Morphological study of the fetus in the first trimester of the pregnancy: gender differences

Over the past decade, prenatal diagnosis has shifted rapidly from the second trimester into the first trimester. Althougt the nuchal-traslucency scan may detect a small proportion of fetal structural malformations, fetal anatomy is not routinely assessed until the fetal anatomical survey is performed in the second trimester between 18 and 22 weeks. The recent development of high-frequency transvaginal ultrasound transducer has led to vastly improved ultrasound resolution and improved visualization of fetal anatomy earlier in gestation.OBJECTIVE:his study was designed to assess the accuracy of ultrasound anatomy screening before 14 weeks gestation in the population and highlight the differences between a female fetus and one male. Remember that the difference of the gonad, and sex determination, take place between 6 and 10 weeks, while the final phenotypic appearence will be taken only at 13-15 weeks.METHODS:Retrospective review of anatomy ultrasound examination carried out between 11/15 gestation in the population. Early sonografic findings were compared with the 18/22 weeks anatomy ultrasound and postnatal results. Were enrolled 328 women with singleton pregnancies at low risk subjected to ultrasound in the first trimester between March 2014 and September 2016.RESULTS:All 328 patients selectioned had a good echogenicity and the percentage of success in view of the bodies turns out to be high enough. Rate of visualization of the kidneys: 97%, Hands and feet: 100%; we note that the use of 3D techniques has allowed us to have a greater success in the head (100%), massive facial (100%), column (100%) and heart (87%). Thanks to the study of the angle of the genital tubercle was able to know the sex of the fetus early : there was a minimal error rate for sex determination. In the examination of the first trimester we detected 20 fetal malformation inclouding 12 cystis hygromas, 6 cardiac anomaly and 2 case of anencefaly.CONCLUSION:The obtained results are encouraging and show high detection rate and good visualization of fetal organs already at the end of the first trimester of pregnancy and a good ability to discriminate gender differences between the fetuses.