Lifestyle and home remedies. Over-the-counter medications â such as acetaminophen (Tylenol, others), ibuprofen (Advil, Motrin IB, others) and naproxen (Aleve, others) â may help ease knee pain.
What a difference a week makes! This week, a sonographer can see your baby via ultrasound as a tiny white image tucked within the gestational sac. And his heart is beating! For these first few weeks in your baby-to-be's development, he'll be nourished by the yolk sac. The yolk sac provides all the nutrients the embryo needs and produces blood cells until the placenta fully forms later in the pregnancy.
The placenta is formed by cells that originate from the foetus and is therefore the first of the foetal organs to develop. What does the placenta do? The placenta contains a complex network of blood vessels that allow the exchange of nutrients and gases between the mother and the developing foetus. The blood supply of the mother does not actually mix with that of the foetus; this exchange occurs by diffusion of gases and transport of nutrients between the two blood supplies (see figure). The transfer of nutrients and oxygen from the mother to the foetus, and waste products and carbon dioxide back from the foetus to the mother, allows the growth and development of the foetus throughout pregnancy.