Role of Ultrasound and MRI in Diagnosis of Severe Placenta Accreta Spectrum Disorder: An Intraindividual Assessment With Emphasis on Placental Bulge.

BACKGROUND. The "placental bulge" sign (focal area of myometrial-placental bulging beyond the normal uterine contour) on ultrasound (US) or MRI is postulated to represent deeper venous invasion in placenta accreta spectrum (PAS) disorder and may represent severe PAS. OBJECTIVE. The purpose of this study was to evaluate the diagnostic performance and interobserver agreement of US and MRI features for diagnosis of severe PAS, with an emphasis on the placental bulge sign. METHODS. This retrospective study included 62 pregnant women (mean age, 33.2 ± 5.5 [SD] years) with clinically suspected PAS who underwent both US and MRI. Five readers (two maternal-fetal medicine specialists for US, three abdominal radiologists for MRI) independently reviewed images for the given modality, blinded to the final diagnosis, and recorded the presence of a range of findings (nine on US, eight on MRI), including placental bulge. Intraoperative and pathologic findings were used to separate patients into those with and without severe PAS according to International Federation of Gynecology and Obstetrics classification. Diagnostic performance of US and MRI findings for severe PAS was evaluated, multivariable logistic regression was performed, and interob-server agreement was assessed. RESULTS. A total of 58.1% (36/62) of patients had severe PAS. On US, the finding with the highest accuracy for severe PAS was placental bulge (85.5%), which had a sensitivity of 91.7% and specificity of 76.9%. On MRI, the finding with highest accuracy was also placental bulge (90.3%), which had a sensitivity of 94.4% and specificity of 84.6%. In the multivariable regression analysis, placental bulge was an independent predictor of severe PAS on US (odds ratio [OR], 8.94; p = .02) and MRI (OR, 45.67; p = .003). Interobserver agreement analysis showed a kappa value for placental bulge of 0.48 for MRI and 0.40 for US. Given wide 95% CIs, differences among features for a given modality and differences between modalities were not statistically significant. CONCLUSION. The findings suggest a strong performance of placental bulge in diagnosing severe PAS on both US and MRI, with a potentially stronger performance on MRI. Nonetheless, interobserver agreement remains suboptimal for both modalities. CLINICAL IMPACT. Accurate prenatal diagnosis of severe PAS by imaging could help guide maternal counseling and selection of either hysterectomy or uterine-preserving surgery.

Comparison of maternal and perinatal morbidity between elective and emergency caesarean section in singleton-term breech presentation.

The objective of the study was to compare maternal and neonatal adverse outcomes between elective caesarean section (ElCS) and emergency caesarean section (EmCS) for singleton-term breech presentation. This study included women with singleton breech presentation who underwent ElCS or EmCS at term during 2007-2015 at Siriraj Hospital (Thailand). Complete data were collected for 2178 pregnant women. Of those, 1322 (60.7%) women underwent EmCS, and 856 (39.3%) delivered by ElCS. Maternal and perinatal morbidity were compared. There was no maternal or perinatal death in either group. Maternal morbidity was comparable between groups, except for longer hospital stay in the EmCS group (p = .047). One-minute Apgar score was significantly lower in the EmCS group (p = .040). There was no significant difference in 5-min Apgar score between groups. No significant difference was observed for serious maternal and neonatal morbidity between women who underwent ElCS versus those who underwent EmCS for singleton-term breech presentation.IMPACT STATEMENTWhat is already known on this subject? Emergency caesarean section (EmCS) is generally known to be associated with a higher risk of maternal and neonatal complications than elective caesarean section (ElCS).What do the results of this study add? In singleton-term breech presentation, EmCS in tertiary care setting was not associated with an increase in serious maternal and neonatal morbidity compared with EICS. Cord prolapse as an indication for emergency caesarean section was significantly associated with adverse outcomes while advanced cervical dilation ≥7 cm or low foetal station ≥+1 did not have an impact on maternal and neonatal complications.What are the implications of these findings for clinical practice and/or further research? Mean gestational age in both the ElCS and EmCS groups was approximately 38 weeks and 5 d; there were no neonatal cases with respiratory distress syndrome. Our findings suggest further prospective study in planned caesarean section scheduled for 38-39 weeks in patients with term breech presentation. The results of such a study could yield lower rates of both EmCS and potential adverse outcomes.

Measurement of fetal atrioventricular time intervals: A comparison of 3 spectral Doppler techniques.

OBJECTIVE: To establish nomograms for fetal atrioventricular (AV) time intervals assessed by 3 different pulsed-wave Doppler techniques: left ventricular inflow and outflow tracts (LV in/out), superior vena cava and ascending aorta (SVC/AA), and pulmonary artery and pulmonary vein (PA/PV). METHODS: A cross-sectional study was performed in 311 normal fetuses divided into 5 groups between 16 and 38 weeks. Pulsed-wave Doppler-derived AV intervals were measured by interrogation of flow in LV in/out, SVC/AA, and PA/PV. Linear regression analyses were performed to examine correlations with gestational age (GA) and fetal heart rate (FHR). Intraclass correlation coefficients for reproducibility of each method were compared. RESULTS: Pulmonary artery and pulmonary vein revealed the longest mean AV time intervals (P < .001). The AV intervals in all methods were positively correlated with GA (R2  = 0.20-0.36; P < .001) and negatively correlated with FHR (R2  = 0.09-0.19; P < .001). The SCV/AA time intervals demonstrated the weakest influence of FHR. For LV in/out, SVC/AA, and PA/PV, intraobserver and interobserver reliability coefficients showed excellent agreements (all intraclass correlation coefficients ≥ 0.80). CONCLUSION: All pulsed-wave Doppler-derived AV time intervals increased with advancing GA and decreased with increasing FHR. Fetal AV interval measurements can be obtained in a clinically viable fashion with excellent reproducibility.

Sensitivity of multiple first trimester sonomarkers in fetal aneuploidy detection.

BACKGROUND: Multiple first trimester aneuploidy sonomarkers have been introduced recently. OBJECTIVE: To evaluate the efficacy of first trimester sonomarkers in fetal aneuploidy detection without serum markers. METHODS: There were entirely 280 fetuses with 11-13+6 weeks' gestation (crown-rump -length between 45-84 mm) enrolled to assess nuchal translucency thickness (NT), nasal bone (NB), tricuspid regurgitation (TR) and ductus venosus (DV) flow. The performance of each single marker and multiple markers for major fetal aneuploidy screening were determined. RESULTS: Totally, 190 fetuses (67.85%) underwent invasive prenatal diagnosis with 14 major chromosome abnormalities identified including 4 cases of trisomy 21, 4 cases of trisomy 18, 3 cases of trisomy 13 and 3 cases of 45, XO. NT was the most accurate single marker with sensitivity of 71.43% and false-positive rate (FPR) of 4.14% while NB or TR was the most specific marker (99.6%) but lacked sensitivity. Among multiple first trimester-screening sonomarkers, NT plus TR evaluation were the most sensitive test (78.57%) with FPR of 4.76%. CONCLUSION: NT was the most accurate first trimester-screening marker for fetal aneuploidy. NT plus TR assessment as double-screening markers could improve the sensitivity by 7% leading to the lower number of unnecessary invasive prenatal diagnosis.

The efficacy of postpartum tubal sterilization training program with minilaparotomy approach in Ob/Gyn residents.

Objectives: To evaluate the efficacy of postpartum tubal sterilization training program with minilaparotomy approach (PTSMA). Study design: From September 2020 to November 2021, 24 first-year Obstetrics and Gynecology (Ob/Gyn) residents were randomly allocated into 2 groups of traditional apprenticeship learning (watching video clip) versus apprenticeship learning plus PTSMA attending. The program consisted of didactics followed by self-practicing with 2 stations of postpartum tubal sterilization simulators (PTSS). All participants were allowed to perform their first tubal sterilization under supervision within a few days after training. Their surgical skills were blindly evaluated by 2 experts through the recorded videos. Five domains of direct observation of procedural skills (DOPS) score introduced by Royal Thai College of Obstetricians and Gynecologists were assessed. DOPS score, operative time, blood loss and post-op complication were analyzed and compared. Results: Median of total DOPS score in the PTSMA group was higher than the non-PTSMA group (93 vs. 73, p = 0.020). Concerning 2 domains of DOPS score (tubal fishing and tubal sterilization), the PTSMA group had the higher median score than the non-PTSMA group (36 vs. 24, p = 0.045 and 40 vs. 32, p = 0.020). There was no significant difference observed in the median score of 3 other domains (peritoneal cavity accessing, abdominal wall closure and complication prevention), estimated blood loss and operative time. Conclusion: Postpartum tubal sterilization training program with minilaparotomy approach using instructive simulators significantly improved the total DOPS score especially tubal fishing and tubal ligation skills in Ob/Gyn residents. Implications: The study evidently showed the benefit of PTSMA with an inexpensive and simple to prepare models. In unexperienced operators, practicing in model prior to surgery should be encouraged to improve their operative skills.

Distribution of normal nuchal translucency thickness: a multicenter study in Thailand.

AIMS: To establish the normative data distribution of nuchal translucency (NT) thickness in Thai fetuses. METHODS: A cross-sectional multicenter study was conducted among 6,455 women with singleton pregnancies and gestational age between 10 and 14 weeks. For each case, the fetal crown-rump length (CRL) and NT were measured by transabdominal ultrasound. Transvaginal ultrasounds were used in poorly visualized cases. The distribution values of the NT thicknesses and their corresponding 10-mm CRL intervals between 45 and 84 mm were examined to obtain the median and 95th percentiles. Quantile regression modeling across the CRLs was performed to obtain the reference values. RESULTS: Transabdominal ultrasound measurements were successfully done on 6,347 fetuses with 39 cases by the transvaginal route. Fetuses with CRL between 45 and 84 mm and normal outcomes made up a total of 4,352 cases. The mean (SD) gestational age, CRL and NT thickness were 12.5 (0.7) weeks, 60.2 (9.7) mm, and 1.15 (0.38) mm, respectively. The mean normal NT increased linearly with CRL. The quantile regression equation to predict the 95th percentile of the NT thickness (mm) was 0.727 + [0.017 × CRL (mm)]. CONCLUSIONS: The NT thickness in normal Thai fetuses was found to be thinner than in both Caucasian and other Asian populations.

The correlation in antepartum fetal test between full fetal biophysical profile (FBP) and rapid biophysical profile (rBPP).

OBJECTIVE: To determine the correlation between the rapid biophysical profile (rBPP), the combination of amniotic fluid index (AFI), and sound-provoked fetal movement (SPFM) detected by ultrasound, and the full biophysical profile (FBP) in terms of abnormal and normal result. MATERIAL AND METHOD: A prospective study was performed in 200 singleton pregnancies with no fetal anomalies between 30-42 weeks of gestation indicated for non-stress test (NST). All participants received both the standard (FBP) and the new rBPP examinations. Abnormal fetal test was defined as having a score of < or = 6 for FBP or < or = 2 for rBPP. The main outcome measurement was Spearman's correlation coefficient (r) between both examinations. RESULTS: The incidences of the abnormal tests were 1.5% and 6.0% in FBP and rBPP, respectively. The data showed a positive correlation between the two tests (r(s) = 0.67; p < 0.01). Regarding the operative time, FBP assessment was 25.56 +/- 8.75 times longer than rBPP. The number of abnormal NST was remarked at 1.5% while oligohydramnios and abnormal SPFM were detected at 5% and 2%, respectively. Compared to the standard NST, rBPP test was significantly superior in terms of correlation with FBP (r(s) = 0.67 vs. 0.33) and shorter duration of test (1.21 +/- 0.32 min. vs. 21.65 +/- 5.47). CONCLUSION: The statistically significant positive correlation between rBPP and FBP has been revealed. Due to its simplicity, rapidity, and no need of expensive equipment or experienced interpreter the rBPP may be alternatively used as a primary antepartum fetal test in the overcrowded obstetric center or when fetal surveillance tests are limited.

Reverse twin-twin transfusion syndrome after fetoscopic laser photocoagulation of chorionic anastomoses: a case report.

A case of severe twin-twin transfusion syndrome (TTTS) which developed at menstrual age of 17 weeks underwent a fetoscopic laser ablation of the anastomosing vessels. The vascular equator of the anastomoses was noticed to be deviated due to marginal cord insertion of the recipient fetus. The procedure was accomplished uneventfully. However, the recipient fetus died 6 h after the procedure. After the pregnancy was terminated, the donor was found to be counterintuitively plethoric, and the recipient was pale. Similar appearances were noted on the placental territories of each fetus. This is consistent with reverse TTTS. Dye injection study and microscopic examination revealed a residual deep vein-vein anastomosis. This subchorionic vascular connection is still a challenge to coagulate with current placental surgery techniques. To the best of our knowledge, this is the first confirmed case of reverse TTTS as a cause of fetal loss following laser photocoagulation. This report also discusses the technical considerations in the complicated case of in utero placental surgery for TTTS.

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.

Fractional thigh volume by three-dimensional ultrasonography for birth weight prediction.

OBJECTIVE: To determine the correlation between actual birthweight (BW) and fetal weight calculated from fractional thigh volume (ThiV). MATERIAL AND METHOD: The authors have conducted a prospective, cross-sectional study of normal Thai fetal thigh volume. There were 176 eligible pregnant women who met the criteria of singleton with no fetal anomaly were recruited into the present study. Prior to the present study, 3 operators had been trained and standardized for fractional ThiV measurement by an expert for the first 20 cases. To generate the fetal weight calculating formula, fetal ThiV data from the first 100 cases were employed Then, the authors' new prediction formula was compared and validated with the Hadlock's and the Tongsong formula in 56 normal late-third-trimester fetuses. All patients were assessed for 2D fetal biometry and 3D fractional ThiV within one week before delivery. RESULTS: A total of 176 fetuses underwent ultrasound at the gestational age of 38.5 +/- 2.1 weeks. The reproducibility of fractional ThiV measurement technique showned very good correlation in both inter- and intra-observer reliability as observed by the high intraclass correlation (0.971-0.994). By using the regression model, fractional ThiV presents a superior correlation to actual BW (r = 0.965). The fitting formula is characterized by predicted fetal BW (g) = 774.744 + 32.658 x fractional ThiV (ml). The presented new formula shows the smallest absolute percentage error (APE) for BW estimation when compared to that of Hadlock's and Tongsong's. CONCLUSION: Fetal 3D-fractional ThiV is consistent with actual BW The measurement of fractional ThiV can improve the accuracy of fetal weight prediction especially in some eventful conditions.

Previous Adolescent Pregnancy and Breastfeeding Does Not Negatively Affect Bone Mineral Density at the Age of Peak Bone Mass.

PURPOSE: To determine bone mineral density (BMD) at the age of peak bone mass in women who previously experienced pregnancy and breastfeeding during adolescence. MATERIALS AND METHODS: In this retrospective study, female volunteers aged 24-30 years who were pregnant during the age of 15-19 years and have had one to two babies were recruited. All of them experienced breastfeeding without history of bone- or calcium-related problems, such as fracture or low calcium intake. BMD was determined at the femur and L1-L4 spine by dual-energy X-ray absorptiometry. RESULTS: We found that both volunteers who previously experienced breastfeeding and age-matched control volunteers had similar BMD at the L1-L4 spines and femora. Further analysis for site-specific changes of lumbar and femoral BMDs showed that the values of the breastfeeding group were not different from those of the control group except at L1 and L2, where BMD values were greater in breastfeeding group compared with the control group. At both femoral and vertebral sites, T- and Z-scores were apparently similar between the two groups. In addition, the BMD at peak bone mass had no significant correlation with breastfeeding duration. CONCLUSIONS: Teenage pregnancy and breastfeeding did not negatively affect BMD later at the age of peak bone mass. Therefore, breastfeeding can be encouraged in teenage mothers.

Site-Specific Onset of Low Bone Density and Correlation of Bone Turnover Markers in Exclusive Breastfeeding Mothers.

PURPOSE: Lactation often affects calcium metabolism and induces bone loss. Calcium supplementation and a high calcium diet are recommended to prevent bone loss, especially during inadequate calcium intake. Our study aimed at determining bone loss in breastfeeding mothers, and if it occurred, whether it was site specific and there were correlations between serum bone turnover markers. MATERIALS AND METHODS: Since the 6-month exclusive breastfeeding is usually recommended in several countries, our study examined bone mineral density (BMD) in early (1-2 month), mid (3-4 month)-, and late (5-6 month) lactation compared with nonpregnant, nonlactating control women. Site-specific bone loss was monitored in lumbar vertebrae and femora. Bone turnover markers, that is, C-terminal telopeptide of type 1 collagen and N-terminal propeptide of type 1 collagen (P1NP), were determined by electrochemiluminescence immunoassays. RESULTS: The onset of bone loss in exclusive breastfeeding mothers was site specific, for example, in the lumbar bone at mid-lactation and in the femoral bone in late lactation. Serum ionized calcium levels in late lactation were lower than the normal levels. In addition, a correlation was found between bone turnover marker, P1NP, and femoral BMD. CONCLUSIONS: The onset of bone loss in exclusive breastfeeding mothers was site specific, and the lumbar bone was a vulnerable and perhaps better representative site for bone loss detection. It was suggested that the optimal starting time for calcium supplementation should be before the mid-lactation when the bone loss was observed. In addition, the biochemical marker that best predicted the onset of bone loss in lactating women was P1NP.

Comparison of the manual stimulation test and the nonstress test: a randomized controlled trial.

OBJECTIVE: To evaluate manual fetal stimulation (MST) through the maternal abdomen in comparison to standard nonstress test (NST) in terms of nonreactive rates and testing time. MATERIAL AND METHOD: Five hundred and forty high-risk singleton pregnancies at 28 gestational weeks or more were assigned to have either NST or MST using blocked randomization (270 each). All fetal heart rate (FHR) tracings were analyzed blindly using standard NST criteria by one perinatologist. RESULTS: The MST group provided a significantly higher reactive rate than that of the NST group, 98.9% and 84.4% respectively, p < 0.001. Mean testing time of the reactive results of the MST group was also significantly shorter than that of the NST group, 7.94 +/- 6.27 min and 13.91 +/- 9.58 min respectively, p < 0.001. CONCLUSION: This is the first randomized controlled trial (RCT) to demonstrate the distinctive benefit of the simple and less expensive MST. MST significantly reduces the time to reactivity and increases the frequency of reactivity when compared to NST alone.

Rupture of fetal ductus arteriosus aneurysm.

BACKGROUND: Ductus arteriosus aneurysm is a rare fetal disorder. CASE: A 35-year-old primigravida had an uneventful antenatal course. Ultrasound examination at 30 weeks of gestation revealed hydramnios. The fetal ductus arteriosus became saccular and dilated with turbulent flow and diameter of 2.5 cm. It was located at the left upper thorax, just distal to the pulmonic valve and extended to the thoracic aorta. A ductus arteriosus aneurysm was diagnosed prenatally. Five days after diagnosis, preterm labor occurred, and dexamethasone and terbutaline were administered. Six hours after initiation of terbutaline, the fetal heart rate suddenly dropped to 90 beats per minute (bpm). A bedside ultrasound examination performed immediately showed profound bradycardia. The aneurysm became a heterogeneous hypoechoic mass with no pulsation, and the fetal heart rate suddenly disappeared. CONCLUSION: Ductus arteriosus aneurysm can be diagnosed prenatally, and terbutaline or dexamethasone may be associated with a risk for rupture.

Feto-maternal hemorrhage after cordocentesis at Maharaj Nakorn Chiang Mai Hospital.

OBJECTIVE: To evaluate the incidence and volume of feto-maternal hemorrhage following cordocentesis. STUDY DESIGN: Descriptive study. MATERIAL AND METHOD: One hundred and sixteen asymptomatic non-anemic pregnant women with an indication for cordocentesis at 18-22 weeks of gestation between January and June 2004 were recruited. Maternal blood samples were obtained immediately before and 30 minutes after cordocentesis. Fetal cells in the maternal blood were counted using Kleihauer Betke test. About 25,000 maternal cells per slide were scanned by the same examiner. Feto-maternal hemorrhage was considered significant if the fetal bleeding was more than 0.25 ml. RESULTS: There was a significant increase in fetal blood volume in maternal circulation after cordocentesis (Paired Students t test, p < 0.001). A significant hemorrhage (> 0.25 ml) occurred in 63 from 116 women (54. 7%). Only one had marked hemorrhage of more than 5.0 ml and none had massive hemorrhage (> 15 ml). CONCLUSION: Cordocentesis at 18-22 weeks of gestation can be associated with feto-maternal hemorrhage in more than half of the cases but nearly all cases had only minimal hemorrhage and none had massive hemorrhage.

Experience of the first 50 cases of cordocentesis after training with model.

OBJECTIVE: To describe the experience of the first 50 cases of cordocentesis after practicing with cordocentesis model. MATERIAL AND METHOD: Cordocentesis model consisted of a water-filled transparent glass box covered with a rubber latex sheet with or without piece of pork skin. A 30-cm umbilical cord filled with mercurochrome, hung inside the container, was the target for the puncture. As in real practice, the trainee had to try to aspirate the red mercurochrome from the umbilical cord using a spinal needle under ultrasonographic guidance. After practicing with the model for 300 procedures, the trainee was allowed to perform cordocentesis on pregnant women at gestational age of 18-22 weeks by herself under expert supervision with time limit of 30 minutes. The procedure not successful in 30 minutes was considered failure. Duration of procedures, placental site, puncture site, and related complications were recorded for subsequent analysis. RESULTS: After practicing with model for 300 procedures, real cordocentesis was performed by the trainee on 50 pregnant women. The success rate in obtaining fetal blood within 30 minutes was 100%. Most of them (92%) took less than 10 minutes to complete the procedure. Puncture site bleeding and fetal bradycardia were the most common immediate complications, found in 30% and 8% respectively, and spontaneously resolved within few minutes. CONCLUSION: Without any fetal and maternal jeopardy, cordocentesis model is simple, inexpensive but highly effective for the beginner to gain their experience, skill and prepare themselves for cordocentesis with confidence. However, the reduction of fetal loss rate with the training program remains to be further tested.

Update in pre-eclampsia.

Pre-eclampsia, formerly called pregnancy-induced hypertension, refers to the new onset of hypertension (SBP > or = 140 mmHg or DBP > or = 90 mmHg) and proteinuria (> or = 0.3 g protein in a 24-hour urine specimen or 1+ on dipstick) after 20 weeks of gestation in a previously normotensive women. It is a life-threatening, multi-organ involvement disease and remains the leading cause of maternal death. Its clinical manifestations are the result of generalized vasospasm, activation of the coagulation system, and changes in several humoral and autoregulatory systems related to volume and blood pressure control. Pre-eclampsia is responsible for high perinatal mortality and morbidity rates, primarily due to early termination of pregnancy. Fetus growth restriction, oligohyrdramnios and non-reassuring fetal status are the consequences of chronic placental hypoperfusion. Pre-eclampsia does not appear to accelerate fetal maturation, as once believed. Delivery remains the definitive treatment of choice for pre-eclampsia and should be timely. Cesarean section is not necessary and reserved for the obstetrical indications only. The expectant management may be considered for women remote from term (< 32 to 34 weeks of gestation) with stable and uncomplicated severe disease. The supportive management such as blood pressure control, seizure prevention, and fetal well-being assessment are also important to ensure the satisfactory outcome. To date, no screening test has been proved to be reliable and cost-effective. The prevention of pre-eclampsia with antioxidant therapy (vitamin C, E) has shown promise, but large, randomized trials are needed. Although controversy exists, calcium supplementation has shown no benefit in large trials, and most evidence suggests little or no benefit for low-dose aspirin as prevention in women in the low-risk category.

Prevalence of gestational diabetes mellitus (GDM) in women screened by glucose challenge test (GCT) at Maharaj Nakorn Chiang Mai Hospital.

OBJECTIVE: To assess the prevalence of GDM in GCT screened women at Maharaj Nakorn Chiang Mai Hospital. STUDY DESIGN: Retrospective descriptive study. SETTING: Department of Obstetric and Gynecology, Maharaj Nakorn Chiang Mai Hospital. MATERIAL AND METHOD: One thousand pregnant women who attended the antenatal care clinic and delivered at Maharaj Nakorn Chiang Mai Hospital from October 2001 to December 2002 were recruited into the study. Glucose challenge test (GCT), 50-g glucose oral load with 1-hr plasma glucose measurement, was performed in GDM high-risk pregnancies. If GCT was positive, oral glucose tolerance test (OGTT), 100-g glucose orally, was done to confirm the final diagnosis. All relevant data including demographic information, previous obstetric history, risk factors for GDM, GCT and OGTT results and pregnancy outcomes were collected for further statistical analysis. MAIN OUTCOME MEASURES: Prevalence of GDM in GCT screened women, obstetric complications and pregnancy outcomes. RESULTS: There were totally 1000 pregnancies enrolled into the study. Despite 451 pregnant women being eligible for GCT only 411 cases were tested with 164 positive results. 29 cases of GDM were detected with the prevalence of 7.05%. (CI 95% = 0.048, 0.099). As a result, the sensitivity, specificity, positive predictive value, and negative predictive value of GCT were 100%, 64.66%, 17.68% and 0%, respectively. In the GDM group, the common indications for GCT screening were advanced maternal age (75.4%), familial diabetic history (22.1%) and glycosuria (6.8%). Furthermore, only I case of pregnancy-induced hypertension was found with cesarean section, preterm birth, LGA and SGA of 27. 6%, 10.3%, 3.45% and 13.79%, respectively. There were 2 cases of pregestational diabetes mellitus (PGD; 0.2%) with 40 high-risk pregnancies (4%) without screening. CONCLUSION: The selective GCT screening strategy was highly effective and revealed 7.05% of GDM prevalence. Its impact on obstetric complication and pregnancy outcome was inconclusive due to the small number of studied population. Careful history reviewing plays an important role in identifying GDM risk factor for GCT screening.

Validity of antenatal diagnosis of intrauterine growth restriction by umbilical Doppler waveform index.

OBJECTIVE: To evaluate the validity of systolic/diastolic (S/D) ratio of the umbilical artery in predicting intrauterine growth restriction (IUGR). STUDY DESIGN: Diagnostic test study. SETTING: Maharaj Nakorn Chiang Mai Hospital, Chiang Mai University. SUBJECTS: Two hundred and twelve singleton pregnancies between 30 and 42 weeks' gestation with clinical suspicion of IUGR were recruited and followed-up between December 1st 1995 and June 30th 1998. They were sonographically examined for routine fetal biometry and S/D ratio of umbilical artery Doppler waveform measurement within 14 days of delivery. All of them had an accurate date of last menstrual period and were between 30-42 weeks' gestation. MATERIAL AND METHOD: The umbilical artery S/D ratio was obtained by the same experienced sonographer, using the same ultrasound machine, Aloka 680EX, (Tokyo, Japan). The S/D ratio of 3 or greater was considered abnormal, predicting IUGR prenatally for every gestational week. IUGR was defined as low birth weight of less than the 10th percentile of the standard birth weight curve of Maharaj Nakorn Chiang Mai Hospital. MAIN OUTCOME MEASURES: Sensitivity specificity positive predictive value and negative predictive value. RESULTS: The prevalence of IUGR among the study group was 50.9%. The S/D ratio of 3 or greater for predicting of IUGR gave the sensitivity, specificity, positive predictive value, and negative predictive value of 52.96%, 78.85%, 74.42% and 65.08%, respectively. CONCLUSION: The umbilical artery S/D ratio has relatively low sensitivity and is not a suitable test for IUGR screening. However, the specificity is rather high and it may be helpful in combination with other parameters.

Prenatal diagnosis of alpha-thalassemia-1 (SEA type) by chorionic villus sampling.

OBJECTIVE: To describe the experience of prenatal diagnosis for Hb Bart's disease, by chorionic villus sampling (CVS) with DNA analysis. DESIGN: Descriptive study SETTINGS: Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University. SUBJECTS: Sixteen high risk pregnancies at risk of Hb Bart's disease who were eligible for CVS criteria between 1 January, 1999 and May 31, 2000. MATERIAL AND METHOD: Fetal villi were obtained by either transcervical (TC) or transabdominal (TA) CVS route to extract DNA and detect for alpha-thal-1 gene deletion (SEA type) with modified Chang's method. The CVS results were confirmed by either serial ultrasound or cordocentesis or diagnosis after pregnancy termination. MAIN OUTCOME MEASURES: The efficacy, safety and pregnancy outcomes. RESULTS: CVS was successfully done in all of 16 cases (5 with TC and 11 with TA), The mean gestational age was 13.25 +/- 2.9 weeks. The procedure time for TA was shorter than that of TC (4.64 +/- 5.4 vs 10.4 +/- 11.3 min). The CVS result showed as follows: 3 normal fetuses, 7 alpha-thal-1 carriers, 4 fetal Hb Bart's, 1 misdiagnosis and 1 failure to diagnosis due to technical error. The sensitivity and specificity were 100 per cent (4/4) and 90.91 per cent (10/11), respectively. One case of Hb Bart's misdiagnosis and one failure case were later confirmed for alpha-thal-1 trait and alpha-thal-1/ Hb E trait by cordocentesis, respectively. The pregnancy outcomes included 11 livebirths, 4 terminated cases and 1 fetal loss of continuing pregnancies. No serious complications occurred. CONCLUSION: This preliminary experience suggests that CVS is an effective method for early prenatal diagnosis of fetal Hb Bart's.