Week by Week Pregnancy: How Does Your Baby’s Size Change in the Womb?
Pregnancy is a remarkable journey filled with physical and emotional changes. One of the most frequently asked questions by expectant parents is:
“How big is my baby right now?”
Understanding week-by-week pregnancy development helps parents follow their baby’s growth more consciously. In this article, we explain how your baby’s size changes throughout pregnancy, using easy-to-understand fruit comparisons.
Weeks 1–4: The Beginning of Pregnancy
Your baby’s size is approximately a poppy seed.
Fertilization occurs, and the embryo implants in the uterus. Although extremely small, rapid cell division begins. Many women are not yet aware they are pregnant during this stage, but hormonal changes have already started.
Weeks 5–6: The Heartbeat Begins
Your baby’s size is approximately a lentil.
The heart starts beating, and the nervous system begins to develop. Pregnancy can often be detected via ultrasound. Early pregnancy symptoms such as fatigue and nausea are common.
Weeks 7–8: Rapid Development Phase
Your baby’s size is approximately a raspberry.
The basic structure of organs forms, and limb buds become visible. This is a critical period of rapid growth and development.
Weeks 9–12: End of the First Trimester
Your baby’s size is approximately a plum.
The first trimester is completed. The baby’s body structure becomes more defined, and the risk of miscarriage significantly decreases.
Weeks 13–16: Growth Becomes Noticeable
Your baby’s size is approximately an orange.
Muscles and bones strengthen. Some mothers may begin to feel early movements, and energy levels often improve.
Weeks 17–20: Detailed Ultrasound Period
Your baby’s size is approximately an avocado.
Detailed ultrasound examinations are performed to assess organ development. The baby’s senses continue to mature.
Weeks 21–24: A Key Viability Stage
Your baby’s size is approximately a pineapple.
Lung development accelerates, and this stage is considered an important milestone in pregnancy.
Weeks 25–28: Beginning of the Third Trimester
Your baby’s size is approximately a coconut.
The third trimester begins. Brain development accelerates, and the chances of survival outside the womb improve significantly.
Weeks 29–32: Preparing for Birth
Your baby’s size is approximately a melon.
Fat tissue increases, helping the baby regulate body temperature. The body continues preparing for birth.
Weeks 33–40: Almost Time to Meet Your Baby
Your baby’s size ranges from a watermelon to a newborn.
The lungs mature, and birth is approaching. Your baby is now ready to meet the world.
Important Note:
All sizes are approximate. Every pregnancy is unique.
