Obstetric ultrasound: How, why and when

We aimed to determine the prevalence of abnormal umbilical artery (UA), uterine artery (UtA), middle cerebral artery (MCA) and cerebroplacental ratio (CPR) Doppler, and their relationship with adverse perinatal outcomes in women undergoing routine antenatal care in the third trimester.

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Middle cerebral arterial flow redistribution is an indicator for intrauterine fetal compromise in late pregnancy in low‐resource settings: A prospective cohort study

The purpose of this review is to summarize the most recently published literature regarding ultrasound (US) use in limited-resource settings. The body of literature is quite heterogeneous, but several recurring themes emerged from the data. Research regarding education is burgeoning, with studies showing that low-cost training modules can effectively teach US skills to novices. Many studies reported feasibility of training non-physicians to perform US, which allows for task-shifting. Research regarding clinical application of US is broad; especially regarding Echocardiography, Infectious Disease, and OB-GYN. US continues to be a highly utilized tool in limited-resource settings. We identified several common themes among the recent literature: the use of educational interventions to train non-physician providers, the use of US for improved screening methods, and the expanded role of US in clinical purposes including Infectious Disease, Echocardiography, Pulmonary, and Obstetrics.

Ultrasound in the Limited-Resource Setting: A Systematic Qualitative Review

Point-of-care ultrasound has the potential to help inform assessment, diagnosis, and management of illness in low- and middle-income countries (LMIC). To better understand current ultrasound use, barriers and facilitators to use, and perceptions and practices in LMIC, we conducted an anonymous online global survey targeting healthcare providers training and using ultrasound in LMIC. A total of 241 respondents representing 62 countries participated and most were physicians working in publicly-funded urban tertiary hospitals in LMIC. Most had received ultrasound training (78%), reported expertise (65%) and confidence (90%) in ultrasound use, and had access to ultrasound (88%), utilizing ultrasound most commonly for procedures and for evaluations of lungs, heart, and trauma. Access to an ultrasound machine was reported as both the top barrier (17%) and top facilitator (53%); other common barriers included access to education and training, cost, and competition for use and other common facilitators included access to a probe, gel, and electricity, and acceptance by healthcare providers, administrators, and patients. Most (80%) noted ultrasound access was important and 96% agreed that ultrasound improves quality of care and patient outcomes. Improving access to low-cost ultrasound equipment is critical to increasing ultrasound use among those who are trained. 

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A survey of barriers and facilitators to ultrasound use in low- and middle-income countries

OBJECTIVE: To evaluate the role of the middle cerebral artery (MCA) to the umbilical artery (UA) blood velocity waveform’s pulsatility index (PI) screening in proximity to delivery as a predictor of high-risk pregnancy and neonatal outcomes. METHODS: The study used a nested case–control method, consisting of 34 women with high-risk pregnancies and 34 pregnant women who were classified as normal. The MCA/UA PI ratio was evaluated within 14 days before delivery. All subjects’ newborns were evaluated for neonatal outcomes, which included fetal distress, abnormal cardiotocography or fetal heart rate patterns, neonatal mortality, Apgar score, duration of hospitalization, and neonatal intensive care unit (NICU) admission. A cutoff point for MCA/UA PI ratio was assessed using the receiver operating characteristic curve. The correlations between the MCA/UA PI ratio and high-risk pregnancy and neonatal outcomes were assessed with multivariable linear regression based on the cutoff point obtained. RESULTS: The MCA/UA PI ratio in high-risk pregnancy was significantly lower compared with normal pregnancy ( p = .011). The MCA/UA PI ratio of ≤1.32 finding was 6.37 times higher in high-risk pregnancy ( p = .017, AOR 6.37, 95% CI 1.40–28.97), 5.9 times higher in pregnancy with the neonate’s first-minute Apgar less than 7 ( p = .031, AOR 5.90, 95% CI 1.18–29.61), and 18.62 times higher in neonates admitted to the NICU ( p = .023, AOR 18.62, 95% CI 1.43–2702.94). CONCLUSIONS: Low MCA/UA PI is associated with high-risk pregnancies and adverse neonatal outcomes, such as low first-minute Apgar score and NICU treatment. 

Fetal Middle Cerebral Artery and Umbilical Artery Pulsatility Index Doppler Associations With Pregnancy Risk and Neonatal Outcomes

The World Health Organization recommends research to evaluate the effects of a single third trimester Doppler ultrasound examination on preventable deaths in unselected-risk pregnancies, particularly in low- and middle-income countries (LMICs) where the evidence base is scarce. While evaluating such technologies, researchers often ignore women and health care provider perspectives. This study explored the views and experiences of women and healthcare providers regarding the use of advanced ultrasound technology to optimize the health of mothers and their babies in a rural community in mid-western Uganda. We enrolled 53 mothers and 10 healthcare providers, and captured data on their perceptions, barriers, and facilitators to the use of Doppler ultrasound technology using focus group discussions, semi-structured interviews and observations. Using qualitative content analysis, we inductively coded the transcripts in ATLAS.ti 8.0, detecting emerging themes. Women were afraid that ultrasound would harm them or their fetuses and many of them had never seen an ultrasound scan. The majority of the women found their partners supportive to attend antenatal care and use ultrasound services. Healthcare providers in Kagadi Hospital were unfamiliar with Doppler technology and using it to guide clinical decisions. Other barriers to the implementation of Doppler ultrasound included shortage of trained local staff, insufficient equipment, long distance to and from the hospital, and frequent power cuts. We found limited exposure to Doppler ultrasound technology among women and healthcare providers in mid-western Uganda. Engaging male partners may potentially influence the likelihood of accepting and using it to improve the health of women and their fetuses while wide spread myths and misconceptions about it may be changed by community engagement. Healthcare workers experienced difficulties in offering follow-up care to mothers detected with complications and Doppler ultrasound required a high level of training. While introducing advanced ultrasound machines to weak health systems, it is important to adequately train healthcare providers to avoid inappropriate interventions based on misinterpretation of the findings, consider where it is likely to be most beneficial, and embed it with realistic clinical practice guidelines. Globally, nearly three million babies are stillborn every year, but most especially in low- and middle-income countries like Uganda. One of the factors contributing to a high number of stillbirths in low-income countries is the difficulty in identifying complications and accessing high quality care during pregnancy. Although antenatal Doppler scans are being widely used to diagnose complications in high-risk pregnancies in developed countries, studies evaluating it in LMICs are needed before it is implemented on a wide scale. We engaged 53 mothers, eight health workers from a hospital and two healthcare managers from a local government in Uganda to attain their opinions about Doppler ultrasound. We found that spousal involvement may promote acceptance and use of ultrasound services. However, the health workers did not have adequate knowledge about Doppler technology and using it for the benefit of mothers and the mothers feared that ultrasound procedures might harm them or their unborn babies. Making matters worse, the hospital faced frequent power cuts that affected the use of the equipment. Further, mothers must cover a long distance to access the hospital and its services. To reduce the number of babies dying during pregnancy or a few days after birth in Uganda and similar low-resource settings using Doppler technology, it is essential to strengthen the health systems. Starting with the training of healthcare providers to equipping and stabilizing power supply in health facilities, and educating the public about critical health procedures to break myths and misconceptions.

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Antenatal Doppler ultrasound implementation in a rural sub-Saharan African setting: exploring the perspectives of women and healthcare providers.

Ultrasonography is essential in the prenatal diagnosis and care for the pregnant mothers. However, the measurements obtained often contain a small percentage of unavoidable error that may have serious clinical implications if substantial. We therefore evaluated the level of intra and inter-observer error in measuring mean sac diameter (MSD) and crown-rump length (CRL) in women between 6 and 10 weeks’ gestation at Mulago hospital. This was a cross-sectional study conducted from January to March 2016. We enrolled 56 women with an intrauterine single viable embryo. The women were scanned using a transvaginal (TVS) technique by two observers who were blinded of each other’s measurements. Each observer measured the CRL twice and the MSD once for each woman. Intra-class correlation coefficients (ICCs), 95% limits of agreement (LOA) and technical error of measurement (TEM) were used for analysis. Intra-observer ICCs for CRL measurements were 0.995 and 0.993 while inter-observer ICCs were 0.988 for CRL and 0.955 for MSD measurements. Intra-observer 95% LOA for CRL were ± 2.04 mm and ± 1.66 mm. Inter-observer LOA were ± 2.35 mm for CRL and ± 4.87 mm for MSD. The intra-observer relative TEM for CRL were 4.62% and 3.70% whereas inter-observer relative TEM were 5.88% and 5.93% for CRL and MSD respectively. Intra- and inter-observer error of CRL and MSD measurements among pregnant women at Mulago hospital were acceptable. This implies that at Mulago hospital, the error in pregnancy dating is within acceptable margins of ±3 days in first trimester, and the CRL and MSD cut offs of ≥7 mm and ≥ 25 mm respectively are fit for diagnosis of miscarriage on TVS. These findings should be extrapolated to the whole country with caution. Sonographers can achieve acceptable and comparable diagnostic accuracy levels of MSD and CLR measurements with proper training and adherence to practice guidelines.

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Measurement error of mean sac diameter and crown-rump length among pregnant women at Mulago hospital, Uganda

Background: The mean central corneal thickness (CCT) values are known to have an influence on intraocular pressure measurement and vary widely with age, sex and ethnicity. Little is known about the pattern of CCT in central Uganda. Aim: To determine the mean central corneal thickness and its associated factors among adult patients attending Mulago Hospital eye clinic, Kampala Uganda. Design and Method: A cross sectional study was done from August to October 2016 on 270 adult patients selected by systemic random sampling. The study included all adult patients who attended the eye clinic during the study period and consented to the study excluding those who had conditions causing abnormal thinning, thickening or irregularity of the cornea. The participants were evaluated by history taking and ocular examination including visual acuity assessment, slit lamp examination, central cornea thickness measurement, intraocular pressure measurement and funduscopy. Data were collected using a pretested questionnaire, entered using Epidata and analyzed by STATA11.0. Results: Of the 270 patients examined, 61% were female, 39% male, the mean age being 42 years ranging from 18 to 96 years. The mean central corneal thickness for both eyes was 539.3 (SD ± 41.65 μm) ranging from 332 μm to 701 μm and mean intraocular pressure was 15 (SD ± 5.34) mmHg. Gender, ethnicity, IOP, glaucoma, hypertension, diabetes, refractive error, were not statistically significantly associated with central cornea thickness. However central cornea thickness was statistically significantly associated with systolic blood pressure (r = -0.24, p = 0.025) and age (p = 0.002). A one-year increase in age reduced the mean central cornea thickness by 0.54 μm. Conclusion: The average CCT of Ugandan adult population was 539.3 ± 41.65 μm which falls in the category of normal central cornea thickness. Central corneal thickness reduced with increasing age and increasing systolic blood pressure. 

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Sam Ali

Papers

Antenatal Doppler ultrasound implementation in a rural sub-Saharan African setting: exploring the perspectives of women and healthcare providers.

Measurement error of mean sac diameter and crown-rump length among pregnant women at Mulago hospital, Uganda

The Mean Central Cornea Thickness and Associated Factors among Adult Patients Attending Mulago Hospital Eye Clinic Kampala, Uganda