Publication:

The role of foetal assessment by ultrasound at 11-13+6 weeks of gestation

Background The prevalence of congenital anomalies has been increasing over the years, and it is estimated that every year 1 in 33 infants are affected by some sort of congenital anomaly. At 12 weeks of intrauterine gestation, most of the major foetal structures complete their development and also proper delineation of the foetal anatomy is possible by the time of routine NT scan at 11-13+6 weeks.

Methods This was a prospective study of 110 cases who underwent a first trimester 11-13+6 weeks scan for congenital foetal abnormalities. The eligibility criteria for selection of cases were first trimester pregnancy between the 11-13+6 weeks gestation and CRL between 45 mm and 84 mm.

Results The study found that the detection rate of foetus abnormalities was 15.4% in mothers over 35 years old. Total 2.7% of the present study population were detected to be high risk for trisomy 21. All the 110 cases in present study were followed up till delivery/ termination. MTP was performed in 8.1% cases with lethal anomalies and in 1 cases of structural anomaly with missed abortion, D and E was done. 91% delivered live and healthy babies. There was no intrauterine foetal death or still born in present study.

Conclusions Ultrasound at 11-13+6 weeks must be mandatory, not only for the detection of major foetal anomalies but also for diagnosis of multiple pregnancy and abnormal pregnancy like missed abortion, molar pregnancy and ectopic pregnancy.