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Biomedical subjects

L R Leader

Publications and source records attributed to L R Leader.

9 recordsLinked to original sources

The use of clearplan home ovulation detection kits in unexplained and male factor infertility.

One hundred and five couples with unexplained infertility and 43 couples whose infertility was thought to be due to reduced sperm motility were recruited. The median duration of infertility was 36 months (range 12-168). Couples were randomly allocated to either using Clearplan home ovulation detection kits for 3 cycles or were advised about the optimal time during their menstrual cycle to achieve a pregnancy. The clinical details of the 2 groups were similar. In couples with unexplained infertility over the study period 10 (20.4%) in the Clearplan group and 9 (16%) in the control group conceived with 58% of pregnancies occurring in the first cycle. In couples with reduced sperm motility, the results were disappointing with only 2 (8%) pregnancies in the Clearplan group and 2 (11.1%) in the controls. Assisted reproduction technology may not be justified as the first line of management in patients with unexplained infertility.

Adult

Vaginal delivery after caesarean section.

In a prospective study of 318 consecutive pregnancies complicated by previous Caesarean section, 193 (61%) had an elective repeat Caesarean section, 125 (39%) had a trial of labour and 80 (64%) of these women achieved a vaginal delivery. The incidence of uterine rupture was 0.8% (1 of 125). The vaginal delivery rate was not influenced by the indication for the first Caesarean section (including cephalopelvic disproportion), birth-weight, health insurance status, use of epidural analgesia or oxytocin in labour. Perinatal morbidity was unaffected by the mode of delivery and maternal morbidity was comparable following elective and emergency repeat Caesarean section. Patients having a vaginal deliver spent significantly less time in hospital. We conclude that vaginal delivery after lower segment Caesarean section is safe and should be considered in most patients after a critical review of the indication for the first Caesarean section.

Female

The clinical value of Clearplan home ovulation detection kits in infertility practice.

A home ovulation testing kit, Clearplan, that detects the urinary luteinizing hormone (LH) surge was used by 32 patients on a donor insemination programme for 50 cycles to indicate when to first attend the clinic for a serum LH test to determine ovulation. Using Clearplan significantly reduced the number of clinic attendances (4.06 +/- 1.5) compared to the preceding control cycle (7.06 +/- 2.0 p less than 0.001). One serum LH peak was missed using Clearplan. Ovulation was predicted within 2 days of the serum LH surge in 77% of cycles. Home ovulation determination has the potential to reduce the stress and cost of fertility programmes.

Appointments and Schedules

Effect of hypoxia and catecholamines on the habituation rates of chronically catheterized ovine fetuses.

Integrated electromyographic, electrocortical (ECoG) and electro-ocular activity were recorded in 13 chronically prepared fetal sheep (130-145 days). Fetal movements and the rate of habituation to repeated suffusions of cold saline against the fetal skin were recorded. Experiments were repeated during an intravenous infusion of noradrenaline to the fetus (0.4 microgram/kg estimated fetal weight/min) and during hypoxia induced by altering the oxygen content of the inspired air to the ewe to 9%. Repeated stimulation with cold saline resulted in an increase in fetal movements (p = 0.009). The number of stimuli for habituation was similar in high-voltage and in low-voltage ECoG activity. The rate of fetal habituation was significantly faster during the infusion of noradrenaline compared with control measurements (p = 0.009). During hypoxia, the number of spontaneous fetal movements prior to stimulation decreased (p = 0.002). Habituation rates were also faster during hypoxemia compared with control measurements (p = 0.003). These findings may help to explain the rapid habituation rates seen in some human fetuses in at 'at risk' pregnancies.

Acoustic Stimulation

The changes in fetal habituation patterns due to a decrease in inspired maternal oxygen.

Habituation is widely regarded as a basic form of learning. A fully functioning central nervous system is probably required for a normal habituation pattern. Habituation of the behavioural response to vibroacoustic stimulation was studied in 23 normal human fetuses whose gestational age was 36 or more weeks. Eighteen were tested whilst their mothers breathed either air or a 12% oxygen in nitrogen mixture. The test was repeated the following day with the order of the gases reversed. In addition five fetuses were tested while their mothers breathed air on both occasions. Of the 18 fetuses 17 had a normal habituation pattern when tested in air but only two had a normal pattern when their mothers breathed 12% O2. Four of the five fetuses tested both days in air had normal patterns on the second day. Altering the amount of inspired maternal O2 alters the fetal habituation pattern.

Female

Measurement of fetal responses to vibroacoustic stimuli. Habituation in fetal sheep.

Electrocortical (ECoG) and integrated electromyographic (EMG) activity was recorded in 6 chronically prepared fetal sheep (132-145 days). Recording were made in fetuses prior to and during repeated vibroacoustic stimulation. In the undisturbed fetus, two patterns of ECoG activity were apparent; high (HV) and low voltage (LV). The fetus responded to this broad spectrum stimulus during both LV and HV ECoG activity. In 18 of the 20 experiments, repeated stimulation was not associated with a change in the background ECoG activity. All fetuses responded at least once to the stimulus. Habituation of the EMG response was observed during both HV and LV ECoG activity. The rate of habituation was independent of the background ECoG activity and was unchanged when experiments were repeated at intervals of more than 3 days. These results show that fetal sheep also respond to vibroacoustic stimulation and with repetition habituation occurs.

Acoustic Stimulation

The accuracy of maternal observation of fetal movements.

The accuracy of maternal observation of fetal movements was assessed in 20 patients during the last trimester of pregnancy. The effect of factors such as smoking, obesity, education and gestational age were correlated with maternal observations to establish the accuracy of the latter.

Female

The effect of ethanol on habituation and the cardiovascular response to stimulation in fetal sheep.

Fetal cardiovascular (CVS) changes, forelimb movements (FM) and rates of habituation to repeated stimulation, with suffusions of cold saline over the skin, were measured in 12 chronically catheterized fetal sheep aged 130-145 days. Stimulation of the fetuses caused a significant rise in heart rate (HR) (p less than 0.01) and blood pressure (BP) (p less than 0.001) and FM (p less than 0.01). When the ewe was given an intravenous (i.v.) infusion of ethanol which produced fetal ethanol levels of 87 +/- 1.1 mg/100 ml, the number of spontaneous FM decreased (p less than 0.05). After i.v. ethanol, repeated stimulation of the fetuses still caused an increase in FM (p less than 0.01) and a rise in HR (p less than 0.05) and BP (p less than 0.02) but the fetuses habituated more rapidly (7.25 +/- 1.28 stimuli) compared to control experiments performed prior to (21.5 +/- 3.57 stimuli) or after the ethanol (17.75 +/- 5.83, p less than 0.01). Fetal exposure to low concentrations of ethanol does affect the patterns of response and habituation of the developing fetal central nervous system.

Animals