Parathyroid hormone-related peptide in the human fetal uro-genital tract.

Using a polyclonal antiserum raised against the first 34 amino acids of human parathyroid hormone-related peptide (PTHrP), we have localized PTHrP throughout the uro-genital tract of the human fetus aged between 8 and 40 weeks. Staining was present in the developing mesonephros, metanephros, gonads and in both the adrenal cortex and medulla. In particular, the developing mesonephric and metanephric renal tubules were intensely positive. Using Northern hybridization analysis we have detected a complex pattern of PTHrP mRNA transcripts ranging in size from 1.4 to 4.5 kb in early second trimester human fetal kidney. The presence of PTHrP in the mesonephros and metanephros provides evidence for a role for PTHrP in the regulation of fetal calcium metabolism. However, its presence in the gonad and adrenal gland invites the possibility of a wider role for PTHrP.

Listeriosis revisited: the role of the obstetrician.

The clinical course and outcome is described of three pregnancies complicated by listeriosis encountered during a 6-month period. All three ended in preterm labour characterized by the passage of meconium by the fetus. Two babies died in the early neonatal period and the third survived with neurological handicap. Although the diagnosis of listeriosis was made only after delivery, all the mothers had a pyrexial illness before delivery. A high index of suspicion is needed for the early detection and prompt treatment of this life-threatening perinatal infection. Effective advice concerning prevention of listeriosis by avoidance of high-risk foods must be given to women during pregnancy.

Morphometry of the second trimester fetal brain. Comparison of ultrasonographic and post-mortem findings.

With the increasing use of ultrasound examination in the antenatal period the lack of morphological correlates has become a problem. This study was carried out in order to correct this deficiency. An antenatal real-time ultrasound scan of the fetal head was performed and measurements of the biparietal diameter, occipitofrontal diameter, head circumference and cerebral ventricle-to-hemisphere ratio were undertaken in 103 fetuses at 13-24 weeks gestation. After prostaglandin termination of pregnancy, the fetal brains were perfused in situ through the right carotid artery with 10% formal saline. Horizontal slices of the fetal head were cut, photographs were obtained and measurements of the same parameters as in the ultrasound examination were undertaken. There is a significant correlation (p less than 0.001) between the ultrasonographic and post-mortem measurements of all parameters. Also several anatomical structures of the fetal brain are now confidently identified in the antenatal ultrasound scan, using the anatomical preparations for comparison.

Calcium homeostasis in second trimester fetuses.

The concentrations of ionised calcium ions (Ca++), total calcium, parathyroid hormone, pH, total protein, albumin, sodium, and potassium were measured in paired fetal and maternal blood from pregnancies at 15 to 24 weeks' gestation. Pure fetal blood samples were obtained fetoscopically. The concentrations of fetal ionised calcium ions (n = 26); mean (SD) 1.33 (0.12) mmol/l (5.32 (0.48) mg/100 ml) and those of parathyroid hormone (n = 9); 68 (19) pmol/l (58 (16) micrograms/100 ml) were significantly higher than those of the mothers: 1.18 (0.09) mmol/l (4.7 (0.4) mg/100 ml), and 40 pmol/l (less than 34 micrograms/100 ml), respectively. There was no difference between measured fetal and maternal total calcium, pH, and electrolytes. The fetal total protein and albumin concentrations increased with gestation but were always lower than the equivalent maternal values. The calculated total calcium was 0.23-0.45 mmol/l (0.9-1.8 mg/100 ml) higher in the fetal than in maternal blood from the same pregnancy. There were no fetal arteriovenous differences in ionised calcium ions despite higher venous pH.

Prenatal measurement of the fetal cerebellum and cisterna cerebellomedullaris by ultrasound.

The fetal cerebellum can be visualized with ultrasound throughout the second trimester. We describe a technique for measuring the transverse and anteroposterior cerebellar diameters and the measurement of the cisterna magna in the same plane between 14 and 32 weeks gestation. Nomograms for these measurements against gestational age showed good correlation, and narrow confidence limits for the transverse cerebellar diameter. The transverse cerebellar diameter was also measured directly in 79 fetuses after midtrimester abortion and the measurements obtained were compared with the ultrasound TCD nomogram. Good correlation, was obtained between the post mortem measurements and the ultrasound TCD nomogram. Routine use of these measurements and nomograms should prove valuable in the diagnosis of congenital abnormality of the posterior fossa and may also be of use in assessing the effect of severe intrauterine growth retardation and other insults on cerebellar growth and development. The narrow confidence limits obtained with the TCD nomogram should enable it to be used with confidence in clinical practice.

The safety of fetoscopy: (I). Effect of umbilical vessel puncture on the fetal heart rate and cord histology.

The fetal heart rate (FHR) was continuously monitored during 42 umbilical vessel punctures performed at the placental insertion of the cord in 24 diagnostic fetoscopies in which pure fetal blood was obtained. In only one patient did a deceleration first appear during puncture and aspiration of fetal blood. In two patients decelerations preceded fetoscopy and in two others they began during the fetoscopy but before puncture of an umbilical vessel. In 19 patients, the FHR did not change at all during the procedure. Fetal haemorrhage after sampling was either absent or minimal. Six pregnancies were terminated because a positive diagnosis had been made and 18 healthy babies were born. Umbilical cords were examined after 7 terminations of pregnancy and after 6 deliveries. In the former group the puncture could just be seen with the naked eye and the needle track was demonstrated histologically in 6. No traces of the puncture or other abnormalities were found in the cords after delivery. Fetal blood sampling from umbilical cord vessels, particularly at the placental insertion of the cord, is the technique of choice since pure fetal blood can be obtained without increasing the risk of fetoscopy.

Hepatic portoenterostomy for biliary atresia. A comparative study of histology and prognosis after surgery.

Specimens of excised tissue from the porta hepatis in 26 infants with extrahepatic biliary atresia undergoing hepatic portoenterostomy were analysed histologically for the presence and size of biliary ductules. No correlation could be found between the establishment of effective biliary drainage and the number or size of biliary ductules. it is suggested that prognosis after surgery may be related to the intrahepatic lesion and age of the child at operation rather than to the histology of the extrahepatic bile duct remnants.