怀孕第 29 周的宝宝

A Closer Look at Week 29

At 29 weeks, your baby's brain has reached an important functional milestone: it can now regulate primitive breathing and body temperature independently. While these functions are still immature and would require NICU support if your baby were born now, the fact that the brainstem has developed these capabilities is a significant step toward readiness for life outside the womb.

The skeletal system is fully developed in terms of structure — all 300+ bones are present. However, unlike adult bones, they are still soft and pliable, composed largely of cartilage that will gradually harden (ossify) over time. This flexibility is by design: soft bones allow the baby to fold compactly within the uterus and pass through the birth canal. The skull plates, in particular, are intentionally unfused, allowing them to overlap during delivery — which is why some newborns have a slightly cone-shaped head immediately after birth.

Varicose veins — swollen, twisted veins that appear blue or purple beneath the skin, most commonly on the legs — are a frequent occurrence in the third trimester. They are caused by increased blood volume, the weight of the uterus pressing on the large veins (particularly the inferior vena cava), and hormonal changes that relax the walls of blood vessels. Spider veins (smaller, web-like networks) may also appear on the legs, face, or around the nose.

Elevating your legs whenever possible, wearing compression stockings, doing regular gentle exercise (walking and swimming are ideal), and avoiding standing for prolonged periods can all help manage varicose veins and improve circulation. Most pregnancy-related varicose veins improve significantly in the weeks and months following delivery.