Prenatal diagnosis of hemoglobin Bart's hydrops fetalis by HPLC analysis of hemoglobin in fetal blood samples.

Since HbF and HbA are not found in fetuses with Hb Bart's hydrops fetalis the feasibility of prenatal diagnosis of homozygous alpha-thalassemia 1 by fetal hemoglobin typing was examined. Blood samples were obtained from fetuses at 18 to 22 weeks of gestation by cordocentesis in 32 pregnant women at risk of having a child with homozygous alpha-thalassemia 1 (alpha-thal-1). The samples were analyzed by a PCR-based method for the diagnosis of alpha-thal-1 (SEA type) and the proportion of hemoglobin fractions were determined by automated HPLC. DNA analysis showed that 8 of the 32 fetuses were homozygotes for alpha-thal-1, 17 were heterozygous for alpha-thal-1 (alpha-thal-1 trait), and a normal complement of four a-globin genes was found in 7 cases. The Hb typing in fetuses with homozygous alpha-thal-1 showed a peak of unbound Hb (Hb Bart's and Hb Portland) and no HbF, HbA and HbA The alpha-thal-1 trait chromatograms showed unbound Hb, pre HbF, HbF and HbA peaks. The chromatogram of normal fetuses showed HbF and HbA peaks without HbA2. In these cases the HbA proportion is between 3% and 10% with no apparent differences between the 18h and 22nd week of gestation. As the analysis of fetal Hb types by HPLC is facile and speedy and the results correspond with those obtained by DNA analysis, fetal Hb typing by automated HPLC is a convenient prenatal diagnostic method for homozygous alpha-thal-1. The method is recommended for prenatal diagnosis in populations with a high frequency of alpha-thal-1.

Prenatal sonographic markers of trisomy 21.

OBJECTIVE: To describe the sonographic characteristics of fetuses with trisomy 21. DESIGN: A prospective descriptive analysis. SETTING: Department of Obstetrics and Gynecology, Faculty of Medicine, Maharaj Nakorn Chiang Mai Hospital, Chiang Mai University. SUBJECTS: Pregnancies at risk of trisomy 21 between 14-27 weeks' gestation. RESULTS: Thirty-six fetuses with subsequently proven trisomy 21 were prenatally evaluated by ultrasound in the second trimester. The main indications for detailed ultrasound examinations were advanced maternal age and abnormal findings on routine ultrasound. All of them had chromosome analysis by amniocentesis or cordocentesis. Nineteen (52.78%) had one or more abnormal findings. The common sonographic findings included thickened nuchal fold (33.33%), short femur (19.44%), and mild pyelectasis (22.22%). The other uncommon abnormalities included major anomalies (cardiac malformations, ventriculomegaly, duodenal atresia, esophageal atresia), hyperechoic bowel, echogenic intracardiac foci, abnormalities of extremities. In this study, rare minor markers but more specific markers including sandal gap, clinodactyly and mid-phalanx hypoplasia of the fifth finger were demonstrated. CONCLUSION: About half of the fetuses with trisomy 21 had abnormal sonographic findings in the second trimester. The most common marker was thickened nuchal fold. Although prenatal ultrasound can not permit a definite diagnosis of trisomy 21, about half of them have sonographic markers, warranting cytogenetic testing.

Sonographic morphology scores (SMS) for differentiation between benign and malignant ovarian tumor.

The objectives of this cross-sectional descriptive analysis are to determine the sensitivity and specificity of sonographic morphology scores (SMS) in distinguishing between benign and malignant ovarian tumors and to determine the best cut-off score. The study was conducted at the Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University. Two hundred and forty eight nonpregnant patients scheduled for elective surgery for ovarian tumors between July, 1996 and March, 1998 were recruited into the study and were sonographically examined in 24 hours of surgery by the same sonographer to evaluate inner wall structure, wall thickness, septum, echogenicity and score of the tumors. The final diagnosis was pathologically confirmed as the gold standard. It was found that the score of 9 from reciever operating characteristic curve was the best cut-off score, giving the sensitivity of 93.1 per cent and specificity of 75.6 per cent. In conclusion, the SMS system is probably useful in distinguishing ovarian malignancy from benign ovarian tumor.

Prenatal diagnosis: 10-year experience.

To evaluate the indications and results of prenatal diagnosis of the high risk pregnant women attending the antenatal care clinic at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai University during 1988-1998, we analysed 2,315 amniocenteses, 1,000 cordocenteses, and 11,895 obstetric ultrasound examinations. Among the amniocentesis group, 2,017 cases (87%) were done with the indication of advanced maternal age. The prevalence of major abnormal fetal chromosomes among high risk pregnancies was 1:58. Of 1,000 cases with cordocentesis, the most common indication was fetal risk of severe thalassemia (658 cases; 65.8%) and followed by fetal risk of chromosome abnormalities (272 cases; 27.2%). In the group of cordocentesis for diagnosis of thalassemia, 99 and 49 pregnancies were affected with Hb Bart's disease and homozygous beta-thalassemia, respectively. Thirty three cases with indication of chromosome analysis had fetuses with abnormal chromosomes. The major indications of ultrasonography included suspicion of intrauterine growth restriction (IUGR), determination of gestational age and screening anomalies, respectively. In conclusion, our extensive experience has enabled us to prenatally detect most fetuses with severe thalassemia, and fetuses with abnormal chromosomes as well as anomalies in a significant number, contributing a great deal to our population. Therefore, we recommend that systematic prenatal diagnosis, either amniocentesis, cordocentesis or ultrasound should be provided to every high risk pregnant woman for a healthy newborn.

Prenatal sonographic diagnosis of holoprosencephaly.

The purpose of this series was to describe the sonographic features of fetal holoprosencephaly prenatally. The study was undertaken at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai University. A total of 12 fetuses with prenatal diagnosis of holoprosencephaly were sonographically evaluated and followed-up. The study revealed that all showed monoventricular cavity, fused thalami, no falx and cavum septum pellucidum. Eight of them were correctly diagnosed sonographically in the first two trimesters. Extrafacial anomalies were also identified in half of the fetuses and all of them had facial abnormalities. Twenty-five per cent (3 cases) had polyhydramnios and only one case had oligohydramnios. Chromosome study revealed that 70 per cent had normal chromosomes, 30 per cent were aneuploidy, trisomy 13; 2 cases and trisomy 18; 1 case. In conclusion, this series indicates that ultrasound has a high predictive value in the diagnosis of holoprosencephaly. The most valuable clue to the diagnosis is the demonstration of the single ventricle. Additionally, demonstration of facial abnormalities may add confidence to the diagnosis. Conversely, should any of these facial features be serendipitously encountered, a careful examination of the intracranial contents is recommended.

Sexually transmitted disease prevalence in brothel-based commercial sex workers in Chiang Mai, Thailand: impact of the condom use campaign.

One hundred and ninety five (195) brothel-based commercial sex workers (CSW) in Chiang Mai, Thailand, were screened for sexually transmitted disease (STD) between October 1994 and April 1995, prior to their enrollment in a multi-center comparative trial of the effectiveness of two strategies using male and female condoms. These CSW had a mean age of 22.2 (SD 4.3) years. Forty-seven per cent were Thai and 57.4 per cent had no formal education. Median duration of prostitution was 16 months and median cost for sexual service was 50 baht (US$ 2) per client. Ninety-four per cent of CSW reported always using condoms with clients. There were 63 (32.3%) CSW infected with at least one type of the STD screened. The prevalence of STD included chlamydial infection (16.9%), gonococcal infection (14.4%), condyloma accuminata (4.6%), moluscum contagiosum (2.6%) and trichomoniasis (1.0%). There was no statistically significant risk factor for STD found in this study. Despite an active programme for prevention of STD in CSW and the provision of free condoms, STD were diagnosed in one-third of the screened CSW in Chiang Mai. The programme needs to be strengthened by more intensive education and practice in the correct and consistent use of condoms and integrated with other STD prevention programmes.

Study of intrauterine growth from birthweight at Maharaj Nakhon Chiang Mai Hospital.

Intrauterine growth curve and normogram for newborns at Maharaj Nakhon Chiang Mai Hospital are constructed. Birthweight at various gestational weeks of deliveries were determined within 24 hrs after birth. All 1,311 Thai pregnant women selected, fitted the criteria of inclusion deliveries at Maharaj Nakhon Chiang Mai Hospital from May 1983 to April 1991 (8 yrs). Their gestational age distribution was between 28 wks to 42 wks. Clinical status at birth was satisfactory. There were no obstetric or medical complications during pregnancy. Mean birthweight and standard deviation of newborns for each gestational age at delivery were calculated and presented in tabular and graphic form. Mean birthweight for 40 wks of gestation was 3.144 +/- 382 g. In addition, normogram of 10th, 50th, 90th percentile ranks of birthweight for each gestational age was constructed. These values may be useful as baseline data of intrauterine growth curve to evaluate fetal growth in our population.

Ultrasonic measurement of the fetal head to abdominal circumference ratio in normal pregnancy.

The relation between fetal HC/AC ratio and menstrual age was determined from 14th-40th weeks gestations by analysis of 1,211 measurements examined with real-time ultrasound scanner Aloka 630, 650. The mean HC/AC ratio with +/- 2SD and percentile ranks were determined and presented in both graphic and tabular forms. The mean ratio was 1.207 at 14 week's but decreased slowly until 30 week's when the ratio was 1.110 thereafter there was a rather sharp fall in the mean ratio 1.010 at 36 weeks and 0.967 at 40 weeks and then the variability decreases. Interestingly, HC/AC ratio value for each gestational week in this study was not so different from those of western studies. We hope that the value from this large series is important baseline data for evaluation of fetal growth in our population and is more appropriate for application with Thai women than caucasian data.

Ultrasonic fetal transverse trunk diameter in normal northern Thai women.

Fetal transverse trunk diameter (TTD) were measured by two obstetric sonographers, using Aloka model SSD 630 and 650. The measurements were performed on 1,009 occasions in 235 women during normal pregnancies between the 14th and 40th weeks (age range 17-37 years) (4.5 measurements per pregnancy, on average). The relation between TTD and menstrual age was determined and mathematical modeling of the data demonstrated that the linear quadratic function was optimal (r2 = 0.973). The most fitted regression equation was obtained by regression analysis. 1.) TTD = -2.69055 + 0.38326 G.A - 0.00140137 GA2 2.) GA = 7.222585 + 2.82632 TTD + 0.02605 TTD2. Interestingly, TTD value for each gestational week in this study is not so different from that of the European data. Predicted TTD values for a given gestational week were determined and presented in tabular form. The values from this study may be important baseline data for evaluation of fetal growth in our population.

Sonographic femur length/abdominal circumference ratio in normal pregnancies among Thais.

The relationship between sonographically measured foetal length (FL) and abdominal circumference (AC) (expressed as FL/AC ratio * 100) was studied in 455 normal pregnancies between the 14th and 40th gestational weeks. By analysis of 1,197 measurements for each parameter, this ratio was found to be independent of menstrual age, with a normal range after 21 weeks (mean + 2 S.D.) of 2038 + 2.6. This mean ratio is different from the values of a previous western study (22+2). The ratio obtained from the Thai study hopefully will be the baseline for the Thai population and may be used for further study about intrauterine growth retardation.