Association between lower uterine wall thickness measured at 18-22 weeks of gestation and risk of Preterm Birth: a prospective cohort study.

BACKGROUND: Preterm labour prediction has been relied on history of previous preterm birth and cervical length of current pregnancy. However, universal cervical length measurement has some limitation. We aim to find a surrogate marker of cervical length to close the gap in preterm prevention program and lower uterine wall thickness seems promising. We generate the nomogram of lower uterine wall thickness during 18-22 weeks of gestation and evaluate the accuracy of LUW thickness as a predictor of preterm delivery before 37 weeks. METHODS: This prospective cohort study included 524 Thai singleton pregnant women at 18-22 weeks of gestation between November 2016 and October 2017. After signing informed consent, transabdominal ultrasonography was performed to examine fetal anatomical structures and to measure LUW thickness. The results were blinded to the caregivers. The outcomes of all pregnancies were followed. The LUW thickness at 10th percentiles was established and was correlated with the outcomes of pregnancy. The performance of LUW thickness at 10th percentile as a predictor of preterm delivery was calculated. The intra-observer and inter-observer reliability of measurement were assessed by intraclass correlation coefficient and Bland-Altman plot. RESULTS: Of the 524 pregnant women, 64 (12.2%) delivered before 37 weeks of gestation. The reference value of lower uterine wall thickness at 18-22 weeks was established. Mean and 10th percentile of LUW thickness were 6.2 and 4.5 mm respectively. The inter-observer and intra-observer variation of measurement were small (intraclass correlation coefficient = 0.926 and 0.989 respectively). Using LUW thickness at less than 4.5 mm as a predictor of preterm delivery, we found a 2.37 folds increased risk of preterm delivery after adjustment of other factors (p = 0.037). Sensitivity, specificity, positive predictive value and negative predictive value were 14% (95% CI: 6.64-25.02), 92.8% (95% CI: 90.06-95.12), 22.5% (95% CI: 12.66-36.76) and 88% (95% CI: 86.92-89.08) respectively. CONCLUSIONS: The measurement of LUW thickness by transabdominal ultrasonography is feasible and reproducible. The risk of delivery before 37 weeks of gestation is increased significantly if the LUW thickness at 18-22 weeks is less than 4.5 mm. TRIAL REGISTRATION: The study protocol was approved by institutional ethical committee (COA No. Si 657/2016).

Correlation between lower uterine wall thickness measured by transabdominal ultrasonography and cervical length measured by transvaginal ultrasonography in Thai pregnant women.

BACKGROUND: Preterm labor is one of major obstetric challenges and can be predicted by cervical length at mid-trimester. In some settings, transvaginal ultrasound is not available and the screening and prevention of preterm labor will be suboptimal. We hope to find a correlation between other marker i.e. lower uterine wall thickness measured by transabdominal ultrasonography and cervical length measured by transvaginal ultrasonography in Thai pregnant women during 16-32 weeks of gestation. METHODS: This study was a cross-sectional study. 166 singleton pregnant women were invited to participate in the study between June 2015 and December 2015. Transabdominal ultrasonography was performed to measure the lower uterine wall thickness and transvaginal ultrasonography was performed to measure the cervical length. The Spearman's rank correlation was used to evaluate the correlation between the two parameters. The inter-observer variation was assessed by using Bland-Altman plot. The outcomes of all pregnancies were followed and only those who delivered at term were included for the calculation of normal value of lower uterine wall thickness. RESULTS: There was a highly positive correlation between lower uterine wall thickness and cervical length (rs = 0.767, n = 166, p < 0.001). For those who had short cervical length (defined as less than 30 mm) at GA 16-24 weeks (n = 10), the mean corresponding lower uterine wall thickness was 4.4 mm (SD 0.50). The inter-observer variation of the measurement of lower uterine wall thickness and cervical length were small. The lower uterine wall thickness tended to be slightly thinner when the gestation advanced. (mean 5.4 mm at 16-20 weeks and 5.1 mm at 28-32 weeks). CONCLUSION: There was a highly positive correlation between lower uterine wall thickness measured by transabdominal ultrasonography and cervical length measured by transvaginal ultrasonography in Thai pregnant women.

Incidence and risk factors of preterm premature rupture of membranes in singleton pregnancies at Siriraj Hospital.

AIM: To obtain the incidence of preterm premature rupture of membranes (PPROM) at Siriraj Hospital during 2012-2016 and to identify its possible risk factors in singleton pregnancies. METHODS: This study was a retrospective case-control study. The institutional ethical committee has approved the study. The medical records of eligible cases were reviewed. To assess the risk factors of PPROM, the data of the cases with PPROM in 2016 were compared with the data of pregnant women who did not have PPROM and delivered at term. Fifteen variables of interest were studied. RESULTS: During the 5-year period, there were 43 727 deliveries at Siriraj Hospital and 1280 (2.93%) cases had PPROM. In 2016, 252 pregnant women were diagnosed PPROM and data of 199 cases were compared with the data of 199 control cases. Mean latency period was 2 days and mean gestational age at birth was 34.7 weeks in PPROM group. Logistic regression analysis showed that diabetes mellitus, poor weight gain and history of previous preterm birth were the factors that significantly associated with PPROM, with adjusted odds ratio (OR) 3.22 (95% confidence interval [CI] 1.47-7.05), 2.58 (95% CI 1.63-4.07) and 8.81 (95% CI 2.81-28.69), respectively (P < 0.05), while multiparity decreased the risk of PPROM (adjusted OR = 0.36, 95% CI 0.23-0.57) (P < 0.001). CONCLUSION: The incidence of PPROM during 5-year period was 2.93%. Diabetes mellitus, poor maternal weight gain and history of previous preterm birth significantly increased risk of PPROM while multigravida reduced the risk.

Fetal cardiac function measured by myocardial performance index of small-for-gestational age fetuses.

AIM: The aim of this study was to demonstrate the changes of right and left myocardial performance indices (MPI) in small-for-gestational age (SGA) fetuses during 28-40 weeks of gestation. MATERIAL AND METHODS: Singleton pregnant women during 28-40 weeks of gestation were enrolled. Estimated fetal weight was used to classify the subjects into appropriate-for-gestational age (AGA) and SGA groups. The Doppler indices of umbilical and middle cerebral arteries, including amniotic fluid index, were used to distinguish constitutional SGA (both normal Doppler indices and amniotic fluid index) from intrauterine growth restriction (IUGR) fetuses (abnormal Doppler indices and/or oligohydramnios). MPI was obtained and compared between the groups. Inter- and intra-observer variations were also assessed. RESULTS: Fifty women had AGA fetuses whereas another 50 cases had SGA fetuses (41 constitutional SGA and nine IUGR). Right MPI in AGA fetuses was constant whereas left MPI was slightly increased. The MPI of SGA fetuses were significantly greater than those of AGA fetuses starting from 30 weeks gestation until delivery (P < 0.01 and <0.05 in right and left side, respectively). Subgroup analysis demonstrated right and left MPI of IUGR fetuses increased with advancing gestation and were significantly greater than those of constitutional SGA and AGA fetuses, which appeared to be similar. The reproducibility of the test was high. CONCLUSIONS: In SGA fetuses, the MPI of right and left ventricles was significantly increased with advancing gestation compared to AGA cases.

Fetal long QT syndrome manifested as atrioventricular block and ventricular tachycardia: a case report and a review of the literature.

Fetal onset of congenital long QT syndrome (LQTS) is a rare manifestation, and prenatal diagnosis is difficult. This report describes a boy who presented with both atrioventricular (AV) block and ventricular tachycardia during the antenatal period. The early postnatal electrocardiogram showed prolongation of the QT interval and AV block, subsequently leading to a polymorphic ventricular tachycardia torsade de pointes. This unique feature of congenital LQTS has a poor outcome, but the boy was successfully treated with beta-blockers and implantation of an automated cardioverter-defibrillator. The intrauterine manifestation of fetal AV block and ventricular tachycardia should raise a high suspicion of congenital LQTS, and the strong association with a malignant clinical course should warrant special evaluation. The literature on the prenatal diagnosis, fetal therapy, and neonatal outcome of this condition also are reviewed.

Comparison of the efficacy and safety of titrated oral misoprostol and a conventional oral regimen for cervical ripening and labor induction.

OBJECTIVE: To compare the efficacy and safety of titrated oral misoprostol and a conventional oral regimen for cervical ripening and labor induction. METHODS: A randomized double-blind trial of women with term singleton pregnancies with indications for labor induction. Participants were allocated to receive 20 mL of misoprostol solution (1 µg/mL) orally every 1 hour for 4 doses then titrated to 40 µg every 1 hour (titrated group) or 50 µg of misoprostol orally every 4 hours up to 12 hours (conventional group). Primary outcomes were success rate of cervical ripening within 12 hours, interval from first dose until more favorable cervix or active labor occurred, and total dose of misoprostol. RESULTS: Sixty-four participants were included. Mean total dose of misoprostol and incidence of tachysystole were significantly higher in the titrated compared with the conventional group (236.2±110.1 µg vs 103.1 ± 35.7 µg; P=0.001 and 25.0% vs 6.3%; P=0.03), whereas success rate, interval from drug administration to more favorable cervix and delivery, proportion of patients delivered vaginally within 12 hours and 24 hours, need for oxytocin augmentation, cesarean delivery rate, maternal adverse effects and complications, and neonatal outcome were not significantly different (P>0.05). CONCLUSION: Conventional oral misoprostol is as effective as titrated misoprostol for cervical ripening and labor induction, but has a lower incidence of tachysystole and a lower total dose of misoprostol is required. ClinicalTrial.gov: NCT00886860.

Specificity of fetal tricuspid regurgitation in prediction of Down syndrome in Thai fetuses at 17-23 weeks of gestation.

OBJECTIVE: To assess the specificity of tricuspid regurgitation (TR) in prediction of Down syndrome in Thai fetuses at 17-23 weeks' gestation and to determine the prevalence of TR among normal chromosome fetuses in a high-risk population. MATERIAL AND METHOD: A prospective study was performed in 395 high-risk pregnant women who underwent amniocentesis or cordocentesis for fetal karyotyping at 17-23 weeks. The presence or absence of TR was determined by pulsed wave Doppler at the time of prenatal diagnosis. TR was diagnosed when the regurgitation flow was observed for at least half of systole or > or = 70 milliseconds with maximum velocity of > or = 100 cm/sec. The diagnostic values of TR for detection of Down syndrome were calculated. RESULTS: The prevalence of TR was 3.8% (14/370) in normal chromosome fetuses and 40% (2/5) in Down syndrome fetuses. Fetuses with TR had a higher chance to be Down syndrome (11.1%) than those without TR (0.8%) (95% CI of the difference, 0.09-32.9, p = 0.036). Specificity, sensitivity, NPV and PPV of TR in prediction of Down syndrome were 95.9%, 40%, 99.2% and 11.1%, respectively. Among normal chromosome fetuses with TR, 14.3% (2/14) had congenital cardiac abnormalities. CONCLUSION: TR is not only a high specificity secondary ultrasound marker at 17-23 weeks to identify fetuses with Down syndrome in high-risk pregnant women but also associates with the risk of cardiac defects in normal chromosome fetuses.

Spatio-temporal image correlation (STIC) used by general obstetricians is marginally clinically effective compared to 2D fetal echocardiography scanning by experts.

OBJECTIVES: To assess the effectiveness of spatio-temporal image correlation (STIC) used by general obstetricians as compared with 2D scanning. METHODS: As many as 30 pregnant women at 17-21 weeks' gestation were enrolled. 2D ultrasound was performed by a fetal echocardiologist; STIC was performed by a general obstetrician. Time, accuracy of measurement of diameter of great vessels and quality of the pictures obtained by the two methods were compared. RESULTS: The mean time required by 2D ultrasound was significantly shorter than that by STIC (5.2 +/- 1.9 min vs 9.8 +/- 2.7 min; P < 0.001). The measurement of the diameter of the great vessels showed some difference but the mean score of the pictures obtained by both methods were not significantly different. By using 2D ultrasound, acceptable quality pictures were obtained in 51.9, 44.4 and 51.9% of cases for 4-chamber, 5-chamber and 3-vessel views, respectively. Meanwhile by using STIC, the percentages were 77.8, 59.3 and 37%. CONCLUSION: Our study suggested that STIC used by general obstetricians to check normality of fetal cardiac structures at 17-21 weeks' gestation has marginal clinical effectiveness when compared to 2D scanning by a fetal echocardiologist, and should need some improvement before it can be used as a tool to expand a fetal cardiac screening program.