Oxytocin use in South Africa - a review

Objective. Oxytocin is one of the most frequently used drugs in labour and there are many different dosage regimens. The aim of this study was to examine the use of oxytocin by obstetricians in South Africa. Methods. A specially designed questionnaire was drawn up and distributed to specialists according to an address list obtained from the South African Society of Obstetricians and Gynaecologists. Results. Three hundred and fifty questionnaires were distributed, with 174 processed for analysis. The majority of obstetricians (70.3%) reported that they would not use oxytocin for induction of labour in a patient with a previous would not consider the use of oxytocin in a patient with a multifetal pregnancy. Most respondents used oxytocin for induction of labour in multigravid patients and 91.9% also used oxytocin for augmentation in these patients. However, clinicians would not use oxytocin if the patient was a grand multipara. Conclusions. Most clinicians adhere to accepted protocols practised internationally, with a few exceptions. The use of oxytocin for both induction and augmentation of labour in women with one previous caesarean section is not practised in South Africa, despite evidence suggesting its safety. S Afr Med J 2004; 94: 839-845

Outcome of Pregnancy in the Morbidly Obese Woman

Background: Obesity is a growing global health problem. In South Africa, more than half of the adult women are overweight and almost 30% areobese. The problems associated with obesity, such as diabetes, hypertension, thrombo-embolism and coronary heart disease, are well described in the non-pregnant population, but the condition itself holds specific risks during the ante-, intra- and postpartum periods of the pregnant woman.Of particular concern is the intrapartum period. Complications such as slow progress during labour and increased rates of caesarean section arebest addressed proactively. For this reason certain sources advocate that all morbidly obese women be referred for evaluation of the pregnancy andplanning of labour and delivery by an anaesthetist and a specialist obstetrician. The aim of this study was to determine whether morbidly obese women are at increased risk of adverse outcomes, compared to women with a normal body mass index (BMI).Methods: A case control study design was used. In this study a normal BMI was defined as 20–25 kg/m2 and morbid obesity as a BMI of≥ 40 kg/m2. The BMI was calculated from the weight and height measured at the booking visit. The cases in this study comprised the first hundred morbidly obese women seen at the Obstetric Special Care Clinic in Tygerberg Hospital (TBH), a secondary and tertiary referral centre. The controls (n = 209) were women with normal BMIs and singleton pregnancies who booked as low-risk patients at the Bishop Lavis Midwife Obstetric Unit (MOU) during the same calendar period. A minimum ratio of 2:1 controls-to-case was used, with controls also matched for primi- or multiparity. Patients booking at the MOU with significant obstetric risk factors are referred to TBH for antenatal care. These women were not considered as controls. However, low-risk women who met the inclusion criteria at booking and who subsequently developed risks or complications were included, as the selection was done according to findings at the booking visit.The main outcomes to be determined were: ante-, intra- and postpartum maternal complications, rate of epidurals, and perinatal outcomes.Results: Women in the morbidly obese group were significantly older (p < 0.001) and of higher parity (p < 0.001) than those with normal BMIs. There was no difference in the numbers of primigravidae. Significantly more women in the morbidly obese group had experienced at least one miscarriage (p = 0.002). In similar fashion, significantly more of the previous deliveries in the morbidly obese group had been by caesarean section (p < 0.001). Again, significantly more women in the morbidly obese group had previously experienced pregnancies complicated by hypertension (p < 0.001). In the index pregnancies studied, morbidly obese women experienced more hypertension (p < 0.001), diabetes (p = 0.02) and urinary tract infections (p < 0.001) than controls. They underwent induction of labour more often (p < 0.001) and had a higher rate of caesarean delivery (p < 0.001). Epidural anaesthesia was planned for all morbidly obese patients, but only 14% received it. During delivery, perineal damage was more common in morbidly obese women (p < 0.001) and their babies were significantly larger (p < 0.001). There was one perinatal death.Conclusions: Morbidly obese women experienced increased complications during pregnancy and childbirth. Due to the high rate of caesareansections and the potential difficulties of emergency anaesthesia among these women, epidural anaesthesia during labour should be planned andadministered as often as possible

O- And H-Isotope Study of the Carbon Leader Reef at the Tau Tona and Savuka Mines (Western Deep Levels) South Africa: Implications for the origin and evolution of Witwatersrand Basin Fluids

The Carbon Leader Reef is a ~1 m thick conglomeratic unit with a thin bituminous base, and is one of the major gold-bearing conglomerate horizons in the Central Rand Group of the Witwatersrand Basin. It consists of alternating conglomerate and quartzite layers and was metamorphosed under greenschist facies conditions. Bulk rock δ18O and δD values of the Carbon Leader Reef range from 7.2‰ to 10.8‰ (mean = 10.6‰) and −27 to −65 (mean = −41‰), respectively. The narrow range in δ18O values, together with the lack of correlation between the δ18O value and the modal % matrix minerals, suggests that the original detrital minerals and the authigenic matrix minerals have similar oxygen isotope composition. Calculated δD values of the fluid, assuming that it was in isotope equilibrium with the bulk rock at the estimated peak metamorphic temperature of 350°C, range from −1‰ to −40‰. This suggests that the ultimate origin of the fluid was a mixture of meteoric and metamorphic water. These data are not consistent with the ingress of large quantities of externally derived fluid post burial metamorphism. Gold-rich sections of the Carbon Leader Reef do not have significantly different δ18O values than the adjacent gold-poor section, which suggests that gold mineralization is not related to interaction with significant amounts of externally derived hydrothermal fluids