fetal health surveillance (fhs): part 1 - introduction maternal newborn orientation learning module...
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Slide 2 Fetal Health Surveillance (FHS): Part 1 - Introduction Maternal Newborn Orientation Learning Module Reproductive Care Program of Nova Scotia Revised July, 2013 Slide 3 Objectives Review physiology influencing the fetal heart rate Describe tools for fetal surveillance Doppler The electronic fetal monitor (EFM) Review Intermittent Auscultation (IA) of the FHR Slide 4 References: www.sogc.org Slide 5 Physiology related to the FHR Intrinsic and extrinsic factors Homeostatic mechanisms Slide 6 Intrinsic Factors Internal mechanisms of FHR control Central Nervous System Medulla oblongata controls HR, BP Mid-brain to cortex controls FHR and changes that occur in response to fetal states and activity Autonomic Nervous System Sympathetic - FHR, strength of cardiac contractions Parasympathetic - FHR via vagus nerve Slide 7 Intrinsic factors Hormones - catecholamines Epinephrine HR, BP, stroke volume and cardiac output Norepinephrine blood flow to vital organs during hypoxemia Angiotensin, aldosterone potent vasoconstrictors acting in response to hemorrhage or hypoxemia Slide 8 Intrinsic factors Baroreceptors pressure receptors located in aortic arch and carotid respond to changes in BP to or the FHR Chemoreceptors located in aortic arch, carotid, and medulla oblongata respond to changes in pO 2 and pCO 2 to or the FHR Slide 9 Intrinsic factors Fetal behavioral states and development Quiet/active sleep, awake Advancing gestation Used with permission, 2013 NCAST University of Washington Slide 10 Extrinsic factors Factors in the fetal environment that affect oxygen availability, fetal well-being, and the FHR Maternal health Placenta Umbilical cord Slide 11 Extrinsic factors Maternal influences: pO 2 respiratory status, smoking O 2 carrying capacity Hgb, blood volume Uterine blood flow circulation, venous return Uterine contractions normal, tachysystole, hypertonus Slide 12 Extrinsic factors - placenta Maternal arterioles Slide 13 Extrinsic factors Normal placentaCalcified placenta Slide 14 Extrinsic factors Slide 15 Umbilical Cord Abnormalities Nuchal cordTrue knot Slide 16 Extrinsic factors Umbilical cord influences Slide 17 Homeostatic Mechanisms Regulating mechanisms that allow the fetus to adapt to the stresses of labour and birth Reflex responses Normal responses Compensatory responses Protect fetal integrity Dependent on fetal reserve Decompensation Slide 18 Methods and tools for FHS Williams Obstetrics Slide 19 Leopolds Maneuver - an essential skill Williams Obstetrics 1 2 3 4 Slide 20 Fetal Health Surveillance - Principles SOGC advises: (2007) The normal, healthy fetus is well-equipped to withstand the repeated, transient hypoxia associated with labour contractions. Intermittent auscultation (IA) is the preferred method of fetal surveillance for healthy women without risk factors for adverse outcomes. Slide 21 Decisions around methods of FHS Always consider a womans choice Use of EFM supported for pregnancies with complications Hypertension Postmaturity >42 weeks IUGR Prematurity Multiple pregnancies Continuous EFM for augmentation / mostly continuous for induction Slide 22 Auscultation Auscultate the FHR q 15 minutes in active labour, q 5 minutes during second stage once active pushing has begun Slide 23 Auscultation procedure 60-second count results in greatest accuracy Baseline rate is assessed between contractions. Check maternal pulse to confirm FHR Record rate, rhythm (regular or irregular), and accelerations (abrupt increases) and/or decelerations (gradual or abrupt) Slide 24 Ausculation classification Normal FHR: FHR 110 to 160 Regular rhythm Accelerations Abnormal FHR: Outside normal range Decelerations Slide 25 Documentation NS Partogram (RCP) http://rcp.nshealth.ca/publications/labour-partogram-companion-guide Slide 26 If the FHR is abnormal on auscultation. Auscultate the FHR after the next contraction to confirm the characteristics (SOGC) Assess potential causes attempt to eliminate or reduce the effect Recheck maternal pulse, V/S Initiate EFM Slide 27 Part 2 Analysis and interpretation of EFM tracings Interventions recommended in the event of atypical or abnormal tracings Slide 28 Thank you! We welcome your feedback. Please take a few moments to complete a short evaluation: http://rcp.nshealth.ca/education/learning-modules/evaluation If you have any questions, please contact the RCP office at [email protected] or [email protected]