First Trimester of Pregnancy

Weeks 1 through 13 of Gestation

During the first trimester of pregnancy, the fetal development of your baby is certainly not obvious.

Although you will not feel your baby move during this time, and it seems like little is happening...

...nothing could not be further from the truth.

A lot is happening with your baby and your body!

Your uterus will undergo dramatic changes and by the eighth week, your blood volume will start to expand.

Normally, your uterus only weighs a few ounces but by the end of your pregnancy, it will weigh about two pounds!

It is not unusual for some women - about 25% - to experience some painless spotting also called implantation bleeding. Implantation bleeding will NOT look like a period: you will have little blood and it will be brownish or pink. It usually will start about 10 days after ovulation.

You will likely have your first prenatal care appointment with your care provider during the first trimester of pregnancy. During your first visit, some blood will be drawn for some lab work and your attendant will go over your medical history.

Prenatal visits will occur every 4 weeks until the 28th week after which time their frequency will increase.

You may be able to hear your baby's heart tones between 10 to 13 weeks with a Doppler - a hand-held ultrasound device.

If you refuse to use ultrasounds, then you will need to wait until the second trimester when a fetoscope can be used. But do not worry - even if you cannot hear a heartbeat during this time - as long as your uterus is growing and you are gaining weight then your baby is just fine.

Fetal Development During the First Trimester of Pregnancy