First Trimester Preeclampsia Screening and Prevention:Perspective in Chinese Mainland

Preeclampsia(PE),a multisystem disorder in pregnancy,is one of the leading causes of perinatal morbidity and mortality that poses financial and physical burdens worldwide.Preterm PE with delivery at<37 weeks of gestation is associated with a higher risk of adverse maternal and perinatal outcomes than term PE with delivery at≥37 weeks of gestation.A myriad of first trimester screening models have been developed to identifying women at risk of preterm PE.In fact,the Fetal Medicine Foundation(FMF)first trimester prediction model has undergone successful internal and external validation.The FMF triple test enables the estimation of patient-specific risks,using Bayes theorem to combine maternal characteristics and medical history together with measurements of mean arterial pressure,uterine artery pulsatility index,and serum placental growth factor.Establishing a quality control process for regular monitoring and to ensure data standardization,reliability,and accuracy is key to maintaining optimal screening performance.The rate of preterm PE can be reduced by 62%by using the FMF prediction model,followed by the administration of low-dose aspirin.Recent evidence has also demonstrated that metformin has the potential for preventing PE in patients at high-risk of the disorder.In this article,we will summarize the existing literature on the different screening methods,different components of risk assessment,therapeutic interventions,and clinical implementation of the first trimester screening and prevention program for PE with specific considerations for Chinese mainland.

Cross-Sectional Survey of Views on COVID-19 and Its Vaccines Among Pregnant Women

Objective:The objective of this study is to evaluate the acceptance of pregnant women with regards to coronavirus disease 2019 (COVID-19) vaccination during pregnancy and to identify any significant changes in their anxiety and knowledge on COVID-19 compared to our previous study.Methods:This cross-sectional survey was performed in the antenatal clinics of United Christian Hospital and Tseung Kwan O Hospital of Hong Kong,China.Questionnaires were distributed to pregnant women for self-completion when attending follow-up from August to October 2021.Apart from basic demographic data,the questionnaire comprised of questions including knowledge on COVID-19 and its vaccines in pregnancy as well as attitudes and behaviors of pregnant women and their partners toward COVID-19.Continuous variables were analyzed by Student’s test and Levene’s test was used to confirm normal distribution and homogeneity of variance for continuous variables,whereas categorical variables were analyzed by the Chi-squared test or Fisher’s exact test as appropriate.AP value of <0.05 was considered to be statistically significant.Results:A total of 816 completed questionnaires were included for analysis.Pregnant women were less worried about COVID-19 in the current survey as compared to the last survey (393/816,48.2%vs.518/623,83.1%,P<0.001).Fewer pregnant women believed that pregnancy were more susceptible to contract SARS-CoV-2 as compared to the last survey (265/816,32.5%vs.261/623,41.9%,P<0.001).They have significant knowledge gap and concerns about COVID-19 vaccines.Nearly half of the participants believed that pregnant women cannot have COVID-19 vaccination (402/816,49.3%) and it is unsafe to fetus (365/816,44.7%).Around a third of women perceived that they were more prone to the side effects and complications of COVID-19 vaccines than the general population (312/816,38.2%) and did not recognize that maternal COVID-19 vaccination could effect transferral of antibodies to the fetus to promote postnatal passive immunity (295/816,36.2%).Most of them had not been vaccinated (715/816,87.6%) and only (12/715) 1.7% of them would consider vaccination during pregnancy.Conclusion:Despite the local and international recommendations for pregnant women to be vaccinated,the uptake of COVID-19 vaccines during pregnancy remained extremely low.Efforts should be made to effectively provide information about the safety and benefits of COVID-19 vaccines during pregnancy.There is an urgent need to booster vaccination rates in pregnant women to avoid excessive adverse pregnancy outcomes related to COVID-19.

Screening and Prevention of Preeclampsia

Preeclampsia(PE)is a multisystem disorder of pregnancy classically characterized by hypertension with significant proteinuria after 20 weeks'gestation.This disorder is one of the leading causes of maternal and perinatal morbidity and mortality.PE can be subdivided into preterm PE(with delivery at<37 weeks'gestation)and term PE(with delivery at≥37 weeks'gestation).Preterm PE is associated with a higher risk of adverse maternal and perinatal outcomes than term PE.Traditional method of screening as recommended by professional guidelines has limited predictive performance and therefore should be updated to reflect recent scientific evidence that the target of screening should be preterm PE,the best way to identify the high-risk group is the Bayes-based method that combines maternal risk factors and biomarkers,the threshold should be set at screen positive rate of 10%,aspirin should be started before 16 weeks'gestation,and the daily dose should be higher than 100mg.

First Trimester Screening for Preeclampsia:An Asian Perspective

Preeclampsia(PE)is one of the leading causes of maternal and perinatal morbidity and mortality worldwide.This disorder has profound short-term and long-term impacts on both the affected woman’s and her child’s health.Early-onset PE requiring preterm delivery(preterm PE)is of particular importance because it is associated with a higher risk of adverse pregnancy outcomes than term PE.First trimester screening model developed by the Fetal Medicine Foundation(FMF),which uses Bayes-theorem to combine maternal characteristics and medical history together with measurements of mean arterial pressure,uterine artery pulsatility index,and serum placental growth factor,has been proven to be effective and have superior screening performance to that of traditional risk factor-based approach for the prediction of PE.Identification of high risk pregnant women for preterm PE and giving aspirin prophylaxis before 16^(th)week of gestation would reduce the incidence of preterm PE.In Asia,although the prevalence of PE is slightly lower than the global estimation,early screening and prevention of this life-threatening condition is still crucial.The FMF Bayestheorem based screening method has been validated in a large-scale prospective Asia-wide study and revealed that the first trimester triple test achieves the highest detection rate,compared with the traditional risk factor-based approaches,and that the screening performance is comparable to the published data from the FMF in East Asian women.However,in order to achieve optimal screening performance,the key is to establish standardized methods for biomarker measurements and regular biomarker quality assessment,as each biomarker is susceptible to inaccurate measurement,thus affecting performance of screening.Furthermore,it is of great importance to emphasize that the optimal preventive effect of aspirin on preterm PE is clearly associated with good compliance to treatment.In conclusion,global implementation of an effective first trimester“screen and prevent”program for preterm PE would provide the opportunity to reduce the risk of both short-term maternal and perinatal morbidity and mortality,with the possibility of intergenerational prevention of future chronic diseases for both the mother and her offspring.

How Different Are Diverse Populations inScreening for Preeclampsia?

There is a big question on the level of differences between diverse populations.Genetically speaking,a pair of random individuals from two different populations can be more similar than two random individuals from any single population.1 The human genome project was key in showing how similar all humans are,describing that although humans may have different haplotypes,haplotype frequencies,and to some extent,different combinations of alleles,both common and rare haplotypes are often shared across populations.2 Studies in very different populations,such as Europeans,sub-Saharan Africans,and East Asians,have shown that complex phenotypes influenced primarily by rare alleles may correspond poorly with population labels and other population-typical traits.