Question by Ana Maria: Can a twin pregnancy be detected after a transvaginal ultrasound was done al 5.2 weeks?
I had an u/s done yesterday at 5.2 weeks. The u/s throws a gestational age of 7.4 weeks and only one sac is seen. I still think I am pregnant with twins. Can it be possible? My Hcg levels triple every 48 hours.
Best answer:
Answer by ~*Lariena ♥'s her baby boy*~
I'd be willing to bet that you are more along the lines of 7.4 weeks as the first trimester scans are the most accurate out of the entire pregnancy. First trimester scans are the most accurate because every embryo grows at a specific rate. Second and third trimester, the baby grows at different rates.
You may be thinking your HCG is tripling because the value will be higher for 7.4 weeks vs. 5.2 weeks.
Well it sounds like one of two things. Either you have identical twins in the same sac (fraternal twins never share a sac) which has caused it to be a bit bigger, or you’re just further along than you thought with a singleton pregnancy. Monoamniotic twins (twins who share an amniotic sac) are very rare though so chances are you’re just having one baby and further along than you thought. Was the baby(ies) seen? Or just the sac? Common not to see a fetal pole before 6 weeks.