Higher levels of estrogen and progesterone increase blood volume everywhere including your nasal membranes. (mattressadvisor.com)
They are crucial to maintain increased blood volume, the growth and cellular development of your baby and a healthy placenta. (ohbabynutrition.com)
Due to increased blood volume considering the fact that two babies are developing in you, you are more likely to have rapidly increased weight gain. (themamaneeds.com)