I. Staboulidou

Fetal nasal bone in screening for trisomies 21, 18 and 13 and Turner syndrome at 11–13 weeks of gestation

To investigate the performance of first‐trimester screening for aneuploidies by including assessment of the fetal nasal bone in the combined test of maternal age, fetal nuchal translucency (NT) thickness, fetal heart rate (FHR) and serum free β‐human chorionic gonadotropin (β‐hCG) and pregnancy‐associated plasma protein‐A (PAPP‐A).

Hypertensive disorders in pregnancy: screening by uterine artery Doppler at 11–13 weeks

To examine the performance of screening for hypertensive disorders in pregnancy by a combination of the maternal factor‐derived a‐priori risk with the uterine artery (UtA) pulsatility index (PI) and to determine whether it is best in such screening to use the mean PI of the two arteries, the highest PI or the lowest PI.

Reference range of birth weight with gestation and first-trimester prediction of small-for-gestation neonates.

Firstly, to establish a reference range of birth weight with gestation at delivery; secondly, to identify maternal characteristics that are significantly associated with birth weight; and thirdly, to determine if combinations of maternal characteristics, fetal nuchal translucency thickness (NT), and serum concentrations of free beta‐human chorionic gonadotrophin (β‐hCG) and pregnancy‐associated plasma protein‐A (PAPP‐A) are significant predictors of small‐for‐gestational‐age (SGA) neonates in the absence of preeclampsia.

The 11-13-week scan: diagnosis and outcome of holoprosencephaly, exomphalos and megacystis

To determine the prevalence and outcome of fetuses with holoprosencephaly, exomphalos and megacystis diagnosed at 11–13 weeks of gestation.

Ductus Venosus Doppler at 11 to 13 Weeks of Gestation in the Prediction of Outcome in Twin Pregnancies

OBJECTIVE: To examine the independent contribution of abnormal flow in the ductus venosus at 11 to 13 weeks of gestation in the prediction of adverse pregnancy outcome in relation to chorionicity. METHODS: This was a prospective study in 516 dichorionic and 179 monochorionic twin pregnancies in which the fetal ductus venosus flow was assessed at 11 0/7 to 13 6/7 weeks of gestation. The prevalence of reversed a-wave in the fetal ductus venosus was compared between monochorionic and dichorionic pregnancies and between those with and without pregnancy complications. Comparisons between each of the pregnancy outcomes and the normal outcome group and between monochorionic and dichorionic pregnancies were made using the Mann-Whitney U-test for continuous variables and the χ2 test and Fisher exact test for categorical variables. RESULTS: The prevalence of reversed a-wave in at least one of the fetuses was significantly higher in monochorionic than in dichorionic pregnancies (18.4% compared with 8.3%, P<.001) and in pregnancies complicated by miscarriage (28.6%, P=.005), fetal aneuploidy (70.0%, P<.001), and twin–twin transfusion syndrome (38.5%, P<.001) compared with the pregnancies with two healthy live births (7.7%). Pregnancy outcome was normal in 33 of the 43 (76.7%) dichorionic and in 14 of the 33 (42.4%) monochorionic twins with reversed a-wave in at least one of the fetuses. CONCLUSION: In twins, reversed a-wave in the ductus venosus at 11 to 13 weeks of gestation is associated with increased risk for aneuploidies, miscarriage, and development of severe twin–twin transfusion syndrome. However, in about 75% of dichorionic twins and 40% of monochorionic twins with reversed a-wave, the pregnancy outcome is normal. LEVEL OF EVIDENCE: II

Screening for adverse pregnancy outcome by ductus venosus Doppler at 11-13(+6) weeks of gestation

OBJECTIVE: To estimate the independent contribution of abnormal flow in the ductus venosus at 11 to 13+6 weeks of gestation in the prediction of major fetal abnormalities and fetal death. METHODS: This was a prospective assessment of singleton pregnancies by maternal history, serum free β-hCG, pregnancy-associated plasma protein A (PAPP-A), fetal nuchal translucency thickness, and ductus venosus Doppler. The patients were subdivided into five groups: normal outcome (n=10,120), miscarriage or fetal death (n=185), abnormal karyotype (n=95), and major cardiac (n=20) or noncardiac defect (n=70). Regression analysis was performed to determine the significance of the contribution to adverse outcome of reversed a-wave in the ductus venosus, maternal characteristics, fetal delta nuchal translucency, maternal serum log PAPP-A multiples of the median, and log free β-hCG multiples of the median. RESULTS: The prevalence of reversed a-wave was significantly higher in the groups with miscarriage or fetal death (10.8%), abnormal karyotype (62.1%), and fetal cardiac defect (25.0%) than in the normal outcome group (3.7%), but not noncardiac defect (4.3%). An adverse outcome was observed in 2.7% of the fetuses with nuchal translucency at or below the 95th centile (in 2.6% of those with normal a-wave and in 7.0% of those with reversed a-wave) and in 19.3% of the fetuses with nuchal translucency above the 95th centile (in 8.9% of those with normal a-wave and in 70.9% of those with reversed a-wave). CONCLUSION: Reversed a-wave is associated with increased risk for chromosomal abnormalities, cardiac defects, and fetal death. However, in about 80% of cases with reversed a-wave, the pregnancy outcome is normal. LEVEL OF EVIDENCE II

Two-stage first-trimester screening for trisomy 21 by ultrasound assessment and biochemical testing

This study was carried out to examine the performance of a contingent policy in first‐trimester screening for trisomy 21, in which the estimated risk was first derived by a combination of maternal age, fetal nuchal translucency (NT) thickness, presence/absence of the nasal bone, blood flow in the ductus venosus or flow across the tricuspid valve, and biochemical testing was carried out only in those who were found to have an intermediate risk. We also examined the performance of a policy in which the estimated risk was first derived by a combination of maternal age and biochemical testing, and ultrasound examination was carried out only in those with an intermediate risk.

First trimester aneuploidy screening in the presence of a vanishing twin: implications for maternal serum markers

To assess the impact of a vanishing twin on the levels of the biochemical markers used in the first trimester aneuploidy screening.

Isolated single umbilical artery and fetal karyotype

To determine the need for fetal karyotyping in cases of an isolated single umbilical artery (SUA) identified during the second‐trimester routine anomaly scan.

First-Trimester Uterine Artery Doppler and Serum Pregnancy-Associated Plasma Protein-A in Preeclampsia and Chromosomal Defects

Objective: We examined the potential value of the uterine artery pulsatility index (PI) in pregnancies with fetal aneuploidies and in those that developed preeclampsia (PE) with the aim of distinguishing between these complications in pregnancies with low pregnancy-associated plasma protein-A (PAPP-A). Methods: Uterine artery PI and serum PAPP-A at 11–13 weeks were measured in 165 cases of PE, including 33 that required delivery before 34 weeks (early PE) and 132 with late PE, and in 301 cases with aneuploidies, including 200 with trisomy 21. Each case of aneuploidy and PE was matched with 4 unaffected controls. Results: Serum PAPP-A was lower in early PE (0.58 multiples of the normal median, MoM) and in trisomy 21 (0.54 MoM), trisomy 18 (0.22 MoM) and Turner syndrome (0.51 MoM) – but not in late PE (0.90 MoM) – than in controls (1.01 MoM). Uterine artery PI was higher in early PE (1.52 MoM), late PE (1.20 MoM), trisomy 18 (1.20 MoM) and Turner syndrome (1.29 MoM) – but not in trisomy 21 (1.02 MoM) – than in controls (1.0 MoM). Conclusion: The uterine artery PI at 11–13 weeks may be useful in distinguishing between low PAPP-A due to trisomy 21 and early PE.