Navigating Your Pregnancy Journey: A Week-by-Week Pregnancy Guide

Welcome to your pregnancy journey! Over the next several months, you'll witness the incredible process of your baby's growth and development. Each week brings new changes and milestones. In this detailed guide, based on information from respected medical sources, we explore the stages of pregnancy from conception to birth. Let’s embark on this week-by-week exploration into the development of your baby.

Weeks 1-4: The Beginning

Pregnancy begins with the first day of your last menstrual period, even though conception has not yet occurred. By the end of week 4, fertilisation has occurred, and the cluster of cells, now called a blastocyst, has implanted in the lining of your uterus. These cells will develop into the embryo and placenta.

4 week pregnant women

Source: Mayo Clinic, American Pregnancy Association

Weeks 5-8: Early Development

During weeks 5 to 8, the embryo grows rapidly, developing the foundations of its organs, muscles, and nervous system. The heart begins to beat around week 6, and by week 8, the neural tube, which becomes the brain and spinal cord, has formed.

Source: Cleveland Clinic, MedlinePlus

Weeks 9-13: From Embryo to Foetus

By the end of week 9, the embryo is considered a foetus. Major organs have begun their basic functions, and facial features have started to become more defined. The foetus is about the size of a grape by week 12, and the risk of miscarriage significantly decreases.

Source: Johns Hopkins Medicine, MedlinePlus

Weeks 14-18: Quickening and Growth

The second trimester often brings relief from morning sickness, and the mother might start to feel the baby's movement, known as quickening, around week 18. The foetus’ ears are developing, enabling it to hear muffled sounds from the outside world.

Source: American Pregnancy Association, Mayo Clinic

Weeks 19-23: Sensory Development

During this stage, the foetus can hear your voice and may start to react to loud sounds. The skin begins to be covered by a protective coating called vernix. If you're having an ultrasound, it might be possible to determine the baby’s sex.

23 week pregnant women

Source: Cleveland Clinic, WebMD

Weeks 24-28: Viability and Growth

A key milestone of this stage is the viability of the foetus, generally around week 24, meaning it could survive outside the womb with specialised care. The brain is rapidly developing, and the eyes begin to open.

Source: Stanford Children’s Health, MedlinePlus

Weeks 29-33: Gaining Weight and Maturing

The baby continues to put on weight and develop fat layers, which will regulate their temperature after birth. The bones are fully developed, but still soft and pliable. The baby begins to position itself for birth.

Source: Johns Hopkins Medicine, Mayo Clinic

Weeks 34-40: The Final Countdown

These final weeks are marked by further weight gain and the baby moving into the birth canal in preparation for delivery. The lungs are maturing and preparing for breathing. It's common for the mother to feel more uncomfortable during this stage, making it important to focus on comfort and rest.

36 week pregnant women

Source: Cleveland Clinic, Stanford Children’s Health


Understanding the week-by-week development of your baby can help you connect more deeply with the pregnancy process and prepare for the changes in your body. Using supportive accessories like the Sleepybelly pregnancy pillow can enhance comfort and support as your body changes. Remember, a well-informed pregnancy is a healthier one for both you and your baby.

To Access These References Online:

- Mayo Clinic: [] (

- American Pregnancy Association: [](

- Cleveland Clinic: [] (

- MedlinePlus: [] (

- Johns Hopkins Medicine: [](

- WebMD: [] (

- Stanford Children’s Health: [](

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