Effect of adrenaline on extradural anaesthesia, plasma lignocaine concentrations and the feto-placental unit during elective caesarean section.

Extradural anaesthesia was induced with either 2% lignocaine or 2% lignocaine with adrenaline 1:200,000 in 20 patients undergoing elective Caesarean section. With the adrenaline-containing solution, a smaller dose of lignocaine was required to produce an adequate block and the lignocaine concentrations in both mother and neonate were significantly smaller compared with the plain solution. Arterial pressures were less in the adrenaline group, but there was no difference in umbilical flow velocity waveform, fetal heart rate or fetal outcome.

Monozygotic twin pregnancy: diagnostic and Doppler ultrasound studies.

Of 178 consecutive twin pregnancies, 63 were both monozygotic and also studied prenatally by real-time B-scan (and usually Doppler) ultrasound. The 48 pregnancies with monochorionic placentas (in which vascular anastomoses are almost universal) were compared with the 15 monozygotic pregnancies having dichorionic placentas. The type of placenta found at delivery was predicted with substantial accuracy by ultrasound examination in mid-pregnancy.

Prediction of the small for gestational age twin fetus by Doppler umbilical artery waveform analysis.

In 89 consecutive twin pregnancies, monthly Doppler ultrasound measurements were made of the umbilical artery blood flow velocity waveforms of each fetus. In total, 453 Doppler studies were performed. Of the 178 infants, 32 were small for gestational age (SGA); only 24 of the 82 SGA Doppler studies were abnormal, giving an overall sensitivity of the test in the prediction of the SGA fetus of 29% and a positive predictive value of 34%.

Twin-to-twin transfusion syndrome: what are appropriate diagnostic criteria?

One hundred seventy-eight consecutive twin pregnancies were studied to reevaluate the standard diagnostic criteria for chronic twin-to-twin transfusion syndrome of an intertwin hemoglobin difference greater than 5 gm/dl and a birth weight difference greater than 20%. Hemoglobin differences greater than 5 gm/dl were found in six pregnancies with monochorionic placentas but also in seven with dichorionic placentas. Birth weight differences greater than 20% occurred no more commonly in monochorionic than in dichorionic pregnancies.

Value of antenatal diagnosis of abnormalities of the urinary tract.

Objective: To assess the value of antenatal diagnosis of abnormalities of the urinary tract on ultrasonography.

Design: Retrospective study.

Setting: Two obstetric units in Glasgow.