Comparisons of first and second trimester screening for fetal anomalies

Ann N Y Acad Sci. 1998 Jun 18;847:200-9. doi: 10.1111/j.1749-6632.1998.tb08941.x.


Four thousand fifty unselected pregnant women bearing a total of 4,078 fetuses were examined by transvaginal sonography (TVS) at 14 weeks of gestational age and rescreened via transabdominal sonography (TAS) at 21 weeks. Fifty-four of 88 anomalies were correctly identified at first scan whereas 34 were not; of these, 24 were discovered at second trimester rescreening, and the remaining 10 were observed later in pregnancy or after birth. The sensitivity of TVS screening with respect to final outcome was 61.4% (54 of 88 malformations in total) and 69.2% in comparison to TAS screening results (54 malformations detected among 78 recognized within 21 weeks). The association between fetal malformation and chromosomal aberrations was also investigated: in our study population there were 21 aneuploidies, 14 of which were recognized because of abnormal findings at the 14 weeks' TVS, 5 at the TAS rescreening, and 2 after birth in neonates free of structural abnormalities.

Publication types

  • Comparative Study

MeSH terms

  • Chromosome Aberrations
  • Congenital Abnormalities / diagnostic imaging*
  • Congenital Abnormalities / genetics
  • False Negative Reactions
  • Female
  • Fetus / abnormalities*
  • Humans
  • Infant, Newborn
  • Pregnancy
  • Pregnancy Trimester, First
  • Pregnancy Trimester, Second
  • Sensitivity and Specificity
  • Ultrasonography, Prenatal* / instrumentation
  • Ultrasonography, Prenatal* / methods
  • Vagina