Wirawit Piyamongkol

Single transvaginal sonographic measurement of cervical length early in the third trimester as a predictor of preterm delivery

Objective To evaluate the accuracy of a single sonographic measurement of cervical length early in the third trimester as a predictor of preterm delivery. Methods A total of 771 women attending the antenatal clinic at the Maharaj Nakorn Chiang Mai Hospital between January 1, 1990, and November 30, 1993, with singleton gestations, cervical competence, accurate dates of last menstrual period, and gestational ages between 28–30 weeks, were recruited into the study. Forty-one were excluded, ten because of induced preterm delivery, 24 because of measurement problems, and seven because they were lost to follow-up. We analyzed the remaining 730 women. Results Ninety-one (12.5%) women ended with preterm births and the remaining 639 (87.5%) delivered at term. The mean (± standard deviation) cervical lengths of the term and preterm groups were statistically significantly different at 37 ± 5 and 34 ± 6 mm, respectively (P < .001). The likelihood ratio of cervical length at various cutoff points was calculated. The appropriate cutoff point based on the receiver operating characteristic curve (35 mm) was associated with a significantly increased likelihood of preterm delivery (20 versus 7%) and was detected in two-thirds of preterm births. This cutoff point gave a sensitivity and specificity of 65.9 ± 5.1% (95% confidence interval [CI]) and 62.4 ± 5.2% (95% CI), respectively. Conclusion A single transvaginal sonographic measurement of cervical length at 28–30 gestational weeks can be used to predict the risk of preterm delivery, using a cutoff point of 35 mm, but its cost-effectiveness should be assessed further.

Cordocentesis at 16-24 weeks of gestation: experience of 1320 cases

The objective of this study was to assess the safety and efficacy of diagnostic cordocentesis at midpregnancy. 1320 singleton pregnancies with no obvious congenital anomalies, a gestational age of 16–24 weeks, and proper indications underwent cordocentesis using the freehand technique. The results of each procedure was prospectively collected and subsequently analysed for the results and pregnancy outcomes. The mean maternal age was 31.1 years and the mean gestational age at the time of cordocentesis was 19.8 weeks. The most common indication was the risk of severe thalassaemia syndrome (69.8%) and was followed by rapid karyotyping. Of 1320 cordocenteses, 1281 (97%) were done successfully at the first attempt. The mean duration of the procedure was 10.5 min and was significantly longer in the first 50 cases of practice for each operator. The maternal blood contamination rate was higher when the cord insertion was targeted. The procedure‐related complications included transient bleeding at puncture site (20.2%), transient fetal bradycardia (4.3%), chorioamnionitis (two cases), and cord haematoma (one case). Of 1281 successful cases, 184 fetuses had severe disease. The total fetal loss rate was 3.2% and the procedure‐related loss was 1%. The other obstetric complications were comparable with those in the general population. We conclude that cordocentesis at midpregnancy is a useful, relatively safe, and effective procedure for prenatal diagnosis. Copyright

Antenatal sonographic features of 100 alpha-thalassemia hydrops fetalis fetuses.

To characterize the sonographic findings of α‐thalassemia hydrops fetalis.

Prenatal sonographic diagnosis of VATER association.

We examined the potential role of sonography in the prenatal diagnosis of the VATER association, a spectrum of fetal anomalies that includes vertebral defects, imperforate anus, tracheoesophageal fistula, and radial and renal dysplasia.

Identification of fetuses with hemoglobin Bart's disease using middle cerebral artery peak systolic velocity

To determine the sensitivity and specificity of middle cerebral artery peak systolic velocity (MCA‐PSV) in mid‐pregnancy for the identification of homozygous α‐thalassemia‐1 (hemoglobin (Hb) Barts disease) in fetuses at risk of the disease.

Training in cordocentesis: the first 50 case experience with and without a cordocentesis training model

To compare the outcomes of the first 50 cordocenteses at mid‐gestation performed by operators who either or not received training on an in vitro model earlier.

Fetal ventricular shortening fraction in hydrops fetalis.

OBJECTIVE: To estimate fetal ventricular shortening fraction, representing cardiac contractility, derived from cardiospatiotemporal image correlation with M-mode display “STIC-M” in fetuses with hydrops fetalis secondary to high-output (fetal anemia) and low-output causes (congenital heart defects). METHODS: A cross-sectional study was conducted in normal fetuses (group 1), fetuses with hemoglobin Barts disease with (group 2) and without (group 3) hydrops fetalis, and those with hydrops fetalis resulting from cardiac defects (group 4). Volume data sets of cardiospatiotemporal image correlations were acquired for each group for subsequent offline analysis with cardiospatiotemporal image correlation with M-mode display. Group 1 data were used to construct reference ranges of left and right ventricular shortening fraction for assessment of fetuses in the remaining groups. RESULTS: A total of 606 measurements, 15–35 per week, were performed in normal fetuses to construct reference ranges as well as Z-scores of left and right ventricular shortening fraction. Both parameters were decreased with increasing gestation with weak correlation (r2=0.141, P<.001 and r2=0.055, P<.001, respectively). Shortening fraction did not significantly change among 111 fetuses with hemoglobin Barts disease with and without hydrops. However, left and right ventricular shortening fraction were significantly decreased (mean Z-scores 5 standard deviations and 8 standard deviations below the mean, respectively) in 21 hydropic fetuses as a result of congenital heart defects (P<.001). CONCLUSION: Fetuses with hydrops fetalis secondary to cardiac defects and anemia have a different pattern of shortening fraction. Hydrops fetalis resulting from cardiac defect is primarily caused by cardiac decompensation; whereas in fetal anemia, it is probably caused by hypervolemia with cardiac decompensation occurring when the cardiac compensatory mechanism is exhausted. LEVEL OF EVIDENCE: II

Comparison of red blood cell hematology among normal, α-thalassemia-1 trait, and hemoglobin Bart's fetuses at mid-pregnancy

The objective of this study was to compare red blood cell indices among normal, α‐thalassemia‐1 trait, and hemoglobin (Hb) Barts fetuses at mid‐pregnancy. A total of 87 pregnancies (88 fetuses) at risk of homozygous α‐thalassemia‐1, who underwent cordocentesis including the measurement of Hb level and red blood cell indices of fetuses at 18–22 weeks of gestation at Maharaj Nakorn Chiang Mai Hospital, were recruited into this study. The final outcome was based on the fetal DNA analysis using PCR technique for SEA type α‐thalassemia‐1. Fetuses were divided into three groups: normal, α‐thalassemia‐1 trait, and homozygous α‐thalassemia‐1 (Hb Barts disease). The mean gestational age of the 87 pregnant women recruited into the study was 18.7 ± 0.8 weeks. According to the DNA analysis, the incidence of Hb Barts disease, α‐thalassemia‐1 trait, and normal fetuses were 29.5%, 45.5%, and 25%, respectively. The mean Hb level, mean corpuscular volume, mean corpuscular Hb, and mean cell Hb concentration were significantly different in all three groups of fetuses. Moreover, these differences were also found among fetuses with the α‐thalassemia‐1 trait and those that were normal. Ninety‐two percent of fetuses with Hb Barts disease had some degree of anemia at mid‐pregnancy. However, two Hb Barts fetuses did not have anemia. Furthermore, two fetuses in the α‐thalassemia‐1 trait group were mildly anemic, but most (95%) were not. There is a highly significant difference in red blood cell indices among normal, α‐thalassemia‐1 trait, and Hb Barts fetuses, and most fetuses with Hb Barts disease have some degree of anemia from mid‐pregnancy. Am. J. Hematol., 2008.

Accuracy of fetal heart-rate variability interpretation by obstetricians using the criteria of the National Institute of Child Health and Human Development compared with computer-aided interpretation.

Aim: To evaluate the accuracy of fetal heart rate variability interpretation by obstetricians using the criteria of the National Institute of Child Health and Human Development (NICHD), compared with computer‐aided analysis as a gold standard.

Prenatal sonographic features of sacrococcygeal teratoma

Objective: To describe the potential role of ultrasound in prenatal diagnosis of fetal sacrococcygeal teratoma (SCT). Subjects: A total of four fetuses with prenatal diagnosis of SCT were sonographically evaluated and followed‐up. Results: Fetal SCT was diagnosed at 13, 17, 26 and 27 weeks of gestation. Three of them had predominantly solid tumors with scattered cystic areas, whereas the other one had an entirely cystic tumor. One had a rapid growth tumor and finally developed early hydrops. Three had polyhydramnios and delivered prematurely. The diagnosis was posnatally confirmed in all cases. In the case with the large tumor, a cesarean section was done to avoid traumatic delivery. Two cases survived and the tumors were successfully resected, whereas the others died due to heart failure secondary to hydrops in one case and prematurity in the other one. Conclusion: This small series suggests that SCT be readily diagnosed in utero, possibly as early as first trimester. The important clue was an abnormal mass in the sacrococcygeal area. The prenatal diagnosis can contribute to changes in clinical decision.