Ultrasound dating of pregnancy


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. You may know when your LMP was, but not when you actually conceived.



As well as the combined test, most private healthcare clinics offer non-invasive prenatal testing (NIPT), which is the most accurate (up to 99 per cent) screening test for Down's Syndrome. The dating scan will also show if you're expecting twins, triplets, or more. It's helpful to know about twins early on, and it's easier to see whether or not they share a placenta during the first trimester. As long as the timings are right, you can have the NT scan and blood test at the same appointment as your dating scan. That's because the screening test needs an accurate due date to be reliable.

Hormones in your blood vary according to your stage of pregnancy.

That will happen at your next routine scan at about 20 weeks However, some major problems can be seen at your dating scan, such as issues with the umbilical cord or with your baby's skull or abdominal wall.