Training Course in Reproductive Health/Chronic Disease
Ultrasonography: Recommendations for
its appropriate use
in routine antenatal care in Nigeria
Review prepared for the 12th Postgraduate Course in
Reproductive Medicine and Biology, Geneva, Switzerland
Reproductive Health Care Centre
Department of Obstetrics and Gynaecology
Federal Medical Centre
Supervisor: Margaret Usher-Patel
Implementing Best Practice Initiative
WHO/Department of Reproductive Health and Research
Obstetric ultrasonography has grown in popularity since it was introduced
over four decades ago. It had proliferated and its use if not controlled,
which suggests that ad hoc use is open to misuse and could be a drain on the
limited human and economic resources available without corresponding
improvement in fetal and maternal outcomes.
The objective of this paper is to review current literature on the
appropriate use of ultrasound during routine antenatal care and make
recommendations for the appropriate use of ultrasound in Nigeria. The
concern is that the Federal Republic of Nigeria is the largest black nation
in the world with a vast population. Despite the amount of human and
material resources available, the majority of the population are still
living below the poverty line. Only 50% of the women receive antenatal care
and if scarce resources are wasted on unnecessary equipment and the
performance of scans by unskilled practitioners, technical, human and
financial resources are wasted that could be used to increase access to the
services and improve maternal and neonatal outcomes.
Extensive search mechanisms available through the WHO Headquarters
electronic resources (The OVID, Medline, Popline and Cochrane data bases)
were searched and other sites, such as the Blackwell SYNERGY and on-line
journals. A manual search was also conducted, and Google search to determine
the type of information available to the lay public. 54 papers were obtained
Four systematic review were identified, three of them Cochrane reviews,
eight randomized controlled trials and a number of other studies were
reviewed. The main findings were that routine ultrasound has not resulted in
improved fetal and maternal outcome when compared with the selective use
(only when clinically indicated). The cost of routine ultrasound is high and
the unnecessary human and material resources could be channelled to other
The conclusions reached is that ultrasound can be a useful tool in the
antenatal period when employed judiciously based on sound clinical
judgement. It should not be used indiscriminately. It should be used by
trained, accredited and regulated practitioners. National guidelines should
be available to guide use and inform both the practitioner and client. The
recommendations made should support the further study of this issue in
Nigeria and the formation of a national working group to develop national
standards and protocols of practice.
Obstetric ultrasonography has grown in popularity over the last thirty
years and is fast becoming a standard component of antenatal care. In
routine antenatal care it is used mainly to check the normal progression of
pregnancy and identify deviations from the norm. In principle it is being
used as a modern diagnostic and monitoring aid to undertake timely and
appropriate clinical interventions to reduce maternal and perinatal
morbidity and mortality. This paper questions whether the misapplication of
this effective technology may however end up increasing the cost in all its
ramifications (human technical and material resources) of routine antenatal
care to all stake-holders without corresponding improvement in fatal or
The diagnostic ultrasound employed in medicine is a sophisticated electronic
technology which utilizes pulses of high frequency sound waves (>20,000 Hz)
which is undetectable by the human ear (1,2). The transducer emits
pulses of high frequency sound waves which pass through the tissue and some
are reflected back at difference tissue interphase. The intensity of the
reflected echo depends on the characteristics of tissue on the path of the
propagated sound wave. Conductivity of ultrasound increases with the density
of the material/tissue. Therefore, the velocity of ultrasound varies through
various body organs with air having the slowest velocity of about 331 meter
per second and bone having a much faster velocity of 4,080 meter per second
The reflected wave is picked by the same transducer and converted into
electronic signals for computer processing before it is displayed on the
screen based on its intensity and position. The spatial relationship of the
multiple displays forms the real-time images seen on the screen.
The technology of ultrasound has progressed from the earlier large and
cumbersome models, which were modifications of military Sound Navigation and
Ranging (SONAR) devices used for submarine military operations to the more
sophisticated real-time, 3-dimensional and the doppler flow sonography in
use today (3). The earlier applications were in therapy rather than
diagnosis utilising its heating and disruptive properties at higher doses
(frequency and duration related) in physical and rehabilitation therapy, and
neurosurgical ablations (4).
First application in diagnostic medicine was in neurosurgery in the early
1940s (5), later the unidirectional A-mode was used for tissue diagnosis of
surgical materials (intestine, breast, etc) (5). Application to living
tissue developed over the next ten years with what was termed a safe range
of sound frequency (20,000 - 20,000,000 Hz). Today only 3-10 MHz are
employed in clinical practice (6,7,8) . Ultrasonography was introduced into
obstetrics through the pioneering work of Professor. Ian Donald in Glasgow,
At that time, the ultrasound equipment was handled mainly by people involved
with its development and their associates who were adequately exposed to its
functionality and competent in its use.
In Nigeria, the technology was introduced about 30 years ago. For a long
time, it was found in only one centre, University College Hospital, Ibadan
and it was handled by highly skilled professionals. The advances in
technology has made the ultrasound machine small and portable. Although it
remains very expensive, nowadays it is possible to find this equipment in
virtually every nook and cranny of the country.
Initially, it was in the purview of the Radiologists. As the popularity of
ultrasound increases so is its use and now more and more obstetrician and
general practitioners are using ultrasonography in routine antenatal care.
Many of these machines are operated by individuals who are either
inadequately trained or have received no training at all. Up till the moment
of this review ultrasonography has no definite place in the undergraduate
curriculum. Attempts are being made to entrench it into the postgraduate
training, but this has still not been formalized or standardized. Those who
were involved with obstetric ultrasonography either had a formal
postgraduate training or were trained on the job. Majority of those who are
actually practising ultrasonography now either had ad-hoc training or no
training at all.
Training appears to be a none issue. A quick search of literature published
over the last twenty years in Nigeria identified 61 papers written on the
use of ultrasound (PubMed - National Library of Medicine). None of these
papers addressed the issue of standardization or guidelines for standard
practice. Most were focused on the fetal assessment and the diagnosis of
The unsuspecting pregnant woman accepts the procedure without due
consideration to the fact that the quality of ultrasound imaging does not
only depend on the sophistication and resolutions of the equipment alone,
but also on the experience and expertise of the operator (1,9 ,10,11) .
Mistakes could occur at any level, but the frequency of mistake tends to
reduce with expertise and experience (11,12) .
Moreover, from the literature reviewed it would appear that routine
ultrasonography has not been found to result in improved fetal or maternal
outcome (13,14) . The resources used on unnecessary ultrasound scans may be
better utilised elsewhere in the health services (15) or the patient's home.
To use ultrasonography to provide our clients with the most appropriate and
effective level of obstetric care, it is important that not only are
practitioners trained in the appropriate use of this equipment, but also its
use is governed by guidelines. Moreover, to protect the rights of the mother
and unborn child, the level of performance should be periodically audited
and governed by a regulatory body (15).
- To review current literature to determine the appropriate use of
ultrasound during routine antenatal care.
- To identify a series of recommendations that can be used to guide the
appropriate use of ultrasound during routine antenatal care in Nigeria.
Literature search for this review
employed many different channels. The OVID database was searched through the
WHO Headquarters electronic resources. The Medline, Popline, and the
Cochrane databases were also searched using several approaches.
The Lancet was obtained on-line through the WHO Intranet and also the
Headquarters electronic resources.
The Blackwell SYNERGY was also searched and some details obtained from
on-line journals through the WHO Headquarters electronic resources
subscriptions. The Googles search was used mainly to identify information
available to the general public.
Manual search of relevant journals was also done.
The keywords and phrases used in the search include:
ultrasound in pregnancy
in early pregnancy
in late pregnancy
effectiveness AND obstetric ultrasound
ultrasound and fetal outcome
in pregnancy AND safety.
Federal Republic of Nigeria is the largest black nation in the world and
the population is projected to be about 120 million (projection from 1991
census) . It was however estimated to be 116,928,000 in 2001 by the UNFPA
The budgetary allocation to health is far below the minimum recommended
proportions of the national budget of 5-7%; it ranged between 1.5% to 2.5%
of the national budget (16).
Per capital income is low, the gross domestic product (GDP) was $884.00
at the international rate but when the prevailing exchange rate in 2001 is
taken into consideration it will come to $350.00 (or even lower 2 years
later). The estimated government expenditure on health is about 2.2% of the
GDP. The average standard of living is quite low.
Despite this, the fertility rate is still high - 5.6% (17). Obstetric
cost is not borne by the employer or government so any extra cost must be
meaningful and worthwhile for the poor family. From figure 1 it is possible
to determine that on average approximately 60% of Nigerian women receive
ante natal care and 50% of these women will make at least 4 or more ante
natal visits during their pregnancy (18). If ultrasound is used at every
visit this has huge implications for the use of resources that might better
be employed reaching the 40% of the population that receive no antenatal
care. At the Federal Medical Centre, Abeokuta, the average number of
ante-natal visits per woman is 6, but can range from 1 to 14. Ultrasound is
used selectively when medically indicated.
Figure 1: Percentage of women with 4+ ante natal care visits in 20 African
Results of the Review
From the literature reviewed it would appear is if there is no
improvement in the outcome of pregnancy with the use of routine ultrasound
(18). The weight of evidence is in favour of the use of ultrasonography only
when clinically indicated (19-20). Routine ultrasonography can only be
justified in areas where the incidence of fetal anomaly is high and
pregnancy termination, at least before 24 weeks, is allowed legally (2) and
The literature defines many valid uses for diagnostic ultrasonography and
verifies the indications for use in pregnancy. There is a case for judicious
use in pregnancy and in situations where the prevalence of pelvic infection
is high with resultant pelvic adhesions. It is also useful for confirming
early pregnancy and determining the site of implantation early enough to
diagnose ectopic pregnancy before rupture (21).
The need for appropriate level of training, accreditation and regulation of
the practice of ultrasonography is an area that needs further investigation
so that the practice can be standardised and quality of care assured. The
literature has been used to define a framework for recommending a standard
of use in Nigeria for routine antenatal care.
Critical Analysis and Discussion
When to use Ultrasound in Early Pregnancy?
WHO has undertaken a randomised controlled trial of routine antenatal
care and as a result recommends four visits during pregnancy (24). Three
systematic reviews on the use of ultrasound in pregnancy discouraged routine
use, but did not specify frequency of use or recommend when ultrasound
should be used (1,10,22,23). These reviews focused on the clinical use of
ultrasound, which in itself can help to define appropriate time frames for
As previously stated the usefulness of ultrasound in pregnancy, when
clinically indicated, has rarely been questioned. The controversy has mainly
been over the routine use of ultrasound in all pregnancies(3).
As noted by Neilson in the Cochrane Review on Ultrasound for Fetal
Assessment in Early Pregnancy (2002) (10) there are a number of indications
for its use in early pregnancy. These include more accurate calculation of
gestational age, early identification of multiple pregnancy and diagnosis of
non-viable pregnancies, early bleeding, inappropriately grown (growth
restriction or macrosomia) and certain other fetal malformation.
Complications can however arise in pregnancy without clear warning signs or
risk factors. For this reason there is a case for routine screening in
pregnancy (early, late or both). Earlier diagnosis of ectopic pregnancy is
also worthy of note here especially in combination with serial or critical
beta hCG levels.
Using ultrasound to confirm pregnancy is not a difficult task, however, to
make appropriate diagnosis of complications of early pregnancy can be
challenging in inexperienced hands. A lot depends on the quality of the
machine and the experience and expertise of the operator. Routine
ultrasonography in the hands of inexperienced operator could do more harm
than good (10). Findings of unclear significance may add to the anxiety and
distress of the parents-to-be and lead to mismanagement (13).
Common applications of ultrasound in early pregnancy
Ultrasound provides the anatomic dimension of early pregnancy growth and
confirmation of pregnancy (26). The cost of the procedure will however still
be far more expensive than the standard simple urinary pregnancy (hCG) test
following a missed period. The advantage of ultrasound in the confirmation
of viability and localisations of the implantation site should possibly only
be considered when a complication such as ectopic pregnancy is suspected.
Early ultrasound gestational age dating is generally believed to be more
accurate (25,26). A multi-centred study undertaken Campbell et al conducted
on 4,527 women in 1985 found that there is no clear evidence that this, when
done routinely, will lead to fewer overall inductions rate or contribute
significantly to improved fetal outcome (31). Figure 2 provides a summary of
Figure 2. Percentage of patients delivering spontaneously
within (+/-) one, two, three, four and > four weeks of estimated date of
delivery based on the last menstrual period and ultrasound at 12 - 18 weeks.
Ewigman et al (1993) (18) conducted a randomised controlled involving 15,151
pregnant women at low risk for perinatal problems to determine if routine
use of ultrasound decreased the frequency of adverse pregnancy outcomes. The
conclusion reached was that routine use of ultrasonography did not improve
perinatal outcomes as compared with selective use. A similar conclusion was
reached even for multiple pregnancies. In this study, there were 68 and 61
multiple pregnancies in the ultrasound screening group and control group
respectively. The rate of adverse outcome of 25% in the ultrasound screening
group was not significantly different from 37.7% in the control group
(Relative risk0.7, 95% CI, 0.39 to 1.11). Again, this study demonstrates
that routine use of ultrasound does not improve outcome in multiple
pregnancy despite early diagnosis. Table 1 shows the rate of adverse
perinatal outcomes of 5.0% ultrasound group and 4.9% in the control group.
(Relative risk 1.0, CI 0.9 - 1.2).
Table 1. Adverse Perinatal Outcomes in the
Ultrasound-Screening and Control Groups
N = 7549
N = 7473
N = 136
Vaginal bleeding during early pregnancy is one of the indications for
ultrasonography (2,10,26,28). Viability can be determined and the different
varieties of abortions diagnosed. Molar pregnancy is one of the
differentials that could be diagnosed on sonography. Any associated pelvic
mass could also be evaluated as discussed earlier. Again ultrasound is used
as a diagnostic tool if indicated by the history and initial examination of
the client and there is concern for her welfare or that of the fetus.
The fetal heart rate can be detected sonologically at about 6 weeks of
gestation, from the last normal menstrual period in a regular 28-day cycle.
If at an age more than 6 weeks, the fetal cardiac activity could not be
demonstrated, or the gestational sac with a fetal pole less than 6 mm but no
fetal heart motion, or no demonstrable growth in the size of the fetal pole
in 2 weeks (26), an early fetal loss is diagnosed. Again ultrasound is
warranted if the history and initial examination show there is a reason for
concern. It is important however to remember that women to need to be
reassured that they and their baby are progressing well and ultrasound is a
very reassuring tool.
Routine ultrasound leads to earlier and more complete detections of multiple
gestations. However from the literature review it would appear not to lead
to better fetal outcome (10,18,24). The detection of multiple pregnancy
should give a theoretical advantage to the obstetrician to make adequate
preparations ahead to achieve better feto-maternal outcome but the evidence
from Ewigman et al large randomised controlled trials did not confirm this,
as noted above.
When the detection of fetal abnormality is a specific aim of routine early
pregnancy ultrasound screening, the number of planned pregnancy termination
increases (10). Fetuses who would have ended in perinatal death would have
been eliminated. Such programme is only justified in areas (countries) where
incidence of fetal malformation is high and pregnancy termination is legal
(13,28). Many studies have been carried out on the sensitivity of ultrasound
in detecting congenital defect in pregnancy (10,33,34,35,36). Some of these
were done in conjunction with biochemical screening for trisomies (37,38).
Diagnosis depends on several factors, including resolution of the equipment,
expertise of the sonologist, nature of the defect, size (or age) of fetus
and extensive or thoroughness of the examination (27,28,29).
When to use Ultrasound in Late Pregnancy?
Routine late pregnancy ultrasound has not been found to be associated
with improvements in overall perinatal mortality. This is the conclusion of
a Cochrane systematic review of seven large randomised controlled trials,
updated 2002. However, ultrasonography could be carried out for specific
indications to assist the practitioner in clinical decision and management
process. Some of these indications are discussed below.
- Placenta praevia, occurring in 0.5% of pregnancies (1) is a clinical
situation whereby the placenta is situated wholly or in part in the lower
uterine segment. Ultrasonography is now the best modality of locating
placenta position (1). About 10% of placenta extending into the lower
uterine segment in early pregnancy scan remain low at term (39). Any
vaginal bleeding in late pregnancy would necessitate an obstetric
ultrasound to determine the source. A less frequent but also a major cause
of antepartum haemorrhage, abruptio placenta can also be evaluated with
- Fetal growth monitoring and weight estimation can be used to detect
those at risk of intrauterine death, and prevention of neonatal
complications remains one of the major thrusts for antenatal care (1,24).
Symphysiofuncal height estimation has been demonstrated to compare poorly
with ultrasound fetal anthropometry when predicting or estimating fetal
weight (40). Serial measurement is necessary to detect poor fetal growth
and each is fetus used as its own control against the background of
appropriate normogram (41). It is however note worthy that routine late
pregnancy ultrasound may not be justified as it has not been associated
with identifiable benefits to the fetus (10). The increase in rate of
intervention for fetal macrosomia has not been found to reduce incidence
of shoulder dystocia in labour (42). This obstetric emergency has been
found to occur even when least suspected as it can occur in non-macrosomic
- Low or excess of amniotic fluid around the fetus may give an
indication of fetal general well being or signal pathological process in
the fetus or its environment. Fetus facing a chronic compromise may shunt
blood flow away for abdominal viscera (including the kidneys) to vital
areas like the brain leading to reduced urinary output hence reducing
amniotic fluid formation (44). Excess of amniotic fluid can result from
osmotic diuresis in fetus of diabetic mothers or where there is a
placental tumour (over production). It can also be due to decreased
turnover when the fetus has problem with swallowing (congenial duodenal
atresia, hypertrophy, etc). Assessment of amniotic fluid volume could be
used as an indication of fetal well being. Ultrasound measurement of
maximum pool perpendicular depth (the sum of measurement from the 4
quadrants form the amniotic fluid index) (1). The ultrasound forms the
major component of the fetal biophysical profile to assess fetal reserve
that has a lot of bearing on fetal outcome (45).
- A number of structural defects are mainly diagnosed in the latter part
of pregnancy. Among these are some craniospinal defects (hydrocephaly
microcephaly) gastro intestinal abnormalities (atresia,
tracheo-oesosphageal fistula, obstruction), urinary tract malformation and
some skeletal defects (46). The diagnosis of such defects may allow ample
time to plan intervention, extra - or intrauterine. It also allows women
counselling and options that they otherwise might not be offered (47).
- At times determining fetal presentation may be difficult clinically so
ultrasound could be employed. Some authorities have even employed
ultrasound to determine fetal head position in labour when routine digital
examination has failed (48).
- The routine use of ultrasound in pregnancy has to be considered
against the backdrop of potential hazards. Theoretically, some of the
ultrasonic energy propagated through the tissue is converted to heat, and
some biological effects have been produced in laboratory experiments using
continuous waves for a long time (1). Most producers used in diagnostic
ultrasonography emit energies less than 20mW/cm2 which is far
below the arbitrary hazard level of 100mW/cm2 (49) . Advice has
been given to minimise the "dwell-time" (time spent insinuating a
particular area) employing the "ALARA" (as low as reasonably attainable)
principle (50) so that potential hazard would be averted. Newer generation
of equipment are developed with safety features.
- A large study undertaken by Kieler et al (1998) who followed up women
who participated in the original randomised clinical trials on ultrasound
use in Sweden found that their children between 8 to 9 years demonstrated
some association between ultrasound exposure and delayed speech (51,52)
significantly fewer boys that were right handed (10,50), but no adverse
effect on school performance and neuro-behavioural function at
follow-up10. In another randomised controlled clinical trial by Newnham et
al (1993), a significant reduction in the weight of babies exposed
frequently to ultrasound in-utero was found compared with those unexposed
(51). The recommendation from these studies is to reduce the frequency of
exposure to both ultrasound imaging and Doppler flow examination to the
necessary minimum. The time spent on examination should not exceed 20 - 30
minutes and "fetal keepsake" videos should be discouraged as it tends to
increase exposure (52). All available regional guidelines on
ultrasonography dwelt much on the issue of safety (28,30,47).
Cost of ultrasonography
Apart from the cost of procuring and maintaining the equipment, the cost
of training personnel and overhead cost should be taken into consideration
when considering the use of using ultrasonography for screening and
diagnosis in comparison to other modalities. Henderson et al (2002)
published a study examining the (15) "bottom-up and top-down" costing of
antenatal ultrasound screening. They noted that on the average the NHS will
be spending between £14 to £16 per scan while the family will contribute
between £9 and £15 per scan. This took health service cost, staff time,
consumable, etc into consideration on the side of NHS while the woman bears
the cost of travel and childcare expenses, the opportunity costing of unpaid
time, etc (13). They concluded that repeated visit would be a drain on the
economy. On the average of scan in the United States of America is about
$200 per scan and a study (LeFevre et al ) (19) estimated the amount
of money spent on routine scan with no clinical indication to be about $1
billion. These unnecessary expenses could be avoided if ultrasonography is
employed only for high risk group or specific indications.
Training, Accuracy and Misuse
The need for adequate training for ultrasonographers have been emphasized
in most of the literature cited including all the guidelines (10,30,33,49).
The sensitivity of a screening programme depends on the expertise and
experience of the operator (1,2,10,11,12,27,55). Pick up rate of fetal
anomaly improves as the operator gains experience.
Women generally have an expectation of ultrasound that may not be met in
reality (34) due to the competence of the practitioner. It has been reported
in the literature and press that a number of physicians misapply or misuse
ultrasound by relying on highly technical procedure rather than their
clinical acumen by resorting to the scan without good indication for use.
Overuse is not associated with improved outcome.
Ultrasound scans are being done for indication that can only be regarded as
social. The unnecessary exposure to ultrasonic energy just for sex
determination or for fetal keepsake videos (54, 55) are some of the examples
that could be cited. It should be noted that too frequent use of ultrasound
has been associated with intrauterine growth restriction (51).
Existing Practice Guidelines
Three documents on standardisation of the practice of ultrasonography
were identified (30,33,49) from Malaysia, Canada and the United Kingdom. The
European Federation of Societies for Ultrasound in Medicine and Biology
(EFSUMB) document was also consulted (56) and used in conjunction with this
literature review to propose a framework for the safe practice of
ultrasonography in Nigeria in routine antenatal care.
The Malaysian guideline (49)
The Perinatal Society of Malaysia observed that the use of
ultrasound had become widespread in both private and government hospitals.
It was used freely without indication (49). This observation raised concerns
regarding the safety, usefulness and necessity of ultrasound in pregnancy.
In 1998 this concern prompted the invitation of the Malaysian Society of
Ultrasound in Medicine and the Obstetrical and Gynaecological Society of
Malaysia to convene a joint workshop to discuss safe practice. The workshop
came up with a guideline for the practise of obstetric ultrasonography
considering 4 major areas.
- The role of ultrasound in pregnancy
- The role of ultrasound for specific indication and
a guideline on the indication.
- The training aspects of the ultrasonographer.
- The safety of ultrasound.
The justification for at least one scan in pregnancy was
made and the different indications were outlined. The issue of informed
consent and patient education were addressed. They recommended three levels
of training and the requirement for practice. The safety issue was
considered and recommendations made on specialised ultrasonographic
The Canadian Guideline (30)
In November 1993, the Health Services Utilization and
Research Commission (HSURC) convened a meeting of a working group to
evaluate the use of prenatal ultrasound. A total of 24,823 prenatal scans
were performed in 1 year, an average of 1.5 scans for pregnancy in
Saskatchewan compared with 1.7 and 2.1 in British Columbia and Ontario
respectively. Only 40% of these were done in the hospital others were done
in private offices or clinics (30). They undertook a comprehensive
literature review and at the end concluded that screening ultrasound cannot
be recommended for all women given its lack of demonstrated impact on
perinatal mortality and morbidity. Recommendations were made as it concerns
the health care providers, government and district health boards and the
researchers. The issue of quality and reliability of scanning and the need
for adequate training and continuing medical education were addressed. The
need to ensure safety and monitor or evaluate quality continuously were also
The United Kingdom Royal College Guideline (33)
Following the 1997 report of the Royal College of Obstetrics and
Gynaecologists on the working party on ultrasound screening for fetal
abnormalities, some problems were identified on the variable ways ultrasound
screening were being conducted throughout the country. Although sonographers
are trained to look at all structures, local resources such as the quality
of equipment and the time available for examination may dictate what is
A supplementary working group was convened in 1998 to produce a standard
guideline for practice. The group agreed on a two-stage ultrasound
examination programme in initial scan at booking and the second one around
20 week. Recommendations on purpose and content of the early scan and the
"20 week" anomaly scan were outlined. The details of the procedure and
standards were stated. Safety measures, patients education, counselling and
support were outlined. Good record keeping, quality control, audit and
training were addressed.
Other notable international bodies, such as the American College of
Obstetrics and Gynaecology, The European Federation of Societies for
Ultrasound in Medicine and Biology have also produced good guidelines but
the full papers were not available at the time of this review.
The issue of routine ultrasound should not occupy the centre stage since
it has not been associated with commensurate improvement in overall
perinatal morbidity and mortality (1,10) despite the high cost (15).
In a country like Nigeria with low per capital income, the poor resources
should not be spent on high technology if the desired result of improved
health and outcome of pregnancy can not be achieved. The expectations of the
women are largely not met (53). Although it is fair to state that the
psychological satisfaction of parent-to-be is improved, particularly with
3-dimensional ultrasound, but the clinical improvement in fetal and maternal
outcome is still not apparent. Ultrasound in pregnancy is a useful tool that
can assist in clinical management of pregnancy, based on a sound clinical
It is obvious that the technology has a role to play in the provision of
ante-natal care in the hands of a skilled practitioner and at the
appropriate time, base don sound clinical history, examination and
judgement. From this literature review it would seem that practitioners who
have been trained should employ it under strict professional guidelines for
definite indications in its use. At all time the use must be in the hands of
skilled practitioner and it must be seen to have it's limitations.
Little is documented about the use of ultrasound in developing countries. It
would appear that there is a need to undertake a more in-depth study and
establish an international expert committee to consider the peculiar
situation in these areas of the excessive use of this equipment and
recommend guidelines for practice. Perhaps this is an area to which WHO
could contribute its expertise. It seem as if this useful but expensive
procedure needs to be strategically applied if we are to avoid wasting
valuable resources that could be better employed to prevent maternal and
neonatal morbidity and mortality. As an outcome of this review, when I
return to Nigeria, I will work with my colleagues from the Society of
Gynaecology and Obstetrics of Nigeria (SOGON) to advocate for the
establishment of a task force to study issue and prepare national
The following recommendations are made based on this
- The practice of obstetric ultrasound should be under a regulatory
- Ultrasound should be used based on clinical judgement and if justified
by a thorough history and clinical examination.
- There should be a minimum level of competence required to be able to
- Practice should be accredited and competence regularly assessed.
- The need to train and retrain should be mandatory and initiated in all
- The equipment employed must meet minimum safety standard as required
in other countries where such guidelines are being followed.
- Specialized scanning should be reserved for those with advanced
- Regional centres should be developed with high expertise and be well
equipped to act as referral centres for the basic and intermediate level
- The general public needs to be educated on the usefulness and
potential harzards of ultrasound.
- Women about to undergo ultrasonography should be counselled thoroughly
and their consent obtained.
- Proper records must be kept.
- Periodic auditing of the practice at various levels have to be done to
assess quality of service.
- It is recommended that the appropriate bodies in Nigeria will get
together and convene a committee to work out the safe and effective
practice of obstetric ultrasonography in Nigeria.
- A global multicentre randomised controlled trial of adequate power is
advocated to determine the immediate and remote effects of ultrasounds in
I am grateful to the management and staff of Geneva Foundation for
Medical Education and Research for inviting me to attend this very
interesting programme. I wish to thank the International Association for
Maternal Neonatal Health (IAMANEH) for sponsoring my participation.
My indebtedness to all the members of staff of the Department of
Reproductive Health and Research, World Health Organization, is hereby
registered especially to my excellent and untiring supervisor, Ms Margaret
Usher-Patel. I am also grateful to Ms Lucy Adokojok and Ms Archana Shah and
Dr Metin Gulmezoglu for their assistance and Henri Koulla for helping me to
obtain a portable computer.
I also acknowledge the contributions of all our teachers and support staff
and welcome the opportunity to improve my knowledge and practice.
Above all, I am grateful to the Almighty God for seeing me through and being
with my family back home.
- Bricker L, Neilson JP. Routine ultrasound in late pregnancy (after 24
weeks gestation) (Cochrane Review). Issue 2, 2003. [Abstract]
- Page DM. Obstetrical Ultrasound in Pregnancy. Atlanta Perinatal
Associates. Electronic Database. 2002.
- Gold RB. Ultrasound imaging during pregnancy. Fam Plann Perspect. 1984
- Woo J. A short History of the Development of Ultrasound in Obstetrics
and Gynaecology. 2002. [Free
- Dussik KT. Uber die Möglichkeit hochfrequente mechanische Schwingungen
als diagnostisches Hilfsmittel zu verwerten. Z Neurol Psychiat. 1942
- Wild JJ. The use of ultrasonic pulses for the measurement of
biological tissues and the detection of tissue density changes. Surgery.
- Wild JJ, Neal D. Use of high frequency ultrasonic waves for detecting
changes in texture in living tissue. Lancet. 1951 1:655.
- Wild JJ, Reid J. Current developments in ultrasonic equipments of
medical diagnosis. IRE Trans Ultrason Engng. 1957 5:44-56.
- Donald I, MacVicar J, Brown TG. Investigation of abdominal masses by
pulsed ultrasound. Lancet. 1958 1:1188-1195.
- Neilson JP. Ultrasound for Fetal Assessment in Early Pregnancy
(Cochrane Review). Issue 2, 2003. [Abstract]
- Taipale P, Ammala M, Salonen R, Hiilesmaa V. Learning curve in
ultrasonographic screening for selected fetal structural anomalies in
early pregnancy. Obstet Gynecol. 2003 Feb;101(2):273-8. [PubMed]
- Vayssiere C, Moriniere C, Camus E, Le Strat Y, Poty L, Fermanian J,
Ville Y. Measuring cervical length with ultrasound: evaluation of the
procedures and duration of a learning method. Ultrasound Obstet Gynecol.
2002 Dec;20(6):575-9. [PubMed]
- Thompson E, Freake D, Worrall G. Are rural general
practitioner--obstetricians performing too many prenatal ultrasound
examinations? Evidence from western Labrador. CMAJ. 1998 Feb
- Scientific basis for the content of routine antenatal care. II. Power
to eliminate or alleviate adverse newborn outcomes; some special
conditions and examinations. Acta Obstet Gynecol Scand. 1997
- Henderson J, Bricker L, Roberts T, Mugford M, Garcia J, Neilson J.
British National Health Service's and women's costs of antenatal
ultrasound screening and follow-up tests. Ultrasound Obstet Gynecol. 2002
- National Population Report Projection from the 1991 National Census
- WHO. Countries - Nigeria. [Free
- Ewigman BG, Crane JP, Frigoletto FD, LeFevre ML, Bain RP, McNellis D.
Effect of prenatal ultrasound screening on perinatal outcome. RADIUS Study
Group. N Engl J Med. 1993 Sep 16;329(12):821-7. [PubMed]
- LeFevre ML, Bain RP, Ewigman BG, Frigoletto FD, Crane JP, McNellis D.
A randomized trial of prenatal ultrasonographic screening: impact on
maternal management and outcome. RADIUS (Routine Antenatal Diagnostic
Imaging with Ultrasound) Study Group. Am J Obstet Gynecol. 1993
- Bakketeig LS. Routine ultrasonography in late pregnancy is not
justified! [Danish] (Rutine UL-scanning i sidste halvdel af svangerskabet
synes ikke berttiget!). Ugeskrift for Laeger. 2001 163(42):5813-4, 2001
- American Society for Reproductive Medicine, Practice Committee Report.
Technical Bulletin. Early Diagnosis and Management of Ectopic Pregnancy.
March 2001. [Free
- Bricker L., Neilson JP. Routine Doppler ultrasound in pregnancy.
(Cochrane Review). Issue 2, 2003. [Abstract]
- Roberts T, Henderson J, Mugford M, Bricker L, Neilson J, Garcia J.
Antenatal ultrasound screening for fetal abnormalities: a systematic
review of studies of cost and cost effectiveness. BJOG. 2002
- Villar J, Ba'aqeel H, Piaggio G, Lumbiganon P, Miguel Belizan J,
Farnot U, Al-Mazrou Y, Carroli G, Pinol A, Donner A, Langer A, Nigenda G,
Mugford M, Fox-Rushby J, Hutton G, Bergsjo P, Bakketeig L, Berendes H,
Garcia J. WHO antenatal care randomised trial for the evaluation of a new
model of routine antenatal care. Lancet. 2001 May 19;357(9268):1551-64. [PubMed]
- Carroli G, Villar J, Piaggio G, Khan-Neelofur D, Gulmezoglu M, Mugford
M, Lumbiganon P, Farnot U, Bersgjo P. WHO systematic review of randomised
controlled trials of routine antenatal care. Lancet. 2001 May
- Baltzer FR. Early pregnancy detection: past, present, future.
In: Corson S.L.; Derman R.J. and Tyrer L.B. (Editors) Fertility control.
Boston, Massachusetts, Little, Brown, 1985.
- Eik-Nes SH, Salvesen KA, Okland O, Vatten LJ. Routine ultrasound fetal
examination in pregnancy: the 'Alesund' randomized controlled trial.
Ultrasound Obstet Gynecol. 2000 Jun;15(6):473-8.
- Kallen K. Mid-trimester ultrasound prediction of gestational age:
advantages and systematic errors. Ultrasound Obstet Gynecol. 2002
- National Electronic Library for Health. Informed Choice for
Professionals. Routine ultrasound scanning in the first half of
pregnancy. Midirs and The NHS Centre for Reviews and Dissemination. 2002.
- Saskatchewan Health Services Utilization and Research Commission. The Use of Ultrasound in Pregnancy. Summary Report No 7. March
- Campbell S, Warsof SL, Little D, Cooper DJ. Routine ultrasound
screening for the prediction of gestational age. Obstet Gynecol. 1985
- Ewigman BG, Crane JP, Frigoletto FD, LeFevre ML, Bain RP, McNellis D.
Effect of prenatal ultrasound screening on perinatal outcome. RADIUS Study
Group. N Engl J Med. 1993 Sep 16;329(12):821-7. [PubMed]
- Report of the Royal College of Obstetrics and Gynaecology Working
Party. Ultrasound Screening. 2000. [Free
- Acharya G, Morgan H. First-trimester, three-dimensional transvaginal
ultrasound volumetry in normal pregnancies and spontaneous miscarriages.
Ultrasound Obstet Gynecol. 2002 Jun;19(6):575-9. [PubMed]
- Borruto F, Comparetto C, Acanfora L, Bertini G, Rubaltelli FF. Role of
ultrasound evaluation of nuchal translucency in prenatal diagnosis. Clin
Exp Obstet Gynecol. 2002;29(4):235-41. [PubMed]
- Zhang WH, Levi S, Alexander S, Viart P, Grandjean H. Sensitivity of
ultrasound screening for congenital anomalies in unselected pregnancies.
Rev Epidemiol Sante Publique. 2002 Dec;50(6):571-80. [PubMed]
- Spencer K, Nicolaides KH. Screening for trisomy 21 in twins using
first trimester ultrasound and maternal serum biochemistry in a one-stop
clinic: a review of three years experience. BJOG. 2003 Mar;110(3):276-80.
- Moran CJ, Tay JB, Morrison JJ. Ultrasound detection and perinatal
outcome of fetal trisomies 21, 18 and 13 in the absence of a routine fetal
anomaly scan or biochemical screening. Ultrasound Obstet Gynecol. 2002
- Rizos N, Doran TA, Miskin M, Benzie RJ, Ford JA. Natural history of
placenta previa ascertained by diagnostic ultrasound. Am J Obstet Gynecol.
1979 Feb 1;133(3):287-91. [PubMed]
- Harding K, Evans S, Newnham J. Screening for the small fetus: a study
of the relative efficacies of ultrasound biometry and symphysiofundal
height. Aust N Z J Obstet Gynaecol. 1995 May;35(2):160-4. [PubMed]
- Holmes RP, Soothill PW. Intra-uterine growth retardation. Curr Opin
Obstet Gynecol. 1996 Apr;8(2):148-54. [PubMed]
- Weeks JW, Pitman T, Spinnato JA 2nd. Fetal macrosomia: does antenatal
prediction affect delivery route and birth outcome? Am J Obstet Gynecol.
1995 Oct;173(4):1215-9. [PubMed]
- Gonen R, Spiegel D, Abend M. Is macrosomia predictable, and are
shoulder dystocia and birth trauma preventable? Obstet Gynecol. 1996
Oct;88(4 Pt 1):526-9. [PubMed]
- Bilardo CM, Nicolaides KH, Campbell S. Doppler measurements of fetal
and uteroplacental circulations: relationship with umbilical venous blood
gases measured at cordocentesis. Am J Obstet Gynecol. 1990
- Awad MM. The fetal biophysical profile score: a routine screening
technique for pregnant women. J Egypt Soc Obstet Gynecol. 1991
- Chitty LS. Ultrasound screening for fetal abnormalities. Prenat Diagn.
1995 Dec;15(13):1241-57. [PubMed]
- Magriples U, Copel JA. Accurate detection of anomalies by routine
ultrasonography in an indigent clinic population. Am J Obstet Gynecol.
1998 Oct;179(4):978-81. [PubMed]
- Akmal S, Tsoi E, Kametas N, Howard R, Nicolaides KH. Intrapartum
sonography to determine fetal head position. J Matern Fetal Neonatal Med.
2002 Sep;12(3):172-7. [PubMed]
- Perinatal Society of Malaysia. Guideline on the use of Ultrasound in
Pregnancy. 1996. [Free
- Kieler H, Axelsson O, Haglund B, Nilsson S, Salvesen KA. Routine
ultrasound screening in pregnancy and the children's subsequent
handedness. Early Hum Dev. 1998 Jan 9;50(2):233-45. [PubMed]
- Newnham JP, Evans SF, Michael CA, Stanley FJ, Landau LI. Effects of
frequent ultrasound during pregnancy: a randomised controlled trial.
Lancet. 1993 Oct 9;342(8876):887-91. [PubMed]
- Campbell JD, Elford RW, Brant RF. Case-control study of prenatal
ultrasonography exposure in children with delayed speech. CMAJ. 1993 Nov
- Akhan SE, Nardirgil G, Tecer A, Yüksel A. The quality of
antenatal care in Turkey and the role of ultrasonography in the antenatal
care system. Archives of Gynecology and Obstetrics. Published on-line
- U.S. Food and Drug Administration, Center for Devices and Radiological
Health [CDRH], Consumer Information: Fetal Keepsake Videos.
Electronic Publication Updated 2002. [Free
- Todros T, Faggiano F, Chiappa E, Gaglioti P, Mitola B, Sciarrone A.
Accuracy of routine ultrasonography in screening heart disease prenatally.
Gruppo Piemontese for Prenatal Screening of Congenital Heart Disease.
Prenat Diagn. 1997 Oct;17(10):901-6. [PubMed]
- European Federation of Society for Ultrasound in Medicine and
Biology, Watchdog Committee. 1994 Clinical Safety Statement. Eur J
Ultrasound. 1995 2:77.
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