Effects of strict public health measures on seroprevalence of anti-SARS-CoV-2 antibodies during pregnancy.

INTRODUCTION: A substantial number of people infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain asymptomatic throughout the course of infection. Nearly half of pregnant women with coronavirus disease 2019 (COVID-19) are asymptomatic upon diagnosis; these cases are not without risk of maternal morbidity. Here, we investigated the seroprevalence of anti-SARS-CoV-2 antibodies in an unselected sample of pregnant women in Hong Kong. METHODS: This prospective cohort study included pregnant women who presented for routine Down syndrome screening (DSS) between November 2019 and October 2020; all women subsequently delivered at the booking hospitals. Serum antibodies against SARS-CoV-2 were analysed using a qualitative serological assay in paired serum samples taken at DSS and delivery for all participants. RESULTS: In total, 1830 women were recruited. Six women (0.33%) were seropositive at the DSS visit; this seropositivity persisted until delivery. Of the six women, none reported relevant symptoms during pregnancy; one reported a travel history before DSS and one reported relevant contact history. The interval between sample collections was 177 days (range, 161-195). Among women with epidemiological risk factors, 1.79% with travel history, 50% with relevant contact history, and 0.77% with community SARS-CoV-2 testing history, were seropositive. CONCLUSION: The low seroprevalence in this study suggests that strict public health measures are effective for preventing SARS-CoV-2 transmission. However, these measures cannot be maintained indefinitely. Until a highly effective therapeutic drug targeting SARS-CoV-2 becomes available, vaccination remains the best method to control the COVID-19 pandemic.

Relationship between viral load, infection-to-delivery interval and mother-to-child transfer of anti-SARS-CoV-2 antibodies.

OBJECTIVE: To investigate the association of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load and infection-to-delivery interval with maternal and cord serum concentrations of anti-SARS-CoV-2 immunoglobulin G (IgG) antibodies and transplacental transfer ratio in pregnant women with active or recovered SARS-CoV-2 infection. METHODS: This was a prospective case series of consecutive pregnant women with laboratory-confirmed SARS-CoV-2 infection between 27 March 2020 and 24 January 2021. We collected information regarding deep throat saliva or nasopharyngeal swab (NPS) reverse transcription polymerase chain reaction (RT-PCR) test results, serial cycle threshold (Ct) values at and after diagnosis, demographic, clinical and outcome data, and neonatal NPS RT-PCR results. Qualitative and quantitative analysis of IgG and immunoglobulin M (IgM) antibodies against SARS-CoV-2 was performed in maternal and cord blood serum samples obtained at delivery. Correlation of maternal Ct values, infection-to-delivery interval, infection duration and viral load area under the curve (AUC) with gestational age (GA) at diagnosis, maternal and cord serum IgG concentrations and transplacental transfer ratio of IgG were evaluated using Pearson's correlation. RESULTS: Twenty pregnant women who consented to participate and who had delivered their babies by 31 January 2021 were included in the study, comprising 14 who had recovered from coronavirus disease 2019 (COVID-19) and six with active infection at delivery. The median GA at clinical manifestation was 32.7 (range, 11.9-39.4) weeks. The median infection-to-delivery interval and infection duration were 41.5 (range, 2-187) days and 10.0 (range, 1-48) days, respectively. The median GA at delivery was 39.1 (range, 32.4-40.7) weeks and the median seroconversion interval was 14 (range, 1-19) days. Of 13 neonates born to seropositive mothers with recovered infection at delivery, 12 tested positive for anti-SARS-CoV-2 IgG. All neonatal NPS samples were negative for SARS-CoV-2 and all cord sera tested negative for IgM. The median transplacental transfer ratio of IgG was 1.3 (interquartile range, 0.9-1.6). There was a negative correlation between infection-to-delivery interval and anti-SARS-CoV-2 IgG concentrations in maternal (r = -0.6693, P = 0.0087) and cord (r = -0.6554, P = 0.0068) serum and a positive correlation between IgG concentration in maternal serum and viral load AUC (r = 0.5109, P = 0.0310). A negative correlation was observed between transfer ratio and viral load AUC (r = -0.4757, P = 0.0409). CONCLUSIONS: In pregnant women who have recovered from COVID-19, anti-SARS-CoV-2 IgG concentrations at delivery increased with increasing viral load during infection and decreased with increasing infection-to-delivery interval. The median transplacental transfer ratio of IgG was 1.3 and it decreased with increasing viral load during infection. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Second tier non-invasive prenatal testing in a regional prenatal diagnosis service unit: a retrospective analysis and literature review.

INTRODUCTION: The Hong Kong Hospital Authority has newly introduced a new Down's syndrome screening algorithm that offers free-of-charge non-invasive prenatal testing (NIPT) to women who screen as high risk. In preparation for this public-funded second tier NIPT service, the present study was conducted to retrospectively analyse women eligible for NIPT and to review the local literature. METHODS: Our retrospective study included women screened as high risk for Down's syndrome (adjusted term risk ≥1:250) during the period of 1 January 2015 to 31 December 2016. We performed descriptive statistics and multivariable logistic regression to examine the factors associated with women's choice between NIPT and invasive testing. We also reviewed existing local literature about second tier NIPT. RESULTS: The study included 525 women who screened positive: 67% chose NIPT; 31% chose invasive diagnostic tests; and 2% declined further testing. Our literature review showed that in non-research (self-financed NIPT) settings, NIPT uptake rates have been increasing since 2011. Nulliparity, first trimester status, higher education, maternal employment, and conception by assisted reproductive technology are common factors associated with self-financed NIPT after positive screening. Among women choosing NIPT, the rates of abnormal results have typically been around 8% in studies performed in Hong Kong. CONCLUSION: Implementation of second tier NIPT in the public setting is believed to be able to improve quality of care. We expect that the public in Hong Kong will welcome the new policy.

Factors associated with depression in people with epilepsy: a retrospective case-control analysis.

PURPOSE: This study investigated factors associated with depression in people with epilepsy. METHODS: All adult patients attending our epilepsy clinic in 2018 were screened for inclusion in this study. Eligible patients were divided into case and control groups, depending on the presence of co-morbid depression. Depressive disorders were diagnosed by a psychiatrist. Demographics and clinical characteristics, including epilepsy features and antiepileptic drug use, were compared between groups. The factors contributing to onset of depression after diagnosis of epilepsy were further analysed by binomial logistic regression. Statistical significance was set at P<0.05. RESULTS: Forty four patients with epilepsy who had depression and 514 patients with epilepsy who did not have depression were included in this study (occurrence rate=7.9%). Female sex (P=0.005), older age (P<0.001), temporal lobe epilepsy (P=0.01), and higher number of antiepileptic drugs used (P=0.003) were associated with depression in patients with epilepsy. No differences were observed in other epilepsy-related factors including aetiology, seizure type, and laterality of epileptic focus. Binomial logistic regression showed that female sex (P=0.01; odds ratio [OR]=3.56), drug-resistant epilepsy (P<0.001; OR=4.79), and clonazepam use (P<0.001; OR=14.41) were significantly positively associated with risk of depression after epilepsy diagnosis, whereas valproate use (P=0.03; OR=0.37) was significantly negatively associated with risk of depression. CONCLUSION: Female sex, refractoriness, and clonazepam use may be risk factors for depression after epilepsy diagnosis. Valproate may protect against depression in people with epilepsy. Better understanding of clinical features may aid in medical management or research studies regarding co-morbid depression in people with epilepsy.

Pre-hospital stroke screening and notification of patients with reperfusion-eligible acute ischaemic stroke using modified Face Arm Speech Time test.

OBJECTIVES: To investigate the effects of pre-hospital stroke screening and notification on reperfusion therapy for patients with acute ischaemic stroke. METHODS: Pre-hospital stroke screening criteria were established based on a modified version of the Face Arm Speech Time (FAST) test. Screening was performed during ambulance transport by emergency medical service (EMS) personnel who completed a 2-hour training session on stroke screening. Temporal trends affecting acute ischaemic stroke investigation and intervention were compared before and after implementation of the pre-hospital screening. RESULTS: From July 2018 to October 2019, 298 patients with suspected stroke were screened by EMS personnel during ambulance transport prior to hospital arrival. Of these 298 patients, 213 fulfilled the screening criteria, 166 were diagnosed with acute stroke, and 32 received reperfusion therapy. The onset-to-door time was shortened by more than 1.5 hours (100.6 min vs 197.6 min, P<0.001). The door-to-computed tomography time (25.6 min vs 32.0 min, P=0.021), door-to-needle time (49.2 min vs 70.1 min, P=0.003), and door-to-groin puncture time for intra-arterial mechanical thrombectomy (126.7 min vs 168.6 min, P=0.04) were significantly shortened after implementation of the pre-hospital screening and notification, compared with historical control data of patients admitted from January 2018 to June 2018, before implementation of the screening system. CONCLUSION: Implementation of pre-hospital stroke screening using criteria based on a modified version of the FAST test, together with pre-arrival notification, significantly shortened the door-to-reperfusion therapy time for patients with ischaemic stroke. Pre-hospital stroke screening during ambulance transport by EMS personnel who complete a 2-hour focused training session is effective for identifying reperfusion-eligible patients with stroke.

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.

Magnetic resonance imaging of the fetal brain.

INTRODUCTION: This review covers the recent literature on fetal brain magnetic resonance imaging, with emphasis on techniques, advances, common indications, and safety. METHODS: We conducted a search of MEDLINE for articles published after 2010. The search terms used were "(fetal OR foetal OR fetus OR foetus) AND (MR OR MRI OR [magnetic resonance]) AND (brain OR cerebral)". Consensus statements from major authorities were also included. As a result, 44 relevant articles were included and formed the basis of this review. RESULTS: One major challenge is fetal motion that is largely overcome by ultra-fast sequences. Currently, single-shot fast spin-echo T2-weighted imaging remains the mainstay for motion resistance and anatomical delineation. Recently, a snap-shot inversion recovery sequence has enabled robust T1-weighted images to be obtained, which is previously a challenge for standard gradient-echo acquisitions. Fetal diffusion-weighted imaging, diffusion tensor imaging, and magnetic resonance spectroscopy are also being developed. With multiplanar capabilities, superior contrast resolution and field of view, magnetic resonance imaging does not have the limitations of sonography, and can provide additional important information. Common indications include ventriculomegaly, callosum and posterior fossa abnormalities, and twin complications. There are safety concerns about magnetic resonance-induced heating and acoustic damage but current literature showed no conclusive evidence of deleterious fetal effects. The American College of Radiology guideline states that pregnant patients can be accepted to undergo magnetic resonance imaging at any stage of pregnancy if risk-benefit ratio to patients warrants that the study be performed. CONCLUSIONS: Magnetic resonance imaging of the fetal brain is a safe and powerful adjunct to sonography in prenatal diagnosis. It can provide additional information that aids clinical management, prognostication, and counselling.

Indications for and pregnancy outcomes of cervical cerclage: 11-year comparison of patients undergoing history-indicated, ultrasound-indicated, or rescue cerclage.

OBJECTIVES: To review and compare pregnancy outcomes of patients undergoing history-indicated, ultrasound-indicated, or rescue cerclage. DESIGN: Case series with internal comparison. SETTING: A regional obstetric unit in Hong Kong. PATIENTS: Women undergoing cervical cerclage at Kwong Wah Hospital between 1 January 2001 and 31 December 2011. INTERVENTIONS: Cervical cerclage. MAIN OUTCOME MEASURES: Pregnancy outcomes including miscarriage, gestational age at delivery, birth weight, and duration of pregnancy prolongation. RESULTS: Overall, 47 patients were included. Nine (19.1%) pregnancies resulted in miscarriage. The median gestational age at delivery was 35.7 weeks. Among the 23 patients who had history-indicated cerclage, only four (17.4%) had three or more previous second-trimester miscarriages or preterm deliveries. Among the 15 patients who had ultrasound-indicated cerclage, preoperative cervical length of ≤1.5 cm was associated with shorter prolongation of pregnancy, compared with that of >1.5 cm (median, 12.1 vs 18.4 weeks; P=0.009). Among the nine women who had rescue cerclage, those who underwent the procedure before 20 weeks of gestation delivered earlier than those underwent cerclage later (median, 22.5 vs 34.1 weeks; P=0.048). CONCLUSIONS: Patients eligible for the Royal College of Obstetricians and Gynaecologists-recommended history-indicated cerclage remain few. The majority of patients may benefit from serial ultrasound monitoring of cervical length with or without ultrasound-indicated cerclage.

Intensive care unit admission of obstetric cases: a single centre experience with contemporary update.

OBJECTIVES. To review the characteristics of a series of obstetric patients admitted to the intensive care unit in a regional hospital in 2006-2010, to compare them with those of a similar series reported from the same hospital in 1989-1995 and a series reported from another regional hospital in 1998-2007. DESIGN. Retrospective case series. SETTING. A regional hospital in Hong Kong. PATIENTS. Obstetric patients admitted to the Intensive Care Unit of Kwong Wah Hospital from 1 January 2006 to 31 December 2010. RESULTS. From 2006 to 2010, there were 67 such patients admitted to the intensive care unit (0.23% of total maternities and 2.34% of total intensive care unit admission), which was a higher incidence than reported in two other local studies. As in the latter studies, the majority were admitted postpartum (n=65, 97%), with postpartum haemorrhage (n=39, 58%) being the commonest cause followed by pre-eclampsia/eclampsia (n=17, 25%). In the current study, significantly more patients had had elective caesarean sections for placenta praevia but fewer had had a hysterectomy. The duration of intensive care unit stay was shorter (mean, 1.8 days) with fewer invasive procedures performed than in the two previous studies, but maternal and neonatal mortality was similar (3% and 6%, respectively). CONCLUSION. Postpartum haemorrhage and pregnancy-induced hypertension were still the most common reasons for intensive care unit admission. There was an increasing trend of intensive care unit admissions following elective caesarean section for placenta praevia and for early aggressive intervention of pre-eclampsia. Maternal mortality remained low but had not decreased. The intensive care unit admission rate by itself might not be a helpful indicator of obstetric performance.