1
|
Baburamani AA, Tran NT, Castillo-Melendez M, Yawno T, Walker DW. Brief hypoxia in late gestation sheep causes prolonged disruption of fetal electrographic, breathing behaviours and can result in early labour. J Physiol 2021; 599:3221-3236. [PMID: 33977538 DOI: 10.1113/jp281266] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/21/2021] [Indexed: 01/22/2023] Open
Abstract
KEY POINTS Brief episodes of severe fetal hypoxia can arise in late gestation as a result of interruption of normal umbilical blood flow Systemic parameters and blood chemistry indicate complete recovery within 1-2 hours, although the long-term effects on fetal brain functions are unknown Fetal sheep were subjected to umbilical cord occlusion (UCO) for 10 min at 131 days of gestation, and then monitored intensively until onset of labour or delivery (<145 days of gestation) Normal patterns of fetal behaviour, including breathing movements, episodes of high and low voltage electorcortical activity, eye movements and postural (neck) muscle activity, were disrupted for 3-10 days after the UCO Preterm labour and delivery occurred in a significant number of the pregnancies after UCO compared to the control (sham-UCO) cohort. ABSTRACT Complications arising from antepartum events such as impaired umbilical blood flow can cause significant fetal hypoxia. These complications can be unpredictable, as well as difficult to detect, and thus we lack a detailed understanding of the (patho)physiological changes that occur between the antenatal in utero event and birth. In the present study, we assessed the consequences of brief (∼10 min) umbilical cord occlusion (UCO) in fetal sheep at ∼0.88 gestation on fetal plasma cortisol concentrations and fetal behaviour [electrocortical (EcoG), electo-oculargram (EOG), nuchal muscle electromyography (EMG) and breathing activities] in the days following UCO. UCO caused a rapid onset of fetal hypoxaemia, hypercapnia, and acidosis; however, by 6 h, all blood parameters and cardiovascular status were normalized and not different from the control (Sham-UCO) cohort. Subsequently, the incidence of fetal breathing movements decreased compared to the control group, and abnormal behavioural patterns developed over the days following UCO and leading up to the onset of labour, which included increased high voltage and sub-low voltage ECoG and EOG activities, as well as decreased nuchal EMG activity. Fetuses subjected to UCO went into labour 7.9 ± 3.6 days post-UCO (139.5 ± 3.2 days of gestation) compared to the control group fetuses at 13.6 ± 3.3 days post-sham UCO (144 ± 2.2 days of gestation; P < 0.05), despite comparable increases in fetal plasma cortisol and a similar body weight at birth. Thus, a single transient episode of complete UCO late in gestation in fetal sheep can result in prolonged effects on fetal brain activity and premature labour, suggesting persisting effects on fetal cerebral metabolism.
Collapse
Affiliation(s)
- Ana A Baburamani
- Department of Perinatal Imaging and Health, Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Nhi T Tran
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia.,The Ritchie Centre, Hudson Institute of Medical Research, and Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Margie Castillo-Melendez
- The Ritchie Centre, Hudson Institute of Medical Research, and Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Tamara Yawno
- The Ritchie Centre, Hudson Institute of Medical Research, and Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - David W Walker
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| |
Collapse
|
2
|
Polglase GR, Schmölzer GM, Roberts CT, Blank DA, Badurdeen S, Crossley KJ, Miller SL, Stojanovska V, Galinsky R, Kluckow M, Gill AW, Hooper SB. Cardiopulmonary Resuscitation of Asystolic Newborn Lambs Prior to Umbilical Cord Clamping; the Timing of Cord Clamping Matters! Front Physiol 2020; 11:902. [PMID: 32848852 PMCID: PMC7406709 DOI: 10.3389/fphys.2020.00902] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/06/2020] [Indexed: 12/14/2022] Open
Abstract
Background: Current guidelines recommend immediate umbilical cord clamping (UCC) for newborns requiring chest compressions (CCs). Physiological-based cord clamping (PBCC), defined as delaying UCC until after lung aeration, has advantages over immediate UCC in mildly asphyxiated newborns, but its efficacy in asystolic newborns requiring CC is unknown. The aim of this study was to compare the cardiovascular response to CCs given prior to or after UCC in asystolic near-term lambs. Methods: Umbilical, carotid, pulmonary, and femoral arterial flows and pressures as well as systemic and cerebral oxygenation were measured in near-term sheep fetuses [139 ± 2 (SD) days gestation]. Fetal asphyxia was induced until asystole ensued, whereupon lambs received ventilation and CC before (PBCC; n = 16) or after (n = 12) UCC. Epinephrine was administered 1 min after ventilation onset and in 3-min intervals thereafter. The PBCC group was further separated into UCC at either 1 min (PBCC1, n = 8) or 10 min (PBCC10, n = 8) after return of spontaneous circulation (ROSC). Lambs were maintained for a further 30 min after ROSC. Results: The duration of CCs received and number of epinephrine doses required to obtain ROSC were similar between groups. After ROSC, we found no physiological benefits if UCC was delayed for 1 min compared to immediate cord clamping (ICC). However, if UCC was delayed for 10 min after ROSC, we found significant reductions in post-asphyxial rebound hypertension, cerebral blood flow, and cerebral oxygenation. The prevention of the post-asphyxial rebound hypertension in the PBCC10 group occurred due to the contribution of the placental circulation to a low peripheral resistance. As a result, left and right ventricular outputs continued to perfuse the placenta and were evidenced by reduced mean pulmonary blood flow, persistence of right-to-left shunting across the ductus arteriosus, and persistence of umbilical arterial and venous blood flows. Conclusion: It is possible to obtain ROSC after CC while the umbilical cord remains intact. There were no adverse effects of PBCC compared to ICC; however, the physiological changes observed after ROSC in the ICC and early PBCC groups may result in additional cerebral injury. Prolonging UCC after ROSC may provide significant physiological benefits that may reduce the risk of harm to the cerebral circulation.
Collapse
Affiliation(s)
- Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Georg M Schmölzer
- Centre for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, AB, Canada
| | - Calum T Roberts
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Douglas A Blank
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Shiraz Badurdeen
- Newborn Research Centre, The Royal Women's Hospital, Melbourne, VIC, Australia
| | - Kelly J Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
| | - Suzanne L Miller
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Vanesa Stojanovska
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
| | - Robert Galinsky
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
| | - Martin Kluckow
- Department of Neonatology, Royal North Shore Hospital, The University of Sydney, Sydney, NSW, Australia
| | - Andrew W Gill
- Centre for Neonatal Research and Education, The University of Western Australia, Subiaco, WA, Australia
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| |
Collapse
|
3
|
Polglase GR, Blank DA, Barton SK, Miller SL, Stojanovska V, Kluckow M, Gill AW, LaRosa D, Te Pas AB, Hooper SB. Physiologically based cord clamping stabilises cardiac output and reduces cerebrovascular injury in asphyxiated near-term lambs. Arch Dis Child Fetal Neonatal Ed 2018; 103:F530-F538. [PMID: 29191812 DOI: 10.1136/archdischild-2017-313657] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 10/23/2017] [Accepted: 11/05/2017] [Indexed: 11/03/2022]
Abstract
BACKGROUND Physiologically based cord clamping (PBCC) has advantages over immediate cord clamping (ICC) during preterm delivery, but its efficacy in asphyxiated infants is not known. We investigated the physiology of PBCC following perinatal asphyxia in near-term lambs. METHODS Near-term sheep fetuses (139±2 (SD) days' gestation) were instrumented to measure umbilical, carotid, pulmonary and femoral arterial flows and pressures. Systemic and cerebral oxygenation was recorded using pulse oximetry and near-infrared spectroscopy, respectively. Fetal asphyxia was induced until mean blood pressure reached ~20 mm Hg, where lambs underwent ICC and initiation of ventilation (n=7), or ventilation for 15 min prior to umbilical cord clamping (PBCC; n=8). Cardiovascular parameters were measured and white and grey matter microvascular integrity assessed using qRT-PCR and immunohistochemistry. RESULTS PBCC restored oxygenation and cardiac output at the same rate and in a similar fashion to lambs resuscitated following ICC. However, ICC lambs had a rapid and marked overshoot in mean systemic arterial blood pressure from 1 to 10 min after ventilation onset, which was largely absent in PBCC lambs. ICC lambs had increased cerebrovascular injury, as indicated by reduced expression of blood-brain barrier proteins and increased cerebrovascular protein leakage in the subcortical white matter (by 86%) and grey matter (by 47%). CONCLUSION PBCC restored cardiac output and oxygenation in an identical time frame as ICC, but greatly mitigated the postasphyxia rebound hypertension measured in ICC lambs. This likely protected the asphyxiated brain from cerebrovascular injury. PBCC may be a more suitable option for the resuscitation of the asphyxiated newborn compared with the current standard of ICC.
Collapse
Affiliation(s)
- Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
| | - Douglas A Blank
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Samantha K Barton
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Suzanne L Miller
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Vanesa Stojanovska
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Martin Kluckow
- Department of Neonatology, Royal North Shore Hospital and University of Sydney, Sydney, New South Wales, Australia
| | - Andrew W Gill
- Centre for Neonatal Research and Education, The University of Western Australia, Subiaco, Western Australia, Australia
| | - Domenic LaRosa
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Arjan B Te Pas
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
4
|
Soo JY, Wiese MD, Berry MJ, Morrison JL. Does poor fetal growth influence the extent of fetal exposure to maternal medications? Pharmacol Res 2018; 130:74-84. [DOI: 10.1016/j.phrs.2018.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/18/2017] [Accepted: 02/01/2018] [Indexed: 10/18/2022]
|
5
|
Hua Y, Yang S, Zhou K, Guo N, Zhu Q, Zhou R, Mu D, Jiang X. Impact of intrauterine balloon aortic valvuloplasty on gestational outcome in a fetal goat model. Fetal Diagn Ther 2011; 30:100-7. [PMID: 21464555 DOI: 10.1159/000324503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 01/17/2011] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Intrauterine balloon aortic valvuloplasty (IUBAV) has been used to correct critical aortic valve stenosis. Evaluation of the intervention-related risk is necessary. The purpose of this study was to establish an experimental goat model for ultrasound-guided IUBAV intervention and investigate the immediate and long-term effects of IUBAV on the fetus, gestational outcome and mother's safety. STUDY DESIGN Fifteen pregnant goats with twin gestation in the 2nd and 3rd trimester were anesthetized to establish the surgical procedure. One fetus of the twins received IUBAV intervention, the other served as a control. The data were collected at three time points: immediately before and after IUBAV, and 24 h after birth. Critical organs including the heart, brain, lung and liver from the fetuses/newborns were collected after IUBAV or 24 h after birth. RESULTS IUBAV intervention immediately induced a significant decrease of pH and Ca(2+), as well as an increase of blood glucose and lactic acid levels (p < 0.05). IUBAV also caused an increase in stress hormones (epinephrine 1-fold, norepinephrine 4-fold, and cortisol 1-fold; p < 0.05). Following the operation, all of the mother goats recovered, but in 60% (6/10) preterm delivery occurred. Neither pathological changes in fetal critical organs nor a significant difference in metabolism or growth parameters were detected between IUBAV and control kids. CONCLUSIONS Ultrasound-guided IUBAV intervention induced a strong but transient stress response in the operated fetus, which did not result in irreversible histological changes in the fetus or the mother, but may disrupt the continuation of normal gestation in the long term. Preterm delivery is the major risk in this goat IUBAV model.
Collapse
Affiliation(s)
- Yimin Hua
- Department of Pediatric Cardiology, West China Second University Hospital, and West China Medical School, Sichuan University, Chengdu, China.
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Miller SL, Loose JM, Jenkin G, Wallace EM. The effects of sildenafil citrate (Viagra) on uterine blood flow and well being in the intrauterine growth-restricted fetus. Am J Obstet Gynecol 2009; 200:102.e1-7. [PMID: 18845296 DOI: 10.1016/j.ajog.2008.08.029] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 06/19/2008] [Accepted: 08/08/2008] [Indexed: 11/25/2022]
Abstract
OBJECTIVE This study examined whether the type-5 phosphodiesterase inhibitor sildenafil citrate (Viagra; Pfizer, New York, NY) could increase uterine blood flow in intrauterine growth restriction (IUGR), thereby improving fetal oxygenation and well being. STUDY DESIGN In fetal sheep, we induced IUGR at 105-110 days (0.7 gestation) using single umbilical artery ligation (SUAL). In SUAL and control animals, we measured uterine blood flow (UBF) and blood gases before and after sildenafil administration. RESULTS SUAL fetuses were hypoxemic compared with controls. Following sildenafil, UBF was significantly decreased in both SUAL and control ewes for approximately 40 minutes. In response to sildenafil, pO(2) was decreased in SUAL and control fetuses and both groups displayed significant hypotension and tachycardia. At postmortem SUAL fetal body weight was significantly reduced by 23% compared with controls. CONCLUSION Sildenafil does not improve UBF or fetal well being in SUAL-induced IUGR pregnancies and should be used with caution in IUGR and healthy pregnancies because of its detrimental effects on uteroplacental perfusion and on the fetus.
Collapse
|
7
|
Morrison JL. SHEEP MODELS OF INTRAUTERINE GROWTH RESTRICTION: FETAL ADAPTATIONS AND CONSEQUENCES. Clin Exp Pharmacol Physiol 2008; 35:730-43. [DOI: 10.1111/j.1440-1681.2008.04975.x] [Citation(s) in RCA: 201] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
8
|
Abstract
On the back of sheep experiments showing that uterine hypoxia induces a rapid and sustained elevation of fetal activin A levels, we undertook two prospective studies to explore whether this novel observation could be exploited clinically. The first was a prospective labour ward study investigating whether umbilical arterial activin A levels at delivery correlated with either neonatal hypoxic ischaemic encephalopathy or pH. Unfortunately, we were unable to demonstrate a link with either, but found that levels were significantly depressed among those who had an emergency Caesarean section, suggesting a possible role in active labour. Second, we investigated the link between activin A and intrauterine growth restriction (IUGR), a condition of fetoplacental hypoxia, by measuring levels in women presenting for antenatal ultrasound biometry with clinical suspicion of a small baby. We found that, compared to pregnancies with a baby that was small for gestational age (SGA) but otherwise healthy, levels were 2.4 and 8 times higher, respectively, in pregnancies complicated by IUGR, and those complicated by both IUGR and preeclampsia. However, a single blood sample of activin A was unable to distinguish between IUGR and SGA pregnancies with sufficient sensitivity to be clinically useful. Our studies were unable to demonstrate clinical utility for the experimental observation linking activin A and hypoxia.
Collapse
Affiliation(s)
- Stephen Tong
- Department of Obstetrics and Gynaecology, Monash University, Victoria, Australia.
| |
Collapse
|
9
|
Supramaniam VG, Jenkin G, Loose J, Wallace EM, Miller SL. Chronic fetal hypoxia increases activin A concentrations in the late-pregnant sheep. BJOG 2006; 113:102-9. [PMID: 16398778 DOI: 10.1111/j.1471-0528.2005.00791.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To determine whether activin A concentrations are altered in chronic fetal hypoxemia and intrauterine fetal growth restriction (IUGR). DESIGN In vivo animal experimental model. SETTING Department of Physiology, Monash University. POPULATION Chronically catherised fetal sheep in late pregnancy. METHODS Chronic fetal hypoxia and IUGR were experimentally induced by single umbilical artery ligation (SUAL) in catheterised fetal sheep. Maternal and fetal blood samples and amniotic fluid (AF) samples were collected during surgery and thereafter on alternate days, until the time of delivery for analyte measurement. Fetal blood gas parameters were measured daily. MAIN OUTCOME MEASURES Plasma and AF was used to analyse activin A, prostaglandin E2 (PGE2) and cortisol and fetal blood gas analysis was undertaken in whole blood. RESULTS SUAL produced asymmetric IUGR and non-acidaemic chronic fetal hypoxia and resulted in preterm labour (129 [3] days). AF activin A concentrations were 10-fold higher in the SUAL group than in controls whereas levels in the fetal and maternal circulations were similar between groups. CONCLUSIONS SUAL-induced IUGR and fetal hypoxaemia increases AF activin A. This may be an important adaptive or protective response to IUGR.
Collapse
Affiliation(s)
- V G Supramaniam
- Department of Physiology, Monash University, Clayton, Victoria, Australia
| | | | | | | | | |
Collapse
|