In all the excitement of knowing we are having girls and also with work stuff keeping me busy I forgot to post all about what's going on in there this week! How could I forget??
At 17 weeks the babies are growing fast now, different sources seem to quote different things but we know last week they weighed about 6 ounces each (one site says they should be 4!)
This week fat begins to form and will continue to do so until they are born. Fat is important to the body's heat production and metabolism. Right now, at 17 weeks, water makes up about 3 ounces and fat 0.018 ounces of the baby's body.
In a baby at term, fat makes up about 5.25 pounds of the total average weight of 7.7 pounds. The placenta is continuing to grow at an amazing rate. The placenta will continue to develop in tandem with the baby and it will weigh more than a pound at birth! By this week, the placenta is large and well established with a network of blood vessels that exchange nutrients and waste.
The extra fat will help keep them warm after the birth, but for now, my amniotic fluid does the job for them, keeping them at a constant 37.5C - slightly warmer than my own body temperature.
One site says that the babies are now recognisably either a boy or a girl, with a visible penis and testes or a fledgling uterus and vagina. If you're having a girl, she already has around two million eggs in her ovaries. Well we know this now! and as they are girls they won't be needing their ovaries for a very very long time!!
Connections are constantly forming in their brains, meaning they have more control over their limbs, fingers and toes. Their blood circulation is well established, and each has an umbilical cord that is becoming thicker and longer to transport oxygen and nutrients into their little bodies. Each baby and their placenta are almost the same size.
Well no wonder I'm expanding so fast - and gaining more weight. I think to date since I did the IVF I've gained about 10-12 lbs which seems to be about right for twins.