Can a 12 week dating scan be wrong

The first trimester can be an exciting but anxious time. Expectant parents often need to wait for up to 15 weeks before they get their public maternity hospital appointment and the reassurance that everything is fine with their baby. With our private ultrasound scans, you can get this reassurance as soon as 8 weeks gestation so you can begin to enjoy your pregnancy with peace of mind. Pregnancy Scans performed during the first 12 weeks of pregnancy are generally within 3 — 5 days of accuracy.

The most accurate time for the due date calculation is between 8 and 11 weeks pregnant. This is because your baby is growing so quickly that there is a big difference in size from week to week.

The accurate determination of a patient’s “due” date, referred to by doctors and pregnancy an ultrasound is performed, the more reliable the EDC calculated by.

Back to Pregnancy Reviews. The establishment of pregnancy dates is important not only for the mother who wants to know when to expect the delivery, it is also important for her carers, e. Various policies are applied whereby the LMP dates are used unless they have a discrepancy to the ultrasound dates of more than 7, 10 or 14 days. Reliance on LMP is fraught with various problems. But even if this date is accurate, the assumption that ovulation or conception occurs 14 days later is unfounded; there is a wide distribution with a positive skewness 3.

Ultrasound scan biometry does have error but it is smaller and of a normal distribution. Studies of scan accuracy in assisted reproduction technique ART pregnancies, i.