To analyze the effect of hypoxaemia on heart rate variability (HRV) in fetal lambs by means of power spectrum, the intrauterine surgical operations were performed at 116-125 gestational days in 7 lambs. Arterial catheter was inserted in the fetal femoral artery and sent to aorta abdominalis, and blood pressure was recorded continually on tape recorder. The microspheres were injected via the arterial catheter to block the micrangium of placenta, thus making an animal model of fetal hypoxaemia. The fetal blood sample was drawn through the catheter for blood gas analysis. In terms of the heart beat variability power spectral density, there were four consistent components, namely very low (VL, 0.01-0.025 cycle/beat), low (L, 0.025-0.125 cycle/beat), middle (M, 0.125-0.2 cycle/beat), and high (H, 0.2-0.5 cycle/beat). Integrated peaks in the power spectrum were compared before and after administration of microsphere. The spectral power in the L frequency components was significantly increased (0.07 +/- 0.01 vs. 0.21 +/- 0.03, P<0.01), and the spectral power in the H frequency components was significantly reduced (0.53 +/- 0.1 vs. 0.27 +/- 0.05, P<0.05). There was no significant difference in M and VL. The times of microsphere injection were related to fetal blood pH (r=0.585, p<0.01), PCO2 (r=0.5, p<0.05) and PO2 (r=0.75, P<0.01). The results clearly demonstrate the association between change of power spectrum of heart rate variability and the effect of hypoxia of the fetus in labour.
Animals ; Blood Gas Analysis ; Female ; Fetal Blood ; Fetal Hypoxia ; physiopathology ; Fetal Monitoring ; Heart Rate, Fetal ; physiology ; Pregnancy ; Sheep

PURPOSE: Prolonged fetal hypoxia stimulates erythropoiesis in fetal life and induces increased nucleated erythrocytes(NRBC) counts at the early newborn period. To evaluate the relationship between prolonged fetal hypoxia and neonatal intraventricular hemorrhage (IVH), and the prediction of neonatal IVH by neonatal NRBC. METHODS: We compared the daily courses of the absolute NRBC count in preterm new- boms at 34 weeks' gestation or earlier with(n=17) and without(n=20) IVH for 7 days of life. RESULTS: Absolute NRBC counts at birth were higher in neonates with IVH than in control neonates(2,499/mm3+/-3,748 and 412/mm3+/-272, respectively, P=0.0022). The cut-off value of 1,000/mm3 for absolute NRBC counts at birth showed the best parameter estimate of the predictive model for IVH at early newborn period with 100% of positive predictive value and 74.1% of negative predictive value. CONCLUSION: Prolonged fetal hypoxia inducing fetal erythropoiesis near labor is closely related to IVH at early newborn period. Thabsolute NRBC counts at birth is the very important predictable marker for the condition.
Erythroblasts* ; Erythropoiesis ; Fetal Hypoxia ; Hemorrhage* ; Humans ; Infant, Newborn* ; Parturition ; Pregnancy

INTRODUCTIONIntrapartum fetal monitoring is essential for the identification of fetal hypoxia to reduce perinatal morbidity and mortality. Cardiotocography is associated with low specificity for fetal acidosis and poor perinatal outcome leading to unnecessary operative deliveries. ST waveform analysis of the fetal electrocardiogram has been shown to be a promising adjunctive intrapartum assessment tool. We aim to present the pathophysiology, the role of intrapartum monitoring and the practical usage of this relatively new technology in our review.

METHODSAn electronic search of Medline and OVID was carried out, followed by a manual search of the references identified by the electronic search.

RESULTSThe incorporation of ST waveform analysis to cardiotocography has been shown to reduce the rates of neonatal metabolic acidosis, moderate and severe neonatal encephalopathy, thus improving perinatal outcome. The reduction in operative delivery rates due to fetal distress is also significant. The pathophysiology and practical usage of this technology were discussed.

CONCLUSIONSWith more accurate identification of fetal hypoxia and reduction of unnecessary intervention rates, incorporation of ST waveform analysis of fetal electrocardiography into cardiotocography can improve the standard of intrapartum fetal monitoring.

Electrocardiography ; utilization ; Female ; Fetal Hypoxia ; diagnosis ; Fetal Monitoring ; instrumentation ; methods ; Humans ; Pregnancy ; Singapore

OBJECTIVE: To investigate the relationship between umbilical plasma erythropoietin(epo) concentrations and umbilical cord pH in high risk pregnancies. METHODS: We measured epo concentrations and gas in 103 cases of cord blood obtained from 88 cesarean section (15 of twin) composed of 39 cases of normal control (12 of normal twins), 45 cases of high risk pregnancies and 4 cases of unclassified group using an RIA kit from december,1998 to December, 1999. Statistical analysis was performed using the student's t test and regression analysis. P values less than 0.05 were considered statistically significant. RESULTS: Umbilcal plasma epo concentrations revealed significant inverse correlation (P<0.05) with umbilical acidosis and cord blood epo levels, and it were significantly higher in GDM and IUGR than normal pregnancies (control: 1.60 1.15, n=39 versus GDM: 7.78 7.18, n=11 versus IUGR: 64.77 90.57 n=10, p<0.05), but 11 cases of fetal distress and 13 cases of preeclampsia did not differ significantly from umbilical plasma epo of normal control. CONCLUSIONS: Elevated epo concentrations in cord blood indicate fetal hypoxia and It is significantly increased in IUGR and GDM, these findings show that cord blood epo may serve as a clinically useful marker for chronic fetal hypoxia.
Acidosis ; Cesarean Section ; Erythropoietin* ; Female ; Fetal Blood* ; Fetal Distress ; Fetal Growth Retardation ; Fetal Hypoxia ; Hydrogen-Ion Concentration ; Plasma ; Pre-Eclampsia ; Pregnancy* ; Umbilical Cord

The vasculosyncytial membrane (VSM), primary site of fetomaternal exchange is formed when syncytiotrophoblast surrounds the terminal villi and make a close contact with capillaries. Some syncytiotrophoblast forms thin single layer of villous and some syncytial nuclei become piled up to form the syncytial knots (SKs). Undoubtedly there is a clear-cut inverse relation between villous VSM and fetal hypoxia. In preeclampsia (PE) the hypoxia injury disrupts the syncytial architecture which in turn initiates other complications of PE. Present study was designed to observe the morphological and histomorphometric features of 84 placentas from control and PE (42 each) collected from Department of Obstetrics and Gynecology. Neonatal weight and placental weight were reduced in PE than the controls but the feto-placental index did not differ. The SK density and VSM thickness was found to be increased and was statistically significant in PE cases. In relation to SKs, the VSM thickness was twofold increased than the controls and was statistically significant. The SKs in the present study were classified as type-1, 2a, 2b, and 3. Type 1 was found to be 62% in control and 47% in PE, type 2a and 2b were 38% in control and 37% in PE, and type 3 was in 8% of PE cases. All the parameters of present study reveal the adverse effects of PE influencing on both morphological and microscopical features of the placenta resulting in fetal hypoxia.
Anoxia ; Capillaries ; Fetal Hypoxia ; Gynecology ; Membranes ; Obstetrics ; Placenta ; Pre-Eclampsia ; Trophoblasts

The vasculosyncytial membrane (VSM), primary site of fetomaternal exchange is formed when syncytiotrophoblast surrounds the terminal villi and make a close contact with capillaries. Some syncytiotrophoblast forms thin single layer of villous and some syncytial nuclei become piled up to form the syncytial knots (SKs). Undoubtedly there is a clear-cut inverse relation between villous VSM and fetal hypoxia. In preeclampsia (PE) the hypoxia injury disrupts the syncytial architecture which in turn initiates other complications of PE. Present study was designed to observe the morphological and histomorphometric features of 84 placentas from control and PE (42 each) collected from Department of Obstetrics and Gynecology. Neonatal weight and placental weight were reduced in PE than the controls but the feto-placental index did not differ. The SK density and VSM thickness was found to be increased and was statistically significant in PE cases. In relation to SKs, the VSM thickness was twofold increased than the controls and was statistically significant. The SKs in the present study were classified as type-1, 2a, 2b, and 3. Type 1 was found to be 62% in control and 47% in PE, type 2a and 2b were 38% in control and 37% in PE, and type 3 was in 8% of PE cases. All the parameters of present study reveal the adverse effects of PE influencing on both morphological and microscopical features of the placenta resulting in fetal hypoxia.
Anoxia ; Capillaries ; Fetal Hypoxia ; Gynecology ; Membranes ; Obstetrics ; Placenta ; Pre-Eclampsia ; Trophoblasts

Aspiration of amniotic fluid, whether being meconium-stained or not, can cause a respiratory distress in neonates. This disorder may result in fatal consequence including unexpected death. Fetal hypoxia stimulates fetal gasping respiration, which can provoke massive amniotic fluid aspiration. A new born male-baby was found dead on the next day after vaginal delivery, and according to the statement of care-giver there was no serious event to the baby except for poor feeding. The diagnosis of amniotic fluid aspiration was confirmed at autopsy. The authors present the autopsy findings, clinical features and courses, failing medicolegal system and medical negligence, with literature review.
Amniotic Fluid ; Autopsy ; Female ; Fetal Hypoxia ; Humans ; Infant, Newborn ; Malpractice ; Respiration

OBJECTIVE: To examine the relationship of the amniotic, and maternal infiammatory responses and decreased amniotic fluid in patients with preterm PROM. METHODS: Fifty three patients with preterm PROM in singleton pregnancy who delivered preterm neonates (gestational age<35 weeks) within 3 days of amniocentesis were included. Amniotic fluid index(AFI) was measured by transabdominal ultrasonography at amniocentesis. Amniotic fluid was cultured far aerobic and anaerobic bacteria and mycoplasma. The intensity of the inflammatory response was evaluated by clinical and histologic chorioamnionitis. The intensity of fetal hypoxia was evaluated by 1 min Apgar score, 5 min Apgar score, and pH of cord blood at birth. RESULTS: The prevalence of oligohydramnios, which was defined when measured AFI was equal or less than 5.0, was 34% (18/53). The prevalence of positive amniotic fluid culture was 45% (24/53) and that of patients with was significantly higher than that of patients without oligohydramnios (78% [14/l8] vs 29% [10/35], p<0.01). Intrauterine inflammatory response was significantly stronger in patients with oligohydratnnios than in patients with adequate amniotic fluid (pathologic chorioamnionitis 100% [l6/16] vs 63% [19/30], clinical chorioamnionitis 39% [7/18] vs 6% [2/35]; p<0.01 for each). However, no significant difference was found in the intensity of fetal hypoxia (I min Apgar score <7 67% [12/18] vs 66% [23/35], 5 min Apgar score <7 39% [7/l8] vs 26% [9/35], pH of cord artery blood at birth 7.27+0.13 vs 7.22+0.13; p>O.I, for each). CONCLUSION: Oligohydramnios in patients with preterm PROM is strongly pedictive for positive amniotic fluid culture, and is associated with a robust host response in amniotic, and maternal cornpartments, but not with fetal hypoxia.
Amniocentesis ; Amniotic Fluid ; Apgar Score ; Arteries ; Bacteria, Anaerobic ; Chorioamnionitis ; Female ; Fetal Blood ; Fetal Hypoxia* ; Humans ; Hydrogen-Ion Concentration ; Infant, Newborn ; Mycoplasma ; Oligohydramnios* ; Parturition ; Pregnancy ; Prevalence ; Ultrasonography

Perinatal asphyxia can cause ischemic injury to immature kidney of neonates. Proximal renal tubule is the most sensitive area, showing various manifestations ranging from mild reversible injury to irreversible tubular necrosis. Aminoglycosides can be nephrotoxic in therapeutic range in immature or damaged kidney. Thess are the very important factors to be taken into corsideration on fluid therapy and nephrotoxic drugs in neonates. The purpose of this study is to detect renal dysfunction resulting from asphyxia and gentamicin treatment. The results were as follows; 1) Urinary 2-microglobulin concentration was significantly higher in neonatal asphyxia group irrespective of meconium stain (p<0.05). The group with neonatal asphyxia only (Ia) showed a gradual decline in urinary 2-microglobulin concentration and no significant difference shown when compared with control group on 7 days old (p>0.05). The group with neonatal asphyxia and meconium stain (Ib) received gentamicin for 7 days. Their urinary 2-microglobulin concentration dropped on 4 the day and increased again on 7 th day (p<0.05). The group with meconium stain only(3) showed no significant difference in urinary 2-microglobulin concentration when compared with control group (p>0.05). 2) No differences were shown in serum creatinine, serum sodium level and urinary creatinine concentrations between each group (p>0.05). 3) No differences were shown in creatinine clearance between each group (p>0.05).Fractional excretion of urinary sodium (FENa) was significantly higher on lst day in group, I, but no differences were shown afterwards (p>0.05). 4) There is no relationship between urinary 2-microglobulin concentration and serum creatinine level, creatinine clearance of FENa. 5) No differences were shown in incidence of renal dysfunction between each group. In conclusion, acute tubular injury by perinatal asphyxia recovered soon after birth. But nephrotoxic gentamicin worsened the recovering tubular injury. In case of mild fetal hypoxia without neonatal asphyxia, proximal tubular injury was not significant.
Aminoglycosides ; Asphyxia* ; Creatinine ; Fetal Hypoxia ; Fluid Therapy ; Gentamicins* ; Humans ; Incidence ; Infant, Newborn* ; Kidney ; Kidney Tubules, Proximal ; Meconium ; Necrosis ; Parturition ; Sodium

BACKGROUND: The aim of the present study was to investigate the changes in the patterns of power spectrum of R-R interval variability on fetal lamb EKG during acute fetal hypoxia. METHODS: Acutely instrumented six fetal lambs during the third trimester of gestation(115 to 145 days) was subjected to reproducible hypoxia by reduction of maternal placental blood flow with complete obstruction of maternal abdominal aorta for 60 seconds. RESULTS: Power spectral density of low, middle and high frequency increased significantly on hypoxia compared to that of baseline state. Power density of high frequency was significantly higher than that of low and middle frequency in baseline state. And the power density of low and high frequency was significantly higher than that of middle frequency in hypoxic state and 1 minute of recovery. CONCLUSIONS: The conclusion is that an increase in power density of low frequency during hypoxia suggested increased sympathetic activity and increased power density of high frequency throughout the experimental procedures suggested active respiratory movements of fetal lambs close to term and increased parasympathetic activity, reflecting rapidly the autonomic nervous system changes of the fetal lambs.
Anoxia* ; Aorta, Abdominal ; Autonomic Nervous System ; Electrocardiography ; Female ; Fetal Hypoxia ; Heart Rate* ; Heart* ; Humans ; Pregnancy ; Pregnancy Trimester, Third