{"id":3400,"date":"2020-05-15T04:30:42","date_gmt":"2020-05-15T04:30:42","guid":{"rendered":"http:\/\/fetalradiology.in\/?p=3400"},"modified":"2020-05-15T04:30:45","modified_gmt":"2020-05-15T04:30:45","slug":"technical-challenges-in-sonography-of-gravid-obese-women-pitfalls-and-solutions","status":"publish","type":"post","link":"https:\/\/fetalradiology.co.in\/?p=3400","title":{"rendered":"TECHNICAL CHALLENGES IN SONOGRAPHY OF GRAVID OBESE WOMEN: PITFALLS AND SOLUTIONS"},"content":{"rendered":"

Author:\u00a0<\/strong>Avni KP Skandhan, Aster MIMS,\u00a0 Kottakkal, Kerala. Email: avniskandhan@gmail.com<\/p>\n

The World Health Organization (WHO) defines an individual as overweight<\/span> (1)<\/span> if their body mass index (BMI) is \u2265 to 25 Kg\/m<\/span>2. <\/span>An individual with a BMI \u2265 30 Kg\/m<\/span>2 <\/span>is defined as obese.<\/span>(1)<\/span>\u00a0<\/span><\/p>\n

The American College of Obstetricians and Gynaecologists (ACOG) describes three levels of obesity that reflect the increasing health risks that go along with increasing BMI, with the lowest risk being a BMI of 30 \u2013 34.9 Kg\/m<\/span>2<\/span>, medium risk is a BMI of 35.0\u201339.9 Kg\/m<\/span>2<\/span> and the highest risk is a BMI of 40 Kg\/m<\/span>2<\/span> or greater.<\/span>(2)<\/span> The same categories of obesity are classified as <\/span>Classes I, II and III respectively by the National Institute for Health and Clinical Excellence.<\/span>(3).<\/span><\/p>\n

T<\/span>he worldwide prevalence of obesity nearly tripled between 1975 and 2016; with over 1.9 billion adults who are obese <\/span>(1)<\/span>, thus transforming obesity from a clinical concern to a socio-clinical concern. The effects of obesity on pregnancy may extend from the prenatal to the perinatal period and have long-term consequences for the foetus. Several studies have reported an increased risk of complications like miscarriage, stillbirth, pre-eclampsia, gestational diabetes and thromboembolic disorders in obese gravid women.<\/span>(4-14)<\/span> Obese gravid women also have a\u00a0 higher incidence of caesarean section, anaesthetic problems, wound infections <\/span>(15)<\/span>, and chances of developing hernia.\u00a0 Obesity may also lead to an increase in birth difficulties, macrosomia and perinatal death.<\/span>(4,5)<\/span>\u00a0 Congenital anomalies such as neural tube defect (NTD), orofacial clefts, anorectal atresia, omphalocele, diaphragmatic hernia and congenital heart defects are associated with maternal obesity.<\/span>(6,7, 11-13, 16)<\/span><\/p>\n

Sonography is an important modality for prenatal diagnosis and foetal management and interventions if there are associated foetal abnormalities.<\/span>(8-10)<\/span> Sonography is used to assess the foetal anatomy, screen for foetal anomalies and assess presence of foetal aneuploidies.<\/span>(7, 17, 18)<\/span> Foetal anatomy, foetal anomalies<\/span> (19) <\/span>and estimation of foetal weight<\/span> (18)<\/span> is poorly delineated in an obese gravida sonographically. Several studies have reported a suboptimal visualization of cardiac <\/span>(14,20,21) <\/span>and the cranial and spinal structures <\/span>(5)<\/span> in the obese mothers. The abdominal panniculus of the maternal abdomen limits the visualisation <\/span>(8)<\/span>, due to hampered ultrasound insonation at a greater depth, an increase in the absorption of the ultrasound by the adipose layer and by increased back scatter from refraction leading to degradation of the image quality.<\/span>(5, 17,18, 22, 24, 25)<\/span> Several studies have explored the relationship between ultrasound image visibility and the different BMI groups.<\/span>(5, 6, 10-16)<\/span> These studies largely showed a decreasing ability to scan foetuses of obese women as the obesity category increased. Thornburg et al reported a visibility of 72% <\/span>in Class I patients (BMI: 30-34.9 Kg\/m<\/span>2<\/span> )\u00a0 a\u00a0 visibility of 61% in\u00a0 Class II (BMI : 35 \u2013 39.9 Kg\/m<\/span>2<\/span>) and a visibility of 49% in class III ( BMI \u2265 40 Kg\/m<\/span>2 <\/span>).<\/span>(26)<\/span> A similar study conducted by Dashe et al reported values corresponding to 57%, 41% and 30% respectively. Fuchs et al suggests that even if women with<\/span> Class I obesity have no abdominal folds, the chances of them having a tense hard abdomen leads to a difficulty for ultrasound penetration.<\/span>(28)<\/span> Conversely, women with a Class III obesity have abdominal folds, yet it may be possible to scan through a small abdominal \u2018\u2018window\u2019\u2019.<\/span>(28)<\/span> Sonography in obese mothers may result in inability to view structures and necessitate a repeat examination to the extent mothers may need to be called for repeated scans and yet there is a suboptimal visualisation.<\/span>(5)<\/span>\u00a0<\/span><\/p>\n

The scans demand additional physical stress, on the person doing the sonography during examinations because of the various technical challenges that are encountered due to additional allocation of time and pressure in the scan period.<\/span>(5)<\/span> At times the people carrying out sonography end up acquiring muscular injuries as a result of performing such scanning methodologies.<\/span>(29-31)<\/span> The stress exists not only for the person performing the sonography but also in the obese mothers who end up having multiple scans, leaving them apprehensive especially if they have an underlying family history of anomalies.<\/span>(9)<\/span>\u00a0<\/span><\/p>\n

Various studies have been conducted to better understand how to improvise the visibility in the obese mothers to optimize foetal visualisation.<\/span>(5, 6, 10-16)<\/span> The primary goal in doing this is to minimise the distance between the sonography probe and the foetus, and to take maximal leverage\u00a0of the various advanced ultrasound technologies available in the newer ultrasound machines for the post-processing <\/span>(32)<\/span>. \u00a0<\/span><\/p>\n

After a review of articles; the various modifications that can be attempted in such scenarios to improve visibility can be at the:\u00a0<\/span><\/p>\n

1) Maternal end\u00a0<\/span><\/p>\n

2) Ultrasound machine\u00a0<\/span><\/p>\n

3) Technique<\/span><\/p>\n

Maternal End:<\/b><\/p>\n