It will usually take place at your local hospital ultrasound department.The person performing the scan is called a sonographer.If you do know the conception date, this is classed as day 14 and not day one.If you have an irregular cycle, or if you've recently been taking the contraceptive pill, working out the date from your LMP isn't a very accurate method.It's wonderful to see a little blob with a heartbeat that will become your baby. If you are unsure of the first day of your last period you will be offered a dating ultrasound when you are between 10 and 14 weeks pregnant.But ultrasounds can also lift the lid on a few worries you might be having. The main reason for the ultrasound is to work out how many weeks pregnant you are, and to estimate your due date.You may have calculated the length of your pregnancy from the first day of your last menstrual period (LMP). However, conception doesn't actually occur until around 14 days after your LMP, or later if your cycle is longer than 28 days. Multiple pregnancy: antenatal care for twin and triplet pregnancies CG129.
The combined test involves a blood test and measuring the fluid at the back of the baby's neck (nuchal translucency) with an ultrasound scan.You may need to have a full bladder for this scan, as this makes the ultrasound image clearer.You can ask your midwife or doctor before the scan if this is the case. Find out more about what happens during a pregnancy ultrasound scan.This means that accurate dating reduces your chance of having your labour induced because your baby is thought to be overdue.
It may also help you to avoid feeling disappointed towards the end of your pregnancy if you think your baby is late when he's not.
Standard Ultrasound – Traditional ultrasound exam which uses a transducer over the abdomen to generate 2-D images of the developing fetus .