Fetal development in pregnancy week 18: fetus in fifth month
We have two more ounces! Your "getting bigger-n-better by the minute baby" is already up to 7 ounces and 6 inches! This is a big week for their baby skin. There are now two distinct layers—the epidermis (or the surface skin) and dermis. Currently, their skin is covered with a greasy, waxy, cheese-like substance, known as vernix caseosa. Sure, it sounds pretty nasty, but this mixture of fatty secretions covering your little swimmer from head to toe is the best way to protect their oh-so-thin skin from bruising and abrasions as well as chapping caused by amniotic fluid exposure (and your little one is swimming in that stuff!).
Well, you know the birthing process? Where you have to push something the size of a watermelon out a hole the size of a grape? That adorable little greased piglet would have a lot harder time getting through the birth canal without the vernix caseosa. Fun fact for momma’s with baby girls: it’s a uterus within a uterus! Your little girl will have developed a uterus and vagina canal by the end of this week.
And how's mom doing? POP!
If you haven’t yet, you will soon be seeing the last of your inn-y belly button—until after you’ve pushed your little monkey out. If it’s getting difficult to breathe, you can thank your not-so-small belly for squishing your lungs—which will be more and more cramped for space as the pregnancy Keep in mind that as you grow (and grow and grow) in size you produce more blood (for both of you), which lowers your blood pressure. So standing up quickly and/or occasional fast movements may cause slight dizziness or lightheadedness progresses. Not that this is surprising as everything else in your mid-section is getting properly squooshed as well. (What else is new?!!).
Keep in mind that as you grow (and grow and grow) in size you produce more blood (for both of you), which lowers your blood pressure. So standing up quickly and/or occasional fast movements may cause slight dizziness or lightheadedness.
This is totally normal, but means you shouldn’t be too quick to jump to your feet when your team scores a goal. It's better to just punch the air in excitement or clap gleefully. One more fun pregnancy symptom to add to the list: you are producing more melanin, which can cause dark patches of skin to occur on random parts of your body. Don’t worry—these dark spots (unlike your parent’s age spots) will retreat soon after birth.