Question 531
{"accessible":false,"alternatives":[{"id":2663,"text":"a diastolic notch in the uterine arteries should always be absent"},{"id":2664,"text":"the ductus venosus flow shows a positive A wave"},{"id":2662,"text":"the pulsatility index (PI) of middle cerebral artery is always lower than PI of umbilical artery"},{"id":2666,"text":"the umbilical artery diastolic flow is absent in third trimester"},{"id":2665,"text":"the umbilical cord has two veins and one artery"}],"archived":false,"correctAlternativeId":2664,"explanation":"\u003cp\u003eThe pulsatility index (PI)\u0026nbsp;of MCA should always be more than the PI of the umbilical artery, and their ratio (cerebroplacental ratio) should be more than 1.08. A reversal of this indicates fetal brain-sparing phenomenon that occurs in\u0026nbsp;fetal distress and intrauterine growth restriction.\u003c/p\u003e\u003cp\u003eDiastolic notch in uterine arteries may persist normally up to 18-22 weeks of gestation. The presence of a notch after 22 weeks indicates\u0026nbsp;increased uterine vascular resistance and\u0026nbsp;warrants monitoring of the patient.\u003c/p\u003e\u003cp\u003eNormally ductus venosus shows positive A wave. Reversal of the A wave may be seen in severe intrauterine growth restriction as well as in tricuspid regurgitation.\u003c/p\u003e\u003cp\u003eThere are two arteries and one vein in the umbilical cord.\u003c/p\u003e\u003cp\u003eUmbilical artery diastolic flow increases in the third trimester and its S/D ratio decreases (usually remaining below 3).\u003c/p\u003e","id":531,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/531","nextQuestionPath":null,"relatedArticles":[{"id":13824,"title":"Fetal ductus venosus flow assessment","link":"/articles/fetal-ductus-venosus-flow-assessment?lang=gb"},{"id":13860,"title":"Umbilical arterial Doppler assessment","link":"/articles/umbilical-arterial-doppler-assessment?lang=gb"},{"id":33737,"title":"Fetal middle cerebral artery pulsatility index","link":"/articles/fetal-middle-cerebral-artery-pulsatility-index?lang=gb"},{"id":46591,"title":"Cerebroplacental ratio","link":"/articles/cerebroplacental-ratio?lang=gb"}],"alsoUsedIn":[{"id":233,"kind":"RestrictedPage","title":"Page 233 (in no courses)","link":"https://radiopaedia.org/admin/restricted_pages/233"},{"id":240,"kind":"Course","title":"Radiology Review Course - Melbourne - page 240","link":"https://radiopaedia.org/courses/radiology-review-course-melbourne-2019/pages/240"},{"id":240,"kind":"Course","title":"Radiology Review Course - Melbourne - page 240","link":"https://radiopaedia.org/courses/radiology-review-course-melbourne-2018/pages/240"},{"id":240,"kind":"Course","title":"Radiology Review Course - Melbourne - page 240","link":"https://radiopaedia.org/courses/radiology-review-course-melbourne-2020/pages/240"},{"id":240,"kind":"Course","title":"Radiology Review Course - page 240","link":"https://radiopaedia.org/courses/radiology-review-course-online/pages/240"},{"id":641,"kind":"Course","title":"Lectures by Alexandra Stanislavsky - page 641","link":"https://radiopaedia.org/courses/lectures-by-alexandra-stanislavsky/pages/641"},{"id":641,"kind":"Course","title":"Radiopaedia 2020 - Lectures Only - page 641","link":"https://radiopaedia.org/courses/radiopaedia-2020-exclusive/pages/641"},{"id":641,"kind":"Course","title":"Obstetrics \u0026 Gynaecology Lectures - page 641","link":"https://radiopaedia.org/courses/obgyn-lectures/pages/641"},{"id":641,"kind":"Course","title":"2020 Virtual Conference Private Use - page 641","link":"https://radiopaedia.org/courses/2020-virtual-conference-private-use/pages/641"}],"stem":"\u003cp\u003eWhich of the following is correct regarding a normal antenatal\u0026nbsp;Doppler ultrasound\u0026nbsp;study?\u003c/p\u003e","menuLinks":[{"text":"Report problem with question","url":"https://docs.google.com/forms/d/e/1FAIpQLSfO3soWYhOjJ7yErSysyCe5V4A1CqW7WK3rDA7MtAkecMGqNw/viewform?entry.1624461248\u0026entry.553583435=https://radiopaedia.org/questions/531"}],"attemptsPercentages":[{"alternativeId":"2665","percentage":15},{"alternativeId":"2663","percentage":13},{"alternativeId":"2662","percentage":16},{"alternativeId":"2666","percentage":3},{"alternativeId":"2664","percentage":53}],"promptToLogin":false,"questionManager":false,"articleId":"uterine-artery-flow-notching"}