Use of Ultrasonography in Determining Fetal Outcome of Pregnant Women - Dissertation Example

? ULTRASONOGRAPHY OF PREGNANT WOMEN WITH PERCEIVED DECREASED FETAL MOVEMENT: A META ANALYSIS By Ultrasonography of Pregnant Women with Perceived Decreased Fetal Movement: A Meta-Analysis 1.0 Introduction Stillbirth rates are placed at about 3.2 million a year globally. In first world countries the rate is 5 per 1000 births and poorer countries at 32 per 1000. [1] In the US, intrauterine fetal death (IUFD hereafter) occurs every 6.4/1000 births, according to a 2002 survey. IUFD is death before delivery that takes place from 20 or more weeks in gestation. Stillbirth or any other kind of fetal injury is sought to be prevented through antenatal surveillance. [2] Some women who have given stillbirths were not considered as having risk factors and thus, did not undergo any antepartum examination. It is therefore recommended that pregnant women look for signs of decreased fetal movement (DFM hereafter) using the several strategies available such as the Cardiff “count to ten” model. Upon a DFM presentation by a pregnant woman, she should be immediately subjected to further examination to determine the health condition of the baby. A symphysio fundal height (SFH hereafter) test measures the growth of the baby and a test to measure the volume of amniotic fluid are conducted. Electronic type of examination may also be conducted such as: cardiotocography; vibro-acoustic simulation; Doppler, and; ultrasound [3]. Ultrasonography or ultrasound uses high-frequency sound waves to bounce off tissues so that its echoes are converted into a picture of the organ or tissues examined. Relative to DFM, Ultrasonography is employed to determine growth of the fetus, the volume of amniotic fluid as well as anatomy, organ blood flow and umbilical artery resistance [4]. The aim of this paper is to summarize the available clinical evidence from the data extracted from five selected articles from various sources such as BM Pregnancy and Childbirth, Seminars in Perinatalogy, Journal in Obstetrics and Gynaecology and American Journal of Obstetrics and Gynaecology relative to the use of Ultrasonography in determining fetal outcome of pregnant women who presented a decreased fetal movement. These articles are dated 1991 up to 2009. 2.0 Data Synthesis Data were combined from five studies involving a total of 69,751 pregnant women, with 49,631 serving as the test group and the remaining 20, 120 as the control group. Studies in these cases took as long as 5 years and as short as 7 months. In the combined test group, 6,996 pregnant women were presented with DFM and 1370 in the control group. An estimated 5976 pregnant women presenting DFM were made to undergo ultrasound examination in the study group and 1040 in the control group indicated retrospectively. Fig. 1 is a representation of the patients involved in the study, although the Tveit et al cohorts was reduced from 46,143 test group to 5,000 for convenience in graphic presentation. 3.0 Quality Assessment These five studies did not actually focus on the usefulness of ultrasonography as an investigation tool in DFM cases. Their treatment of it was mostly incidental to the study of DFM either in comparison with cohorts that have not reported DFM or are untested. Only in the study of Froen was ultrasonography investigated, in comparison with other tools such as SFH measurement and cardiotocography, as a useful DFM assessment tool. Moreover, in many of these studies figures in percentage are given and not the actual numbers so sometimes there is impreciseness in the figures where actual numbers have to be cited. Fig. 1 Data Synthesis of Five Studies 4.0 Evaluation Studies In the study conducted by Whitty et al (1991) Ultrasonography was used as a tool for initial examination, along with NST, on pregnant women who presented DFM. Of the 292 pregnant women who were with the test group, only 27 or 9.2% showed incidental ultrasonographic findings. The outcome characteristics show that 3% of the control group had IUGR [5]. An IUGR finding is significant because it is associated with perinatal fetal death. Fetuses with IUGR have a perinatal mortality rate of about 5 to 30 times higher than those with normal weights [6]. In the study conducted of Gagnon et al (1988), fetuses with IUGR were observed to have manifested 40% decrease in gross fetal body movements. Subsequent intervention through acoustic stimulation was able to reverse DFM [7]. On the other hand, the study conducted by Froen et al (2008) consisted of reviewing cases of 3014 DFM reports in Norway and set guidelines for the management of DFM. The study compared the use and usefulness of NST/CTG, ultrasound and Doppler in DFM-related cases. Ultrasonography was indicated for estimation of fetal weight, amniotic volume and fetal movement [8]. Low amniotic volume can be manifested in DFM. [9] The placenta must maintain a normal volume of amniotic fluid any divergence either resulting in decrease or increase may lead to fetal and neonatal morbidity and mortality [10]. Sinha et al(2007) reviewed the result of women who had reported DFM (study group) with those of women who made no such report (control group). This was a retrospective study and hence, did not involved clinical interventions. The group learned that initial assessment was made through BP checks, urine analysis with dipstick, cardiotocograph (CTG) and symphysio fundal height measurement (SFH). However, further tests such as ultrasound were conducted where the SFH showed a small baby or when there was more than once presentation of DFM. [11] The study done by Tveit et al (2009) focused on establishing the difference between results when interventions are introduced such as uniform guidelines on DFM management and information on DFM to pregnant women and when such interventions were absent. Two sets of data are crucial in Tveit study: the total number of births and the proportion of stillbirths before the interventions, and; the total number of births and the proportion of stillbirths after the interventions. The ultrasound data in the Tveit study was however, only a comparison of the frequency of its use between pre-intervention and during intervention. As indicated, Ultrasonography use increased by 8% from 86% when there was no intervention to 94% when there was intervention. [12] Finally, the study conducted by Heazell et al (2005), was aimed at determining which investigation is most appropriate after a pregnant woman reports a DFM. The study employed ultrasound and liquor volume assessment only as discretionary investigations when placental insufficiency and fetal abdominal circumference is less than 10th centile. The basic assessment consisted of BP measurement, urine analysis, symphyseal fundal height measurement, and cardiotocography. [13] 5.0 Meta-Analysis The total number of pregnant women considered in the five studies was 69,751 including both those in the control and test groups. Out of this number, however, only 8,366 had presented with DFM, with 1,370 belonging to the control group. Out of 8,366, only 7,016 were made to undergo Ultrasonography either as initial assessment after a DFM is presented or as subsequent investigation examination after an abnormality related to DFM had been detected. In the latter case, general indications for Ultrasonography include fetal growth assessment, amniotic fluid volume measurement and fetal movement. In cases where ultrasound examination yielded confirmation or existence of abnormalities, the highest incidence was for IUGR or intrauterine growth restriction where the growth of the fetus is determined to be insufficient for the gestation age. As earlier stated, IUGR figures in a lot of stillbirths and appropriate intervention must therefore be taken to remedy it and prevent perinatal Table 1 fetal death. Other findings also include reduced liquor volume, macrosomia, abnormal presentation and placenta previa. There are women with DFM who, upon Ultrasonography, exhibited not only one but two or more adverse findings. In most cases, however, the studies did not specify the precise findings and were therefore just written off either as not indicated, in cases where there are adverse findings but the writers did not specify them, or unknown when the researchers are noncommittal as to whether the ultrasound engendered any findings at all as in the case of the studies of Tveit et al (2009) and Froen et al (2008). Only in two of the studies can the overall usefulness of ultrasonography be deduced, but without specifically stating the precise areas. Tveit et al (2008), wrote that the ultrasonography of 2764 patients allowed 94% of them to receive quality intervention and Froen et al (2008) wrote that in 86.2% of those who undergo ultrasonography, viz., 3014, or 2,833, the obstetricians had indicated that they perceived the investigation tool to be useful after the abnormality is found. The combined data from these two studies resulted in 87.1% ultrasonography usefulness after an abnormality is detected. In one study, viz., Heazell et al (2005), expressly established the value of ultrasonography as to its specificity, sensitivity, positive predictive and negative predictive as a source of information in fetal growth and liquor volume assessments. The group rated this investigation tool highest, viz., 91.3% as to specificity in 35 patients who underwent ultrasonography and lowest in sensitivity at 33.3%. In combination with SFH, however, the researchers rated it with 95.6% in specificity and 75% (the highest compared to cardiotocography and SFH alone) with 35 patients. 6.0 Discussion This meta-analysis included 5 separate studies conducted by various researchers in as early as 1985 and as late as 2007. Overall, the studies were not really directly conducted to establish the usefulness of Ultrasonography as an investigation tool in DFM cases, but had only incidentally tackled Ultrasonography as one of the investigation tools in DFM cases. The focus of these studies was to compare results between one cohort that has presented DFM with another who has not, or between one cohort that has received intervention for DFM or with another who has not. Only one study, viz., Froen et al, directly studied Ultrasonography as a useful investigation tool in DFM. Ultrasound was only indicated for fetal weight assessment, amniotic fluid volume measurement, and fetal movement. This was not however, a randomized controlled trial, but is primarily based only on the perception of the obstetricians handling the patients as to the usefulness of the investigation tools in DFM. These perceptions were not rationalized or justified except that both NST/CTG and ultrasound were standard initial assessment tools. What is significant in the results of this study, however, is the inclusion of the “only finding” data to indicate the frequency that an investigation tool is the only tool, from amongst the other two, which has detected certain fetal abnormalities or adverse conditions. In the rest of the studies, the use of Ultrasonography was discretionary, rather than standard, upon the clinician. In majority of these studies, there was no clear cut rationale as to why this type of investigation tool was resorted to, and not any other, or its advantages over other investigation tools in DFM. 7.0 Conclusion In the various studies reviewed by this paper for meta-analysis, there is insufficient data to establish clearly the usefulness of ultrasonography as an investigation tool in the assessment and follow-up examination of DFM reports. This is because the involvement of the investigation tool in these studies was merely incidental, considering that they were really intent on researching DFM as an antenatal incidence. This, even the data that can be culled from these studies on the subject are varied. They certainly do not constitute randomized and controlled studies of ultrasonography in relation to DFM. End Notes [1] Sarabatnam Arulkumaran, Lesley Regan, David Farquharson, Ash Monga, and Aris Papageorghiou, Oxford Desk Reference: Obstetrics and Gynaecology (US: Oxford University Press, 2011) 144. [2] John T. Keenan, Catherine Spong and Charles Lockwood, eds., Management of high-risk pregnancy: an evidence-based approach, 5th Edition (Wiley-Blackwell, 2007) 95. [3] Arulkumuran, 144. [4] Ibid. [5] Janice Whitty, David Garfinkel, and Michale Divon, M. ‘Maternal Perception of Decreased Fetal Movement as an Indication for Antepartum Testing in a Low Risk Population.’ Am J Obstet Gynecol 1991; 165:1084-8. [6] Sanjat Datta, Anesthetic and obstetric management of high-risk pregnancy. 3rd Edition (Springer, 2004) 519. [7] Jean-Pierre Lecanuet, Fetal development: a psychobiological perspective (Routledge, 1995) 136. [8] J. Frederik Froen, Jukie Tveit, Eli Saastad, Per Bordahl, Babill Stray-Pedersen, Alexander Heazell, Vicki Flenady, and Ruth Fretts, ‘Management of Decreased Fetal Movements’ (Semin Perinatol 2008) 32:307-311. [9] Susan Blackburn, Maternal, fetal, & neonatal physiology: a clinical perspective 3rd Edition (Elsevier Health Sciences, 2007). [10] Eberhard Merz, Ultrasound in obstetrics and gynecology, 3rd Edition (Thieme, 2005). [11] D. Sinha, A. Sharma, V. Nallaswamy, M. Jayagopal, and N. Bhatti, ‘Obstetric Outcome in Women Complaining of Reduced Fetal Movements’ (Journal of Obstetrics and Gynaecology, 2007; 27(1): 41-43. [12] Julia Tveit, Eli Saastad, Babill Stray-Pedersen, Per Bordahl, Vicki Flenady, Ruth Fretts, & J. Frederik Froen, ‘Reduction of Late Stillbirth with the Introduction of Fetal Movement Information and Guidelines – A Clinical Quality Improvement.’ (BMC Pregnancy and Childbirth 2009, 9:32) Biomed Central http://www.biomedcentral.com/. [13] A. Heazell, G. Sumathu, and N. Bhatti, ‘What Investigation is Appropriate Following Maternal Perception of Reduced Fetal Movements? (Journal of Obstetrics and Gynaecology 2005; 25(7): 648-650). References: Avery's diseases of the newborn Avery's Diseases of the NewbornAuthorsH. William Taeusch, Roberta A. Ballard, Christine A. Gleason, Mary Ellen AveryEditorsH. William Taeusch, Roberta A. Ballard, Christine A. Gleason, Mary Ellen AveryEdition8, illustratedPublisherElsevier Health Sciences, 2005 Read More