Immunogenicity and reactogenicity of heterologous COVID-19 vaccination in pregnant women

This open-labeled non-inferiority trial evaluated immunogenicity and reactogenicity of heterologous and homologous COVID-19 vaccination schedules in pregnant Thai women. 18-45-year-old pregnant women with no history of COVID-19 infection or vaccination and a gestational age of ≥12 weeks were randomized 1:1:1 into three two-dose primary series scheduled 4 weeks apart: BNT162b2-BNT162b2 (Group 1), ChAdOx1-BNT162b2 (Group 2), and CoronaVac-BNT162b2 (Group 3). Serum antibody responses, maternal and cord blood antibody levels at delivery, and adverse events (AEs) following vaccination until delivery were assessed. The 124 enrolled participants had a median age of 31 (interquartile range [IQR] 26.0-35.5) years and gestational age of 23.5 (IQR 18.0-30.0) weeks. No significant difference in anti-receptor binding domain (RBD) IgG were observed across arms at 2 weeks after the second dose. Neutralizing antibody geometric mean titers against the ancestral Wuhan strain were highest in Group 3 (258.22, 95% CI [187.53, 355.56]), followed by Groups 1 (187.47, 95% CI [135.15, 260.03]) and 2 (166.63, 95% CI [124.60, 222.84]). Cord blood anti-RBD IgG was correlated with, and equal to or higher than, maternal levels at delivery (r = 0.719, P < .001) and inversely correlated with elapsed time after the second vaccination (r = -0.366, P < .001). No significant difference in cord blood antibody levels between groups were observed. Local and systemic AEs were mild-to-moderate and more frequent in Group 2. Heterologous schedules of CoronaVac-BNT162b2 or ChAdOx1-BNT162b2 induced immunogenicity on-par with BNT162b2-BNT162b2 and may be considered as alternative schedules for primary series in pregnant women in mRNA-limited vaccine settings.

Pregnancy outcomes among women affected with thalassemia traits

OBJECTIVE

To compare the maternal and perinatal outcomes between a group of pregnant women diagnosed with thalassemia traits and normal controls.

STUDY DESIGN

A retrospective cohort study was conducted on singleton pregnant women affected and unaffected by thalassemia traits who attended an antenatal care clinic and delivered in Siriraj Hospital. Thalassemia status for all subjects was diagnosed by hemoglobin typing and/or DNA analysis. Patient charts were reviewed from January 2007 to December 2018. The control participants were randomly selected from the same period, with a control-case ratio of around 1:1.

RESULTS

Overall, 1288 women with thalassemia traits (348 with α thal-1 trait, 424 with β thal trait and 516 with HbE trait) and 1305 women in the control group were recruited. Baseline characteristics of both groups were similar, with the exception that the hematocrit level in the first trimester in the thalassemia trait group was significantly lower than that in the control group (34.8 ± 3.4% VS 36.9 ± 3.0%; p < 0.001). The prevalence of pregnancy-induced hypertension (PIH) was higher in the thalassemia trait group, at 6.9% VS 4.7% in the control group; p = 0.018. When subgroups were analyzed between each thalassemia trait, the number of maternal anemias in the first and third trimester was higher for all thalassemia traits compared to the normal group. The β thal and HbE traits increased the risk of PIH, with a relative risk (RR) = 1.67 and 1.66, respectively.

CONCLUSIONS

Thalassemia traits minimally but significantly increase the risk of hypertensive disorders and maternal anemia. In addition, physiological changes during pregnancy may worsen the severity of anemia in the pregnant women with thalassemia traits.

Seroprevalence of Zika virus in pregnant women from central Thailand

Zika virus (ZKV) infection in a pregnant woman, especially during the first trimester, often results in congenital anomalies. However, the pathogenic mechanism is unknown and one-third of ZKV infected pregnancies are asymptomatic. Neutralizing antibodies against ZKV has been reported in 70% of Thai adults, but the prevalence among pregnant women is unknown. Currently, vaccines and specific treatments for ZKV are under development. A better understanding of the immune status of pregnant women will increase the success of effective prevention guidelines. The prevalence of ZKV infection in pregnant women in antenatal care clinics was investigated during the rainy season from May to October 2019 at Siriraj Hospital, Bangkok, Thailand. We recruited 650 pregnant women (39.42% first, 52.26% second and 7.36% third trimester) and found that 30.77% had ZKV-specific IgG, and 39.81% had neutralizing antibodies (nAb) against ZKV (titer ≥10). Specific and neutralizing antibody levels varied by maternal age, trimester, and month. We further characterized the cross-reaction between ZKV and the four Dengue virus (DENV) serotypes by focused reduction neutralization test (FRNT) and found that cross-reactions were common. In conclusion, about 60% of pregnant women who living in central Thailand may be at risk of ZKV infection due to the absence of neutralizing antibodies against ZKV. The functions of cross-reactive antibodies between related viral genotypes require further study. These findings have implications for health care monitoring in pregnant women including determining the risk of ZKV infection, assisting the development of a flavivirus vaccine, and informing the development of preventative health policies.

Zika virus isolation, propagation, and quantification using multiple methods

Zika virus (ZIKV) was isolated from the archival urine, serum, and autopsy specimens by intrathoracic inoculation of Toxorhynchitis splendens and followed by three blind sub-passaging in C6/36 mosquito cells. The virus isolates were identified using an immunofluorescence assay and real-time reverse transcription-polymerase chain reaction (real-time RT-PCR). This study analyzed 11 ZIKV isolates. One isolate (0.6%) was obtained from 171 urine samples, eight (8.7%) from 92 serum samples and two from tissues of an abortive fetus. After propagation in C6/36 cells, ZIKV was titrated by plaque and focus forming unit (FFU) assays in Vero cell monolayers, and viral genomes were determined via real-time and digital RT-PCR. Plaque and FFU assay quantitations were comparable, with the amount of infectious viruses averaging 106-107 PFU or FFU/ml. Real-time RT-PCR semi-quantified the viral genome numbers, with Ct values varying from 12 to 14. Digital RT-PCR, which precisely determines the numbers of the viral genomes, consistently averaged 10-100 times higher than the number of infectious units. There was good correlation between the results of these titration methods. Therefore, the selection of a method should be based on the objectives of each research studies.

The efficacy of erbium-doped yttrium aluminum garnet (Er:YAG) laser in the treatment of decreased sexual sensation: a randomized, placebo-controlled trial

Vaginal laxity, a common cause of decreased sexual sensation, is a common problem affecting the quality of life of women worldwide. Recently, lasers and energy-based devices (EBDs) have been applied in the treatment of this condition. The aim of this study was to compare the efficacy and safety of Er:YAG laser and placebo in treating decreased sexual sensation in Asians. Forty-two patients with decreased sexual sensation were randomized into 2 groups: intervention (laser treatment) and control (placebo treatment). Both groups received two treatments, at 1-month interval. Subjective and objective evaluations were done at baseline, 1-, 3-, and 6-month follow-ups. Pain score and adverse effects were also recorded. In the laser group, there was significant improvement in the patients' vaginal tightness satisfaction at 1- and 3-month follow-ups (P = 0.002 and 0.004) and also in the patients' overall satisfaction at 1- and 3-month follow-ups (P = 0.003 and 0.001). Pelvic floor muscle contraction was significantly better in the laser group after the first treatment (P = 0.043). No serious adverse effects were noted. Er:YAG laser provides improvement of sexual sensation for an average of 3 months following treatment. Mild and transient adverse effects such as leukorrhea, dryness, dysuria, vaginal itching, and spot bleeding were noted in the laser group, and these were not significantly different from the control group.

Accuracy of Third Trimester Ultrasound for Predicting Large-for-Gestational Age Newborn in Women with Gestational Diabetes Mellitus

Objective: To determine the accuracy of ultrasonography for predicting a large-for-gestational-age (LGA) newborn in women with gestational diabetes mellitus (GDM).Materials and Methods: Singleton pregnancy, diagnosed with GDM were recruited. They underwent ultrasonography at 32-36 weeks’ gestation for fetal biometry. Biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). Estimated fetal weight (EFW) was derived from these 4 parameters by Hadlock formula. Delivery of an LGA newborn in women with the ultrasound finding of LGA fetus was the primary outcome.Results: Of 345 studied women, 107 (31%) had an LGA newborn. EFW of ≥ 90 th percentile at third trimester ultrasonography was found in 13 women, all of whom had an LGA newborn. It had a positive predictive value (PPV), specificity, sensitivity and negative predictive value (NPV) of 100%, 100%, 12.1% and 71.7% respectively to predict LGA at birth. Considering each fetal parameter individually, AC > 90 th percentile and HC > 90 th percentile had odds ratios (OR) with 95% confidence intervals of the newborn being LGA of 6.5 (3.3-12.8) and 2.0 (1.0-4.0) respectively while EFW > 85 th percentile had the highest OR of 9.3 (1.1-77.9). Lowering cutoff values of EFW to 80 th and 70 th percentile increased the sensitivity and NPV for prediction of LGA at birth while reducing the PPV and specificity slightly.Conclusion: EFW derived from the third trimester ultrasonography in GDM had high PPV and specificity with low to moderate sensitivity and NPV to predict an LGA newborn in GDM.

Comparative analysis of a Thai congenital-Zika-syndrome-associated virus with a Thai Zika-fever-associated virus

In this study, we compared the characteristics of two strains of Zika virus (ZIKV) isolated in Thailand, one isolated from a febrile patient and one isolated from tissues of a fetus medically terminated due to congenital Zika syndrome (CZS). Replication profiles showed that the isolate from the fetal tissues replicated significantly more slowly than the fever-associated isolate in human lung A549 cells during the first 24 hours postinfection but showed a similar growth profile over longer-term infection. A much smaller difference was observed in Aedes albopictus C6/36 cells. In a quasispecies analysis, a high proportion (approximately 20%) of nonfunctional genomes was identified, caused by an adenine insertion in the prM gene. This insertion was found to be present in two Thai fever strains and as such may represent a common feature of Thai endemic ZIKV. Comparison between viral RNA copy number and viral titer showed that the isolate from fetal tissues was produced more efficiently than the fever-associated isolate. Together, these results suggest that different ZIKV isolates differ in their replication capacity, and this might contribute to the fetotropic potential of a particular strain.

Correlation Between Third Trimester Glycemic Variability in Non-Insulin-Dependent Gestational Diabetes Mellitus and Adverse Pregnancy and Fetal Outcomes

BACKGROUND

Gestational diabetes mellitus (GDM) is a pregnancy-related metabolic complication. Despite optimal glycemic control from self-monitoring blood glucose (SMBG) in non-insulin-dependent GDM, variations in pregnancy outcomes persist. Glycemic variability is believed to be a factor that causes adverse pregnancy outcomes. Continuous glucose monitoring system (CGMS) detects interstitial glucose values every 5 minutes, and glycemic variability data from CGMS during the third trimester may be a predictor of fetal birth weight and pregnancy outcomes. The aim of this study was to investigate correlation between third trimester glycemic variability in non-insulin-dependent GDM and fetal birth weight.

METHOD

This prospective study was conducted in 55 pregnant volunteers with non-insulin-dependent GDM that were recruited at 28 to 32 weeks' gestation from the outpatient clinic of the Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital during the study period of August 1 to December 31, 2016. Patients had CGMS installed for at least 72 hours and glycemic variability data were analyzed.

RESULTS

Of 55 enrolled volunteers, the data from 47 women were included in the analysis. Mean CGMS duration was 85.5 ± 12.83 hours. No statistically significant correlation was identified between glycemic variability in third trimester and birth weight percentiles, or between third trimester CGMS parameters and pregnancy outcomes in the study.

CONCLUSION

Based on these findings, third trimester glycemic variability data from CGMS are not a predictor of fetal birth weight percentile, and no significant association was found between CGMS parameters and adverse pregnancy outcomes; thus, CGMS is not necessary in non-insulin-dependent GDM.

Prediction and prevention of pre-eclampsia in Asian subpopulation

The benefit of the early administration of aspirin to reduce preterm pre-eclampsia among screened positive European women from multivariate algorithmic approach (ASPRE trial) has opened an intense debate on the feasibility of universal screening. This review aims to assess the new perspectives in the combined screening of pre-eclampsia in the first trimester of pregnancy and the chances for prevention using low-dose aspirin with special emphasis on the particularities of the Asian population. PubMed, CENTRAL and Embase databases were searched from inception until 15 November 2017 using combinations of the search terms: preeclampsia, Asian, prenatal screening, early prediction, ultrasonography, pregnancy, biomarker, mean arterial pressure, soluble fms-like tyrosine kinase-1, placental growth factor, pregnancy-associated plasma protein-A and pulsatility index. This is not a systematic review or meta-analysis, so the risk of bias of the selected published articles and heterogeneity among the studies need to be considered. The prevalence of pre-eclampsia and serum levels of biochemical markers in Asian are different from Caucasian women; hence, Asian ethnicity needs to be corrected for in the algorithmic assessment of multiple variables to improve the screening performance. Aspirin prophylaxis may still be viable in Asian women, but resource implication needs to be considered. Asian ethnicity should be taken into account before implementing pre-eclampsia screening strategies in the region. The variables included can be mixed and matched to achieve an optimal performance that is appropriate for economical restriction in individual countries.

Reference centile chart for fetal liver length of Thai fetuses

OBJECTIVE

To create a reference centile chart for fetal liver length of Thai fetuses.

DESIGN

Prospective, cross-sectional study.

SETTING

Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University.

MATERIAL AND METHOD

A total of 752 pregnant women, who attended the antenatal clinic at Siriraj Hospital, Mahidol University, Bangkok, were recruited between 13-40 weeks of gestation. Each fetus was measured only once for the purpose of this study. Using real-time ultrasound with a 3.5 MHz convex transducer; the authors measured fetal liver length. The mean and standard deviation (SD) were estimated at each week of gestation using linear regression modeling.

RESULTS

A total of 750 fetuses were measured for fetal liver length. Linear regression models were fitted to estimate the mean and 95% confidence interval for liver length at each gestation age. The centile chart of liver length was also presented

CONCLUSION

A reference centile chart for fetal liver length of Thai fetuses has been created.

Sonographic morphological pattern in the pre-operative prediction of ovarian masses

The study was undertaken to evaluate the accuracy of sonographic morphological pattern in the detection of ovarian malignancy. A total of 123 patients with a suspicion of ovarian pathology, who were scheduled for elective surgery at the Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University were included in the study. All patients underwent sonographic examination prior to surgery by the same physician. The sonographic morphological pattern of each patient was compared to the histological diagnosis of the ovarian tumors. Of the 120 patients with an ovarian lesion, the sonographic morphological pattern of 10 had a sensitivity of 88.6 per cent and a specificity of 89.4 per cent in detection of malignant ovarian tumors. The positive predictive value, negative predictive value, and the accuracy rate were 77.5, 95.0, and 89.2 per cent, respectively. In the present study, a score of 9 would be the best discriminator between benign and malignant ovarian masses, giving a sensitivity of 97.1 per cent and specificity of 82.4 per cent. As stand alone, the present results confirm that ultrasonography is still a useful diagnostic tool in the differentiation of benign from malignant ovarian masses.