1
|
Zhang S, Lock MC, Tie M, McMillen IC, Botting KJ, Morrison JL. Cardiac programming in the placentally restricted sheep fetus in early gestation. J Physiol 2024; 602:3815-3832. [PMID: 38975864 DOI: 10.1113/jp286702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 06/13/2024] [Indexed: 07/09/2024] Open
Abstract
Fetal growth restriction (FGR) occurs in 8% of human pregnancies, and the growth restricted newborn is at a greater risk of developing heart disease in later adult life. In sheep, experimental restriction of placental growth (PR) from conception results in FGR, a decrease in cardiomyocyte endowment and an upregulation of pathological hypertrophic signalling in the fetal heart in late gestation. However, there is no change in the expression of markers of cellular proliferation nor in the level of cardiomyocyte apoptosis in the heart of the PR fetus in late gestation. This suggests that FGR arises early in gestation and programs a decrease in cardiomyocyte endowment in early, rather than late, gestation. Here, control and PR fetal sheep were humanely killed at 55 days' gestation (term, 150 days). Fetal body and heart weight were lower in PR compared with control fetuses and there was evidence of sparing of fetal brain growth. While there was no change in the proportion of cardiomyocytes that were proliferating in the early gestation PR heart, there was an increase in measures of apoptosis, and markers of autophagy and pathological hypertrophy in the PR fetal heart. These changes in early gestation highlight that FGR is associated with evidence of early cell death and compensatory hypertrophic responses of cardiomyocytes in the fetal heart. The data suggest that early placental restriction results in a decrease in the pool of proliferative cardiomyocytes in early gestation, which would limit cardiomyocyte endowment in the heart of the PR fetus in late gestation. KEY POINTS: Placental restriction leading to fetal growth restriction (FGR) and chronic fetal hypoxaemia in sheep results in a decrease in cardiomyocyte endowment in late gestation. FGR did not change cardiomyocyte proliferation during early gestation but did result in increased apoptosis and markers of autophagy in the fetal heart, which may result in the decreased endowment of cardiomyocytes observed in late gestation. FGR in early gestation also results in increased hypoxia inducible factor signalling in the fetal heart, which in turn may result in the altered expression of epigenetic regulators, increased expression of insulin-like growth factor 2 and cardiomyocyte hypertrophy during late gestation and after birth.
Collapse
Affiliation(s)
- Song Zhang
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Science, University of South Australia, Adelaide, SA, Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Science, University of South Australia, Adelaide, SA, Australia
| | - Michelle Tie
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Science, University of South Australia, Adelaide, SA, Australia
| | - I Caroline McMillen
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Science, University of South Australia, Adelaide, SA, Australia
| | - Kimberley J Botting
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Science, University of South Australia, Adelaide, SA, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Science, University of South Australia, Adelaide, SA, Australia
| |
Collapse
|
2
|
Tartaglia S, Zanfini BA, Gueli Alletti S, Draisci G, Lanzone A. The Importance of Fetoplacental Doppler Velocimetry for Fetal Surveillance During General Anesthesia for Non-obstetric Surgery. Cureus 2024; 16:e52382. [PMID: 38230384 PMCID: PMC10790955 DOI: 10.7759/cureus.52382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2024] [Indexed: 01/18/2024] Open
Abstract
Fetal heart rate monitoring during general anesthesia for non-obstetric surgery at viable gestational ages is recommended to evaluate fetal well-being during the intervention. Alteration induced by anesthetic drugs could mimic fetal acute hypoxia, leading to pointless Cesarean sections. We report a case of a pregnant woman in the third trimester undergoing neurosurgical surgery. The continuous heart rate registration showed a non-reassuring pattern, potentially inducing the multidisciplinary team to expedite the delivery. The seriate fetoplacental Doppler evaluations were reassuring about normal fetal conditions, suggesting that ultrasound surveillance could be more reliable than intraoperative heart rate monitoring.
Collapse
Affiliation(s)
- Silvio Tartaglia
- Dipartimento di Scienza Della Salute Della Donna e del Bambino e di Sanità Pubblica, Fondazione Policlinico Universitario Agostino Gemelli IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico), Rome, ITA
| | - Bruno A Zanfini
- Dipartimento di Scienze dell'Emergenza, Anestesiologiche e Della Rianimazione, Fondazione Policlinico Universitario Agostino Gemelli IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico), Rome, ITA
| | - Salvatore Gueli Alletti
- Dipartimento di Scienza Della Salute Della Donna e del Bambino e di Sanità Pubblica, Fondazione Policlinico Universitario Agostino Gemelli IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico), Rome, ITA
| | - Gaetano Draisci
- Dipartimento di Scienze dell'Emergenza, Anestesiologiche e Della Rianimazione, Fondazione Policlinico Universitario Agostino Gemelli IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico), Rome, ITA
| | - Antonio Lanzone
- Dipartimento di Scienza Della Salute Della Donna e del Bambino e di Sanità Pubblica, Fondazione Policlinico Universitario Agostino Gemelli IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico), Rome, ITA
| |
Collapse
|
3
|
Zhao J, Zhang J, Xu Y, Dong J, Dong Q, Zhao G, Shi Y. Nanotechnological approaches for the treatment of placental dysfunction: recent trends and future perspectives. Nanomedicine (Lond) 2023; 18:1961-1978. [PMID: 37990993 DOI: 10.2217/nnm-2023-0194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023] Open
Abstract
The transitory placenta develops during pregnancy and mediates the blood flow between the mother and the developing baby. Placental dysfunction, including but not limited to placenta accreta spectrum, fetal growth restriction, preeclampsia and gestational trophoblastic disease, arises from abnormal placental development and can result in significant adverse maternal and fetal health outcomes. Unfortunately, there is a lack of treatment alternatives for these disorders. Nanocarriers offer versatility, including extended circulation, organ-specific targeting and intracellular transport, finely tuning therapeutic placental interactions. This thorough review explores nanotechnological strategies for addressing placental disorders, encompassing dysfunction insights, potential drug-delivery targets and recent strides in placenta-targeted nanoparticle (NP) therapies, instilling hope for effective placental malfunction treatment.
Collapse
Affiliation(s)
- Jian Zhao
- Delivery Rooms, Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China
| | - Jungang Zhang
- General Surgery, Cancer Center, Department of Hepatobiliary and Pancreatic Surgery and Minimally Invasive Surgery, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, 310014, China
| | - Yan Xu
- Medical Research Center, Zhoushan Hospital of Traditional Chinese Medicine Affiliated to Zhejiang Chinese Medical University, Zhoushan, 316000, China
| | - Juan Dong
- Delivery Rooms, Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China
| | - Qichao Dong
- Delivery Rooms, Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China
| | - Guoqiang Zhao
- Delivery Rooms, Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China
| | - Ying Shi
- Center for Reproductive Medicine, Department of Obstetrics, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, 310014, China
| |
Collapse
|
4
|
Drake RR, Louey S, Thornburg KL. Intrauterine growth restriction elevates circulating acylcarnitines and suppresses fatty acid metabolism genes in the fetal sheep heart. J Physiol 2022; 600:655-670. [PMID: 34802149 PMCID: PMC9075772 DOI: 10.1113/jp281415] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 11/17/2021] [Indexed: 02/03/2023] Open
Abstract
At birth, the mammalian myocardium switches from using carbohydrates as the primary energy substrate to free fatty acids as the primary fuel. Thus, a compromised switch could jeopardize normal heart function in the neonate. Placental embolization in sheep is a reliable model of intrauterine growth restriction (IUGR). It leads to suppression of both proliferation and terminal differentiation of cardiomyocytes. We hypothesized that the expression of genes regulating cardiac fatty acid metabolism would be similarly suppressed in IUGR, leading to compromised processing of lipids. Following 10 days of umbilicoplacental embolization in fetal sheep, IUGR fetuses had elevated circulating long-chain fatty acylcarnitines compared with controls (C14: CTRL 0.012 ± 0.005 nmol/ml vs. IUGR 0.018 ± 0.005 nmol/ml, P < 0.05; C18: CTRL 0.027 ± 0.009 nmol/mol vs. IUGR 0.043 ± 0.024 nmol/mol, P < 0.05, n = 12 control, n = 12 IUGR) indicative of impaired fatty acid metabolism. Uptake studies using fluorescently tagged BODIPY-C12-saturated free fatty acid in live, isolated cardiomyocytes showed lipid droplet area and number were not different between control and IUGR cells. mRNA levels of sarcolemmal fatty acid transporters (CD36, FATP6), acylation enzymes (ACSL1, ACSL3), mitochondrial transporter (CPT1), β-oxidation enzymes (LCAD, HADH, ACAT1), tricarboxylic acid cycle enzyme (IDH), esterification enzymes (PAP, DGAT) and regulator of the lipid droplet formation (BSCL2) gene were all suppressed in IUGR myocardium (P < 0.05). However, protein levels for these regulatory genes were not different between groups. This discordance between mRNA and protein levels in the stressed myocardium suggests an adaptive protection of key myocardial enzymes under conditions of placental insufficiency. KEY POINTS: The fetal heart relies on carbohydrates in utero and must be prepared to metabolize fatty acids after birth but the effects of compromised fetal growth on the maturation of this metabolic system are unknown. Plasma fatty acylcarnitines are elevated in intrauterine growth-restricted (IUGR) fetuses compared with control fetuses, indicative of impaired fatty acid metabolism in fetal organs. Fatty acid uptake and storage are not different in IUGR cardiomyocytes compared with controls. mRNA levels of genes regulating fatty acid transporter and metabolic enzymes are suppressed in the IUGR myocardium compared with controls, while protein levels remain unchanged. Mismatches in gene and protein expression, and increased circulating fatty acylcarnitines may have long-term implications for offspring heart metabolism and adult health in IUGR individuals. This requires further investigation.
Collapse
Affiliation(s)
- Rachel R. Drake
- Center for Developmental Health, Knight Cardiovascular Institute, School of Medicine, Oregon Health and Science University, Portland, Oregon, USA,Department of Chemical Physiology and Biochemistry, School of Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Samantha Louey
- Center for Developmental Health, Knight Cardiovascular Institute, School of Medicine, Oregon Health and Science University, Portland, Oregon, USA
| | - Kent L. Thornburg
- Center for Developmental Health, Knight Cardiovascular Institute, School of Medicine, Oregon Health and Science University, Portland, Oregon, USA,Department of Chemical Physiology and Biochemistry, School of Medicine, Oregon Health and Science University, Portland, Oregon, USA
| |
Collapse
|
5
|
Richardson BS, de Vrijer B, Brown HK, Stitt L, Choo S, Regnault TRH. Gestational age impacts birth to placental weight ratio and umbilical cord oxygen values with implications for the fetal oxygen margin of safety. Early Hum Dev 2022; 164:105511. [PMID: 34839188 DOI: 10.1016/j.earlhumdev.2021.105511] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 11/03/2021] [Accepted: 11/17/2021] [Indexed: 11/03/2022]
Abstract
BACKGROUND We determined the impact of gestational age (GA) from near term to term to post-term on birth/placental weight ratio and cord oxygen values with implications for placental transport efficiency for oxygen, fetal O2 consumption relative to delivery or fractional O2 extraction, and oxygen margin of safety. MATERIALS AND METHODS A hospital database was used to obtain birth/placental weight ratios, cord PO2 and other information on patients delivering between Jan 1, 1990 and Jun 15, 2011 with GA > 34 completed weeks (N = 69,852). Oxygen saturation was calculated from the cord PO2 and pH data, while fractional O2 extraction was calculated from the oxygen saturation data. The effect of GA grouping on birth/placental weight ratio, cord PO2, O2 saturation, and fractional O2 extraction values, was examined in all patients adjusting for pregnancy and labor/delivery covariates, and in a subset of low-risk patients. RESULTS Birth/placental weight ratio and umbilical venous O2 values increased with advancing GA, supporting the conjecture of increasing placental transport efficiency for oxygen. However, umbilical arterial O2 values decreased while fractional O2 extraction increased with successive GA groupings, indicating that fetal O2 consumption must be increasing relative to delivery. CONCLUSIONS Fetal O2 consumption can be seen as ever 'outgrowing' O2 delivery over the last weeks of pregnancy and leading to a continued lowering in systemic oxygen levels. While this lowering in oxygen may trigger feedback mechanisms with survival benefit, the 'oxygen margin of safety' will also be lowered increasing perinatal morbidity and mortality which appear to be hypoxia related.
Collapse
Affiliation(s)
- Bryan S Richardson
- Department of Obstetrics and Gynecology, University of Western Ontario, London, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Canada; Department of Pediatrics, University of Western Ontario, London, Canada; Lawson Health Research Institute, University of Western Ontario, London, Canada.
| | - Barbra de Vrijer
- Department of Obstetrics and Gynecology, University of Western Ontario, London, Canada; Lawson Health Research Institute, University of Western Ontario, London, Canada
| | - Hilary K Brown
- Interdisciplinary Centre for Health & Society, University of Toronto, Toronto, Canada
| | - Larry Stitt
- Department of Obstetrics and Gynecology, University of Western Ontario, London, Canada
| | - Sheryl Choo
- Department of Obstetrics and Gynecology, University of Western Ontario, London, Canada
| | - Timothy R H Regnault
- Department of Obstetrics and Gynecology, University of Western Ontario, London, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Canada; Lawson Health Research Institute, University of Western Ontario, London, Canada
| |
Collapse
|
6
|
The Enigma of the Adrenarche: Identifying the Early Life Mechanisms and Possible Role in Postnatal Brain Development. Int J Mol Sci 2021; 22:ijms22094296. [PMID: 33919014 PMCID: PMC8122518 DOI: 10.3390/ijms22094296] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/15/2021] [Accepted: 04/19/2021] [Indexed: 11/17/2022] Open
Abstract
Dehydroepiandrosterone (DHEA) and its sulfated metabolite (DHEAS) are dynamically regulated before birth and the onset of puberty. Yet, the origins and purpose of increasing DHEA[S] in postnatal development remain elusive. Here, we draw attention to this pre-pubertal surge from the adrenal gland—the adrenarche—and discuss whether this is the result of intra-adrenal gene expression specifically affecting the zona reticularis (ZR), if the ZR is influenced by the hypothalamic-pituitary axis, and the possible role of spino-sympathetic innervation in prompting increased ZR activity. We also discuss whether neural DHEA[S] synthesis is coordinately regulated with the developing adrenal gland. We propose that DHEA[S] is crucial in the brain maturation of humans prior to and during puberty, and suggest that the function of the adrenarche is to modulate, adapt and rewire the pre-adolescent brain for new and ever-changing social challenges. The etiology of DHEA[S] synthesis, neurodevelopment and recently described 11-keto and 11-oxygenated androgens are difficult to investigate in humans owing to: (i) ethical restrictions on mechanistic studies, (ii) the inability to predict which individuals will develop specific mental characteristics, and (iii) the difficulty of conducting retrospective studies based on perinatal complications. We discuss new opportunities for animal studies to overcome these important issues.
Collapse
|
7
|
Ghi T, Di Pasquo E, Dall'Asta A, Commare A, Melandri E, Casciaro A, Fieni S, Frusca T. Intrapartum fetal heart rate between 150 and 160 bpm at or after 40 weeks and labor outcome. Acta Obstet Gynecol Scand 2020; 100:548-554. [PMID: 33051873 DOI: 10.1111/aogs.14024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/25/2020] [Accepted: 10/06/2020] [Indexed: 11/29/2022]
Abstract
INTRODUCTION A baseline fetal heart rate between 110 and 160 bpm is considered normal. However, among normal fetuses the average baseline heart rate has been shown to diminish progressively and the 90th centile of the fetal heart rate at 40 weeks of gestation has been consistently found at around 150 bpm. The aim of our study was to assess the labor and neonatal outcome of fetuses at 40 gestational weeks or beyond, whose intrapartum baseline fetal heart rate was between 150 and 160 bpm. MATERIAL AND METHODS Retrospective cohort study including singleton pregnancies with spontaneous onset of labor, gestational age between 40+0 and 42+0 weeks, category I CTG trace according to the FIGO guidelines 2015 with baseline fetal heart rate between 110 and 160 bpm during the first 60 minutes of active labor. Exclusion criteria were maternal hyperpyrexia at admission, fetal arrhythmias, maternal tachycardia (>110 bpm) and uterine tachysystole (>5 contractions/10 minutes). The following outcomes were compared between fetuses with a baseline ranging between 110 and 149 bpm and those with a baseline ranging between 150 and 160 bpm: incidence of meconium-stained amniotic fluid, intrapartum hyperpyrexia, mode of delivery, Apgar at 5 minutes <7, arterial pH <7.1 and Neonatal Intensive Care Unit admission, incidence of a composite adverse neonatal outcome. RESULTS In all, 1004 CTG traces were included in the analysis, 860 in Group 110-149 bpm and 144 in Group 150-160 bpm. Group 150-160 bpm had a significantly higher incidence of meconium-stained amniotic fluid (odds ratio [OR] 2.6; 95% CI 1.8-3.8), maternal intrapartum hyperpyrexia (OR 4.7; 95% CI 1.1-14.6), urgent/emergent cesarean section for suspected fetal distress (OR 13.4; 95% CI 3.3-54.3), Apgar <7 at 5th min (OR 9.13; 95% CI 1.5-55.1) and neonatal acidemia (OR 3.5; 95% CI 1.5-55.1). Logistic regression including adjustiing for potential confounders showed that fetal heart rate between 150 and 160 bpm is an independent predictor of meconium-stained amniotic fluid (adjusted odds ratio [aOR] 2.2; 95% CI 1.5-3.3), cesarean section during labor for fetal distress (aOR 10.7; 95% CI 2.9-44.6), neonatal acidemia (aOR 2.6; 95% CI 1.1-6.7) and adverse composite neonatal outcome (aOR 2.6; 95% CI 1.2-5.6). CONCLUSIONS In fetuses at 40 weeks or beyond, an intrapartum fetal heart rate baseline ranging between 150 and 160 bpm seems associated with a higher incidence of labor complications.
Collapse
Affiliation(s)
- Tullio Ghi
- Department of Obstetrics and Gynecology, University of Parma, Parma, Italy
| | - Elvira Di Pasquo
- Department of Obstetrics and Gynecology, University of Parma, Parma, Italy
| | - Andrea Dall'Asta
- Department of Obstetrics and Gynecology, University of Parma, Parma, Italy
| | - Arianna Commare
- Department of Obstetrics and Gynecology, University of Parma, Parma, Italy
| | - Elena Melandri
- Department of Obstetrics and Gynecology, University of Parma, Parma, Italy
| | - Alessia Casciaro
- Department of Obstetrics and Gynecology, University of Parma, Parma, Italy
| | - Stefania Fieni
- Department of Obstetrics and Gynecology, University of Parma, Parma, Italy
| | - Tiziana Frusca
- Department of Obstetrics and Gynecology, University of Parma, Parma, Italy
| |
Collapse
|
8
|
Lear CA, Westgate JA, Ugwumadu A, Nijhuis JG, Stone PR, Georgieva A, Ikeda T, Wassink G, Bennet L, Gunn AJ. Understanding Fetal Heart Rate Patterns That May Predict Antenatal and Intrapartum Neural Injury. Semin Pediatr Neurol 2018; 28:3-16. [PMID: 30522726 DOI: 10.1016/j.spen.2018.05.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Electronic fetal heart rate (FHR) monitoring is widely used to assess fetal well-being throughout pregnancy and labor. Both antenatal and intrapartum FHR monitoring are associated with a high negative predictive value and a very poor positive predictive value. This in part reflects the physiological resilience of the healthy fetus and the remarkable effectiveness of fetal adaptations to even severe challenges. In this way, the majority of "abnormal" FHR patterns in fact reflect a fetus' appropriate adaptive responses to adverse in utero conditions. Understanding the physiology of these adaptations, how they are reflected in the FHR trace and in what conditions they can fail is therefore critical to appreciating both the potential uses and limitations of electronic FHR monitoring.
Collapse
Affiliation(s)
- Christopher A Lear
- Department of Physiology, The Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
| | - Jenny A Westgate
- Department of Physiology, The Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand; Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
| | - Austin Ugwumadu
- Department of Obstetrics and Gynaecology, St George's, University of London, London, United Kingdom
| | - Jan G Nijhuis
- Department of Obstetrics and Gynaecology, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, Netherlands
| | - Peter R Stone
- Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
| | - Antoniya Georgieva
- Nuffield Department of Obstetrics and Gynaecology, The John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Tomoaki Ikeda
- Department of Obstetrics and Gynaecology, Mie University Graduate School of Medicine, Mie, Japan
| | - Guido Wassink
- Department of Physiology, The Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Department of Physiology, The Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- Department of Physiology, The Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand; Department of Paediatrics, Starship Children's Hospital, Auckland, New Zealand.
| |
Collapse
|
9
|
Yadav BK, Krishnamurthy U, Buch S, Jella P, Hernandez-Andrade E, Yeo L, Korzeniewski SJ, Trifan A, Hassan SS, Haacke EM, Romero R, Neelavalli J. Imaging putative foetal cerebral blood oxygenation using susceptibility weighted imaging (SWI). Eur Radiol 2018; 28:1884-1890. [PMID: 29247352 PMCID: PMC5884705 DOI: 10.1007/s00330-017-5160-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/03/2017] [Accepted: 10/27/2017] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To evaluate the magnetic susceptibility, ∆χ v , as a surrogate marker of venous blood oxygen saturation, S v O 2, in second- and third-trimester normal human foetuses. METHODS Thirty-six pregnant women, having a mean gestational age (GA) of 31 2/7 weeks, underwent magnetic resonance imaging (MRI). Susceptibility-weighted imaging (SWI) data from the foetal brain were acquired. ∆χ v of the superior sagittal sinus (SSS) was quantified using MR susceptometry from the intra-vascular phase measurements. Assuming the magnetic property of foetal blood, ∆χ do , is the same as that of adult blood, S v O 2 was derived from the measured Δχ v . The variation of ∆χ v and S v O 2, as a function of GA, was statistically evaluated. RESULTS The mean ∆χ v in the SSS in the second-trimester (n = 8) and third-trimester foetuses (n = 28) was found to be 0.34± 0.06 ppm and 0.49 ±0.05 ppm, respectively. Correspondingly, the derived S v O 2 values were 69.4% ±3.27% and 62.6% ±3.25%. Although not statistically significant, an increasing trend (p = 0.08) in Δχ v and a decreasing trend (p = 0.22) in S v O 2 with respect to advancing gestation was observed. CONCLUSION We report cerebral venous blood magnetic susceptibility and putative oxygen saturation in healthy human foetuses. Cerebral oxygen saturation in healthy human foetuses, despite a slight decreasing trend, does not change significantly with advancing gestation. KEY POINTS • Cerebral venous magnetic susceptibility and oxygenation in human foetuses can be quantified. • Cerebral venous oxygenation was not different between second- and third-trimester foetuses. • Foetal cerebral venous oxygenation does not change significantly with advancing gestation.
Collapse
Affiliation(s)
- Brijesh Kumar Yadav
- Department of Radiology, Wayne State University School of Medicine, 4201 St. Antoine, Detroit, MI, 48201, USA
- Department of Biomedical Engineering, Wayne State University College of Engineering, Detroit, MI, USA
| | - Uday Krishnamurthy
- Department of Radiology, Wayne State University School of Medicine, 4201 St. Antoine, Detroit, MI, 48201, USA
- Department of Biomedical Engineering, Wayne State University College of Engineering, Detroit, MI, USA
| | - Sagar Buch
- The MRI Institute for Biomedical Research, Waterloo, ON, Canada
| | - Pavan Jella
- Department of Radiology, Wayne State University School of Medicine, 4201 St. Antoine, Detroit, MI, 48201, USA
| | - Edgar Hernandez-Andrade
- Perinatology Research Branch, NICHD/NIH/DHHS, Hutzel Women's Hospital, 3990 John R, 4 Brush, Detroit, MI, 48201, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Lami Yeo
- Perinatology Research Branch, NICHD/NIH/DHHS, Hutzel Women's Hospital, 3990 John R, 4 Brush, Detroit, MI, 48201, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Steven J Korzeniewski
- Perinatology Research Branch, NICHD/NIH/DHHS, Hutzel Women's Hospital, 3990 John R, 4 Brush, Detroit, MI, 48201, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI, USA
| | - Anabela Trifan
- Department of Radiology, Wayne State University School of Medicine, 4201 St. Antoine, Detroit, MI, 48201, USA
| | - Sonia S Hassan
- Perinatology Research Branch, NICHD/NIH/DHHS, Hutzel Women's Hospital, 3990 John R, 4 Brush, Detroit, MI, 48201, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - E Mark Haacke
- Department of Radiology, Wayne State University School of Medicine, 4201 St. Antoine, Detroit, MI, 48201, USA
- Department of Biomedical Engineering, Wayne State University College of Engineering, Detroit, MI, USA
- The MRI Institute for Biomedical Research, Waterloo, ON, Canada
| | - Roberto Romero
- Perinatology Research Branch, NICHD/NIH/DHHS, Hutzel Women's Hospital, 3990 John R, 4 Brush, Detroit, MI, 48201, USA.
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA.
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI, USA.
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, USA.
| | - Jaladhar Neelavalli
- Department of Radiology, Wayne State University School of Medicine, 4201 St. Antoine, Detroit, MI, 48201, USA.
| |
Collapse
|
10
|
Bednov A, Espinoza J, Betancourt A, Vedernikov Y, Belfort M, Yallampalli C. l-arginine prevents hypoxia-induced vasoconstriction in dual-perfused human placental cotyledons. Placenta 2015; 36:1254-9. [DOI: 10.1016/j.placenta.2015.08.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/20/2015] [Accepted: 08/26/2015] [Indexed: 10/23/2022]
|
11
|
Aksoy T, Richardson BS, Han VK, Gagnon R. Apoptosis in the Ovine Fetal Brain Following Placental Embolization and Intermittent Umbilical Cord Occlusion. Reprod Sci 2015; 23:249-56. [PMID: 26346442 DOI: 10.1177/1933719115602774] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The purpose of this study was to compare the regional distribution of apoptotic cells in the near term ovine fetal brain caused by prolonged moderate hypoxia, as seen in placental insufficiency, and intermittent severe hypoxia, as seen in umbilical cord compression, which may then contribute to adverse neurodevelopment in the postnatal life. We hypothesized that apoptosis in the fetal brain will be increased in response to both prolonged moderate hypoxia and intermittent severe hypoxia. Twenty-one near term (126-127 days) sheep were divided into 3 groups: control (CON; n = 7), placental embolization (EMB; n = 7), and umbilical cord occlusion (UCO; n = 8). The EMB group had microsphere injections into the umbilical arterial circulation until the oxygen content was at 50% of baseline value. The UCO group had complete cord occlusion for 2 minutes every hour, 6 times a day for 2 consecutive days. At 4 pm on day 2, the animals were euthanized; fetal brains were fixed and prepared for apoptosis staining using the terminal uridine deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay method. In the cerebellar white matter, there was a 3-fold increase in the number of TUNEL positive cells per 1000 cells in both EMB and UCO animals as compared to CON (P = .017). There was also a significant increase in the frontal cortical grey matter (layers 1-3) in EMB animals as compared to CON (P = .014). As such, apoptosis in the near term fetal sheep brain is altered with both sustained moderate hypoxia and intermittent severe hypoxia in the latter part of pregnancy, with potential for long-term neurological sequelae.
Collapse
Affiliation(s)
- Tuba Aksoy
- Departments of Obstetrics and Gynecology, Physiology, and Pediatrics, The Lawson Health Research Institute, Western University, London, Ontario, Canada
| | - Bryan S Richardson
- Departments of Obstetrics and Gynecology, Physiology, and Pediatrics, The Lawson Health Research Institute, Western University, London, Ontario, Canada
| | - Victor K Han
- Departments of Obstetrics and Gynecology, Physiology, and Pediatrics, The Lawson Health Research Institute, Western University, London, Ontario, Canada
| | - Robert Gagnon
- Department of Obstetrics and Gynecology, McGill University Health Centre, Montreal, Quebec, Canada
| |
Collapse
|
12
|
|
13
|
Zhang S, Regnault TRH, Barker PL, Botting KJ, McMillen IC, McMillan CM, Roberts CT, Morrison JL. Placental adaptations in growth restriction. Nutrients 2015; 7:360-89. [PMID: 25580812 PMCID: PMC4303845 DOI: 10.3390/nu7010360] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 12/22/2014] [Indexed: 12/17/2022] Open
Abstract
The placenta is the primary interface between the fetus and mother and plays an important role in maintaining fetal development and growth by facilitating the transfer of substrates and participating in modulating the maternal immune response to prevent immunological rejection of the conceptus. The major substrates required for fetal growth include oxygen, glucose, amino acids and fatty acids, and their transport processes depend on morphological characteristics of the placenta, such as placental size, morphology, blood flow and vascularity. Other factors including insulin-like growth factors, apoptosis, autophagy and glucocorticoid exposure also affect placental growth and substrate transport capacity. Intrauterine growth restriction (IUGR) is often a consequence of insufficiency, and is associated with a high incidence of perinatal morbidity and mortality, as well as increased risk of cardiovascular and metabolic diseases in later life. Several different experimental methods have been used to induce placental insufficiency and IUGR in animal models and a range of factors that regulate placental growth and substrate transport capacity have been demonstrated. While no model system completely recapitulates human IUGR, these animal models allow us to carefully dissect cellular and molecular mechanisms to improve our understanding and facilitate development of therapeutic interventions.
Collapse
Affiliation(s)
- Song Zhang
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5001, Australia.
| | - Timothy R H Regnault
- Departments of Obstetrics and Gynecology, University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Paige L Barker
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5001, Australia.
| | - Kimberley J Botting
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5001, Australia.
| | - Isabella C McMillen
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5001, Australia.
| | - Christine M McMillan
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5001, Australia.
| | - Claire T Roberts
- The Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5001, Australia.
| |
Collapse
|
14
|
Increased collagen deposition in the heart of chronically hypoxic ovine fetuses. J Dev Orig Health Dis 2014; 4:470-8. [PMID: 24924226 DOI: 10.1017/s2040174413000299] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This study determined the effect of chronic intrauterine hypoxia on collagen deposition in the fetal sheep heart. Moderate or severe hypoxia was induced by placental embolization in chronically catheterized fetal sheep for 15 days starting at gestational day 116 ± 2 (term ∼147 days). The fetal right and left ventricle were evaluated for collagen content using a Sirius red dye and for changes in signaling components of pathways involved in collagen synthesis and remodeling using quantitative polymerase chain reaction and Western blot. In severely hypoxic fetuses (n = 6), there was a two-fold increase (P < 0.05) in the percentage staining for collagen in the right ventricle, compared with control (n = 6), whereas collagen content was not altered in the moderate group (n = 4). Procollagen I and III mRNA levels were increased in the right ventricle, two-fold (P < 0.05) and three-fold (P < 0.05), respectively, in the severe group relative to control. These changes were paralleled by a two-fold increase (P < 0.05) in mRNA levels of the pro-fibrotic cytokine, transforming growth factor β (TGF-β1), in the right ventricle. In the right ventricle, the mRNA levels of matrix metalloproteinase 2 (MMP-2) and its activator, membrane-type MMP (MTI-MMP) were increased five-fold (P = 0.06) and three-fold (P < 0.05), respectively, relative to control. Protein levels of TGF-β were increased in the left ventricle (P < 0.05). Thus, up-regulated collagen synthesis leading to increased collagen content occurs in the chronically hypoxic fetal heart and may contribute to the right ventricular diastolic and systolic dysfunction reported in human intrauterine growth restriction fetuses.
Collapse
|
15
|
Thornburg KL, Louey S. Uteroplacental circulation and fetal vascular function and development. Curr Vasc Pharmacol 2014; 11:748-57. [PMID: 24063386 DOI: 10.2174/1570161111311050012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 06/14/2012] [Accepted: 07/12/2012] [Indexed: 12/20/2022]
Abstract
Although blood flow in the placental vasculature is governed by the same physiological forces of shear, pressure and resistance as in other organs, it is also uniquely specialized on the maternal and fetal sides. At the materno-fetal interface, the independent uteroplacental and umbilicoplacental circulations must coordinate sufficiently to supply the fetus with the nutrients and substrates it needs to grow and develop. Uterine arterial flow must increase dramatically to accommodate the growing fetus. Recent evidence delineates the hormonal and endothelial mechanisms by which maternal vessels dilate and remodel during pregnancy. The umbilical circulation is established de novo during embryonic development but blood does not flow through the placenta until late in the first trimester. The umbilical circulation operates in the interest of maintaining fetal oxygenation over the course of pregnancy, and is affected differently by mechanical and chemical regulators of vascular tone compared to other organs. The processes that match placental vascular growth and fetal tissue growth are not understood, but studies of compromised pregnancies provide clues. The subtle changes that cause the failure of the normally regulated vascular processes during pregnancy have not been thoroughly identified. Likewise, practical and effective therapeutic strategies to reverse detrimental placental perfusion patterns have yet to be investigated.
Collapse
Affiliation(s)
- Kent L Thornburg
- Heart Research Center, Oregon Health & Science University, 3303 SW Bond Ave, CH15H, Portland, OR 97239-3098, USA.
| | | |
Collapse
|
16
|
Figueras F, Bennasar M, Eixarch E, Martinez JM, Puerto B, Cararach V, Vanrell JA. Arterial, venous and intracardiac parameters in growth-restricted fetuses: associations with adverse perinatal outcome. ACTA ACUST UNITED AC 2011. [DOI: 10.3109/14722240400017125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
17
|
Maturational changes and effects of chronic hypoxemia on electrocortical activity in the ovine fetus. Brain Res 2011; 1402:38-45. [PMID: 21683944 DOI: 10.1016/j.brainres.2011.05.043] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 04/21/2011] [Accepted: 05/18/2011] [Indexed: 11/22/2022]
Abstract
We have studied the maturation of electrocortical (ECoG) activity in fetal sheep and the impact of chronic hypoxemia using a growth restriction model with placental embolizations. Twenty chronically catheterized fetal sheep (control, n=9; hypoxemic, n=11) were monitored at 116-119, 121-126 and 128-134 days gestational age (term=145 days), with ECoG activity scored using automated analysis of amplitude and frequency components to distinguish low-voltage/high frequency (LV/HF) and high-voltage/low frequency (HV/LF) state epochs, along with indeterminate voltage/frequency (IV/F) and transition period activities. We have shown that multiple aspects of ECoG state activity in the ovine fetus undergo maturational change as electrophysiologic measures of brain development. With chronic fetal hypoxemia, some maturational changes continue to occur, i.e. ECoG activity amplitude and 95% SEF, indicating the resiliency of these parameters to adverse conditioning. However, some maturational changes were altered, i.e. LV/HF and HV/LF incidence and duration, and likely regulated and adaptive with a decrease in the brain's nonessential energy needs, while some were altered, i.e. IV/F incidence and duration, and state transition times, and likely indicating a degree of aberrant development in associated control circuitries. This may then have consequences for disturbed sleep-wake patterns during later life and for adverse neurologic sequelae known to be increased in humans born with growth restriction.
Collapse
|
18
|
Impact on fetal mortality and cardiovascular Doppler of selective ligature of uteroplacental vessels compared with undernutrition in a rabbit model of intrauterine growth restriction. Placenta 2011; 32:304-9. [DOI: 10.1016/j.placenta.2011.01.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Revised: 01/15/2011] [Accepted: 01/17/2011] [Indexed: 11/24/2022]
|
19
|
Gudmundsson S, Dubiel M, Sladkevicius P. Placental morphologic and functional imaging in high-risk pregnancies. Semin Perinatol 2009; 33:270-80. [PMID: 19631087 DOI: 10.1053/j.semperi.2009.04.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The placenta is vital for fetal growth and development. Improvement in ultrasound and magnetic resonance imaging have improved our understanding of placental morphology that can be important as in the case of placental accrete/percreta. Functional imaging is presently mainly performed by the use of Doppler ultrasound and can give information on placental perfusion, which can be vital for clinical diagnosis. This review summarizes the present knowledge on placental imaging and it's clinical value in high-risk pregnancies.
Collapse
|
20
|
Ngan Kee WD, Khaw KS, Lau TK, Ng FF, Chui K, Ng KL. Randomised double-blinded comparison of phenylephrine vs ephedrine for maintaining blood pressure during spinal anaesthesia for non-elective Caesarean section*. Anaesthesia 2008; 63:1319-26. [DOI: 10.1111/j.1365-2044.2008.05635.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
21
|
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]
|
22
|
Shibasaki T, Matsuda H, Kawakami Y, Furuya K. Fetal Leukemia With Umbilical Artery Embolism and Circulatory Failure. Obstet Gynecol 2007; 109:521-3. [PMID: 17267881 DOI: 10.1097/01.aog.0000232508.77614.6d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND This is a case report of fetal leukemia associated with hydramnios. CASE When the hydramnios was treated with amnioreduction, near-term bradycardia was recorded ultrasonographically, resulting in immediate cesarean delivery. At birth, neonatal leukemia was diagnosed and there was no evidence of chromosomal abnormalities. The infant died of pulmonary hemorrhage. Autopsy showed umbilical venous embolization with tumor cells, and there was arterial invasion of the vessel wall by tumor. CONCLUSION Fetal leukemia is extremely rare, and its prenatal diagnosis is difficult. In cases of hepatomegaly, fetal leukemia should be considered in the differential diagnosis.
Collapse
Affiliation(s)
- Tomoko Shibasaki
- Department of Obstetrics and Gynecology, National Defense Medical College, Saitama, Japan.
| | | | | | | |
Collapse
|
23
|
Louey S, Jonker SS, Giraud GD, Thornburg KL. Placental insufficiency decreases cell cycle activity and terminal maturation in fetal sheep cardiomyocytes. J Physiol 2007; 580:639-48. [PMID: 17234700 PMCID: PMC2075561 DOI: 10.1113/jphysiol.2006.122200] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Umbilicoplacental embolization (UPE) in sheep has been used to investigate the effects of placental insufficiency on fetal development. However, its specific effects on the heart have been little studied. The aim of this study was to determine the effects of placental insufficiency, induced by UPE, on cardiomyocyte size, maturation and proliferation. Instrumented fetal sheep underwent UPE for either 10 or 20 days. Hearts were collected at 125 +/- 1 days (10 day group) or 136 +/- 1 days (20 day group) of gestation (term approximately 145 days). Cell size, maturational state (as measured by the proportion of binucleated myocytes) and cell cycle activity (as measured by positive staining of cells for Ki-67) were determined in dissociated cardiomyocytes. UPE fetuses were hypoxaemic, but mean arterial pressures were not different from controls. UPE fetuses were lighter than control fetuses (10 days: -21%, P < 0.05; 20 days: -27%, P < 0.01) and had smaller hearts, but heart weight was appropriate for body weight. Neither lengths nor widths were different between control and UPE cardiomyocytes at either age. Ten days of UPE did not significantly alter the proportion of binucleated myocytes or cell cycle activity in either ventricle. However, 20 days of UPE reduced cell cycle activity in both ventricles by approximately 70% (P < 0.05); the proportion of binucleated myocytes was also lower in UPE fetuses at this age (left ventricle: 31.1 +/- 12.0 versus 46.0 +/- 6.6%, P < 0.05; right ventricle: 29.4 +/- 12.3 versus 46.3 +/- 5.3%, P < 0.05). It is concluded that in the absence of fetal arterial hypertension, placental insufficiency is associated with substantially depressed growth of the heart through suppressed proliferation and maturation of cardiomyocytes.
Collapse
Affiliation(s)
- Samantha Louey
- Heart Research Center, Oregon Health and Science University, Portland, OR 97239-3098, USA.
| | | | | | | |
Collapse
|
24
|
Kisilevsky BS, Davies GAL. Auditory processing deficits in growth restricted fetuses affect later language development. Med Hypotheses 2007; 68:620-8. [PMID: 17010528 DOI: 10.1016/j.mehy.2006.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Accepted: 08/04/2006] [Indexed: 10/24/2022]
Abstract
An increased risk for language deficits in infants born growth restricted has been reported in follow-up studies for more than 20 years, suggesting a relation between fetal auditory system development and later language learning. Work with animal models indicate that there are at least two ways in which growth restriction could affect the development of auditory perception in human fetuses: a delay in myelination or conduction and an increase in sensorineural threshold. Systematic study of auditory function in growth restricted human fetuses has not been reported. However, results of studies employing low-risk fetuses delivering as healthy full-term infants demonstrate that, by late gestation, the fetus can hear, sound properties modulate behavior, and sensory information is available from both inside (e.g., maternal vascular) and outside (e.g., noise, voices, music) of the maternal body. These data provide substantive evidence that the auditory system is functioning and that environmental sounds are available for shaping neural networks and laying the foundation for language acquisition before birth. We hypothesize that fetal growth restriction affects auditory system development, resulting in atypical auditory information processing in growth restricted fetuses compared to healthy, appropriately-grown-for-gestational-age fetuses. Speech perception that lays the foundation for later language competence will differ in growth restricted compared to normally grown fetuses and be associated with later language abilities.
Collapse
Affiliation(s)
- Barbara S Kisilevsky
- School of Nursing, Queen's University and Kingston General Hospital, 92 Barrie Street, Kingston, Ont., Canada K7L 3N6.
| | | |
Collapse
|
25
|
Erkinaro T, Kavasmaa T, Päkkilä M, Acharya G, Mäkikallio K, Alahuhta S, Räsänen J. Ephedrine and phenylephrine for the treatment of maternal hypotension in a chronic sheep model of increased placental vascular resistance †. Br J Anaesth 2006; 96:231-7. [PMID: 16377647 DOI: 10.1093/bja/aei305] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND We hypothesized that ephedrine and phenylephrine are equal with respect to uterine and placental haemodynamics and fetal acid-base status after exposure to maternal hypoxaemia and hypotension in a chronic sheep model of increased placental vascular resistance (R(UA)). METHODS At 114-135 days gestation, chronically instrumented fetal sheep underwent placental embolization leading to increased R(UA). Twenty-four hours after embolization, the ewes were anaesthetized and randomized to receive boluses of ephedrine (n=7) or phenylephrine (n=6) for epidural-induced hypotension after maternal hypoxaemia. Uterine (Q(UtA)) and placental (Q(UA)) volume blood flows and uterine vascular resistance (R(UtA)) and R(UA) were recorded. Uterine (PI(UtA)) and umbilical artery (PI(UA)) pulsatility indices were obtained by Doppler ultrasonography. Fetal arterial blood samples were analysed for acid-base values and lactate concentrations. RESULTS During hypotension, Q(UtA), fetal pH, BE, and Po(2) decreased whereas R(UtA), PI(UtA), R(UA), and fetal lactate concentration increased. With ephedrine, Q(UtA), R(UtA), PI(UtA), R(UA), and fetal Po(2) returned to baseline. Fetal pH, BE, and lactate concentration did not change from hypotensive values. With phenylephrine, Q(UtA) remained lower (P=0.007) and R(UtA) (P=0.007), PI(UtA) (P=0.013), and R(UA) (P=0.050) higher than at baseline. Fetal Po(2) returned to baseline and fetal pH and BE did not change from hypotensive values. However, fetal lactate concentration increased further (mean difference 1.49, 95% confidence interval 0.72-2.26 mmol litre(-1); P=0.004). CONCLUSIONS In a chronic sheep model of increased placental vascular resistance, compared with ephedrine administration, phenylephrine administration was associated with impaired uterine and placental haemodynamics and increased fetal lactate concentrations.
Collapse
Affiliation(s)
- T Erkinaro
- Department of Anaesthesiology and Department of Obstetrics and Gynaecology, Oulu University Hospital, PO Box 21, FIN-90029 OYS, Finland.
| | | | | | | | | | | | | |
Collapse
|
26
|
Cheung CY, Bogic L, Gagnon R, Harding R, Brace RA. Morphologic alterations in ovine placenta and fetal liver following induced severe placental insufficiency. ACTA ACUST UNITED AC 2005; 11:521-8. [PMID: 15582496 DOI: 10.1016/j.jsgi.2004.06.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Umbilical-placental embolization with microspheres has been used as a model of placental insufficiency and intrauterine growth restriction (IUGR). However, the effects of embolization on placental structure and organ morphology of the resulting IUGR fetus are relatively unexplored. In this study using ovine fetuses, we determined the location and distribution of microspheres within the placenta and explored the extent of placental and fetal organ morphologic changes induced by placental embolization. We hypothesized that microspheres administered into the umbilical circulation over 4 days would cause placental damage without significant morphologic alterations in fetal kidney or liver. METHODS Eleven pregnant sheep at 118 +/- 1 (SE) days' gestation were studied. In six fetuses, embolization was induced by injections of 15-microm diameter microspheres on 4 successive days into the fetal descending aorta proximal to the umbilical arteries. Five fetuses served as time controls. RESULTS In embolized fetuses, microspheres were detected in the placenta embedded in the fetal cytotrophoblastic layer or maternal parenchyma adjacent to villous cytotrophoblasts. Fetal cytotrophoblasts appeared normal except for loss of distinct separation between fetal and maternal cell layers. Microspheres were also detected in the fetal membranes within capillaries. The body weights of embolized fetuses were lower than controls, as were the body weight-normalized liver but not kidney weights. In the liver of the embolized fetuses, the number of hematopoietic cell clusters was markedly reduced, whereas the fetal kidneys appeared normal. CONCLUSIONS We conclude that after 4 days of umbilical-placental embolization, microspheres were concentrated at the fetal villi proximal to the apical maternal-fetal interface and in the fetal membranes. There were noticeable morphologic changes in the embolized placentas, with no apparent gross damage to the placenta. The reduction in fetal liver weight and liver extramedullary hematopoietic cell abundance associated with embolization may predispose the fetus to alterations in liver function that could persist after birth.
Collapse
Affiliation(s)
- Cecilia Y Cheung
- Division of Perinatal Medicine, Department of Reproductive Medicine, University of California at San Diego, La Jolla, California 92093-0802, USA.
| | | | | | | | | |
Collapse
|
27
|
Abstract
The aim of this paper is to review the mechanisms by which animal and human fetuses survive prolonged periods of substrate deprivation in utero. Two reasons why such information is important for those who care for growth-restricted fetuses and neonates are as follows. (1) Understanding the physiology is central to designing appropriate tests for determining fetal well-being. For instance, most currently available techniques for monitoring fetal well-being are actually better designed to detect acute than chronic fetal hypoxaemia. (2) There is increasing interest in the medium- and long-term consequences of fetal growth restriction on cardiovascular, neurological and lung function. As an example, the reasons why chronic oxygen deprivation may influence cerebral structure and function are discussed.
Collapse
Affiliation(s)
- Donald M Peebles
- Department of Obstetrics and Gynaecology, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK.
| |
Collapse
|
28
|
Li X, Tang D, Zhou S, Zhou G, Wang C, Zhuang Y, Wu G, Shen L. Redistribution of power spectrum of heart rate variability during acute umbilical artery embolism and hypoxemia in late-gestation fetal sheep. Eur J Obstet Gynecol Reprod Biol 2004; 114:137-43. [PMID: 15140505 DOI: 10.1016/j.ejogrb.2003.10.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2003] [Revised: 08/04/2003] [Accepted: 10/08/2003] [Indexed: 11/28/2022]
Abstract
OBJECTS Fetal heart rate variability (HRV) is subject to a number of factors, including fetal distress. The aim of this study was to investigate the power spectral distribution of fetal heart rate variability during acute hypoxemia following umbilical artery embolism and to test the hypothesis that the relative proportion of frequency domains in total power of HRV, reflects the changes in HRV during hypoxemia more closely than the absolute values. METHODS Acute hypoxemia was induced in seven catheterized late-gestation fetal sheep by repeated injections of microspheres to cause umbilical artery embolism. The very-low, low-, middle- and high-frequency domains (0-0.025, 0.025-0.125, 0.125-0.20, and 0.20-0.50 cycles/beat, respectively) were determined by power spectral analysis. RESULTS Umbilical artery embolism induced marked fetal hypoxemia, hypercapnia and acidosis, accompanied by an increase in heart rate and a decrease in arterial blood pressure. These changes were associated with the increase in power over the entire frequency range and in the relative power in the low-frequency range (P<0.01), and with decrease in the relative power in the high-frequency range (P<0.05). Correlations were found between the relative power in the low- and high-frequency ranges and PO2 and between the relative power in these ranges and mean arterial blood pressure (P<0.05), but not PCO2 or pH. CONCLUSIONS The present study indicates that acute hypoxemia induced by umbilical artery embolism leads to the redistribution of power spectral density of fetal HRV and that the relative proportion of individual frequency domains may reflect the changes in HRV during acute hypoxemia more closely than the absolute power values.
Collapse
Affiliation(s)
- Xiaotian Li
- The Obstetrics & Gynecology Hospital, Fudan University, 419 Fangxie Road, Shanghai 200011, China.
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Maruko K, Maeda T, Kamitomo M, Hatae M, Sueyoshi K. Transplacental transmission of maternal B-cell lymphoma. Am J Obstet Gynecol 2004; 191:380-1. [PMID: 15295401 DOI: 10.1016/j.ajog.2003.12.036] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We report a case of maternal malignant lymphoma transferred to the fetus during pregnancy. A 29-year-old woman developed lymphoma at 29 weeks' gestation, and her infant developed malignant lymphoma at 8 months. Immunohistochemical examinations revealed lymphoid cells of similar characteristics in the maternal, placental, and infant tissues.
Collapse
Affiliation(s)
- Keiko Maruko
- Department of Obstetrics and Gynecology, Kagoshima City Hospital, Kagoshima, Japan
| | | | | | | | | |
Collapse
|
30
|
Abstract
Placental insufficiency is a process leading to progressive deterioration in placental function and a decrease in transplacental transfer of oxygen and nutrients to the fetus. The resulting fetal hypoxemia is the major stimulus involved in the reduction in fetal growth as an attempt to reduce metabolic demands by the growing fetus. Fetal growth restriction (FGR) is the second cause of perinatal death after prematurity and can complicate up to 6% of all pregnancies. It is becoming apparent that its occurrence has major impacts on the fetus and placenta with consequences on the cardiovascular, metabolic and neurological development up to adulthood. We are just starting to unveil some of the basic mechanisms involved in this complex adaptation that may lead to reprogramming of fetal organs development mostly the heart, pancreas, lungs and brain. It is becoming clear that future research is needed to develop strategies to improve antenatal detection of FGR, in addition to reduce the risk of abnormal neurodevelopment during childhood, and onset of common diseases in adulthood following pregnancies complicated with placental insufficiency.
Collapse
Affiliation(s)
- Robert Gagnon
- Departments of Obstetrics, Gynecology and Physiology, University of Western Ontario, St. Joseph's Health Care London, 268 Grosvenor Street, London, Ont., Canada N6A 4V2.
| |
Collapse
|
31
|
|
32
|
Archivée: Utilisation du Doppler Fœtal en Obstétrique. JOURNAL OF OBSTETRICS AND GYNAECOLOGY CANADA 2003. [DOI: 10.1016/s1701-2163(16)31021-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
33
|
Louey S, Cock ML, Harding R. Postnatal development of arterial pressure: influence of the intrauterine environment. Arch Physiol Biochem 2003; 111:53-60. [PMID: 12715275 DOI: 10.1076/apab.111.1.53.15137] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A substantial number of epidemiological studies have shown that small size at birth is associated with an increased risk of developing hypertension and metabolic dysfunction later in life; however these associations have not been found in all studies. In animals, several models have been used to investigate the effects of perturbations to the fetal environment on later arterial pressure, with differing effects on size at birth and arterial pressure. Ovine models include maternal dietary manipulations, antenatal glucocorticoid exposure, and restriction of placental size and function. In our laboratory, we have induced late gestational placental insufficiency and growth restriction in sheep by umbilico-placental embolisation; during the early postnatal period the growth restricted lambs remained small and were hypotensive relative to controls. More recent long-term studies indicate that these growth restricted animals were able to catch up in body weight within the first postnatal year; however, their arterial pressure remained lower than that of controls throughout the first 2 postnatal years (deltaMAP, -4.2 +/- 1.4 mmHg). This relative hypotension may be due to altered vascular or cardiac development resulting from increased vascular resistance or nutrient restriction during fetal life. As late gestational placental insufficiency led to a persistent reduction in arterial pressure from birth to adulthood, our findings do not support the hypothesis that restricted fetal growth per se leads to hypertension after birth. It is likely that the effects of a prenatal compromise on postnatal arterial pressure will vary depending on the nature of the associated developmental perturbations and their gestational timing.
Collapse
Affiliation(s)
- S Louey
- Department of Physiology, Monash University, Victoria, Australia.
| | | | | |
Collapse
|
34
|
Gagnon R, Harding R, Brace RA. Amniotic fluid and fetal urinary responses to severe placental insufficiency in sheep. Am J Obstet Gynecol 2002; 186:1076-84. [PMID: 12015540 DOI: 10.1067/mob.2002.122291] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Our purpose was to test the hypothesis that severe placental insufficiency leads to reductions in fetal urine production and amniotic fluid volume in late-gestation fetal sheep. STUDY DESIGN At 0.85 of gestation, chronically catheterized fetal sheep with ligated urachus were either embolized for 5 days by repeated injection of boluses of 15-microm microspheres into the common fetal umbilical artery until fetal arterial oxygen content was reduced by 50% (n = 6) or were infused with saline solution (n = 6). Amniotic fluid volume was measured daily before embolization by means of an indicator dilution technique and by drainage at autopsy. Fetal urine production, heart rate, and mean arterial blood pressure were measured continuously for 1 hour before embolization and 1 hour after embolization each day. Fetal arterial blood gases, oxygen content, electrolytes, and osmolality were also monitored. RESULTS Five days of placental insufficiency, which reduced fetal arterial oxygen content by 50% and arrested fetal growth, resulted in a reduced amniotic fluid volume without a reduction in fetal urine production. Compared with that of controls, amniotic fluid volume was reduced over the 5-day period by 547 +/- 144 mL (-62%, P <.01). Amniotic fluid composition was also altered, with a significant increase in lactate and sodium concentrations and osmolality on days 4 to 5. On days 2 to 5, there was a progressive increase in amniotic fluid osmolality above that of controls, which paralleled the changes in amniotic fluid sodium concentration (P <.05). Fetuses became hypertensive on days 2 to 4 of embolization, although this response was attenuated by day 5. CONCLUSIONS Chronic severe placental insufficiency caused a reduction in amniotic fluid volume not attributable to reduced fetal urine production. Changes in amniotic fluid composition induced by placental insufficiency suggest an excess intramembranous absorption of amniotic fluid water, in relation to solutes, into the fetal and maternal compartments, which may lead to the development of oligohydramnios.
Collapse
Affiliation(s)
- Robert Gagnon
- Department of Obstetrics and Gynaecology, University of Western Ontario, London, Ontario, Canada
| | | | | |
Collapse
|
35
|
Sterne G, Shields LE, Dubinsky TJ. Abnormal fetal cerebral and umbilical Doppler measurements in fetuses with intrauterine growth restriction predicts the severity of perinatal morbidity. JOURNAL OF CLINICAL ULTRASOUND : JCU 2001; 29:146-151. [PMID: 11329157 DOI: 10.1002/1097-0096(200103/04)29:3<146::aid-jcu1014>3.0.co;2-i] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
PURPOSE This prospective study was performed to determine if the ratio of the middle cerebral artery (MCA) S/D ratio (ratio of peak systolic blood flow velocity to diastolic velocity) to the umbilical artery (UA) S/D ratio (MCA/UA S/D ratio) predicts the degree of neonatal morbidity in fetuses suspected of having intrauterine growth restriction (IUGR). METHODS Sixty-one fetuses were identified prospectively by sonography as having an estimated fetal weight below the 10th percentile for gestational age. The 61 fetuses underwent Doppler sonography in the third trimester and then were stratified into 3 groups based on the MCA/UA S/D ratio: group A, MCA/UA S/D ratio > 1.0 (controls; n = 37); group B, MCA/UA S/D ratio < or = 1.0 (intracerebral blood flow redistribution; n = 16); and group C, reversed or absent UA diastolic flow (n = 8). Outcome variables assessed included gestational age at delivery, birth weight, UA pH, mode of delivery, respiratory distress syndrome requiring intubation, and intracranial hemorrhage. RESULTS The mean MCA/UA S/D ratios in groups A and B were 1.69 + /- 0.61 and 0.59 + /- 0.24, respectively (p < 0.01). The mean gestational ages at delivery for groups A, B, and C were 34.7, 33.2, and 29.0 weeks, respectively. The mean birth weights were below the fifth percentile for age for groups B and C and significantly related to the severity of abnormal Doppler findings (p < 0.01) after correction for age. Mean UA pHs were 7.25 + /- 0.01, 7.19 + /- 0.01, and 7.14 + /- 0.13 for groups A, B, and C, respectively, with significant differences between groups A and B (p < 0.05) and groups A and C (p < 0.05). Respiratory distress syndrome and intracranial hemorrhage were not associated with abnormal Doppler findings after correction for gestational age. The interval between the abnormal Doppler examination and delivery (p < 0.001) and the occurrence of fetal distress requiring cesarean section (p < 0.001) were significantly related to the severity of Doppler findings. CONCLUSIONS In fetuses with suspected IUGR, abnormal MCA/UA S/D ratios are strongly associated with low gestational age at delivery, low birth weight, and low UA pH. Abnormal MCA/UA S/D ratios are also significantly associated with shorter interval to delivery and the need for emergent delivery.
Collapse
Affiliation(s)
- G Sterne
- Department of Radiology, Virginia Mason Medical Center, 1100 Ninth Avenue, Seattle, Washington 9810, USA
| | | | | |
Collapse
|
36
|
Cock ML, Albuquerque CA, Joyce BJ, Hooper SB, Harding R. Effects of intrauterine growth restriction on lung liquid dynamics and lung development in fetal sheep. Am J Obstet Gynecol 2001; 184:209-16. [PMID: 11174504 DOI: 10.1067/mob.2001.108858] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The aim of this study was to determine the effects of intrauterine growth restriction on fetal lung liquid and lung development. STUDY DESIGN Intrauterine growth restriction was induced in 7 fetal sheep from 120 to 140 days' gestation (term, approximately 147 days' gestation) by umbilicoplacental embolization. We used 6 control fetuses. Volumes and production rates of fetal lung liquid were measured, and lungs were removed post mortem (140 days' gestation) for analysis of concentrations of deoxyribonucleic acid, protein, and messenger ribonucleic acid for surfactant proteins A, B, and C. RESULTS Umbilicoplacental embolization induced fetal hypoxemia, hypoglycemia, and intrauterine growth restriction. At 140 days' gestation lung weight was reduced by 34%, and the fetal lung liquid production rate (15.9 +/- 1.8 mL/h for intrauterine growth restriction vs 24.8 +/- 3.9 mL/h for control) and volume (110.9 +/- 16.3 mL for intrauterine growth restriction vs 178.1 +/- 11.9 mL for control) were reduced in the intrauterine growth restriction group. After adjustment for body weight, however, values were not different from those in the control group. Pulmonary deoxyribonucleic acid and plasma cortisol concentrations were elevated by intrauterine growth restriction, but levels of messenger ribonucleic acid for surfactant proteins were unchanged. CONCLUSION In intrauterine growth restriction, lung liquid and lung growth were proportionate to body weight, and surfactant protein expression was unaffected. Alterations in lung deoxyribonucleic acid concentrations suggest that the lungs may be structurally immature.
Collapse
Affiliation(s)
- M L Cock
- Fetal and Neonatal Research Group, Department of Physiology, Monash University, Clayton, Victoria, Australia
| | | | | | | | | |
Collapse
|
37
|
Harding R, Cock ML, Louey S, Joyce BJ, Davey MG, Albuquerque CA, Hooper SB, Maritz GS. The compromised intra-uterine environment: implications for future lung health. Clin Exp Pharmacol Physiol 2000; 27:965-74. [PMID: 11117232 DOI: 10.1046/j.1440-1681.2000.03379.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. Epidemiological studies of infants, children and adults indicate that prenatal compromises that restrict fetal growth and cause low birthweight increase the risk of respiratory deficiencies after birth. 2. It is apparent that the lung has a limited ability to recover from early developmental compromises and that altered development can permanently impair lung architecture. 3. Lung development in utero can be adversely affected by factors associated with fetal growth restriction, namely fetal hypoxaemia, reduced substrate supply and hypercortisolaemia. 4. We have conducted a series of studies of respiratory development in chronically catheterized ovine fetuses and postnatal lambs in which growth restriction was induced during late gestation by embolizing the umbilico-placental vascular bed, a technique that replicates key aspects of human placental insufficiency. 5. During late gestation, restricting the growth of the ovine fetus did not alter lung weight or lung liquid secretion or volume when each factor was related to bodyweight, but it did lead to increased lung DNA concentrations and an increased thickness of the air-blood barrier. Expression of pulmonary surfactant proteins A, B and C were not altered and, hence, it was unlikely that surfactant protein synthesis had been impaired by growth restriction. 6. When growth restriction continued to term, lambs were born with a low birthweight and remained small compared with controls for 8 weeks after birth. Low-birthweight lambs were mildy hypoxaemic and compliances of their lungs and chest wall were, respectively, decreased and increased relative to controls. Pulmonary surfactant proteins A, B and C were not deficient, indicating that decreased lung compliance most likely had a structural basis.
Collapse
Affiliation(s)
- R Harding
- Department of Physiology, Monash University, Clayton, Victoria, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Westgate JA, Bennet L, Gunn AJ. Fetal heart rate variability changes during brief repeated umbilical cord occlusion in near term fetal sheep. BRITISH JOURNAL OF OBSTETRICS AND GYNAECOLOGY 1999; 106:664-71. [PMID: 10428522 DOI: 10.1111/j.1471-0528.1999.tb08365.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To determine whether changes in fetal heart rate variation during repeated umbilical cord occlusions reflect evolving cardiovascular compromise in near term fetal sheep. DESIGN Fetal heart rate variation, fetal mean arterial pressure, electroencephalogram (EEG) and acid-base status were measured during one minute umbilical cord occlusions, repeated either every five minutes (1:5 group) or every 2.5 minutes (1:2.5 group) for four hours or until mean arterial pressure fell below 20 mmHg for two successive occlusions. SAMPLE Fourteen chronically instrumented fetal sheep, mean gestation 126.3 (2.6) days. RESULTS Cord occlusion caused variable decelerations with initial sustained hypertension. In the 1:5 occlusion group mean arterial pressure remained elevated throughout, with little change in acid-base status (pH = 7.34 (0.07), base deficit = 1.3 (3.9) after 4 hours) and no significant change in fetal heart rate variation. In contrast, in the 1:2.5 group from the third occlusion there was progressive hypotension during occlusions, severe progressive metabolic acidaemia (pH 6.92 (0.1), base deficit 17.0 mmol/L (4.7) after the last occlusion) and marked EEG suppression (P < 0.01). Fetal heart rate variation increased with the onset of occlusions (P < 0.05) and then progressively fell with continued occlusions. During the last 30 minutes of occlusions, fetal heart rate variation was severely suppressed in four, but increased in two fetuses, while all six fetuses developed overshoot-instability of fetal heart rate and mean arterial pressure following each occlusion. CONCLUSIONS Acute progressive asphyxia was typically associated with an immediate, transient increase in fetal heart rate variation. Subsequently variation became suppressed in only two-thirds of fetuses during terminal acidaemia and hypotension. Fetal heart rate overshoot-instability may be a useful marker of fetal decompensation following variable decelerations.
Collapse
Affiliation(s)
- J A Westgate
- Department of Obstetrics and Gynaecology, School of Medicine, University of Auckland, New Zealand
| | | | | |
Collapse
|
39
|
Kingdom JC, Hayes M, McQueen J, Howatson AG, Lindop GB. Intrauterine growth restriction is associated with persistent juxtamedullary expression of renin in the fetal kidney. Kidney Int 1999; 55:424-9. [PMID: 9987067 DOI: 10.1046/j.1523-1755.1999.00295.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Intrauterine growth restriction (IUGR) has been linked to impaired renal function and hypertension, suggesting that an adverse prenatal environment could alter kidney development and renin production. METHODS Immunohistochemistry and in situ hybridization were employed to localize renin-containing cells (RCCs) in the deep, middle, and superficial zones of autopsy kidney sections, in parallel with histologic maturation, from unexplained stillborn fetuses of normal weight (N = 26) and stillborn fetuses with IUGR (N = 17). RESULTS In the control group, the number of RCC per 100 glomeruli in the deep zone decreased with advancing gestation from 40 at 20 weeks gestation to five at term (P < 0.001), whereas the opposite change was found in the superficial zone (increase from 5 per 100 to 55 per 100; P < 0.001). In the IUGR group, the density of RCCs in both the superficial and deep zones was similar to the control group at 20 weeks, and no shift in renin gene expression was observed as gestation advanced. Histologic maturation was unaltered. CONCLUSIONS Renin gene expression persists and predominates in the deep renal cortex of the stillborn IUGR fetus, and could contribute to the pathogenesis of neonatal oliguria and/or hypertension during postnatal life.
Collapse
Affiliation(s)
- J C Kingdom
- Department of Obstetrics and Gynaecology, University College London, England
| | | | | | | | | |
Collapse
|
40
|
Ott WJ, Mora G, Arias F, Sunderji S, Sheldon G. Comparison of the modified biophysical profile to a "new" biophysical profile incorporating the middle cerebral artery to umbilical artery velocity flow systolic/diastolic ratio. Am J Obstet Gynecol 1998; 178:1346-53. [PMID: 9662321 DOI: 10.1016/s0002-9378(98)70342-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVES The objective of this study was to determine whether the addition of the middle cerebral to umbilical artery systolic/diastolic velocity waveform ratio to the modified biophysical profile would improve perinatal outcome in patients at high risk. STUDY DESIGN A prospective, randomized outcome study of patients referred to the perinatal laboratory for antenatal surveillance was undertaken. Six hundred sixty-five patients were randomized to two antenatal surveillance protocols: group 1, modified biophysical profile; and group 2, modified biophysical profile plus evaluation of the middle cerebral artery to umbilical artery systolic/diastolic ratio. Patients were followed up serially and neonatal outcome data including gestational age at delivery, birth weight, incidence of cesarean section delivery for fetal distress, admission to the neonatal intensive care unit, days in the neonatal intensive care unit, and the presence of significant neonatal morbidity were tabulated. RESULTS The total population showed no statistical difference in outcome parameters between groups 1 and 2. However, a subgroup of patients evaluated for suspected uteroplacental insufficiency did show a significant reduction in caesarean section for fetal distress in group 2 patients. CONCLUSIONS In a subgroup of patients at risk for uteroplacental insufficiency, the addition of the middle cerebral/umbilical artery ratio to an antenatal surveillance protocol should be expected to improve perinatal outcome.
Collapse
Affiliation(s)
- W J Ott
- Department of Obstetrics and Gynecology, St. John's Mercy Medical Center, St. Louis, Missouri, USA
| | | | | | | | | |
Collapse
|
41
|
Gagnon R, Lamb T, Richardson B. Cerebral circulatory responses of near-term ovine fetuses during sustained fetal placental embolization. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:H2001-8. [PMID: 9362272 DOI: 10.1152/ajpheart.1997.273.4.h2001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To test the hypothesis that, in response to an increase in placental vascular resistance and progressive fetal asphyxia, the changes in external carotid blood flow waveforms are directly related to changes in external carotid vascular resistance, we embolized the fetal side of the placenta in pregnant sheep and measured cerebral and external carotid artery circulatory changes in relation to changes in external carotid artery flow waveforms. Chronically catheterized fetal sheep at 0.85 of gestation were embolized (n = 11) in the descending aorta for 6 h, until fetal arterial pH fell to approximately 6.90. Fetuses became rapidly hypoxemic (P < 0.0001) and developed a mixed respiratory and metabolic acidosis (P < 0.0001 for PCO2, pH, and base excess). There was a transient 40% increase in external carotid blood flow at pH approximately 7.25 and a parallel 32% increase in fetal arterial blood pressure (both (P < 0.01), whereas the external vascular resistance remained unaltered. Cerebral blood flow increased by 130% (P < 0.0001), and cerebral vascular resistance decreased by 125% (P < 0.0001) throughout the study. The external carotid resistance index (RI) decreased by 32% (P < 0.0001) at the time external carotid vascular resistance remained unchanged. This fall in external carotid RI was due almost entirely to a 110% increase in external carotid fundamental impedance (P < 0.001). We conclude that the poor relationship between the changes in external carotid vascular resistance and RI indicated that other hemodynamic factors such as vascular impedance to pulsatile flow must be measured for correct interpretation of changes in flow waveform shape under hypoxic conditions. In addition, changes in external carotid blood flow were not proportional to changes in cerebral blood flow in this model.
Collapse
Affiliation(s)
- R Gagnon
- Department of Obstetrics and Gynaecology, The Lawson Research Institute, The University of Western Ontario, London, Canada
| | | | | |
Collapse
|
42
|
Gagnon R, Murotsuki J, Challis JR, Fraher L, Richardson BS. Fetal sheep endocrine responses to sustained hypoxemic stress after chronic fetal placental embolization. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 272:E817-23. [PMID: 9176181 DOI: 10.1152/ajpendo.1997.272.5.e817] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The purpose of this study was to determine the endocrine and circulatory responses of the ovine fetus, near term, to sustained hypoxemic stress superimposed on chronic hypoxemia. Fetal sheep were chronically embolized (n = 7) for 10 days between 0.84 and 0.91 of gestation via the descending aorta until arterial oxygen content was decreased by approximately 30%. Control animals (n = 8) received saline only. On experimental day 10, both groups were embolized over a 6-h period until fetal arterial pH decreased to approximately 7.00. Regional distribution of lower body blood flows was measured on day 10, before and at the end of acute embolization. On day 10, the chronically embolized group had lower arterial oxygen content (P < 0.05), Po2 (P < 0.01), and placental blood flow (P < 0.05) than controls and higher prostaglandin E2 (PGE2) and norepinephrine plasma concentrations (both P < 0.05). In response to a superimposed sustained hypoxemic stress, there was a twofold greater increase in PGE2 in the chronically embolized group than in the control group (P < 0.05). However, the increase in fetal plasma cortisol in response to superimposed hypoxemic stress was similar in both groups, despite significantly lower adrenocorticotropic hormone and adrenal cortex blood flow responses in the chronically hypoxemic group (both P < 0.05). We conclude that PGE2 response to a sustained superimposed reduction in placental blood flow, leading to metabolic acidosis, is enhanced under conditions of chronic hypoxemia and may play an important role for the maintenance of the fetal cortisol response to an episode of superimposed acute stress.
Collapse
Affiliation(s)
- R Gagnon
- Department of Obstetrics and Gynaecology, University of Western Ontario, London, Canada
| | | | | | | | | |
Collapse
|
43
|
Murotsuki J, Bocking AD, Gagnon R. Fetal heart rate patterns in growth-restricted fetal sheep induced by chronic fetal placental embolization. Am J Obstet Gynecol 1997; 176:282-90. [PMID: 9065169 DOI: 10.1016/s0002-9378(97)70486-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Our purpose was to test the hypothesis that chronic placental insufficiency and intrauterine growth restriction in fetal sheep causes a decrease in the number of fetal heart rate accelerations and fetal heart rate variability. STUDY DESIGN Chronically catheterized fetal sheep were embolized (n = 6) daily with 15 to 50 microns latex microspheres for 21 days between 0.74 and 0.88 of gestation into the abdominal aorta, until fetal arterial oxygen content was decreased by 40% to 50% of the preembolization value. Control animals (n = 6) received saline solution only. Signals from chest electrodes were analyzed on-line with the Sonicaid System 8000 in 2-hour epochs every 6 hours starting at 8 AM over the first 48 hours of hypoxemia and for 2 hours between 8 and 10 AM every other day from day 3 to day 21 of hypoxemia. Umbilical artery Doppler-derived resistance index and fetal plasma catecholamine concentrations were also measured. RESULTS Embolized fetuses had asymmetric intrauterine growth restriction and became chronically hypoxemic (p < 0.001) with a progressive increase in the umbilical artery resistance index (p < 0.001). During the first 48 hours of hypoxemia the number of accelerations and decelerations and both short- and long-term fetal heart rate variability increased initially, followed by a return to control levels by 20 hours after the onset of embolization. After 21 days of hypoxemia the number of accelerations was significantly reduced by 30% compared with controls (p < 0.05). Both short- and long-term fetal heart rate variability in control fetuses gradually increased with advancing gestational age (p < 0.001 and p < 0.01, respectively), whereas in embolized fetuses the fetal heart rate variability remained unchanged and was 20% lower than that of controls on day 21 (both p < 0.01). CONCLUSION Intrauterine growth restriction and long-term hypoxemia in fetal sheep are associated with a decrease in short- and long-term fetal heart rate variability, possibly because of a delay in the normal maturational changes of the autonomic control of fetal heart rate.
Collapse
Affiliation(s)
- J Murotsuki
- Department of Obstetrics and Gynaecology, University of Western Ontario, St. Joseph's Health Centre, Lawson Research Institute, London, Ontario, Canada
| | | | | |
Collapse
|