What are the effects of obstetric ultrasound?
Care utilization and mortality
A recent cluster-randomized trial in Pakistan, Kenya, Zambia, the Democratic Republic of the Congo and Guatemala looked at the effects of antenatal ultrasound use in rural health center settings [20, 21]. After stratifying by country, each of the intervention and comparison clusters were defined as a catchment area of a health center that records about 500 births every year [21]. Pregnant women in the intervention clusters were generally offered two antenatal ultrasound examinations, first exam between 18 and 22 weeks and the second exam between 32 and 36 weeks, and those with identified complications were referred to higher-level health facilities [21]. At the first visit, gestational age was determined and fetal number and position, cervical length, potential amniotic fluid abnormalities and potential congenital abnormalities were examined [21]. At the second visit, placental location and growth were observed in addition to all of the checks performed during the first visit [21]. The intervention package also included health worker training for antenatal ultrasound, emergency obstetric and neonatal care training at higher-level referral facilities and community sensitization events where people were informed about the diagnostic capabilities of ultrasound as well as the antenatal ultrasound services being offered at intervention facilities [21]. This recent study including five countries with a rigorous cluster-randomized design found no difference in intervention and comparison clusters in terms of antenatal care use, facility delivery, stillbirth rate, neonatal mortality and maternal mortality [20].
Another randomized study conducted in South Africa found that routine second-trimester ultrasound scanning did not result in a significant difference in perinatal mortality between the ultrasound scan group and the control group, 4.3 and 4.1% respectively with a relative risk of 1.05 and 95% confidence interval between 0.54 and 2.03 [9, 19]. However, the study also noted that it had low power due to the small sample size [19]. Other studies either did not have enough statistical power to detect significant differences in mortality outcomes [22] or simply speculated that increases in antenatal care visits as a result of ultrasound or postpartum uses of ultrasound will likely reduce mortality outcomes [23, 24].
Some studies that employed a weak study design (limited randomization and absence of control groups) reported that ultrasound services generally appeared to be associated with an increase in the number/proportion of antenatal care use and facility delivery, which is contrary to the findings of a recent large-scale cluster-randomized trial [20, 21].
Ross et al. conducted a study at a rural community health center in Uganda with portable ultrasounds [23]. Exams were offered to women during their first antenatal visit and at 32 weeks gestation, and additional scans were performed when they were deemed appropriate [23]. The study noted that ultrasound exam fees were affordable to all patients at about $2 USD [23]. Lacking a control group, the study utilized a historical control to assess changes in outcome measures pre and post-intervention [23]. Total antenatal care visits at the health center significantly increased from a monthly average of 133.5 visits before the program to 230.3 visits after the program [23]. Over a period of 64 months, the average number of deliveries at the health center also significantly increased from 28.1 deliveries before the program to 45.6 deliveries after the program [23].
Mbuyita et al. conducted a study in Tanzania to determine if mid-level providers were capable of using portable ultrasound machines after training [25]. Compared to baseline data, the number of first antenatal care visits did not change significantly [25]. However, the number of women receiving four or more antenatal care visits increased significantly between baseline (27.2%) and endline (60.3%) periods in the intervention area [25]. The number of facility deliveries also increased significantly between baseline and endline periods in the intervention area [25].
Lastly, Ross et al. examined the components of routine antenatal care services before and after the introduction of routine ultrasound [26]. The study showed significantly increased rates of anemia treatment, deworming, and two doses of intermittent preventive treatment of malaria (IPT2) after the ultrasound intervention [26].
Patient diagnosis and care management
Although recent evidence points to ultrasound having no significant effect on mortality, facility delivery and antenatal care use [20, 21], there were studies reporting that ultrasound in LMICs helped improve the quality of care for both obstetric and non-obstetric conditions [10]. Muller-Rockstroh, in her narrative description about a hospital in Northwest Tanzania, stated that ultrasound scans helped midwives determine the timing and appropriate mode of delivery. Midwives were able to delay or accelerate timing of delivery and determine appropriate management plans based on ultrasound findings [24, 25]. The ability of ultrasound to confirm clinically suspected obstetric complications and even improve patient management has been reported in many other studies [4, 6, 8, 11, 12, 14, 27, 28].
A study in Malawi reported that despite having a learning curve, mid-level providers were able to confirm or improve determination of gestational age using ultrasound [8]. Correct determination of gestational age is necessary to distinguish premature newborns from newborns who are growth-restricted as the required care and interventions are different [8]. Correct determination of gestational age also has implications for preventing mother-to-child transmission of HIV [7].
The utility of ultrasound has been documented in medical emergencies and disaster settings which include obstetric uses as well. Understandably, portable hand-held or hand-carried ultrasound devices have been employed in these situations where there is unreliable access to power and a high need for rapid triage [17]. During a 12-day disaster relief effort in Haiti after the earthquake in 2010, the use of portable hand-held ultrasound devices led to a change in 70% of patient management plans [16]. Portable ultrasound imaging was found especially useful for diagnosing non-traumatic abdominal pain and pregnancy-related symptoms [16].
What are key issues related to health personnel?
Training of health personnel
The training of health personnel is a major factor for quality implementation of obstetric ultrasound services, as appropriate patient management relies on the ability of health personnel to use the machine proficiently and interpret findings accurately [7]. In many LMICs, there is a paucity of health personnel who are capable of providing ultrasound services [29].
A WHO Study Group recommended in its 1998 ultrasound manual that candidates for ultrasound training should have at least two to three years of prior healthcare training [30]. Qualified candidates are then recommended to complete at least 6 months of training in a recognized training center including 50 first trimester pregnancy exams and 200 s and third trimester exams for obstetric applications of ultrasound [30]. It is important to note, however, that recommendations for the different numbers of examinations were given as a guide. A recent review article, which documented training opportunities for ultrasonography in LMICs, concluded that the majority of health personnel using ultrasound in LMICs did not meet the minimum WHO training standards [18]. In Africa, 40.4% of ultrasound service providers completed only a short theoretical course, 14.9% had practical courses with only 2.1% occurring in a hospital environment, and 38.3% had no training at all [7, 31]. Ultrasonography training largely targeted lower- and mid-level practitioners such as local health workers, nurses and midwives as well as non-radiologist physicians [18]. Although the literature suggests that past trainings were not in compliance with WHO’s recommendations, many studies demonstrated that lower- and mid-level providers were capable of providing ultrasound services resulting in improved clinical management [5, 6, 8, 14, 27, 29, 32,33,34,35]. There is also some evidence that general physicians at rural health facilities can adequately provide ultrasound services in terms of correct use and interpretation of findings [14].
When adequate training materials and methods are used, short intensive training courses have been shown to provide significant acquisition of knowledge and practical skills for all levels of health workers in LMICs [10, 17]. There is also evidence that follow-up refresher trainings can be effective for retention of knowledge and skills [10, 17] though the sustainability of these courses after donor funding is expended is not adequately documented. In addition to training, however, it is important to note that there are other issues which are essential in obtaining good clinical readings. These issues include ensuring that the machine is set for the proper application (i.e. obstetric uses) and that the use setting has appropriate lighting, temperature, electrical supply and IT requirements [36]. It is also important to understand the limitations of different ultrasound models and devices. For example, the image quality of portable ultrasound may not be sufficient to identify fetal anomalies and early gestational age.
Concerns about misuse, overuse and miscommunication
Misuse, overuse and lack of communication between health providers and patients have been frequently cited as concerns in the literature. A study in Uganda demonstrated that over half of all obstetric scans performed were considered inappropriate because they were either scans for gestational age estimation outside of the recommended time period, routine monitoring despite no sign of intrauterine growth restriction or re-assessment of the placental position because of the technical inability to determine it with a previous scan [37]. In another study in Botswana, health providers noted that conventional methods such as history taking and physical examination were neglected because of easy access to ultrasound services [2]. There were indications that even in situations where conventional methods would have sufficed, ultrasound diagnosis was recommended for convenience [2]. Such inappropriate use raises concerns because health providers should not neglect conventional methods of providing care [2, 3].
Even when ultrasound services are available, they must be complementary to routine care [4, 7]. This is especially true for obstetric use of ultrasound. For example, estimation of gestational age is more accurate early in pregnancy [8]. As pregnancy progresses, the variation of fetal size increases and it becomes difficult to accurately estimate gestational age by ultrasound alone [8]. Since pregnant women in LMICs often present themselves for antenatal care later in pregnancy, ultrasound dating must be used in conjunction with conventional methods to accurately estimate gestational age [8].
As for cases of misuse, financial incentives for providing unnecessary ultrasound services have been reported as one reason for misuse in LMICs. After the initial ultrasound scan, multiple follow-up scans were often scheduled in private clinics as a way to increase revenue [38, 39]. Using ultrasound for financial gain or any other reason that is not clinically-based, can significantly reduce the cost-effectiveness of services [1] and drive up the costs paid by women and their families.
Lastly, there is evidence for lack of communication between health providers and patients. A study in Botswana reported that the average time of interaction between providers and patients was 15 min, of which only 15% were devoted to communicating with the patient [2]. Health providers were preoccupied with the technical aspects of performing an ultrasound scan and patients received very little attention throughout the process [2]. In a study in Iran, none of the study patients reported receiving written information about the purpose of the ultrasound exam, 48% reported that the ultrasound operator did not answer any questions and 90% reported that they were never shown the image of the fetus on the ultrasound screen [40]. These findings are of concern as patients’ perception of and experience with ultrasound are mainly determined by the quality of their interaction with the health providers [2].
Concerns about fetal sex determination
Prior studies in different countries document that ultrasound has been illegally used for fetal sex determination. In India, the male-dominant sex ratio for children under 5 years is thought to be associated with fetal sex determination and sex-selective abortions [1]. A population-based study in Delhi, India found that 56% of respondents either did not know that fetal sex determination was illegal or thought that it was lawful [9, 41]. In the same study, 2.6% of respondents had ever requested fetal sex determination and when the female sex of the fetus was disclosed, over 63% of them were aborted [9, 41]. In a study in Nepal, 6.8% of surveyed pregnant women received ultrasound exams for fetal sex determination despite it being unlawful [42]. The study also found that compared to women who had at least one live born son prior to the recent pregnancy, women with no live born sons and three or more live born daughters had 1.55 higher odds of receiving an ultrasound exam, which may suggest use for fetal sex determination [42]. Other popular reasons for determining fetal sex were reported to be curiosity and preparation for the baby [43, 44].
Negative consequences of fetal sex determination go beyond obvious legal and ethical violations. Incorrect assessment of the fetal sex can also result in negative experiences for women, especially in settings where son preference is high. Incorrect assessment of the fetal sex is not uncommon. In a study in Ghana, fetal sex was accurately determined in only 86.5% of the cases [45]. A study in Nigeria reported that incorrect assessment of the fetal sex, particularly for mistaking female fetuses as males, resulted in marital conflict, physical violence from husbands, regret of undergoing tubal ligation, negative perception towards ultrasound and negative feelings towards the newborns [46]. Such negative consequences can be exacerbated when accreditation and regulation for ultrasound use are limited [9, 47]. Ethical training for health providers on appropriate uses of ultrasound and regulations for both public and private clinics are important [7].
What issues are important to patients?
Patient perception on ultrasound services
In the studies reviewed, women in LMICs generally held positive views about ultrasound services [23]. Rijken et al. found that on the Thai-Burmese border, ultrasound was considered a tool that could increase safety during pregnancy and childbirth [23, 48]. In a rural Botswana district hospital, pregnant women showed signs of trusting the ultrasound results more than their own bodily sensations to confirm a live fetus [2]. The women expressed relief that “there was life in the baby” (p. 697) [2]. These women also referred to the ultrasound experts as the “Whites” (p. 697) and regarded the same ultrasound services provided by African health providers as substandard [2].
Cultural resistance to ultrasound services was not reported to be a major problem. A study in Zambia reported that patients would often wait in line for ultrasound exams, even after clinic hours were over [6]. In addition, many patients who came for antenatal visits stated that availability of ultrasound was their motivation for attendance [6]. A qualitative study in Tanzania reported that the majority of women desired to receive ultrasound exams despite the lack of understanding about the benefits and the procedures [49]. Those who did not view ultrasound favorably thought that ultrasound would cause harm to the fetus [49].
Negative perceptions or misconceptions about ultrasound were reported in other studies as well [40, 50]. Women interviewed in a study in rural Kenya perceived that undergoing an ultrasound exam meant there was an emergency or a problem with the pregnancy [50]. However, all interviewed women perceived ultrasound to add significant value in reassuring the health and progress of the baby [50]. In another study in Iran, 39% of women chose not to undergo an ultrasound exam due to the following reasons: ultrasound can be harmful (especially with regards to fetal malformation); results are not important; exams are expensive; and busy schedules [40].
Motivation for seeking ultrasound services as well as access to ultrasound services have been documented to differ by social class. A study in Nepal found that the adjusted odds of receiving an ultrasound exam were 3.4 times higher for women who had 7 to 10 years of education and 10.28 times higher for women who had more than 10 years of education compared to women with no formal education [42]. In sub-Saharan Africa, access to obstetric ultrasound in rural areas has shown to be as low as 6% [7, 31].
Providers’ explanations or lack of explanations about the ultrasound scan play a role in terms of patient perception and satisfaction. Women who received ultrasound services in a rural setting in Botswana described that turning the light off before the examination was an unusual experience [2]. Patients normally expect examination rooms to be “brightly lit” (p. 694) [2]. In a study in southeast Nigeria, 70% of study participants reported that they did not interact with the sonographers, 24% reported being afraid prior to the scan, 11% reported being afraid during the scan and 4% reported being afraid after the scan [51].
What are potential issues with the ultrasound device?
Maintenance
Although there are no previous studies rigorously testing the durability of ultrasound machines in LMICs, some studies provide anecdotal accounts. Kozuki et al. describes having to replace refurbished portable ultrasound machines four times in the span of 17 weeks in a study in Nepal due to hardware and software errors [5, 52]. In another study by Kimberly et al., portable ultrasound machines performed well even in excess heat, humidity, dust and long travels in a 6-month study [6]. At the 1-year follow-up visit, however, 38% of the midwives who responded to a follow-up survey cited problems with the ultrasound machine [6]. These problems included depletion of ultrasound gel and flickering image on the ultrasound screen [6]. Another study reported that maintenance was not an issue during the 5-month study period [14]. In fact, a study conducted in extreme conditions of the Amazon jungle reported that portable ultrasound machines functioned well for two two-week trips [53]. However, there is limited evidence for maintenance beyond the research study period. One study describes that establishing a maintenance protocol within routine health systems can be long and difficult [24]. In this study, such difficulty left many ultrasound machines unrepaired [24].
Cost
In high-income countries, there has been many studies assessing the cost effectiveness of using ultrasound to identify fetal abnormalities, as demonstrated by a 2002 review [54]. Cost effectiveness studies are less common for LMICs. Only a few studies provided an overview of program costs and the realized benefits. Bussmann and colleagues reported that in a district hospital in Botswana, initial capital and recurrent costs of the ultrasound were considered affordable, relative to the overall unspent hospital budget in the study period [4]. They also found that “the marginal cost of providing an ultrasound was less than a quarter of providing an X-ray examination” (p. 1030) [4]. The average and marginal costs of an ultrasound diagnosis in improving patient management appeared to be affordable as well, 56.58 USD and 0.64 USD respectively [4]. Lastly, the average and marginal costs of potentially improving a health outcome through an actual change in therapy, were considered affordable, 260.79 USD and 2.93 USD respectively [4]. Overall, the study concluded that providing ultrasound scans in Botswana was financially feasible [4]. Another study in Nepal estimated the impact of ultrasound on the potential to avert perinatal deaths attributable to non-cephalic birth, multiple birth and placenta previa [5, 52]. The study estimated that with an early ultrasound diagnosis, a total of 160 potential perinatal deaths could be averted, which translates to about 65 USD saved per life [5, 52]. This estimation was derived based on the assumption that all early diagnoses will lead to the prevention of perinatal deaths [5, 52], likely overestimating the true impact. However, it also did not adjust for potential disability life years averted by preventing maternal mortality or morbidity [5, 52]. Hence, the estimated impact on averting potential perinatal deaths does not capture the full range of benefits that early ultrasound diagnosis offers.
In summary, there is a lack of high quality cost effectiveness studies on obstetric ultrasound in the literature [54]. The majority of published studies are from high-income countries, and they did not include discussions about longer term costs or cost incurred to women [54].
