Early Fetal Size at 5 Weeks 5 Days: What's Normal?

Question
hello

i had some infertility issues and i luckily have concieved my first child but i am 35 years old and i just had my first vaginal ultrasound and i am considered 5 weeks and 5 days pregnant.  My fetus measured in at 2.7 mm and a heartbeat was seen.  Is 2.7 mm a normal size for the fetus?

I know at my age i am at higher risk for miscarriage and i wanted to check to see if my baby is developing the way it should.  I read online that smaller gestational size in early fetal development could be a risk factor for miscarriage.  Any info would be very helpful thanks so much for your time

Answer
Hello Saige,

At this very early gestational age, size measurements are not accurate.  The margin for error is plus/minus 7 days.  So no determination can be made regarding the viability of the fetus.  You'll have to wait for a 7-8 week ultrasound.

However, the measurement is consistent with dates and there was fetal heart motion, which both are very good signs for viability.

Good luck,

Edward J. Ramirez, M.D., FACOG
Exeutive Medical Director
The Fertility and Gynecology Center
Monterey Bay IVF Program
www.montereybayivf.com

Monterey, California, U.S.A.