Three-dimensional versus two-dimensional ultrasound for fetal nasal bone evaluation in the second trimester.

OBJECTIVES: To compare two-dimensional with three-dimensional ultrasound evaluation of the fetal nasal bone in the second trimester. METHODS: A prospective, non-interventional study was conducted, in 55 singleton fetuses, between 18 and 24 weeks' gestation. Fetal nasal bone length was measured in the midsagittal plane by two-dimensional imaging and in the midsagittal and coronal plane with three-dimensional ultrasound. All three measurements were compared with one another using one-way repeated samples-measures ANOVA and paired samples t-test. RESULTS: The average fetal nasal bone length (mean ± SD) as determined by the three methods was 7.01 ± 0.94 mm for the two-dimensional midsagittal, 6.96 ± 1.34 mm for the three-dimensional midsagittal, and 6.98 ± 1.32 mm for the three-dimensional coronal plane; comparisons between one another were not statistically significant. Unilateral hypoplasia and bifid shape of the fetal nasal bone were detected in 8.2% and 20.4% of cases, respectively, by three-dimensional ultrasound, whereas all cases evaded detection with two-dimensional ultrasound (p < 0.001 and p = 0.001, respectively). CONCLUSIONS: Fetal nasal bone length measured with two-dimensional ultrasound does not differ significantly from three-dimensional measurements. However, three-dimensional ultrasound is superior in detecting unilateral nasal bone hypoplasia or absence and in assessing fetal nasal bone shape. Hence, fetal nasal bone examination in the second trimester should include three-dimensional ultrasound evaluation.

Apert syndrome: the current role of prenatal ultrasound and genetic analysis in diagnosis and counselling.

Apert syndrome is a rare congenital malformation syndrome characterized by the triad of cutaneous and progressive bony syndactyly, midfacial hypoplasia and craniosynostosis. Two missense mutations of the gene encoding the fibroblast growth factor receptor 2 (FGFR2) have been implicated in most cases. We report a case of Apert syndrome detected on prenatal ultrasound. Postnatal genetic analysis showed, for the first time, that the previously reported P253R mutation of the FGFR2 gene is also prevalent in southeast Europe. After prenatal sonographic detection of anomalies suggestive of Apert syndrome, parents should be counselled about prognosis and risk of recurrence, and the option of amniocentesis should be offered.

Fetal abdominal subcutaneous tissue thickness measured by ultrasound at term is associated with birth weight and mode of delivery.

PURPOSE: To determine if measurement of fetal abdominal subcutaneous tissue thickness (FASTT) at term can predict birth weight, mode of delivery and perinatal outcome. METHODS: A prospective study with 352 normal, singleton pregnancies in the vertex presentation examined with real-time ultrasound at 37-39 weeks' gestation. RESULTS: FASTT was positively correlated with birth weight (Pearson's, r = 0.784, p < 0.001). Fetuses with low FASTT were more likely to be delivered through normal vaginal delivery (7.8 +/- 0.1 mm), while higher FASTT was correlated with operative vaginal delivery (7.9 +/- 0.2 mm) and cesarean section (8.6 +/- 0.3 mm) (ANOVA, p = 0.034). In contrast, FASTT was not correlated with intrapartum CTG, labor duration and Apgar scores. CONCLUSIONS: In normal pregnancies, FASTT at term is positively associated with birth weight. With increasing FASTT the likelihood of operative vaginal and cesarean delivery increases. FASTT is not associated with perinatal outcome.

Nuchal cord detected by ultrasound at term is associated with mode of delivery and perinatal outcome.

OBJECTIVES: To evaluate the clinical relevance of nuchal cord in normal, vertex, singleton pregnancies at term, and its effect on mode of delivery and perinatal outcome. STUDY DESIGN: Prospective study with 352 normal, singleton pregnancies, with fetuses in the vertex presentation, examined with real-time ultrasound at 37-39 weeks. Health care workers at labour and delivery blinded to previous detection of nuchal cord. RESULTS: Fetuses of nulliparous women with a nuchal cord were more likely to be delivered with operative vaginal or caesarean delivery (n = 153, p < 0.0001). This was not the case with higher parity (n = 199, p = 0.07). There was no difference between nuchal cord (n = 144) and control groups (n = 208) in amniotic fluid quantity at 37-39 weeks (p = 0.554) or intrapartum CTG (p = 0.9). On the other hand, nuchal cord group had lower Apgar scores at 1 and 5 min (p = 0.001 and 0.027 respectively); this difference remained significant when adjusted for birth weight (p = 0.001 and 0.016), but disappeared when adjusted for mode of delivery (p = 0.048 and 0.319). CONCLUSIONS: Nuchal cord in normal pregnancies at term is associated with increased rate of operative vaginal and caesarean delivery in nulliparae. The presence of a nuchal cord results in slightly lower Apgar scores at 1 and 5 min, mainly as a consequence of higher operative delivery rates.