Prenatal sex determination in Thai pregnant subjects by nested-PCR amplification of fetal Y chromosome-specific sequence.

Detection of a Y-specific sequence in either amniotic cells or the maternal circulation has clinical importance for prenatal sex diagnosis, especially in mothers with severe X-linked disorders. Deoxyribonucleic acid sequences of human ZFY (zinc-finger-Y) gene, a Y-chromosome-specific gene and candidate for the testis-determining factor, were amplified by in vitro nested PCR technique, in amniotic cells or peripheral blood of Thai pregnant subjects carrying male fetuses. This technique permits detection of ZFY gene DNA sequences in as few as a single male cell among 100,000 female cells. The subjects in this study were a group of Thai pregnant women who had been given prenatal fetal sex diagnosis by the cytogenetic method. The results herein demonstrated the usefulness of PCR detection of Y-specific sequences in amniotic cells. The ZFY gene detection method for prenatal sex prediction by nested PCR has been developed experimentally. However, further investigation is necessary to increase reliability of clinical application. With properly designed guidelines, the established nested-PCR technique may be an alternative for the determination of the fetal sex for those pregnancies at risk of X-linked genetic disorders.

Diagnosis of ectopic pregnancy by ultrasound in Siriraj Hospital.

The study of the diagnosis of ectopic pregnancy was carried out during the whole year of 1988 in the Department of Obstetrics & Gynaecology, Siriraj Hospital, in order to find out the characteristics of ultrasonographic findings by using real time ultrasound. Real time ultrasound examination was carried out on 121 patients with suspicion of ectopic pregnancy. The final diagnosis among these patients was ectopic pregnancy, ruptured corpus luteum, ruptured appendicitis, normal pregnancy, abortion, adnexal mass and no gynecologic abnormality encountered in 21 (17.35%), 3 (2.48%), 1 (0.83%), 27 (22.31%), 4 (3.3%), 43 (35.54%) and 22 (18.18%) respectively. Of 21 patients with ectopic pregnancy 17 (80.95%) cases were between 15-30 years of age with the gestational age ranging from 6 to 12 weeks in 16 patients (76.19%). The majority of the patients 18 (85.7%) were para 0-3. The ultrasonographic findings were pelvic mass and fluid in the cul de sac, pelvic mass and fluid in the cul de sac, pelvic mass only and the presence of free fluid alone encountered in 17 (80.95%), 3 (14.28%) and 1 (4.76%) cases respectively.

Percutaneous umbilical cord blood sampling.

Percutaneous umbilical cord blood sampling is a newer, safer, and more convenient technique and can be performed in the second and third trimester of pregnancy by direct puncture of the umbilical vein near its placental insertion, using a needle guided by ultrasound. Between 2-4 ml of pure fetal blood were obtained from 10 pregnancies at between 19 and 39 weeks' gestation. This new procedure offers access to the fetal circulation for diagnosis and therapeutic purposes.

Amniocentesis guided by ultrasound.

Abdominal amniocentesis was performed on 252 pregnant women at Siriraj Hospital during the period from August 1984 to July 1985, 227 cases for fetal lung maturity and 25 cases for genetic study in second trimester. Failure to obtain amniotic fluid encountered in 11 cases (4.36 percent) was directly associated with placental site, fetal position, amount of amniotic fluid and some technical error. Among the complication occurred in 4 cases (1.76 percent).There were premature rupture of membranes, chorioamnionitis, fetal trauma and one case of abortion in second trimester amniocentesis for chromosome study. The results of this study show that failure rate, bloody taped amniotic taped amniotic fluid and major complication can be reduced by using ultrasound guidance.

Chromosome study of partial hydatidiform mole: A case report.

A case of partial hydatidiform mole was admitted with hyperemesis gravidarum, human chorionic gonadotrophine was at high level. Ultrasonographic study showed the empty gestational sac with enlarged placenta which had cystic change in some area. The histologic study showed only hydatidiform mole but chromosome study confirmed classical partial hydatidiform mole which had a triploid (69 XXY) constitution. The clinical findings, ultrasound study and HCG level can emphasize this condition. Histologic and genetic study will confirm the diagnosis.

Partial hydatidiform mole: Report of 1 case.

A case of partial hydatidiform mole admitted with pre-eclampsia delivery of a living baby at 34 weeks was reported. Ultrasonographic study showed foetus with intrauterine growth retardation and cystic change of the placenta. The final diagnosis was made by pathologic histology. We suggested the clinical findings and ultrasonographic findings reminded the physician that some of this foetus has chromosome abnormalities. Correct diagnosis prenatally, will make the opportunity for the physician to manage such cases properly.