Objective::To report the clinical maternal and fetal outcomes of pregnant women with coronavirus disease 2019 (COVID-19), along with any associated pregnancy complications, in Hong Kong, China, and to assess the impact of COVID-19 vaccination on these outcomes.Methods::This prospective registry-based observational study included pregnant women who were recruited through convenient sampling and had a laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection with a cycle threshold (Ct) value result available on admission to eight local hospitals in Hong Kong, China. Data on clinical symptoms, laboratory results, medical treatments, delivery timing and mode, and pregnancy complications were extracted from the Hospital Authority’s electronic medical record system. Maternal, fetal, and pregnancy outcomes were compared between unvaccinated pregnant women with COVID-19 and those who had received at least one dose of COVID-19 vaccine before diagnosis. Nonparametric continuous variables and categorical variables were analyzed using the Mann-Whitney U test and the Pearson’s chi-squared test respectively. A P value less than 0.05 was considered statistically significant. Results::A total of 164 pregnant women were included, of whom 78 (47.56%) were nulliparous. COVID-19 was diagnosed before 28 weeks’ gestation in 30 (18.29%), while 134 (81.71 %) were diagnosed at or after 28 weeks’ gestation. Sixty-two (37.80%) women received at least one dose of COVID-19 vaccine. There were no significant differences between vaccinated and unvaccinated groups in the time interval between COVID-19 diagnosis and delivery, the Ct value, and the gestational age at infection onset or delivery ( P > 0.05). The majority of women were symptomatic at diagnosis regardless of vaccination status (55 (88.71%) in vaccinated group vs. 78 (76.47%) in unvaccinated group ( P = 0.052). Symptoms did not significantly differ between groups except for cough (62.90% vs. 47.06%, P = 0.049). The overall rate of severe COVID-19 in pregnant women was low. In total, 5 (3.05%) patients experienced severe COVID-19, with vaccinated patients more likely to receive low molecular weight heparin (LMWH) as part of their treatment (62.90% vs. 42.16%, P = 0.010). Ninety-two (56.10%) women had a spontaneous vaginal delivery, 7 (4.27%) had an instrumental delivery, and 44 (26.83%) and 21 (12.80%) underwent emergency and elective cesarean sections respectively. For fetal outcomes, 14 (8.48%) babies were born preterm and four (2.65% of nonpreterm babies, n = 151) had low birthweight. The median birthweight percentile was 52.18 th. There were no statistically significant differences in pregnancy complications or fetal outcomes between vaccinated and unvaccinated groups. Conclusion::The overall rate of severe COVID-19 in pregnant women was low. COVID-19 vaccination did not significantly impact maternal outcomes, except for the use of LMWH. Additionally, the study found no significant differences in fetal outcomes and pregnancy complications between vaccinated and unvaccinated individuals.

Objective::To report the clinical maternal and fetal outcomes of pregnant women with coronavirus disease 2019 (COVID-19), along with any associated pregnancy complications, in Hong Kong, China, and to assess the impact of COVID-19 vaccination on these outcomes.Methods::This prospective registry-based observational study included pregnant women who were recruited through convenient sampling and had a laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection with a cycle threshold (Ct) value result available on admission to eight local hospitals in Hong Kong, China. Data on clinical symptoms, laboratory results, medical treatments, delivery timing and mode, and pregnancy complications were extracted from the Hospital Authority’s electronic medical record system. Maternal, fetal, and pregnancy outcomes were compared between unvaccinated pregnant women with COVID-19 and those who had received at least one dose of COVID-19 vaccine before diagnosis. Nonparametric continuous variables and categorical variables were analyzed using the Mann-Whitney U test and the Pearson’s chi-squared test respectively. A P value less than 0.05 was considered statistically significant. Results::A total of 164 pregnant women were included, of whom 78 (47.56%) were nulliparous. COVID-19 was diagnosed before 28 weeks’ gestation in 30 (18.29%), while 134 (81.71 %) were diagnosed at or after 28 weeks’ gestation. Sixty-two (37.80%) women received at least one dose of COVID-19 vaccine. There were no significant differences between vaccinated and unvaccinated groups in the time interval between COVID-19 diagnosis and delivery, the Ct value, and the gestational age at infection onset or delivery ( P > 0.05). The majority of women were symptomatic at diagnosis regardless of vaccination status (55 (88.71%) in vaccinated group vs. 78 (76.47%) in unvaccinated group ( P = 0.052). Symptoms did not significantly differ between groups except for cough (62.90% vs. 47.06%, P = 0.049). The overall rate of severe COVID-19 in pregnant women was low. In total, 5 (3.05%) patients experienced severe COVID-19, with vaccinated patients more likely to receive low molecular weight heparin (LMWH) as part of their treatment (62.90% vs. 42.16%, P = 0.010). Ninety-two (56.10%) women had a spontaneous vaginal delivery, 7 (4.27%) had an instrumental delivery, and 44 (26.83%) and 21 (12.80%) underwent emergency and elective cesarean sections respectively. For fetal outcomes, 14 (8.48%) babies were born preterm and four (2.65% of nonpreterm babies, n = 151) had low birthweight. The median birthweight percentile was 52.18 th. There were no statistically significant differences in pregnancy complications or fetal outcomes between vaccinated and unvaccinated groups. Conclusion::The overall rate of severe COVID-19 in pregnant women was low. COVID-19 vaccination did not significantly impact maternal outcomes, except for the use of LMWH. Additionally, the study found no significant differences in fetal outcomes and pregnancy complications between vaccinated and unvaccinated individuals.

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.

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.