Peter Renou

Controlled trial of fetal intensive care

A fetal intensive care unit was formed at the Queen Victoria Memorial Hospital in 1972. Because of some doubt concerning the value of fetal intensive care, a controlled clinical trial including all high-risk patients was performed. The trial clearly showed that intensive care is associated with improved neurologic and biochemical status of the neonate; however, it is possible that this improvement results from the use of fetal diagnostic tests or some other factor associated with intensive care. Sufficient evidence was gathered to warrant the continuation of fetal intensive care in this hospital, but in other contries, where funding is difficult to obtain, a controlled trial would appear justified.

The collection of human oocytes for in vitro fertilization. I. An instrument for maximizing oocyte recovery rate

An instrument has been devised specifically for the collection of mature oocytes of laparoscopy for the purpose of in vitro fertilization. The instrument was evaluated and the oocytes recovery rate was compared with that obtained with two other instruments, which had been in use previously, in a controlled trial over the same period of time. It was found that the newly devised instrument resulted in the recovery of all of the oocytes from 17 follicles in which aspiration was attempted. The oocytes recovery rate was significantly better with this instrument than with either of the two instrument previously used. It was also apparent that the finer-bore needle of the two instruments previously used was more effective for oocytes recovery. The new instrument is now in routine use for oocyte collection.

A randomized trial of weekly cardiotocography in highrisk obstetric patients

Summary. A randomized clinical trial of once‐weekly antenatal fetal heart rate monitoring in 539 high‐risk patients could find no benefit of monitoring in terms of perinatal mortality, morbidity or Apgar score. The previously well‐documented association between abnormal antenatal fetal heart rate traces and low Apgar score was confirmed. A detailed case review showed that in this population monitoring was irrelevant to almost all of the 13 perinatal deaths.

A failed RCT to determine the best method of delivery for very low birth weight infants

An RCT to determine the optimum method of delivery for very low birth weight (VLBW) infants was canceled after it had been in progress for only 5 months when it was discovered that more than 40% of eligible patients were being withdrawn from the trial before randomization. A review of hospital births before the trial began suggested that the trial was held too late: that a critical shift in obstetric practice towards abdominal delivery of VLBW infants had already occurred. Obtaining patient consent to participation, which had been the main predicted problem, was not difficult.

Transvaginal recovery of oocytes for in vitro fertilization using vaginal ultrasound

Vaginal recovery of oocytes for in vitro fertilization (IVF) was performed in 75 patients using a vaginal puncture transducer. Follicles were aspirated and flushed four times using a controlled vacuum. Oocytes were collected in 74 patients and an average of 5.1 oocytes was collected per patient. An average of 8.8 follicles was aspirated per procedure, giving an oocyte recovery rate of 58% per follicle. Pregnancy was obtained in seven patients (9.3%). The only complication was bleeding from the vagina of an estimated 40 ml in one case.

Clinical features of eight pregnancies resulting from· in vitro fertilization and embryo transfer

In vitro fertilization (IVF) and embryo transfer (ET) have resulted in the birth of nine babies, including twins. One of the twins had a congenital cardiac malformation and seven of the nine babies were girls. Labor occurred preterm in two pregnancies; and in six delivery was by cesarean section. Plasma human chorionic gonadotropin (hCG), progesterone (P), and estriol (E3) measurements and ultrasonic scans showed no obvious differences from pregnancies resulting from natural conception. Cytogenetic studies from cord blood and histologic examination of the placentas were unremarkable. The theoretic risks of pregnancy following IVF and ET are discussed. Definite conclusions cannot be drawn until a large number of babies are delivered and a long-term follow-up is completed. Initial results from the current small sample are encouraging.

FETAL SCALP TISSUE OXYGEN TENSION MEASUREMENTS IN RELATION TO MATERNAL DERMAL OXYGEN TENSION AND FETAL HEART RATE

A membrane covered tissue Po2 electrode is described which can be applied to the fetal scalp early in labour to provide a continuous measurement of fetal tissue Po2. The use of a membrane cover has reduced the oxygen consumption of the electrode and its sensitivity to diffusion conditions in the region of measurement so that it may be calibrated in absolute terms. When the oxygen concentration breathed by the mother was reduced from 100 to 21 per cent or from 21 to 15 per cent fetal tissue Po2 declined more slowly than the maternal tissue Po2. Changes in fetal tissue Po2 associated with various patterns of transitory fetal heart rate change are also presented.

Correlation between urinary estriol excretion and fetal acidosis in high-risk pregnancies.

Abstract Urinary estriol excretion and fetal acid-base status were measured in 80 patients with high-risk pregnancies. Estriol excretion was below normal limits in 24 patients (30 per cent), and in this group the incidence of pH values less than 7.20 was 41 per cent, which was significantly different from that in patients with normal estriol values (p

The utilisation of nuchal translucency as a prenatal marker of Down syndrome, 1993–1999

Summary: A sample of 6038 obstetric ultrasound referrals and reports between January 1993 and June 1999 in a single Melbourne private ultrasound practice was reviewed to determine whether the referral and reporting pattern for nuchal translucency (NT) measurement has changed. The proportion of both 10–14 week ultrasound scans and mid trimester fetal anatomy scan referrals increased significantly over the study period (p < 0.001 and p < 0.001, respectively). There was also a significant increase in NT reporting and the number of specific referrals for an NT measurement over the study period (p = 0.01 and p < 0.001, respectively). If current trends continue it is likely that the 10–14 week scan for NT measurement will become a routine component of antenatal care. Therefore, as a matter of urgency, it is imperative that the best and most cost‐effective screening strategy for Down syndrome in an Australian population is defined

An applicator for the Hulka fallopian tube clip

Use of the Hulka spring clip has advantages over other methods of occluding the fallopian tubes. Since difficulties were experienced with clip applicators from two manufactures, an improved applicator was designed. A similar applicator for use at minilaparotomy is described also.