Is it normal for the gestational age to be a week more than the last menstrual period?

Question

Hi doctor,

I had my last period before 4 weeks 5 days. I confirmed pregnancy by doing a home pregnancy test. When I went to the scan, the doctor told me that the sac measures 0.6 inches and it is 5 weeks 5 days. Why do I have this difference? Is this normal?

Answer 1

Hi,

Welcome to icliniq.com.

There is nothing to be worried about this calculation as it is just a machine reading. You can follow the actual date of gestational age calculations. As per your date, your gestational age is 4 weeks 5 days and gestational sac diameter is 17 millimeters. According to the scan, you have a gestational age of 5 weeks 5 days. Gestational sac diameter is a measurement to predict gestational age in early pregnancy when the embryo or fetal pole is not visible on the ultrasound. You can have a deviation of plus or minus one or two weeks from the actual gestational age and so it is not accurate.

An ideal gestational age that corresponds to the actual pregnancy dating is the crown-rump length (CRL) of the fetus. CRL is the most accurate indicator of gestational age throughout three months of pregnancy. It can be visualized properly after six weeks and you can check your baby's heartbeat too. Go for a rescan after ten to fourteen days. You can able to view the baby, its measurement, and its heartbeat. You can take tablet Folic acid 5mg tablets daily for three months. Avoid intercourse for the first three to four months. Everything is fine as of now.