Gerhard Theron

Stellenbosch University, Obstetrics and Gynaecology, Faculty Member

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Obstetric outcome after successful external cephalic version for breech presentation at term

International journal of gynaecology and obstetrics, Aug 19, 2014

Age, y 78 28.8 ± 6.9 28.5 17.0 43.0 BMI 64 28.5 ± 6.8 27.2 18.2 45.0 External cephalic version (E... more Age, y 78 28.8 ± 6.9 28.5 17.0 43.0 BMI 64 28.5 ± 6.8 27.2 18.2 45.0 External cephalic version (ECV) should be considered for all women with a singleton pregnancy and noncephalic presentation at 37 weeks [1]. Successful ECV does not always translate to a vaginal delivery and a cesarean may still be required [2]. A meta-analysis showed that successful ECV at term compared with spontaneous cephalic presentation was associatedwith a doubling of the cesarean delivery rate [3]. By contrast, a case− control study concluded that the risk of cesarean delivery after successful ECV was not increased [4]. The aim of the present study was to report the obstetric outcome following successful ECV for breech presentation at term performed at a hospital in South Africa. A retrospective descriptive study was conducted to audit the outcome of successful ECV performed at the Fetal Evaluation Clinic at Tygerberg Hospital, Cape Town, over a seven-year period between April 2005 and April 2012. Nominal variables were compared using the χ test and the significance level was set at 0.05. The t test was used to compare normally distributed outcome variables and the Mann-Whitney test was used for non-normally distributed variables. Statistical analysis was performed using SAS version 9.3 (SAS Institute Inc, Cary, NC, USA). Ethical approval was obtained with waiver of informed consent from the Human Research Ethics committee of Stellenbosch University (S11/10/009).

Management of patients with poor symphysis pubis-fundus growth by Doppler flow velocimetry of the umbilical artery - an effective method to detect the fetus at risk

International journal of gynaecology and obstetrics, Oct 1, 1992

This study evaluated Doppler flow velocimetry of the umbilical artery in patients with suspected ... more This study evaluated Doppler flow velocimetry of the umbilical artery in patients with suspected intrauterine growth retardation as detected by poor symphysis-fundus growth (SFG). The sensitivity of Doppler in detecting light for gestational age babies and intrauterine growth retardation was poor. Antenatal complications, neonatal morbidity and perinatal mortality occurred significantly more frequently in patients with abnormal flow. Doppler flow velocimetry is an excellent test to identify babies at high risk for perinatal morbidity and mortality, when poor SFG is present.

Individual and Composite Adverse Pregnancy Outcomes in a Randomized Trial on Isoniazid Preventative Therapy Among Women Living With Human Immunodeficiency Virus

Clinical Infectious Diseases, Sep 30, 2020

Background. International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) P1078, a r... more Background. International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) P1078, a randomized noninferiority study designed to compare the safety of starting isoniazid preventive therapy (IPT) in women living with human immunodeficiency virus (HIV) either during pregnancy or after delivery, showed that IPT during pregnancy increased the risk of composite adverse pregnancy outcomes, but not individual outcomes. Many known factors are associated with adverse pregnancy outcomes: these factors' associations and effect modifications with IPT and pregnancy outcomes were examined. Methods. Pregnant women living with HIV from 8 countries with tuberculosis incidences >60/100 000 were randomly assigned to initiate 28 weeks of IPT either during pregnancy or at 12 weeks after delivery. Using univariable and multivariable logistic regression and adjusting for factors associated with pregnancy outcomes, composite and individual adverse pregnancy outcome measures were analyzed. Results. This secondary analysis included 925 mother-infant pairs. All mothers were receiving antiretrovirals. The adjusted odds of fetal demise, preterm delivery (PTD), low birth weight (LBW), or a congenital anomaly (composite outcome 1) were 1.63 times higher among women on immediate compared to deferred IPT (95% confidence interval [CI], 1.15-2.31). The odds of fetal demise, PTD, LBW, or neonatal death within 28 days (composite outcome 2) were 1.62 times higher among women on immediate IPT (95% CI, 1.14-2.30). The odds of early neonatal death within 7 days, fetal demise, PTD, or LBW (composite outcome 3) were 1.74 times higher among women on immediate IPT (95% CI, 1.22-2.49). Conclusions. We confirmed higher risks of adverse pregnancy outcomes associated with the initiation of IPT during pregnancy, after adjusting for known risk factors for adverse pregnancy outcomes. Keywords. adverse pregnancy outcomes; IPT. Globally, an estimated 10 million people developed tuberculosis (TB) disease in 2018, with 251 000 deaths among people living with human immunodeficiency virus (HIV) . Of those who developed TB, 5.7 million were men, 3.2 million women, and 1.1 million children. People living with HIV comprise 8.6% of the total, of which the vast majority are living in Africa. Active TB is particularly prevalent during pregnancy and the postpartum period . TB disease during pregnancy or the early postpartum period is associated with adverse maternal, pregnancy, and infant outcomes . Active TB in women

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Doppler ultrasonography of the fetoplacental circulation--normal reference values

PubMed, Dec 2, 1989

Normal reference values for the resistance index, A/B ratio and pulsatility index of the umbilica... more Normal reference values for the resistance index, A/B ratio and pulsatility index of the umbilical artery obtained by Doppler ultrasonography are presented. The resistance index and A/B ratio values are very similar to those previously published, indicating no need to formulate normal values for different populations. The pulsatility index differed from other published values, probably reflecting different calculation methods built into the spectrum analysers rather than differences in waveforms. The resistance index had the lowest coefficient of variation and showed least inter-observer variation. For routine use the resistance index is preferable to other indices.

A centile chart for birth weight for an urban population of the Western Cape

PubMed, Dec 1, 1995

Evidence from large epidemiological studies has supported concern that being born light for gesta... more Evidence from large epidemiological studies has supported concern that being born light for gestational age (LiGA) may be detrimental. The incidence of LiGA babies is an important indicator of the health of women of reproductive age in deprived communities. In the assessment of LiGA in the Western Cape, centile charts constructed for populations in other parts of the world are generally used. These charts, however, may not be appropriate. Patients residing in the area served by the Tygerberg Hospital obstetric service, who booked early with singleton pregnancies, had their gestational age confirmed by early ultrasound and delivered between 1 March 1989 and 28 February 1990 were included in the study. The sample consisted of 3,643 patients. The mean birth weight was 2,995 g (SD 573 g) and the range 760-5,080 g. The distribution of birth weight at each week of gestation from 28 to 42 weeks was not normal. The 4-parameter Johnson family of densities was used to model the distribution of birth weight at each gestational age. A comparison of the distribution of birth weight in the study relative to the perinatal growth chart for international reference constructed by Dunn was also made. In addition to considering an overall chart, the sample was subdivided according to a number of characteristics (e.g. gender, firstborn and latter-born babies, smoking habit, hypertensive disorders and induction of labour) in order to explore their impact on the distribution of birth weight. Having explored the potential impact of all these factors, it was concluded that a single chart including all patients could be constructed.

Maximum likelihood estimation of reference centiles

Statistics in Medicine, May 1, 1990

We propose the use of centile estimates which are based on the fitting of appropriate densities b... more We propose the use of centile estimates which are based on the fitting of appropriate densities by maximum likelihood. In the case of cross‐sectional centile estimation, we show that this approach will generally lead to more precise estimates than would result from the use of non‐parametric centile estimates. When longitudinal data are available or a series of cross‐sectional data at different time points, the maximum likelihood approach can be used to simultaneously fit densities to each cross‐section, subject to constraints (for example, smoothness constraints) on the parameters. The variances of these centile estimates are readily obtained and missing values and unequally spaced records are easily accommodated. We illustrate the procedure by means of an application using the Johnson family of densities to a study of weight gain in pregnancy.

The potential of midwives providing primary obstetric care to reduce perinatal deaths in a rural region

International journal of gynaecology and obstetrics, Aug 25, 2000

To determine the proportion of perinatal deaths that could be reduced by midwives providing prima... more To determine the proportion of perinatal deaths that could be reduced by midwives providing primary obstetric services. The study was conducted in a rural region of the Eastern Cape, South Africa. The primary obstetric and final causes of perinatal deaths and avoidable factors related to these deaths were determined in a large town and two small towns. In the three towns 52 (48.6%) of the 107 avoidable factors were related to medical care while 20 (38.5%) of these had the potential to be prevented at the level of care rendered by midwives. In the large town 21 (20.6%) of 102 and in the smaller towns 15 (24.6%) of 61 perinatal deaths had potential for intervention by midwives. The 22.1% of perinatal deaths potentially preventable by midwives presupposes complete patient cooperation within an optimally functioning health system.

The usefulness of a weight gain spurt to identify women who will develop preeclampsia

European Journal of Obstetrics & Gynecology and Reproductive Biology, May 1, 1998

The usefulness of adaptive centiles for weight gain as well as sudden weight gain spurts in ident... more The usefulness of adaptive centiles for weight gain as well as sudden weight gain spurts in identifying women who will develop preeclampsia was assessed. A study sample of 99 women who developed preeclampsia and a control sample of 675 women with normal pregnancies, were randomly selected. Weight gain spurts were identified by the upper bound of adaptive maternal weight centiles. Average changes in weight between successive clinic visits were also assessed. Weight gain exceeding the 90th percentile of the adaptive centiles resulted in estimated sensitivity and specificity of 52% and 66% and weight gain &gt;0.9 kg per week between visits in 76% and 29% respectively. Of women who would develop preeclampsia identified by the adaptive chart, 62.0% exhibited abnormal weight gain prior to the onset of abnormal clinical findings. A sudden weight gain spurt is a far from reliable sign of impending preeclampsia. This reason for weighing women at antenatal visits appears to be unfounded.

Management of postpartum hemorrhage with free-flow pressure controlled uterine balloon

International journal of gynaecology and obstetrics, Jun 15, 2018

The free‐flow uterine balloon allowed water to be expelled from the balloon and intra‐uterine pre... more

Saving Mothers: Report on the Confidential Enquiries into Maternal Deaths in South Africa

South African Family Practice, Jul 7, 2000

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Hypermobility and peripartum pelvic pain syndrome in pregnant South African women

European Journal of Obstetrics & Gynecology and Reproductive Biology, May 1, 1999

To determine the incidence and correlation of joint hypermobility (HM) and peripartum pelvic pain... more To determine the incidence and correlation of joint hypermobility (HM) and peripartum pelvic pain (PPPP) in an homogeneous pregnant South African population. A cross-sectional study among Cape Coloured pregnant women. Joint mobility was measured by Beighton score; PPPP with a specially developed PPPP score. Using the Beighton scores with a cut-off point of HM &amp;amp;gt; or = 5/9, only 4.9% of the 509 pregnant women were hypermobile. Hyperextension of the elbow was the largest contributor to HM (35.4%). No correlation of HM with the incidence of PPPP was established. Only 20 very mild cases of PPPP were recorded. Back pain increased significantly during pregnancy to a mean of 38%. Right handedness occurred in 95.9%. No significant relation was found between HM and the non-dominant side. Hypermobility in pregnant Cape Coloured women was surprisingly low (4.9%) with a decrease with age, but no increase during pregnancy. Peripartum pelvic pain is virtually absent and has no correlation with joint laxity. Back pain increased during pregnancy to a mean of 38%. Right handedness was high (96%) in comparison with the world-wide figure of 85%. No correlation was found between the dominant body side and hypermobility.

Significance and treatment of asymptomatic bacteriuria during pregnancy

International journal of gynaecology and obstetrics, May 1, 1997

Asymptomatic bacteriuria (ASB) is the most common bacterial infection requiring medical treatment... more Asymptomatic bacteriuria (ASB) is the most common bacterial infection requiring medical treatment in pregnancy [l]. Diagnosis and treatment of ASB is important as approximately 20-40% [2] of these women, if untreated during pregnancy, will develop a symptomatic urinary tract infection. A high prevalence of ASB inpregnancy has previously been reported in our population [3]. Screening and treatment have resulted in lower rates of pyelonephritis (24% to 6%) and preterm labor (15% to 10%) [4] and such a programme is therefore of prime importance. The duration of therapy for ASB in pregnancy is currently an important topic of debate. There is increasing evidence that single-dose therapy (well-established for treatment of uncomplicated

Improved cognitive knowledge of midwives practising in the Eastern Cape Province of the Republic of South Africa through the study of a self-education manual

Midwifery, Jun 1, 1999

To determine whether the Maternal Care manual of the Perinatal Education Programme (PEP) is effec... more To determine whether the Maternal Care manual of the Perinatal Education Programme (PEP) is effective in improving the cognitive knowledge of midwives. A prospective controlled trial in a region where PEP was not previously used. The midwifery knowledge of all midwives caring for pregnant women in the three towns was tested before the commencement of the study. The Maternal Care manual was then introduced to the midwives in he study town and they worked through the programme. Following the completion of the manual, all midwives were tested again with the same test. The time interval between the pre and post testing was 12 months. Three towns on the Eastern Cape Province of South Africa. All Midwives caring for pregnant women in three towns. The Maternal Care manual of PEP was studied by the midwives in the study town. Changes in cognitive knowledge were tested with multiple choice questions. A significant improvement (p &lt; 0.0001) was achieved in the study town. The mean score (maximum 70) improved by 22.4 (32%) marks, from 35.9 (51%) to 58.3 (83%). The cognitive knowledge of midwives who completed the Maternal Care manual improved significantly. These findings are to particular importance as the method by which the Maternal Care manual of PEP was applied conforms to the method suggested for the its national use.

Perinatal HIV and Option B+ : editorial

Sustainable development goals : : editorial

Obstetrics and Gynaecology Forum, 2016

In the year 2000 the United Nations adopted the Millennium Declaration that included the Millenni... more

Perinatal HIV and Option B+

South African journal of obstetrics and gynaecology, Oct 26, 2012

The prevalence of HIV among pregnant women using public health services in South Africa is well d... more The prevalence of HIV among pregnant women using public health services in South Africa is well documented. 1 The prevalence rose steeply from 1990 through to 2003. Subsequently a plateau phase has been observed, with the national prevalence at 29 -30%. An important cross-sectional and service-based survey by Goga et al. in 2010 and 2011 reported remarkable success in reducing perinatal mother-to-child transmission (PMTCT) rates 2 (and 'Effectiveness of the National Prevention of Mother-to-Child Transmission (PMTCT) Programme in South Africa: 2011 National SAPMTCT Survey Results' , released by Minister Aaron Motsoaledi on 19 July 2012). Infants between 4 and 8 weeks of age attending primary or community health clinics were included in the study, irrespective of knowledge of maternal HIV status. HIV enzyme-linked immunosorbent assay tests were performed on dried blood spot heel-prick samples, and if positive HIV DNA polymerase chain reaction tests were done. The prevalences of HIV among the mothers and the transmission rates at 6 weeks could be determined. The researchers included 10 000 infants in each sample. The national transmission rates were 3.5% (95% confidence interval (CI) 2.9 -4.1) and 2.7% (95% CI 2.1 -3.2) in 2010 and 2011, respectively.

How safely can post-term pregnancies with uncertain gestational age be followed up using amniotic fluid index measurements?

South African journal of obstetrics and gynaecology, Oct 23, 2014

Objective. To review whether 2 weeks' follow-up is safe for women at 42 weeks with an uncertain g... more Objective. To review whether 2 weeks' follow-up is safe for women at 42 weeks with an uncertain gestational age (GA) and amniotic fluid index (AFI) of ≥10 cm, as well as reassuring cardiotocography (CTG). Methods. A retrospective descriptive study of women with an uncertain GA of 42 weeks was done at Tygerberg Hospital. The women had weekly CTG and AFI determinations. Induction of labour followed non-reassuring CTG or an AFI of <5. Results. A total of 135 women were studied. The time interval between first evaluation at uncertain 42 weeks and delivery ranged between 0 and 46 days (median 10 days). Of the women, 104 had normal vaginal deliveries and 31 (23.0%) caesarean sections. Eleven women (8.1%) with an AFI ≥10 had CS for fetal distress within 2 weeks of the visit at 42 weeks. No neonatal morbidity or mortality was noted. Weekly monitoring with CTG and AFI at 42 weeks with unsure GA is safe. A follow-up visit after 2 weeks cannot be recommended, as 8% of women required CS within less than 2 weeks because of fetal distress.

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Obesity in pregnancy : review

Obstetrics and Gynaecology Forum, Feb 1, 2006

Extracted from text ... Obstetrics & Gynaecology Forum ? February 2006 21 REVIEW OG16:21-28 I... more Extracted from text ... Obstetrics & Gynaecology Forum ? February 2006 21 REVIEW OG16:21-28 Introduction Obesity is a worldwide problem with an ever-increasing prevalence. It has traditionally been regarded primarily as a problem of developed nations, but developing nations are just as much in its grip. South Africa is no exception to this phenomenon. Obesity clearly deserves the description that it has been given by the World Health Organization: an "escalating epidemic" and "one of the greatest neglected public health problems of our time, with an impact on health which may prove to be as great as smoking". A big concern ..

FIGO good clinical practice paper: management of the second stage of labor

International journal of gynaecology and obstetrics, Jan 28, 2021

This good clinical practice paper provides an overview of the current evidence around second stag... more This good clinical practice paper provides an overview of the current evidence around second stage care, highlighting the challenges and the importance of maintaining high‐quality, safe, and respectful care in all settings. It includes a series of recommendations based on best available evidence regarding length of second stage, judicious use of episiotomy, and the importance of competent attendants and adequate resource to facilitate all aspects of second stage management, from physiological birth to assisted vaginal delivery and cesarean at full dilatation. The second stage of labor is potentially the most dangerous time for the baby and can have significant consequences for the mother, including death or severe perineal trauma or fistula, especially where there are failures to recognize and repair. This paper sets out principles of care, including the vital role of skilled birth attendants and birth companions, and the importance of obstetricians and midwives working together effectively and speaking with one voice, whether to women or to policy makers. The optimization of high‐quality, safe, and personalized care in the second stage of labor for all women globally can only be achieved by appropriate attention to the training of birth attendants, midwives, and obstetricians. FIGO is committed to this aim alongside the WHO, ICM, and all FIGO’s 132 member societies.

Predictive value of conditional centile charts for weight and fundal height in pregnancy in detecting light for gestational age births

European Journal of Obstetrics & Gynecology and Reproductive Biology, Mar 1, 1997

To estimate the predictive value of weight and symphysis fundal height (SFH) in pregnancy to dete... more To estimate the predictive value of weight and symphysis fundal height (SFH) in pregnancy to detect light for gestational age (LiGA) births. New conditional centile charts for longitudinal monitoring of maternal weight and fundal height in pregnancy were developed based on the records of 676 women with singleton pregnancies and no complications. The records of these women and of a further sample of 102 women who had LiGA deliveries were used to assess the sensitivity and specificity of the charts in detecting LiGA during pregnancy. Maternal weight is a poor predictor of LiGA births. Fundal height shows moderate predictive ability. The simple cross-sectional chart for fundal height at the 20th percentile cutoff has sensitivity and specificity of 66% in detecting LiGA births. Monitoring via a cross-sectional chart of fundal height offers a potentially useful screening method. The results of this study add support to arguments that routine weighing in pregnancy should be abandoned.

Gerhard Theron

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