies feet.