G. S. H. Yeo

Association of maternal vitamin D status with glucose tolerance and caesarean section in a multi-ethnic Asian cohort: the growing up in Singapore towards healthy outcomes study

Objective Epidemiological studies relating maternal 25-hydroxyvitamin D (25OHD) with gestational diabetes mellitus (GDM) and mode of delivery have shown controversial results. We examined if maternal 25OHD status was associated with plasma glucose concentrations, risks of GDM and caesarean section in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) study. Methods Plasma 25OHD concentrations, fasting glucose (FG) and 2-hour postprandial glucose (2HPPG) concentrations were measured in 940 women from a Singapore mother-offspring cohort study at 26–28 weeks’ gestation. 25OHD inadequacy and adequacy were defined based on concentrations of 25OHD ≤75nmol/l and >75nmol/l respectively. Mode of delivery was obtained from hospital records. Multiple linear regression was performed to examine the association between 25OHD status and glucose concentrations, while multiple logistic regression was performed to examine the association of 25OHD status with risks of GDM and caesarean section. Results In total, 388 (41.3%) women had 25OHD inadequacy. Of these, 131 (33.8%), 155 (39.9%) and 102 (26.3%) were Chinese, Malay and Indian respectively. After adjustment for confounders, maternal 25OHD inadequacy was associated with higher FG concentrations (β = 0.08mmol/l, 95% Confidence Interval (CI) = 0.01, 0.14), but not 2HPPG concentrations and risk of GDM. A trend between 25OHD inadequacy and higher likelihood of emergency caesarean section (Odds Ratio (OR) = 1.39, 95% CI = 0.95, 2.05) was observed. On stratification by ethnicity, the association with higher FG concentrations was significant in Malay women (β = 0.19mmol/l, 95% CI = 0.04, 0.33), while risk of emergency caesarean section was greater in Chinese (OR = 1.90, 95% CI = 1.06, 3.43) and Indian women (OR = 2.41, 95% CI = 1.01, 5.73). Conclusions 25OHD inadequacy is prevalent in pregnant Singaporean women, particularly among the Malay and Indian women. This is associated with higher FG concentrations in Malay women, and increased risk of emergency caesarean section in Chinese and Indian women.

The amniotic sheet: a truly benign condition?

Amniotic sheets are the result of uterine synechiae that have been encompassed by the expanding chorion and amnion. Radiologically they are seen as ‘shelves’ in the amniotic cavity. The benign nature of such amniotic sheets has been documented in many case series in the literature. The objective of this study was to determine the characteristics (if any) of amniotic sheets that predict fetal outcome.

Prediction of neonatal respiratory morbidity by quantitative ultrasound lung texture analysis: a multicenter study

BACKGROUND: Prediction of neonatal respiratory morbidity may be useful to plan delivery in complicated pregnancies. The limited predictive performance of the current diagnostic tests together with the risks of an invasive procedure restricts the use of fetal lung maturity assessment. OBJECTIVE: The objective of the study was to evaluate the performance of quantitative ultrasound texture analysis of the fetal lung (quantusFLM) to predict neonatal respiratory morbidity in preterm and early‐term (<39.0 weeks) deliveries. STUDY DESIGN: This was a prospective multicenter study conducted in 20 centers worldwide. Fetal lung ultrasound images were obtained at 25.0–38.6 weeks of gestation within 48 hours of delivery, stored in Digital Imaging and Communication in Medicine format, and analyzed with quantusFLM. Physicians were blinded to the analysis. At delivery, perinatal outcomes and the occurrence of neonatal respiratory morbidity, defined as either respiratory distress syndrome or transient tachypnea of the newborn, were registered. The performance of the ultrasound texture analysis test to predict neonatal respiratory morbidity was evaluated. RESULTS: A total of 883 images were collected, but 17.3% were discarded because of poor image quality or exclusion criteria, leaving 730 observations for the final analysis. The prevalence of neonatal respiratory morbidity was 13.8% (101 of 730). The quantusFLM predicted neonatal respiratory morbidity with a sensitivity, specificity, positive and negative predictive values of 74.3% (75 of 101), 88.6% (557 of 629), 51.0% (75 of 147), and 95.5% (557 of 583), respectively. Accuracy was 86.5% (632 of 730) and positive and negative likelihood ratios were 6.5 and 0.3, respectively. CONCLUSION: The quantusFLM predicted neonatal respiratory morbidity with an accuracy similar to that previously reported for other tests with the advantage of being a noninvasive technique.

Validation of First Trimester Screening for Trisomy 21 in Singapore with Reference to Performance of Nasal Bone

Introduction: The aim of this study is to describe the performance of first trimester screening (FTS) for trisomy 21 using maternal age, serum biochemistry and fetal nuchal translucency (NT) in a single center and to evaluate the effect of nasal bone on screening performance. Material and Methods: In 12,585 singleton pregnancies, the NT and nasal bone were examined. The majority of these mothers also had their serum biochemical markers analyzed. Risk was computed using different combinations of maternal age, biochemistry, NT and nasal bone. Down syndrome cases were confirmed by karyotyping. Results: There were 12,519 normal pregnancies, 31 with trisomy 21 and 35 with other chromosomal abnormalities. Without considering the nasal bone, the combined FTS detected 87.1% of trisomy 21 fetuses (false positive rate 5.1%), using 1:300 as the risk threshold, and this was further improved to 96.8% with the policy that classifies all fetuses with an absent nasal bone as high risk. Subgroup analysis showed that the detection rate would be 90.9%, with a false positive rate of 3.7%, if nasal bone was incorporated in the risk algorithm, compared to 81.8% and a false positive rate of 5.4% if it was not used. Discussion: FTS is very effective in early detection of trisomy 21 in Singapore. The nasal bone is a useful marker that can substantially improve the screening performance.

Evaluation of an objective method of image assessment for first-trimester nasal bone

To evaluate the degree of agreement in first‐trimester nasal bone assessment in a group of sonographers before and after training, using a semi‐quantitative scoring system.

P32.02: Validation study of endocervical length measurements at first trimester

Introduction: survival of a normal fetus to term in the presence of hydatidiform mole remains an extremely uncommon occurrence. Prenatal diagnosis is possible by ultrasonography showing molar invasion of the normal placenta without clear margin. Antenatal detection of mole co existing with a viable fetus should warrant genetic analysis and search for gross malformation of the fetus. Case report: we report a rare case exhibiting molar pregnancy and a coexisting normal fetus. A 29 year, primigravida had an episode of vaginal bleeding at 18 weeks which suggested avascular lower placenta with multiple cystic area measuring 12 × 5 × 9 cm with normal fetus. She had two weekly growth scan and Doppler as diagnosis was not clear. It was thought to be multiple placental lakes. Growth and Doppler remains normal and had term SVD. Placenta was sent for histopathology which suggested normal placenta with an area of complete hydatidiform mole. It was difficult to differentiate from mosaic CHM, twin with normal co-twin and CHM. Discussion: coexistent live fetus and molar placenta has never been reported. Complications including pre-eclampsia, hyperthyroidism, vaginal bleeding, persistent gestational trophoblastic disease, preterm labour, miscarriage and anaemia increases. Several factors may influence the outcome in partial mole such as karyotype of the fetus, size of the molar placenta, the speed of molar degeneration and fetal anaemia.

P32.03: Reference range and change of endocervical length throughout pregnancy

14 weeks of gestation using transvaginal ultrasonography. Particular attention was paid to differentiate the enodcervix from the isthmus. The distribution of the endocervical lengths was compared with existing publications. An experienced sonographer also classified all images according to the degree of difficulty in visualizing the endocervix. The association between echogenicity of endocervical mucosa, parity and degree of difficulty in measurement was analysed. Results: The median, 5th and 95th percentiles of the endocervix during first trimester were 3.32 cm, 2.45 cm and 4.58 cm, respectively and were similar to the data from recent publications. It was noted that the proportion of images rated as ‘‘difficult to visualize’’ was highest in women with hyperechoic mucosa, as well as those who are multiparous. However, this trend was not statistically significant. Conclusions: The measurement of the endocervical length described in the literature is reproducible in our local population producing similar statistical values and distribution to publication from Greco et al. Technically it seems more challenging to measure the endocervical length in those women with hyperechoic endocervical mucosa and in multiparous women.

P14.05: Obstetric outcome associated with amniotic sheets

Results: The gestation at delivery was later by 3.5 days for the GDM group (P = 0.0005) with no difference in birth weights. The one perinatal mortality was a fetus terminated at 20+6 weeks for trisomy 13. There were fewer caesarean deliveries in those women with diet controlled GDM than in women taking insulin (34% vs. 48% P = 0.005), fewer instrumental deliveries (9 vs. 22 P = 0.028) and fewer admissions to SCN (1 vs. 16 P < 0.001). There were no differences in birth weight, shoulder dystocia, admissions to NICU or 5 minute Apgar scores ≤ 7. The majority of women in both groups delivered without needing induction of labour (70% and 56%). Conclusions: Our approach in the management of diabetes in pregnancy was associated with good outcomes for a cohort of 390 women managed in our unit over a 2-year period. The majority of women in both groups delivered before the need for induction of labour.

P15.05: Ultrasound features of an anomaly of the umbilico‐portal system—a case report

examination showed no further anomalies, especially no craniofacial, urogenital, heart or lung malformations. Therefore, our case concerned a Tetra-amelia, and not a tetra-Amelia syndrome. Tetra-Amelia syndrome is described to be caused by a homozygous WNT3-gene mutation in only one consanguineous family. DNAanalysis of this gene was therefore not performed. The autosomal recessive Roberts syndrome is characterized by tetraphocomelia and is clinically variable. DNA-analysis of the ESCO2-gene was performed. No pathological mutations were found in this gene. In this case the couple was counselled for a low recurrence rate. Meanwhile, a new pregnancy occurred and the prenatal scan at 16 weeks showed normal limbs.

P03.05: Report of a case of right ductus arteriosus in a fetus with right aortic arch

Objectives: To evaluate the diagnostic accuracy of prenatal screening for congenital heart diseases (CHD) based on the combination of the four-chamber view and the three-vessel view in an unselected population. Methods: A prospective study on 8025 scanned fetuses was performed. All singleton pregnancies scheduled for a routine prenatal ultrasound screening at 20–24 weeks’ gestation and subsequently delivered within our unit were included. Data were recorded regarding visualization of the four-chamber view, the outflow tracts and the three-vessel view. Suspected CHD was confirmed by postmortem or postnatal echocardiography. We obtained the followup data of the newborns and calculated the diagnostic accuracy of the test. Results: Major CHD were identified in 32 cases (4.0‰) of which 26 cases (81.3%) were diagnosed antenatally and 6 postnatally. Four cases were false positive. Twenty-one cases were identified by the four-chamber view and five as a result of the abnormal three-vessel view. The sensitive of the four-chamber view alone was 65.6% (17/32), and the specificity was 99.9%. The sensitivity of the combination of the four-chamber view and the three-vessel view was 81.3% (26/32), and the specificity was 99.9%. Conclusions: The three-vessel view is reliable and easy methods to be used in a routine antenatal clinic, along with the four-chamber view. *This project was funded by Beijing Municipal Science and Technology Commission Foundation grant D0906005000091.