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Pregnancy Week by Week - 25 to 28 weeks
A weekly breakdown from 25 to 28 weeks
Week 25
Your baby is the size of a rutabaga. The eye lids will open for the first time and the brain waves are regulating sight and sound. The functioning sense of smell allows baby to experience varying scents and odours. Your baby is urinating into the amniotic fluid to provide a cushioning, supportive environment and to maintain a stable temperature. The wave-like movements that propel food along the digestive tract have commenced. The bone marrow takes over from the liver as the main site of blood cell production.
Week 26
Your baby is the size of a cucumber. Baby boy testicles have started to descend into the scrotum. Your baby begins to inhale and exhale small amounts of amniotic fluid which is essential for the development of the lungs. The intestines are producing enzymes to breakdown nutrients such as sugars, proteins and fats to aid digestion. Your baby’s forming teeth are almost covered with enamel, the thin outer layer of the tooth. Enamel is the hardest tissue in the human body, even stronger than bone. Its purpose is to protect your baby’s teeth from future physical and chemical damage.
Week 27
Your baby is the size of a cauliflower and the brain is now more active. The neurons and synapses, where the brain cells meet, are forming and making complex connections. The tiny air sacs in the lungs called alveoli are expanding to assist baby to breathe and exchange air after birth. Auditory development is progressing as the network of nerves to the ears matures. Your baby may recognise voices although sounds may be muffled as the ears are covered with Vernix Caseosa, the white waxy protective coating on your baby’s skin.
Week 28
Your baby is the size of eggplant. Brain wave activity measures different sleep cycles including the rapid eye movement phase, the stage when dreaming often occurs. The brain is beginning to develop deep ridges and indentations as the amount of tissue increases. A protective covering of myelin forms around the nerves, a process that continues for a year after birth. Your growing baby’s movements are becoming more regular and distinct.
Written by PBC Expo Midwife Hayley Hall
Midwife, Birth Educator and Mum of 4
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