G.B. Theron

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.

Significance and treatment of asymptomatic bacteriuria during pregnancy

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

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

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.

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 Pearsons 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.

Symphysis-fundus growth measurement followed by umbilical artery Doppler velocimetry to screen for placental insufficiency

Umbilical artery Doppler velocimetry is essential in the management of pregnancies with suspected intra-uterine growth restriction (IUGR). It is associated with fewer inductions of labor, admissions to hospital, and a trend to less perinatal deaths w1,2x. Many people use symphysis-fundus (SF) measurements to assess fetal growth w3x. Umbilical artery velocimetry as a primary screening is not recommended w4x, we use it secondary to detection of poor SF growth. The study population consisted of 918 consecutive singleton pregnancies at a community antenatal clinic. Gestational age was confirmed by early ultrasound. Patients with poor SF growth were referred for Doppler velocimetry of the umbilical artery. A Vasoflow Duplex continuous wave Doppler machine was used to determine the resistance index (RI). Values below the 75th centile were regarded as normal. Outcome measures were light-for-gestational-age (LiGA) babies and complications of placental insufficiency. LiGA is defined as a birth weight below the 10th centile. To determine the frequency of a RIGp75 and

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

Objective: To determine the proportion of perinatal deaths that could be reduced by midwives providing primary obstetric services. Method: 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. Results: 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. Conclusion: The 22.1% of perinatal deaths potentially preventable by midwives presupposes complete patient cooperation within an optimally functioning health system.

A centile chart for fetal weight for gestational ages 24 - 27 weeks

The centile chart currently in use for Western Cape birth weight for gestational age covers a gestational age range from 28 to 42 weeks. Advances in maternal fetal and neonatal medicine allow interventions prior to 28 weeks; a growing need therefore exists to extend the chart down to at least 24 weeks. Birth or fetal weight centile charts used in the USA Canada and the UK provide centiles commencing from either 22 or 24 weeks. These charts may not however be appropriate for the population of the Western Cape. The accuracy of fetal or birth weight for gestational age centile charts can be improved by including only women who had their gestational age confirmed by early ultrasound prior to gestational age of 24 weeks. In addition the birth weight of preterm delivered neonates should not be used to establish a norm as these infants were delivered following maternal and/or obstetric complications. The ultrasonic estimated fetal weight (EFW) is the method of choice to establish a reference range for weight for gestational age in early gestation. The EFW should be used in preference to any single ultrasound measurement as it relies on multiple measurements. The aim of this study was to construct a centile chart from 24 to 27 weeks for fetal weight for gestational age taking the above criteria into account. (excerpt)

HIV transmission from mother to child: HAART compared with dual therapy

To the Editor: There are increasing calls for the use of highly active antiretroviral therapy (HAART) for the prevention of perinatal mother-to-child transmission (PMTCT) of HIV.1 This approach does not recognise the weaknesses in health systems to implement complex treatment protocols. In addition, the safety of HAART during pregnancy is uncertain and the consequences of stopping HAART if not required outside pregnancy are unknown. If the same PMTCT of HIV could be attained with a simple regimen with proven safety and known adverse drug effects, this would be a better option in most under-resourced countries.2 The superiority of HAART compared with dual therapy according to World Health Organization (WHO) recommendations for immune-competent women to reduce PMTCT has not been proven.3

The value of adding a universal booking scan to an existing protocol of routine mid-gestation ultrasound scan

To compare 2 routine obstetric ultrasound protocols regarding number of clinically relevant events detected and total ultrasound workload.

Screening for chronic placental insufficiency by Doppler flow velocimetry of the umbilical artery in patients with symphysis-fundus height determined gestational age

Umbilical artery Doppler flow velocimetry is essential in the clinical management of pregnancies where intrauterine growth restriction (IUGR) is suspected w1,2x. In developing countries 40% or more women are uncertain of the date of their last menstrual period (LMP) w3x. In addition, 28% or more women often visit the antenatal clinic for the first time at a gestational age (GA) beyond 24 weeks when ultrasound determination of GA is inaccurate. Symphysis–fundus (SF) measurement is often used to measure fundal height and GA is determined by plotting this value on the 50th centile of a growth curve w4x. For these reasons it is important to determine how the SF determination of the GA will change the interpretation of the resistance index (RI). The study population was comprised of patients with suspected IUGR whose GAs had been confirmed by ultrasound prior to 24 weeks. A single observer determined the SF height and the RI of the umbilical artery with a Vasoflow Duplex continuous wave Doppler machine.