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Biomedical subjects

H J Odendaal

Publications and source records attributed to H J Odendaal.

At least 19 recordsLinked to original sources

Oral misoprostol versus intracervical dinoprostone for induction of labor.

OBJECTIVES: To compare oral misoprostol with dinoprostone for induction of labor and their effects on the fetal heart rate patterns. METHODS: In a randomized controlled trial, 200 patients received either misoprostol 50 mug orally for every 4 h, or dinoprostone 0.5 mg intracervically for every 6 h. Cardiotocographic recordings, in 10-min windows 30, 60, and 80 min after prostaglandin administration during induction and continuously during labor, were compared between the two groups. Primary outcome for effectiveness and safety was assessed in terms of the number of vaginal deliveries within 24 h and fetal heart rate abnormalities during induction and labor respectively. RESULTS: Data from 96 patients in the misoprostol group and 95 in the dinoprostone group were analyzed. There were no significant differences in respect of the number of vaginal deliveries within 24 h (RR 1.12; 95% CI 0.88-1.42). The frequency of suspicious and pathological fetal heart rate patterns did not differ significantly but significantly more cardiotocographs in the dinoprostone group had non-reassuring baseline variability 60 min after dose administration (RR 0.33; 95% CI 0.14-0.77). Maternal and neonatal outcomes did not differ significantly. CONCLUSION: Oral misoprostol is as effective as intracervical dinoprostone for induction of labor with no difference in the frequency of fetal heart rate abnormalities.

Administration, Intravaginal↗

Effects of psychologic stress on fetal development and pregnancy outcome.

Data from animal studies show that maternal stress is associated with disturbances in pregnancy outcomes and offspring development and behavior, possibly as a result of permanent structural and functional changes termed "early-life programming." There is growing interest in whether similar relationships are present in humans. Here we review recent significant findings from the literature on the impact of prenatal psychologic stressors on pregnancy outcome and offspring development, with a particular focus on the developing brain. Relevant papers were searched using PubMed, and reference lists from obtained articles were checked. In humans, prenatal stress is associated with pregnancy complications, developmental, cognitive, and behavioral disorders, and possible onset of psychopathology in later life. In contrast to the available research done in animals, virtually nothing is known about the effects of prenatal stress on morphologic fetal brain development, and the mechanisms underlying subsequent associated behavioral changes.

Animals↗

Bacterial vaginosis diagnosed at the first antenatal visit better predicts preterm labour than diagnosis later in pregnancy.

This study was conducted as part of a double-blind randomised placebo-controlled trial, the aim of which was to determine whether vitamin C could reduce the recurrence risk of pre-term labour. In this study, women with a history of pre-term labour in a preceding pregnancy were randomised to receive either 250 mg vitamin C or a matching placebo twice daily until 34 weeks' gestation. They attended a dedicated pre-term labour clinic every 2 weeks. All women were screened for bacterial vaginosis (BV) at each visit. It was first determined that vitamin C did not have any effect on the presence of BV. Women who were diagnosed with BV before 20 weeks' gestation were at higher risk of delivering pre-term than those who developed BV after 20 weeks.

Ascorbic Acid↗

Comparison between a newly developed PC-based Doppler umbilical artery waveform analyser and a commercial unit.

OBJECTIVES: To determine the accuracy of the resistance index (RI) of flow velocity waveforms of the umbilical artery measured using a newly developed PC-based continuous wave Doppler device (Umbiflow) with regard to systematic and random variations when compared with a commercial standard (Vasoflow). DESIGN: A cohort study. SETTING: The fetal evaluation clinic (FEC) at Tygerberg Hospital. SUBJECTS: Patients referred to the FEC at Tygerberg Hospital with suspected chronic placental insufficiency. OUTCOME MEASURES: The correlation coefficients indicating the strength of the relationship between the two devices and their agreement using the method of Bland and Altman. RESULTS: A total of 248 patients were studied. The mean RIs of the first Doppler assessment were 0.69 (standard deviation (SD) 0.11) and 0.67 (SD 0.11) using the Vasoflow and Umbiflow respectively. The Pearson's correlation coefficient comparing the RI of the first test was 0.85. The degree of agreement between the two methods was excellent, the mean differences being very small (< 0.024) with tight confidence intervals. One hundred and ninety-four patients (78.2%) of patients remained in the same percentile category with both the Vasoflow and Umbiflow. CONCLUSIONS: The accuracy of the Umbiflow has been proved. A non-significant trend towards slightly lower values needs to be considered. This could be addressed by changing the percentile cut-off to slightly lower values.

Cohort Studies↗

Smoking in pregnancy -- what does my patient know ?

A recent study by the Medical Research Council (MRC) Perinatal Mortality Research Unit at Tygerberg Hospital found that 39% of pregnant women smoked cigarettes.1 Smoking in pregnancy is clearly recognised in the literature as an important, dose-related, preventable risk factor for poor perinatal outcome.2 Aprevious MRC finding that 47% of South African coloured women smoke during pregnancy3 stands in sharp contrast to the prevalence in developed countries, for example 15.8% in the USA.4 In a developing country, where poverty in itself increases perinatal mortality and morbidity, this increase in cigarette smoking may have further negative effects on perinatal outcome, despite efforts to optimize antenatal care. It is, therefore, of concern that despite current knowledge of the harmful effects of smoking in pregnancy, such a large percentage of pregnant women at Tygerberg Hospital are smokers. We wondered to what extent pregnant patients at Tygerberg Hospital are aware of the harmful effects of cigarette smoking during pregnancy and after childbirth.

Female↗

Doctors' attitudes and practices regarding smoking cessation during pregnancy.

OBJECTIVE: To investigate the current smoking cessation practices and attitudes of doctors working in the public antenatal services, as well as their perceived barriers to addressing the issue in the context of routine care. STUDY DESIGN: The study was qualitative, consisting of 14 semistructured, one-to-one interviews with doctors purposefully sampled from 5 public sector hospitals in Cape Town, South Africa. RESULTS: The doctors in this study regarded HIV, poor nutrition, alcohol abuse and psychosocial stress as equal or higher risks to pregnant women than smoking. They tended to underestimate the magnitude of the risk of smoking during pregnancy. Doctors were unaware of the guidelines offering clinicians brief, structured approaches to smoking cessation counselling and were generally pessimistic that they could influence the smoking behaviour of pregnant women, especially poor, disadvantaged women who face multiple barriers to achieving health-enhancing behaviour. However, most doctors were concerned about improving their communication with pregnant women about smoking and open to adopting new approaches or tools that could assist them. Perceived barriers to providing smoking cessation interventions included a lack of counselling skills and educational resources, other pressing priorities, too little time, and the levels of stress currently experienced by doctors and midwives working in public sector hospitals as a result of dramatic staff and budget cuts. CONCLUSION: The study suggests that doctors working in the public sector antenatal services are not routinely addressing the issue of smoking during pregnancy or using effective methods to assist women to give up smoking. Doctors need convincing that smoking cessation interventions can be effective. The promotion and provision of evidence-based guidelines such as the Clinical Practice Guideline for Treating Tobacco Use and Dependence (Fiore, 2000), with minimal training, is a possible strategy for integrating smoking cessation interventions into routine antenatal care in South Africa.

Attitude of Health Personnel↗

Sonographic cervical length in threatened preterm labor in a South African population.

OBJECTIVE: In a previous study conducted in the UK we demonstrated that only 8% of women with threatened preterm labor deliver within 7 days. Furthermore, delivery within 7 days occurred in less than 1% of women presenting with a sonographically measured cervical length > or = 15 mm, compared to 37% in those with cervical length < 15 mm. In this study we investigate the potential value of cervical length in the prediction of outcome of threatened preterm labor in a South African population. METHODS: We examined 63 women with singleton pregnancies presenting with regular and painful uterine contractions at 24-36 (mean, 31) weeks of gestation. Women in active labor, defined by the presence of cervical dilatation > or = 3 cm, and those with ruptured membranes were excluded. On admission to the hospital a transvaginal scan was performed to measure the cervical length. The subsequent management was determined by the attending obstetrician. The primary outcome was delivery within 7 days of presentation. RESULTS: Delivery within 7 days of presentation occurred in 20/63 (32%) pregnancies, including 20 of the 30 (67%) cases with cervical length < 15 mm and none of the 33 cases with cervical length > or = 15 mm. Logistic regression analysis demonstrated that the only significant contributor in the prediction of delivery within 7 days was cervical length (odds ratio 0.67; 95% CI 0.54-0.85; P = 0.001) with no significant independent contribution from maternal age, gestational age, body mass index, parity, use of antibiotics, previous history of preterm delivery, cigarette smoking, contraction frequency or use of tocolytics. CONCLUSION: In this South African population, which had a high incidence of delivery within 7 days of presentation with threatened preterm labor, sonographic measurement of cervical length is equally effective as in a lower-risk population in distinguishing between true and false labor.

Abortion, Threatened↗

A community-based obstetric ultrasound service.

OBJECTIVES: To investigate the impact of an ultrasound dating service on obstetric services. METHODS: A prospective trial with 3009 unselected women presenting for antenatal care at two Midwife Obstetric Units in a socioeconomically deprived urban area, South Africa. In the study unit, student ultrasonographers provided a basic ultrasound service. In the control unit, obstetric ultrasound was only available for specific indications. The main outcome measures were number of antenatal visits and referrals for fetal surveillance. RESULTS: The two cohorts were comparable except for the number of primigravidas but stratified analysis according to parity did not affect the results. Ultrasonography did not alter pregnancy outcome but reduced the number of perceived preterm labors/ruptured membranes (12.0 vs. 16.7%, P<0.003), post-term deliveries (8.1 vs. 10.8%, P<0.04) and referrals for fetal surveillance [15.9 vs. 29.6%, P<0.000, RR 0.79 (0.71-0.88)]. CONCLUSIONS: This community-based basic ultrasound service significantly reduced referrals to a regional center for fetal surveillance and delivery.

Adult↗

Maternal and fetal single nucleotide polymorphisms in the epoxide hydrolase and gluthatione S-transferase P1 genes are not associated with pre-eclampsia in the Coloured population of the Western Cape, South Africa.

Oxidative stress is thought to play an important role in the pathophysiology of pre-eclampsia. A defect in certain enzymes responsible for detoxification may cause prolonged exposure to reactive by-products and contribute to maternal endothelial as well as placental damage. Two polymorphisms affecting the function of the biotransformation enzymes epoxide hydrolase and glutathione S-transferase P1 were shown previously to be associated with pre-eclampsia in a Dutch population. The aim of this study was to determine if these two polymorphisms (maternal or fetal) contribute to pre-eclampsia in an anthropologically distinct population (the Western Cape region of South Africa) with a high incidence of the disease. Genomic DNA of mother - infant pairs with severe pre-eclampsia (n = 144), a population control group (n = 156) and control mother - infant pairs with uncomplicated pregnancy outcome (n = 45) were analysed for the EPHX and GSTP1 polymorphisms by polymerase chain reaction amplification and restriction enzyme digestion. Each polymorphism had a similar distribution in case and control subjects (mother and infant). The Val105/Val105 genotype of GSTP1 occurred at a higher frequency than reported for other populations. Neither maternal nor fetal EPHX Tyr113His and GSTP1 Ile105Val polymorphisms appear to contribute significantly to the pathophysiology of pre-eclampsia in the Coloured population of the Western Cape region of South Africa.

Alleles↗

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 lower-segment caesarean section, and 63.7% said that they 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.

Cesarean Section↗

A randomised, double-blind placebo-controlled trial of ascorbic acid supplementation for the prevention of preterm labour.

In a previous study from this institution, patients at high risk for preterm labour were screened for the presence of bacterial vaginosis (BV). When BV was present, they were randomised to receive either treatment (metronidazole) or placebo (vitamin C). There were significantly more patients with preterm labour in the metronidazole group. The aim of this double-blind randomised placebo-controlled trial study was to determine whether vitamin C could indeed reduce the recurrence risk of preterm labour. Patients with a history of preterm labour in a preceding pregnancy were randomised to receive 250 mg vitamin C or a matching placebo twice daily until 34 weeks' gestation. They attended a dedicated premature labour clinic. Significantly more women delivered before term in the group that received vitamin C, but there was no difference in the outcome of the babies between the two groups. Supplementation with vitamin C did not prevent premature labour.

Adolescent↗

The profile and complications of women with placental abruption and intrauterine death.

The aim of this study was to evaluate the profile and outcome of patients with placental abruption and intrauterine death. It was a retrospective study over 2 years from 1 January 1999 to 31 December 2000. All women (n = 96) presenting with placental abruption and intrauterine death at a tertiary referral center were identified from the records of weekly perinatal mortality meetings. Data were reviewed by a single researcher. Hypertensive disorders were diagnosed in 75 per cent (n = 72) women, most often at admission once intrauterine death had already occurred. Thirty-nine per cent had a previous history of hypertensive disease during pregnancy, placental abruption, intrauterine death, or preterm delivery. Twenty-two per cent of patients (n = 21) were unbooked. Major maternal complications occurred in 53 per cent of women. There were no maternal deaths. In conclusion, previous obstetric history and hypertensive disorders are important factors in women with placental abruption causing intrauterine death. Severe complications are common but careful management in a tertiary center can reduce their impact.

Abruptio Placentae↗

Urinary protein excretion and expectant management of early onset, severe pre-eclampsia.

OBJECTIVE: To evaluate the importance of proteinuria in the expectant management of early onset, severe pre-eclampsia. METHODS: In this prospective series of 340 women, 24-h urine collections were performed and monitored twice weekly in a high-care ward. RESULTS: Seventy-four women with at least two 24-h urine collections were grouped into women with a proteinuria increase of > or =2 g (n=29) and with women whose proteinuria decreased, or increased by <2 g (n=45). Major maternal complications, prolongation of gestation, and perinatal outcomes were comparable. Fifty-six (75%) women experienced an increase in proteinuria. When patients with heavy proteinuria (n=83) were compared to those with moderate proteinuria (n=257), maternal and perinatal outcomes were comparable. More days were gained before delivery in the heavy proteinuria group than in the moderate (12 vs. 9; P<0.001). CONCLUSION: Most patients experienced increased proteinuria. Neither the rate of increase nor the amount of proteinuria affected maternal and perinatal outcomes.

Abruptio Placentae↗

Primipaternity and duration of exposure to sperm antigens as risk factors for pre-eclampsia.

OBJECTIVE: To establish whether primipaternity and duration of unprotected sexual cohabitation is associated with an increased risk of pre-eclampsia. METHOD: At a tertiary referral center, the study had a case and control group of 60 multigravid women each, as well as a case and control group of 50 primigravid women each. Information was compiled by means of a confidential questionnaire. RESULT: After multiple logistic regression analysis using age, smoking, hypertension in previous pregnancies, change of paternity and duration of unprotected sexual cohabitation as predictors, the regression coefficients for change of paternity and sexual cohabitation of longer than 6 months in multigravid women were -0.4 (P = 0.15) and -1.4 (P = 0.03), respectively. CONCLUSION: Multigravid women with a period of unprotected sexual cohabitation of longer than 6 months had a decreased risk of pre-eclampsia. Primipaternity was not a significant risk factor for pre-eclampsia.

Adult↗

Preterm labour--is bacterial vaginosis involved?

OBJECTIVE: To assess the efficacy of treatment of bacterial vaginosis (BV) using metronidazole to reduce preterm labour in primigravidae and multigravidae with previous midtrimester abortion or preterm labour. DESIGN: Randomised controlled trial. SETTING: Tertiary academic hospital. METHOD: Two different groups of patients were screened for BV at the first antenatal visit, namely primigravidae and high-risk multigravidae who had had a previous midtrimester abortion or preterm delivery. Patients where BV was diagnosed clinically or on Gram's stain of a smear taken from the posterior vaginal fornix, received either 400 mg metronidazole, or 100 mg vitamin C orally twice daily for 2 days. The Gram's stain was repeated after 4 weeks. If BV was found again, treatment with the same drug was repeated. OUTCOME MEASURES: Preterm delivery, birth weight and perinatal deaths. RESULTS: One thousand and five patients entered the study, but 40 were excluded for various reasons and 10 were lost to follow-up. There were 464 primigravidae, of whom 150 (32%) had BV. Except for the 5-minute Apgar score, no significant differences were found between primigravidae negative for BV and those who received either metronidazole or vitamin C. There were 491 high-risk multigravidae, of whom 127 (26%) had BV. The mean gestational age in the BV-negative group was 37 weeks, in contrast to 37.4 weeks in the vitamin C group and 35.6 weeks in the metronidazole group. Birth weights in these three groups were 2,752 g, 2,759 g and 2,475 g respectively, significantly less (P = 0.0109) in the metronidazole group in comparison with the BV-negative group. Delivery before 37 weeks occurred in 29% of high-risk multigravidae with no BV but in 24% of those who took vitamin C and in 43% who took metronidazole. Differences were significant between the BV-negative and metronidazole groups (P = 0.0231) and also between the metronidazole and vitamin C groups (P = 0.0274). Delivery before 28 weeks occurred in 4% of the high-risk multigravidae with no BV but in 10% of those with BV who took metronidazole. The difference was significant (P = 0.0430). Analysis for maximum likelihood estimates for preterm labour identified only previous preterm labour or midtrimester abortion as risk factors. CONCLUSION: Metronidazole does not seem to reduce the prevalence of preterm labour when given for BV before 26 weeks' gestation.

Adult↗