Ultrasound Dating Formulae used for Pregnancies with Artificial Reproductive Techniques

With the advancement of science and technology, artificial conception is common among women today. It, however, has certain issues associated with it, the unavailability of the right dating formulae being one of them. To overcome this problem, the doctors and researchers have come up with a new invention- an ultrasound dating formulae! Read along to know more about it:
A database of a number of pregnancies conceived with artificial reproductive techniques are studied in order to get accurate results of second-trimester dating formulae as these are applied in different centres where routine ultrasounds are performed by Max Mongelli. The dating formulae for biparietal diameter and femur length are derived for a gestational age ranging from 14-23 weeks from pregnancy. Ultimately, the curves in the result represent linear equations and twelve formulae were published for biparietal diameter and femur length measurements. During the implementation of these formulae, systematic, random errors are calculated as they are applied to the second-trimester scan in precisely dated pregnancies. As a result, the published dating formulae were good for predicting gestational age. 

This comparative study confirms the accuracy of ultrasound dating in the respective clinics like Dr. Max Mongelli’s, thus, supporting the usage of the ultrasound measurements in accordance with the menstrual history for dating pregnancies. Estimating the gestational age by early ultrasound reduces the estimated age when compared to the menstrual dating. These databases include a range of collected data on the maternal and the fetal characteristics with data on pregnancy and delivery. The crown-rump-length based formula is used to calculate the GA at 8-12 weeks of gestation in this analysis. The foetal weight is estimated with sonographic parameters around the mid-trimester ultrasound scan. The exclusion criteria for the process were- multiple pregnancies, gestational and pre-gestational diabetes, preeclampsia, stillbirth and congenital abnormalities. In the third table, the pregnancy duration in the IVF (in vitro fertilisation) pregnancies are presented along with the term rates in fourth table.

There are no differences in the mean pregnancy durations when the delivery is done, between the early and late scan groups irrespective of the process of calculating their gestational age. The gestational age at birth for the singletons had a high correlation assessed from the time of in vitro fertilisation (IVF) and crown-rump length (CRL), from IVF and biparietal diameter (BPD).  In the time of artificial pregnancies, the gestational age measured using all the three methods shows agreeable results. The usage of ultrasound facility is thus a reliable method for estimating the gestational age accurately.