First trimester screening for pre-eclampsia in Chinese pregnancies: case-control study.

OBJECTIVE: To assess the potential of screening for pre-eclampsia (PE) in a Chinese population. DESIGN: Case-control study. SETTING: Teaching hospital in Hong Kong. POPULATION: A total of 3330 women having a viable singleton pregnancy attending first-trimester Down-syndrome screening. METHODS: Mean arterial pressure (MAP), bilateral uterine artery pulsatility index (UtA-PI), and placental growth factor (PlGF) were measured. Screening markers were transformed to multiples of the gestational median (MoM) and adjusted for maternal and pregnancy characteristics. MoM distributions in PE and non-PE pregnancies were compared with published expected values. PE screening performance was assessed using area under receiver operating curves (AUROC). MAIN OUTCOME MEASURES: PE detection rate. RESULTS: A total of 30 (0.9%) women developed either early (<34 weeks) or late (≥34 weeks) onset PE. MAP was dependent on maternal BMI, UtA-PI on fetal crown rump length, uterine artery peak systolic velocity (UtA-PSV) on maternal age and gestation, and PlGF on gestation in non-PE pregnancies. MoM distributions determined using published Fetal Medicine Foundation models deviated significantly from one for both MAP (P < 0.0001) and PI (P < 0.0001), but not PlGF (P = 0.52) in non-PE pregnancies, whilst PlGF MoM distributions in those who developed early as opposed to late onset PE were significantly higher (P = <0.05). AUROC for any PE using multiple markers was 0.72 (95% CI: 0.64-0.81) with detection rates of 72 and 55% for early and late PE, respectively, for a 10% false positive rate. CONCLUSION: Detection rates for PE in our Chinese population were lower than the expected 90-95% even after adjusting MoM for local women's characteristics. FUNDING: General Research Fund (Project number 470513). TWEETABLE ABSTRACT: Pre-eclampsia screening in the Chinese population had detection rates lower than previously published results.

Women's preference for non-invasive prenatal DNA testing versus chromosomal microarray after screening for Down syndrome: a prospective study.

OBJECTIVE: To examine preferences for follow-up testing in women screened with high or intermediate risk for Down syndrome in the first or second trimester. DESIGN: Prospective cohort study. SETTING: Three public hospitals in Hong Kong, China. SAMPLE: Women with pregnancies termed as high risk (≥1:250; HR) or intermediate risk (1:251-1200; IR) for Down syndrome. METHODS: Women with pregnancies screened as HR were offered the choices of: (1) an invasive test plus chromosomal microarray (CMA) to obtain more detailed fetal genetic information; (2) non-invasive cell-free prenatal DNA screening (NIPT) to detect trisomies 13, 18 and 21, and to avoid procedure-related miscarriage; and (3) to decline any further testing. Women received standardised counselling informing them that the reporting times were identical, the procedure miscarriage risk was 0.1-0.2% and that there was no charge for screening. Women with IR pregnancies (1:251-1200) were offered NIPT as a secondary screening test. MAIN OUTCOME MEASURES: Uptake rate for NIPT. RESULTS: Three hundred and forty-seven women had pregnancies deemed as HR; 344 (99.1%) women opted for follow-up testing, 216 (62.2%) of whom chose NIPT. Five hundred and seven of 614 women (82.6%) with IR risk chose NIPT. Seven (21%) of 34 women with nuchal translucency ≥3.5 mm opted for NIPT. CONCLUSION: In a setting where reporting times are similar and there is no cost difference between options, approximately 60% of women with pregnancies classed as HR would opt for NIPT, offering simple but limited aneuploidy assessment, over a diagnostic procedure with comprehensive and more detailed assessment. TWEETABLE ABSTRACT: 60% of pregnant Chinese women prefer NIPT over CMA when screened as high risk for Down syndrome.

Impact of replacing Chinese ethnicity-specific fetal biometry charts with the INTERGROWTH-21(st) standard.

OBJECTIVE: To assess the impact of adopting the INTERGROWTH-21(st) biometry standards in a Chinese population. DESIGN: Retrospective cohort study. SETTING: A teaching hospital in Hong Kong. POPULATION: A total of 10 527 Chinese women with a singleton pregnancy having a second- or third-trimester fetal anomaly or growth scan between January 2009 and June 2014. METHODS: Z-scores were derived for fetal abdominal circumference (AC), head circumference (HC), and femur length (FL) using the INTERGROWTH-21(st) and Chinese biometry standards. Pregnancies with aneuploidy, structural or skeletal abnormalities, or that developed pre-eclampsia were excluded. Z-scores were stratified as <2.5th, <5th, <10th, >90th, >95th, or >97.5th percentile. Birthweight centile, adjusted for gestation and gender, was categorised as ≤3rd, 3rd to ≤5th, 5th to ≤10th, and >10th. Pairwise comparison and the McNemar test were performed to assess biometry Z-score differences and concordance between the INTERGROWTH-21(st) and Chinese standards. MAIN OUTCOME MEASURES: The sensitivity of both the local and INTERGROWTH-21(st) AC standards to identify pregnancies that were small-for-gestational-age (SGA) was assessed. RESULTS: INTERGROWTH-21(st) AC, HC, and FL Z-scores were significantly lower than those obtained using our local reference for AC, HC, and FL (P < 0.0001 for all). The proportion of fetuses with biometry in the <2.5th, <5th, <10th, >90th, >95th, or >97.5th percentiles was statistically significant (P < 0.01 for all). A total of 1224 (15.5%) of the scans at 18-22 weeks of gestation had AC, HC, or FL below the 3rd percentile of the INTERGROWTH-21(st) standard. CONCLUSIONS: Adopting the INTERGROWTH-21(st) standard would lead to a significant number of fetuses being at risk of misdiagnosis for small fetal size, particularly when using HC and FL measures. TWEETABLE ABSTRACT: INTERGROWTH-21(st) biometry assessment in Chinese leads to fetuses being at risk of misdiagnosis of small fetal size.