Dating pregnancy ultrasound vs lmp
For transvaginal ultrasound you can have an empty bladder Dating scans are usually recommended if there is doubt about the validity of the last menstrual period.For example if you a tiny sac can be seen in the uterus, but the baby and its heart beat may not be detected yet.At the first trimester scan they confirm that the fetus is alive, they assess the gestational age by measuring the crown-rump length and will look for any major problems.This is a routine ultrasound examination done at 10 to 14 weeks of gestation.Your prenatal visits will probably be scheduled every month until 32 to 34 weeks.
The earlier the ultrasound is done, the more accurate it is at estimating the baby's due date.A first trimester ultrasound often requires a higher resolution due to the small size of the fetus. yolk sac is a structure that provides nourishment to the fetus while the placenta is developing.Endovaginal ultrasound examination is another option. By about six weeks, an ultrasound can show other things as well.This schedule is flexible, depending on your pregnancy.
If you experience any complications between your scheduled visits, call your doctor immediately.Most dating scans are done with a trans-abdominal transducer and a fullish bladder.