Prelabor screening for intrapartum fetal compromise in low-risk pregnancies at term: cerebroplacental ratio and placental growth factor

OBJECTIVES

To determine the screening performance of low fetal cerebroplacental ratio (CPR), a marker of fetal adaptation to suboptimal growth, and maternal placental growth factor (PlGF) level, both in isolation and in combination, for the prediction of Cesarean section (CS) for intrapartum fetal compromise (IFC) and composite adverse neonatal outcome (CANO).

METHODS

This was a prospective cohort study in low-risk women with uncomplicated singleton pregnancy from 36 weeks' gestation to delivery. CPR and PlGF were assessed fortnightly and intrapartum and neonatal outcomes were recorded. CPR and PlGF values from the final assessment for each woman were corrected for gestational age and assessed for screening performance, firstly as continuous variables and then as binary predictors.

RESULTS

Of the 264 women who consented to participate in the study, 207 were included in the final analysis. Seven pregnancies required CS for IFC and 38 had CANO. Pregnancies delivered by CS for IFC had lower CPR and PlGF centiles than those in all other pregnancies. Pregnancies with CANO had a lower PlGF centile. The greatest areas under the receiver-operating characteristics curves (AUCs) for the prediction of CS for IFC (0.92; 95% CI, 0.86-0.97) and CANO (0.64; 95% CI, 0.54-0.74) were achieved by a combination of CPR 20^th and PlGF 33^rd centile thresholds. This produced sensitivities, specificities and positive likelihood ratios for the prediction of CS for IFC of 100%, 86% and 7.14, respectively, and 34.2%, 87.0% and 2.63, respectively, for the prediction of CANO. There was no statistical difference in the AUC for CS for IFC between the combined model and when CPR was used alone, or for CANO between the combined model and CPR or PlGF in isolation.

CONCLUSIONS

This pilot proof-of-concept study describes the screening performance of CPR and maternal PlGF level for CS for IFC in low-risk women from 36 weeks' gestation. It was found that CPR and maternal PlGF improved the overall predictive utility for CS for IFC, as well as that for CANO. However, given the lack of significant difference between the combined model and its individual components, it is debatable whether the combined model is a superior screening test. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Infant outcome at four years of age after intrapartum sampling of scalp blood lactate for fetal assessment. A cohort study

OBJECTIVE

To correlate the value of lactate in fetal scalp blood at delivery and the outcomes of the offspring at four years of age.

METHODS

Cases where scalp blood lactate was taken within sixty minutes before delivery were identified from the randomized trial "Determination of pH or lactate in fetal scalp blood in management of intrapartum fetal distress". Data were grouped according to the generally accepted cutoffs for normality, pre-acidemia, acidemia and concentrations above mean +2 SD during the second stage. The outcome measures included gross-/fine motor function, vision, hearing, speaking and cognitive disorders, signs of central motor damage and referral to specialized pediatric services.

RESULTS

307 cases were available for final analyse. With normal scalp lactate concentration, the number of children with a diagnosed disorder was lower compared to the pre-acidemic/acidemic groups, although the findings were only significant for fine motor dysfunction (p = 0.036). Elevated lactate values were significantly associated with increased risk for a poorer capacity of attention and understanding of instructions (OR 1.37, 95% CI 1.07-1.74), and for fine motor dysfunction (OR 1.22, 95% CI 1.00-1.49) at the age of four.

CONCLUSION

Higher levels of lactate in fetal scalp blood seems to be associated with increased risk of an aberrant developmental outcome at four years of age in some areas.

Physiology of Alpha-Fetoprotein as a Biomarker for Perinatal Distress: Relevance to Adverse Pregnancy Outcome

The many physiologic roles of human alpha-fetoprotein (HAFP) and its correlation with perinatal distress/pregnancy outcome are rarely addressed together in the biomedical literature, even though HAFP has long been used as a biomarker for fetal birth defects. Although the well being of the fetus can be monitored by the measurement of gestational age–dependent HAFP in biologic fluid levels (serum, amniotic fluid, urine, and vaginal fluids) throughout pregnancy, the majority of clinical reports reflect largely second trimester and (less likely) first trimester testing due to regulatory clinical restrictions. However, reports of third-trimester and pregnancy term measurement of HAFP levels performed in clinical research and/or investigational settings have gradually increased over the years and have expanded our base knowledge of AFP-associated pregnancy disorders during these stages. The different structural forms of HAFP (isoforms, epitopes, molecular variants, etc.) detected in the various biologic fluid compartments have been limited by antibody recognition of specific epitopic sites developed by the kit manufacturers based on antibody specificity, sensitivity, and precision. Concomitantly, the advances in elucidating the various biologic actions of AFP are opening new vistas toward understanding the physiologic roles of AFP during pregnancy. The present review surveys HAFP as a biomarker for fetal distress during the perinatal period in view of its structural and functional properties. An attempt is then made to relate the AFP fluid levels to adverse pregnancy complications and outcomes. Hence, the present review was divided into two major sections: (I) AFP structure and function considerations and (II) the relationship of AFP levels to the distressed fetus during the third trimester and at term.

Hypoxia index in the prediction of abnormal CTG at delivery in uncomplicated pregnancies

OBJECTIVES

The evaluation of hypoxia index (HI) in the prediction of abnormal fetal heart rate at delivery in uncomplicated pregnancies.

MATERIAL AND METHODS

The study group included 148 pregnant patients at term (69 patients with and 79 without brain sparing effect). The value of C/U ratio and HI was determined. Next, its value in predicting abnormal fetal heart rate during labor was evaluated. Then the predictive value of the HI index, C/U and last abnormal values of PI and RI in the MCA and the UA were compared in relation to the analyzed parameters. Evaluation included signs of fetal distress in CTG and abnormal fetal outcome. Then selected parameters, characterizing pregnancy course and fetal outcome with abnormal Doppler indices, were compared.

RESULTS

The designated value of hypoxia index characterized by abnormal neonatal outcome was >10 for sHI and >14 for HI. Low prognostic value of MCA PI and RI, and UA PI and RI has been shown. The highest predictive value was marked by C/U and HI. There were no statistically significant differences in prediction of abnormal fetal heart rate during labor between C/U ratio, HI and sHI.

CONCLUSIONS

The C/U ratio showed the highest sensitivity in the prediction of fetal abnormal heart rate. The C/U ratio, as a easier test, should be recommended as a first-line test in the prediction of abnormal CTG recordings in uncomplicated pregnancies.

[Expression of erythropoietin and its receptor in the brain of newborn rats suffering from fetal distress]

OBJECTIVE

To study the expression of erythropoietin (EPO) and its receptor (EPOR) in the brain of newborn rats suffering fetal distress.

METHODS

A model of fetal distress was prepared by ligating bilateral uterine arteries of the rats with full-term pregnancy for 10 minutes before cesarean sections. The expression levels of EPO and EPOR in the brain of newborn rats were detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot at 0, 2, 6, 12, 24, 48, 72 hrs and 7 days after birth. Serum EPO levels were measured using ELISA simultaneously. The newborn rats born by cesarean sections which were not subjected to uterine artery ligation were used as the control group.

RESULTS

The expression of EPO protein and mRNA in brain tissues in the fetal distress group increased significantly compared with the control group 2, 6 and 12 hrs after birth (P<0.05). The expression of EPOR protein and mRNA in brain tissues in the fetal distress group increased significantly compared with the control group 2, 6, 12, 24 and 48 hrs, and 3 days after birth (P<0.05). Serum EPO levels in the fetal distress group were significantly higher than in the control group 2 hrs after birth.

CONCLUSIONS

The EPO and EPOR levels in the brain increase quickly after birth in newborn rats suffering from fetal distress. The EPOR is high expressed for a longer time than EPO. This can provide a basis for the treatment of neonatal brain damage induced by fetal distress by exogenous EPO.

Conditions associated with placental dysfunction

Placental dysfunction is a term to describe suboptimal placental function leading to variations in the fetal supply of all its necessary required nutrients as well as the disruption in the cleansing of fetal catabolic products. The dysfunctional placenta may interrupt the manufacturing of other essential factors involved in pregnancy conservation, can compromise the fetal appropriate, atraumatic and sterile medium to grow, the immunologic shield from maternal antibodies and the normal amniotic fluid levels. Placental dysfunction can lead to a group of disorders representing a diverse and important category of pathological processes conducting to fetal and neonatal morbidity and mortality. The mechanisms by which these inflammatory processes cause death and disability are diverse and can be separated into four distinct classes: first, placental damage with loss of function; second, induction of premature labor; third, release of inflammatory mediators; fourth, transplacental infection. Several conditions have been associated with placental dysfunction: IUGR, hypertension, hypoxic-ischemic injury, preterm labor, and fetal death.

[Up-regulation of glucose regulated protein 78 induced by 2-deoxyglucose plays a protective role for fetal rat cerebral neuron following intrauterine distress]

OBJECTIVE

To evaluate the influence of up-regulation of glucose regulated protein 78 (GRP 78) induced by 2-deoxyglucose (2DG) on fetal rat cerebral neuron apoptosis following intrauterine distress and the unification of endoplasmic reticulum and mitochondrium.

METHODS

(1) Fetal rat intrauterine distress model was established and rats were divided into normal group (N = 10), ischemia- reperfusion(IR) group (n = 40) and treatment group (n = 40, injection of 2DG into pregnant rats' abdomen after operation ). (2) Neuron apoptosis and the influence of 2DG on apoptosis was detected by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) staining. The expression of GRP78, caspase-9, -12, and cytoron C protein were detected by western blot technique.

RESULTS

(1) The number of TUNEL positive neuron in normal group was 4.3 +/- 1.8/mm2. The expression of GRP78, caspase-9, -12, cytoron C in cytoplasm were 0.012 +/- 0.003, 0.004 +/- 0.003, 0.006 +/- 0.002, 0.012 +/- 0.005, respectively. (2) The number of TUNEL positive neuron in the IR group were 43.6 +/- 11.4/mm2 (reperfusion 3 h), 64.4 +/- 9.3/mm2 (reperfusion 6 h), 74.2 +/- 12.1/mm2 (reperfusion 12 h), 97.3 +/- 8.9/ mm2 (reperfusion 24 h), respectively. They were significantly more than that in normal group (P < 0.05). The expression of GRP78 at corresponding times in IR group were 0.092 +/- 0.008 (reperfusion 3 h), 0.078 +/- 0.006 (reperfusion 6 h), 0.054 +/- 0.009 (reperfusion 12 h), 0.038 +/- 0.007 (reperfusion 24 h), respectively. The expression of cytoron C in cytoplasm at corresponding times in IR group were 0.040 +/- 0.006 (reperfusion 3 h), 0.076 +/- 0.009 (reperfusion 6 h), 0.108 +/- 0.005 (reperfusion 12 h), 0.089 +/- 0.008 (reperfusion 24 h), respectively. The expression of caspase-9 at corresponding times in IR group were 0.042 +/- 0.003 ( reperfusion 3 h), 0.086 +/- 0.007 (reperfusion 6 h), 0.142 +/- 0.006 (reperfusion 12 h), 0.112 +/- 0.009 (reperfusion 24 h), respectively. The expression of caspase-12 at corresponding times in IR group were 0.076 +/- 0.006 (reperfusion 3 h), 0.113 +/- 0.010 (reperfusion 6 h), 0.125 +/- 0.005 (reperfusion 12 h), 0.057 +/- 0.008 (reperfusion 24 h), respectively. They were significantly higher than that in normal group (P < 0.05). (3) The number of TUNEL positive neuron in the treatment group were 19.4 +/- 10.6/mm2 (reperfusion 3 h), 26.4 +/- 12.3 /mm2 (reperfusion 6 h), 39.3 +/- 13.3/mm2 (reperfusion 12 h), 49.3 +/- 13.6/mm2 (reperfusion 24 h), respectively. They were significantly lower than that in IR group, but more than that in normal group (P < 0.05). The expression of GRP78 at corresponding times in the treatment group were 0.158 +/- 0.012 (reperfusion 3 h), 0.175 +/- 0.005 (reperfusion 6 h), 0.125 +/- 0.013 (reperfusion 12 h), 0.079 +/- 0.004 (reperfusion 24 h), respectively. They were significantly higher than that in IR group and normal group (P < 0.05) . The expression of cytoron C in cytoplasm at corresponding times in IR group were 0.026 +/- 0.002 (reperfusion 3 h), 0.042 +/- 0.008 (reperfusion 6 h), 0.062 +/- 0.007 (reperfusion 12 h), 0.045 +/- 0.004 (reperfusion 24 h), respectively. The expression of caspase-9 at corresponding times in IR group were 0.033 +/- 0.002 (reperfusion 3 h), 0.063 +/- 0.005 (reperfusion 6 h), 0.092 +/- 0.005 (reperfusion 12 h), 0.068 +/- 0.008 (reperfusion 24 h), respectively. The expression of caspase-12 at corresponding times in IR group were 0.061 +/- 0.004 (reperfusion 3 h), 0.068 +/- 0.009 (reperfusion 6 h), 0.072 +/- 0.007 (reperfusion 12 h), 0.054 +/- 0.005 (reperfusion 24 h), respectively. They were significantly lower than that in IR group, but higher than that in normal group (P < 0.05).

CONCLUSIONS

Fetal rat cerebral neuron apoptosis following intrauterine distress is associated with the action of endoplasmic reticulum and mitochondrium. Up-regulation of GRP78 induced by 2DG counteracts primary cellular damage caused by endoplasmic reticulum stress. 2DG plays a protective role for fetal rat cerebral neuron following intrauterine distress.

Predictors of umbilical artery acidosis in preterm delivery

OBJECTIVE

The purpose of this study was to investigate the significance of preterm acidosis and its risk factors.

STUDY DESIGN

From a cohort of 786 consecutive singleton neonates who were born after spontaneous or iatrogenic preterm delivery at 24.0-33.6 weeks of gestation from January 1993 to December 2005 with an evaluation of umbilical artery pH at delivery, we extracted demographic, obstetric, neonatal, and placental histologic variables and related them to umbilical artery evidence of fetal acidemia, which was defined as pH <7.10. Excluded were stillbirths and neonates with major congenital anomalies. Fetal distress was defined as nonreassuring fetal hearth rate tracing or biophysical profile or appearance of thick meconium at delivery. Statistical analysis included 1-way analysis of variance and logistic regression with a probability value of <.05 considered significant.

RESULTS

Neonates with umbilical cord evidence of acidosis (n = 34) were born more frequently after abruption (P < .001), fetal distress (P < .001), and by cesarean delivery (P < .04) and were born less frequently after a complete course of corticosteroids (P = .03) and labor (P = .05) than nonacidotic babies (n = 752). Acute inflammatory lesions at placental histologic evaluation were less frequent (P = .049), and placental vascular lesions were more common in acidotic than in nonacidotic preterm neonates (P = .039). Logistic regression analysis demonstrated that cord acidosis was associated independently with the occurrence of abruptio placentae (odds ratio, 7.3; 95% CI, 2.9, 18.8), fetal distress (odds ratio, 12.0; 95% CI, 4.9, 18.3), and vascular placental lesions (odds ratio, 2.8; 95% CI, 1.2, 6.8)

CONCLUSION

In preterm infants, umbilical artery acidosis is significantly more common in the presence of placental abruption, fetal distress, and histologic evidence of placental vascular disease.

Tocolysis and delayed delivery versus emergency delivery in cases of non-reassuring fetal status during labor

AIM

To determine whether fetal intrauterine resuscitation using tocolysis and delayed delivery is better for the fetus than emergency delivery when fetal hypoxia is suspected because of a non-reassuring fetal heart-rate (FHR) pattern using conventional heart rate monitoring.

METHODS

This was a prospective and randomized study, conducted between 2001 and 2004 at Pereira Rossell Hospital, Montevideo, Uruguay. The population consisted of 390 fetuses, in which intrauterine distress was diagnosed using electronic FHR monitoring. Of these, 197 were randomly assigned to the emergency delivery group and 193 to the fetal intrauterine resuscitation group. The inclusion criteria were: term singleton pregnancy, in labor, cephalic presentation, and no placental accidents.

RESULTS

The time between randomization and birth was 16.9 +/- 7.6 min (mean +/- SD) for the emergency delivery group, and 34.5 +/- 11.7 min (mean +/- SD) for the resuscitation group. The relative risk (RR) of acidosis in the umbilical artery (pH < 7.1) in the emergency delivery group was 1.47 (0.95-2.27). The RR of base deficit < or =12 mEq/L in the emergency delivery group was higher than in the resuscitation group (RR = 1.48 [1.0-2.2], P = 0.04). When considering the need for admission to the neonatal care unit, the relative risk was higher in the emergency delivery group than in the resuscitation group (RR = 2.14 [1.23.3.74], P = 0.005). No maternal adverse effects were reported.

CONCLUSION

Tocolysis and delayed delivery renders better immediate neonatal results than emergency delivery when fetal distress is suspected because of a non-reassuring fetal heart pattern. In addition, it may decrease the need for emergency delivery without increasing maternal and fetal adverse side-effects.

Different degrees of fetal oxidative stress in elective and emergent cesarean section

BACKGROUND

Several studies have addressed the influence of labor and mode of delivery on oxidative stress. Still it is unclear whether oxidative stress is related to delivery itself or whether it reflects a pre-existing fetal oxidative status.

OBJECTIVE

To investigate whether the degree of fetal oxidative stress is different between distressed fetuses that were delivered by emergent cesarean section and non-distressed fetuses that were delivered by elective cesarean section.

METHODS

The protocol of this prospective study was approved by the Institutional Review Board Committee. Amniotic fluid and umbilical artery blood were prospectively collected from 21 parturients who were delivered by an emergent cesarean section for non-reassuring fetal heart rate pattern and from 21 parturients who were delivered by an elective cesarean section in a tertiary care center. Oxidative stress was evaluated in amniotic fluid, umbilical cord plasma and erythrocytes by determining malondialdehyde concentration and glutathione peroxidase (GPX) activity.

RESULTS

Malondialdehyde concentration was higher in amniotic fluid (mean +/- SEM) (2.2 +/- 0.7 nmol/l vs. 0.6 +/- 0.02 nmol/l, p < 0.05), in umbilical cord plasma (1.2 +/- 0.2 nmol/l vs. 0.7 +/- 0.3 nmol/l, p < 0.05) and in umbilical cord erythrocytes (159.6 +/- 48.6 nmol/g Hb vs. 85.8 +/- 5.2 nmol/g Hb, p < 0.05) in women delivering by emergent cesarean compared to those delivering by elective cesarean. GPX activity was enhanced in amniotic fluid (12.4 +/- 2.2 U/l vs. 5.1 +/- 0.6 U/l, p < 0.05) and GPX activity/hemoglobin ratio was higher in cord blood (22.0 +/- 0.8 U/g Hb vs. 18.7 +/- 0.9 U/g Hb, p < 0.05) in women delivering by emergent cesarean compared to those delivering by elective cesarean.

CONCLUSION

Distressed fetuses delivered by emergency cesarean exhibited increased malondialdehyde concentrations, an indicative parameter for oxidative damage, and enhanced GPX activity an antioxidant enzyme, in amniotic fluid and umbilical cord blood compared to non-distressed fetuses delivered by elective cesarean section. This is probably an indication of higher fetal oxidative stress.

Meconium-stained liquor during labor is associated with raised neonatal cord blood 8-iso-prostaglandin F2alpha concentration

OBJECTIVE

The purpose of this study was to compare the umbilical arterial 8-iso-prostaglandin F2alpha, concentrations between pregnancies that were complicated by moderate or thick meconium-stained liquor and those with clear liquor.

STUDY DESIGN

Umbilical cord arterial blood samples were collected from 247 singleton pregnancies with either moderate or thick meconium-stained liquor at any stage of labor or clear liquor at all stages of labor for the determination of the total 8-iso-prostaglandins F2alpha concentration.

RESULTS

The median total 8-iso-prostaglandins F2alpha concentration of the meconium-stained liquor group was significantly higher than that of the control group (719.2 vs 115.8 pg/mL). Among the meconium-stained liquor group, those who had a change from "clear liquor" at early labor to "moderate/ thick meconium-stained liquor" at late first stage or at delivery (late meconium-stained liquor group) had higher 8-iso-prostaglandins F2alpha concentration, compared with those who had moderate/ thick meconium-stained liquor since early labor (early meconium-stained liquor group; 959.8 vs 499.9 pg/mL). With the use of multiple regression analysis, meconium-stained liquor, duration of second stage of labor, and abnormal fetal heart tracings were independent determinants of cord blood 8-iso-prostaglandins F2alpha concentration.

CONCLUSION

Moderate or thick meconium-stained liquor is an independent factor for increased oxidative stress in pregnancy.

[Effects of fetal anoxia and acidosis on superoxide dismutase]

OBJECTIVE

To analyze the effects of fetal anoxia, respiratory and metabolic acidosis on the activity of antioxidation in fetal distress.

METHODS

Blood samples were taken from umbilical artery in 386 neonates for blood gas analysis and detection of the concentration of superoxide dismutase (SOD). Normal situation, anoxia, acidosis, respiratory acidosis, metabolic acidosis and mixed acidosis were diagnosed in all neonates according to the results of blood gas values, and the neonate asphyxia was diagnosed according to the Apgar scores (one minute). The effect of anoxia and acidosis to SOD were analyzed with multiple factor analysis of variation.

RESULTS

(1) Among the all 386 cases, 317 were normal, 31 with anoxia, 17 with acidosis, and 21 with both anoxia and acidosis. Among the total cases of acidosis, 8 respiratory, 21 metabolic, and 9 mixed acidosis. (2) The plasma levels of SOD of umbilical artery blood in anoxia, acidosis, both anoxia and acidosis, and normal sitution were (118.5 +/- 7.1) mmol/L, (122.0 +/- 11.4) mmol/L, (140.0 +/- 7.0) mmol/L, and (98.5 +/- 2.6) mmol/L, respectively. The results of unvariate analysis of variance showed that anoxia: F = 4.999 (P < 0.05), acidosis: F = 7.025 (P < 0.01), and both anoxia and acidosis: F = 0.013 (P > 0.05). (3) The plasma levels of SOD with respiratory acidosis, metabolic acidosis and mixed acidosis were (127.3 +/- 18.4) mmol/L, (126.0 +/- 8.1) mmol/L, (150.0 +/- 10.4) mmol/L. The results of univariate analysis of variance showed that respiratory acidosis: F = 4.404 (P < 0.05), metabolic acidosis: F = 3.965 (P < 0.05), and mixed acidosis: F = 0.015 (P > 0.05).

CONCLUSION

The superoxidation and antioxidation can be effected by factors like anoxia and acidosis, respiratory acidosis and metabolic acidosis. However, the mechanisms of these effects are different. There is additive, but not synergistic effects among them.

[Acute fetal distress]

Three different clinical patterns of acute fetal distress may be observed during labor: an ante-partum hypoxia with a persistent nonreactive and "fixed" fetal heart rate (FHR) on admission to the hospital, a progressive intra-partum asphyxia manifested, as the labor continues, by a substantial rise in baseline heart rate, a loss of variability and repetitive severe variable or late decelerations, and finally, as a result of a catastrophic event, a sudden prolonged FHR deceleration to approximately 60 beats per minute lasting until delivery. However the majority of fetuses with nonreassuring tracings of FHR are neurologically intact, as evidenced by the high false-positive rate of electronic fetal monitoring (EFM). Therefore the diagnosis of fetal distress must be corroborated by complementary methods, such as continuous recording of the fetal electrocardiogram or computed-assisted EFM, fetal pulse oximetry or fetal scalp sampling with immediate determination of blood gases or lactates. Defavorable outcome of an acute fetal distress leading to neonatal encephalopathy or death is best predicted by a persisting low Apgar score (<3) for more than 5 minutes and by a severe metabolic acidosis (umbilical artery pH<7,00 and base-excess>-12mmol/l).

Fetal distress increases interleukin-6 and interleukin-8 and decreases tumour necrosis factor-alpha cord blood levels in noninfected full-term neonates

OBJECTIVE

To assess the influence of fetal distress on interleukin-1beta, interleukin-6, interleukin-8 and on tumour necrosis factor-alpha blood levels in noninfected full-term neonates.

STUDY DESIGN

In a multicentre prospective study, cord blood samples were obtained at time of delivery from 234 noninfected full-term neonates for the purposes of measuring serum levels of interleukin-1beta, interleukin-6, interleukin-8 and tumour necrosis factor-alpha using immunoassays. Women were classified into four groups according to the mode of delivery (vaginal delivery or caesarean section) and the presence or absence of fetal distress. The role of labour was also investigated.

RESULTS

No significant relationship was found between cytokine cord blood levels and the mode of delivery. Fetal distress was associated with an increase in interleukin-6 (P = 0.01) and interleukin-8 (P < 0.001) levels, and a decrease in tumour necrosis factor-alpha (P < 0.001). Labour was also associated with a significant increase in interleukin-6 and interleukin-8 cord blood levels (P = 0.01 and P < 0.001, respectively).

CONCLUSION

Fetal distress and labour were each associated with elevated interleukin-6 and interleukin-8 cord blood levels in noninfected full term neonates while only fetal distress was associated with decreased tumour necrosis factor-alpha levels.

A case study of antenatal distress and consequent neonatal respiratory distress

CS, A 42-YEAR-OLD, GRAVIDA 2, para 1 Caucasian woman, presented at her private obstetrician’s office at 36 weeks gestation with a complaint of decreased fetal movement for 24 hours. Fetal heart tones were present, membranes were intact, and there were no contractions. The first pregnancy had resulted in preterm labor at 36 weeks with no neonatal complications. CS’s blood work indicated that she was type AB+, rubella immune, nonreactive rapid plasmin reagin (RPR) for venereal disease, hepatitis B surface antigen negative, and unknown group B streptococci status. Previous history was significant for herpes simplex, with no active disease during this pregnancy. CS was referred for a biophysical profile (BPP) and an oxytocin challenge test.

[Changes of free radicals in fetal rats brain and liver following intrauterine fetal distress]

OBJECTIVE

To analysis the effect of superoxide dismutase (SOD) and malondialdehyde (MDA) on different organs in intrauterine fetal distress.

METHODS

The times of clamping uterine artery in A, B, C groups were 5, 10, 20 minites respectively. By clamping the matenal uterine vessels, we made the model of fetal rat distress. Slam group (13 pups) was used as control. After clamping 10 minutes, Group D (11 pups) was reperfused 5 minutes, and E (8 pups) 20 minutes. We measured the level of SOD and MDA in fetal brains and livers.

RESULTS

The activity of cerebral SOD in group B and C decreased significantly than that of control (P < 0.05, P < 0.01). MDA in group C increased significantly than that of control (P < 0.05). As for liver, only SOD in group C decreased significantly (P < 0.05). In that of reperfusion group, only in group E, cerebral SOD and MDA changed significantly (P < 0.01, < 0.05), livers SOD decreased significantly (P < 0.05).

CONCLUSION

After severe intrauterine fetal distress, changes of free radicals occurred in brains firstly, which provides the proof of early treatment for neonatal hypoxia ischemia brain damage.

Heart rate variability of preterm neonates quantified by energy entropy

Identifying variables predictive of neurobehavioural sequelae is a key objective in the study of high-risk neonates. Examination of heart rate variability (HRV) characteristics may be a finer discriminator of the neonate's response to physiologic stressors than the mean heart rate. The energy entropy of the heart beat tachogram, computed in four different domains, was used to quantify the HRV in 13 preterm neonates. The entropies of energies were computed from 1024 interbeat time intervals obtained once per week from 26 to 35 weeks postconceptional age (PCA). The energy entropy computed in three of the domains, like the standard deviation of intervals, distinguished between the 10 neonates that were measured at 35 weeks PCA with 100% specificity and 67% sensitivity, but did not distinguish between healthy and unhealthy neonates at earlier ages. The findings suggest that energy entropy may be a discerning measure of physiologic stress in the preterm infant, although future research is needed to refine the test and determine statistical significance.

Amniotic fluid composition in the fetal lamb with intrauterine growth restriction

OBJECTIVE

Our aim was to examine changes from normal in the composition of amniotic fluid in fetal lambs with mild and severe hypoxemia and intrauterine growth restriction.

STUDY DESIGN

Pregnant sheep underwent maternal catheterization at 88 to 93 days' gestation and fetal catheterization at 105-112 days' gestation. Twelve pregnancies (group 1) provided control data (fetal PaO 2 18-22 mm Hg), in 12 fetuses (group 2) mild hypoxemia (PaO 2 16-19 mm Hg) was induced by prevention of the normal expansion of maternal blood volume, and in 7 fetuses (group 3) chronic hypoxemia (PaO 2 12-18 mm Hg) developed spontaneously.

RESULTS

In group 2 amniotic fluid osmolality and sodium concentrations were lower (approximately 30 mOsm/kg and 10 mEq/L, P <.05) and urea nitrogen level was higher (10 mg/dL, P <.05) than in group 1. In group 3 osmolality and sodium concentrations at approximately 120 days' gestation were similar to those in group 1. Whereas these values decreased with gestation in groups 1 and 2 (P <.05), they remained unchanged or increased in all fetuses in group 3. Mortality rates in groups 1, 2, and 3 were 1 of 12, 4 of 12 (difference not significant), and 5 of 7 (P <.05), respectively.

CONCLUSION

Absence of normal decrease in amniotic fluid osmolality with gestation, in association with a high perinatal mortality rate, was found in severely but not in mildly hypoxemic fetuses with intrauterine growth restriction.

Comparison between tryptophan methoxyindole and kynurenine metabolic pathways in normal and preterm neonates and in neonates with acute fetal distress

OBJECTIVE

To analyze the kynurenine and methoxyindole metabolic pathways of tryptophan in order to identify changes in premature neonates and in neonates suffering from fetal distress.

METHODS

One hundred and twelve neonates were assigned to three groups: normal neonates (control group), preterm neonates (neonates born before the 37th gestational week) and neonates suffering from fetal distress. Each of these groups was then divided in two subgroups according to the time of birth corresponding with the time of blood sampling: a diurnal subgroup, comprising neonates whose blood was sampled between 0900 and 2100 h, and a nocturnal subgroup, comprising neonates whose blood was sampled between 2100 and 0900 h. Blood samples from the umbilical artery and vein were taken in the delivery room at birth from each neonate for measurement of melatonin, the main methoxyindole pathway metabolite. Urine samples were collected from 0900 to 2100 h (diurnal groups) and from 2100 to 0900 h (nocturnal groups), and the presence of kynurenic acid, xanturenic acid, 3-hydroxyantranilic acid, L-kynurenine and 3-hydroxykynurenine determined.

RESULTS

The results show the existence of diurnal/nocturnal differences in the concentration of melatonin in cord blood and in the urinary excretion of kynurenines. In normal neonates, the production of methoxyindoles (determined as melatonin) is decreased during the day and increases at night, whereas production of kynurenines is high during the day, decreasing at night. In the fetal distress group, a significant increase in the umbilical artery concentration of melatonin was found. This group also showed a reduction in L-kynurenine concentrations in the diurnal and nocturnal groups, and an increase in xanturenic acid and 3-hydroxyantranilic acid during the day. Correlation and regression studies confirmed that the differences in the day/night pattern of the tryptophan metabolic pathways were greater in normal neonates than in the preterm and fetal distress groups.

CONCLUSIONS

The results indicate the existence of an imbalance in tryptophan metabolites in preterm infants and those with fetal distress, blunting the normal diurnal/nocturnal rhythm of both melatonin and kynurenines.

Lipid peroxidation in cord blood: the effect of amniotic fluid volume

OBJECTIVE

To assess the effect of amniotic fluid volume on umbilical cord arterial lipid peroxide levels in relation to intrapartum events.

DESIGN

Prospective observational study.

SETTING

Delivery suite of a teaching hospital, the Chinese University of Hong Kong.

POPULATION

Women with singleton, term, cephalic presentation, and an initially normal fetal heart rate tracing.

METHODS

All pregnancies had amniotic fluid index assessments before and after amniotomy and cord arterial lipid peroxide determination at delivery. Multiple regression analysis.

MAIN OUTCOME MEASURES

Cord arterial malondialdehyde and organic hydroperoxide levels.

RESULTS

In 247 cases following amniotomy levels were inversely correlated with intrapartum amniotic fluid index. Amniotic fluid index during labour was an independent determinant of cord arterial lipid peroxide concentration, along with duration of second stage, absence of epidural, presence of tight nuchal cord entanglement and evidence of fetal distress.

CONCLUSIONS

Oligohydramnios during labour is associated with high levels of lipid peroxidation in the fetus, reflecting an increase in hypoxic cellular damage by free radicals.

Assessment of fetal fibronectin in cervical secretion in cases of equivocal rupture of the membranes at term

BACKGROUND

To evaluate if the presence of fibronectin in cervical secretion might provide information on the natural course of equivocal prelabor rupture of membranes (ROM) at term.

METHODS

One hundred and sixteen women with a history of prelabor ROM at term but without visible amniotic fluid leakage were included in the study. The presence of fetal fibronectin in cervical secretion was determined by a commercially available kit (ROM check; limit of detection 100 ng/ml). Women with (n=49) and without (n=67) a positive fibronectin test were compared with regard to time interval between presumed membrane rupture and delivery, mode of delivery and fetal distress rates.

RESULTS

There was no significant difference in the time interval between presumed ROM and delivery between those with a negative fibronectin test (median: 80 hours) and those with a positive test (median: 64 hours; p=0.28, Mann-Whitney U-test). Neither were there any differences in complicated delivery or fetal distress rates.

CONCLUSION

Determination of fetal fibronectin in cervical secretion with the present method is of limited value in the clinical management of patients with equivocal rupture of the membranes.

[Relationship between catecholamine levels in amniotic fluid and fetal blood flow in fetal distress]

Eighteen cases of complicated pregnancy with fetal distress and/or pregnancy toxemia who underwent Cesarean section (CS) before onset of labor were studied. The resistance indexes (RI) of the umbilical artery (UA) and fetal middle cerebral artery (MCA) were measured by Doppler echography prior to CS. UA blood and amniotic fluid (AF) were obtained during CS and the pH value for the UA and the concentrations of norepinephrine (NE) and epinephrine (E) in AF were measured. A significant correlation between the pH value, MCA-RI/UA-RI ratio and the levels of NE and E in amniotic fluid was obtained. NE and E concentrations in AF obtained from the patients with fetal distress before the onset of labor were 1.92 +/- 0.54 and 1.48 +/- 0.28ng/ml and these concentrations were significantly higher then those from elective CS. The deviations (delta SD) of RI from the normal mean for corresponding gestational age in fetal distress were -4.21 +/- 0.94 in MCA and 1.31 +/- 0.48 in UA. A negative correlation between the pH value and delta SD (UA) was observed but the pH value correlated positively with delta SD (MCA). Furthermore, the MCA-RI/UA-RI ratio showed a significant negative correlation with the NE and E levels in AF. These results suggest that fetal catecholamine affects fetal blood flow in fetal distress.

Lipid peroxidation and superoxide dismutase activity in umbilical and maternal blood

Oxygenation of both mother and child tissues oscillate frequently during labour. We tested the lipid peroxidation caused by reactive oxygen species which are produced in consequence of tissue reoxygenation and the inactivation of these species by the maternal and newborn superoxide dismutase. Total malondialdehyde in concentrations (mean +/- SE) of 1.04 +/- 0.17, 1.57 +/- 0.22, 1.33 +/- 0.14 and 1.36 +/- 0.21 mumol/L was found in maternal plasma and red blood cells and newborn plasma and red blood cells, respectively, after uncomplicated deliveries and 4.93 +/- 1.34, 7.12 +/- 1.37, 4.77 +/- 1.29 and 7.37 +/- 1.51 mumol/L, respectively, after deliveries with clinical signs of foetal hypoxia. In newborns, erythrocyte superoxide dismutase activity reached only 82% of the maternal level (p < 0.05). The results indicate that the maternal and foetal antioxidant defence systems can be overloaded during deliveries with abnormal oxygenation, where increased lipid peroxidation occurred.

Effects of intrapartum stress on fetal adrenal function

OBJECTIVE

Our purpose was to characterize the fetal adrenal response to acute intrapartum stress in otherwise uncomplicated pregnancies.

STUDY DESIGN

Term infants (n = 61) diagnosed as having fetal distress during labor, as indicated by heart rate abnormalities, and delivered of women having normal pregnancies were pair-matched with 61 infants showing no signs of fetal distress or acidemia (controls) on the basis of gestational age and delivery method. Umbilical cord serum dehydroepiandrosterone sulfate and cortisol were measured, and the data were analyzed by two-tailed t test, Fisher's exact test, analysis of variance, and Tukey's multiple range test.

RESULTS

Distressed infants had lower serum levels of dehydroepiandrosterone sulfate (3992 +/- 246 nmol/L, mean +/- SE) than control infants (4853 +/- 283 nmol/L); distressed infants also had higher levels of cortisol (412 +/- 17 nmol/L) than did control infants (299 +/- 16 nmol/L). The dehydroepiandrosterone sulfate/cortisol ratios in control infants (17.7 +/- 1.2) were almost twice those of distressed infants (10.8 +/- 0.9). These same relationships also were noted when the infant pairs were segregated according to whether delivered vaginally (21 pairs) or by cesarean section (40 pairs). The abnormalities in steroid levels in the distressed infants were independent of the presence or absence of acidemia.

CONCLUSION

Intrapartum stress acutely alters fetal adrenal steroidogenesis, leading to increased production of cortisol and decreased secretion of dehydroepiandrosterone sulfate.

Pregnancy specific beta 1 glycoprotein (SP-1) in maternal serum and amniotic fluid; pre-eclampsia, small for gestational age fetus and fetal distress

Pregnancy specific beta 1 glycoprotein (SP-1) levels have been suggested to correlate with certain obstetrical complications. We compared maternal serum SP-1 levels in normal pregnancies (N = 82), and pregnancies complicated by pre-eclampsia (N = 37), small for gestational age fetuses (N = 8) and fetal distress (N = 13). We also compared levels of this protein in mid-trimester amniotic fluid samples obtained from normal (N = 47) and small for gestational age fetuses (N = 25). Despite trends towards low maternal serum and amniotic fluid SP-1 values in complicated pregnancies, there were no statistically significant differences in their levels as compared with normal gestational age matched controls (P > 0.05). These data do not support the use of SP-1 values in clinical practice.

Influence of perinatal conditions on C-reactive protein production

C-reactive protein rises in blood in an acute-phase response in adults, children, and neonates. In a prospective study of the influence of perinatal asphyxia, premature rupture of membranes, hyperbilirubinemia, and respiratory distress syndrome on levels of C-reactive protein in the neonate, we detected no confounding effect on the rise of C-reactive protein level in infants with these pathologic perinatal conditions, as compared with the results of a control group.

[Effect of dietary level of vitamin E on protection of fetus against ischemic distress induced by clamping the uterotubal vessels of pregnant rats]

The effect of dietary vitamin E on the fetal ischemic distress induced by clamping the uterotubal vessels of pregnant rats was studied. The fetal heart rate was measured by the pulsed doppler technique as an index of fetal distress induced by ischemia. On reperfusion after clamping the vessels for 9 min., the decreased fetal heart rate was restored to normal rapidly and completely in the E-supplemented group, but slowly and incompletely in the E-deficient and control groups. On reperfusion after ischemia, the amounts of lipid peroxides, measured as thiobarbituric acid (TBA)-reactive substances, were greatly increased in the fetal brain and liver and in the placenta in the E-deficient and control groups, but not in the E-supplemented group. The vitamin E concentrations in fetal tissues were less than 10% of those in the maternal tissues. But a diet containing a large amount of vitamin E induced significantly increased concentrations of vitamin E in fetal brain and liver. These results suggest that vitamin E may have a protective effect on fetal distress by decreasing lipid peroxides.

Protective effect of vitamin E on fetal distress induced by ischemia of the uteroplacental system in pregnant rats

The effect of dietary vitamin E on the fetal ischemic distress induced by clamping the uterotubal vessels of pregnant rats was studied. The fetal heart rate was measured by the pulsed doppler technique as an index of fetal distress induced by ischemia. On reperfusion after clamping the vessels for 9 min, the decreased fetal heart rate was restored to normal rapidly and completely in the E-supplemented group, but slowly and incompletely in the E-deficient and control groups. On reperfusion after ischemia, the amounts of lipid peroxides, measured as thiobarbituric acid (TBA)-reactive substances, were greatly increased in the fetal brain and liver and in the placenta of in the E-deficient and control groups, but not in the E-supplemented group. The vitamin E concentrations in fetal tissues were less than 10% of those in the maternal tissues. Significant differences were found in the vitamin E concentrations in the maternal serum and liver in the three groups of rats given diet containing different amounts of vitamin E for 2 weeks. No significant differences were found between the vitamin E-deficient and control groups in the levels of vitamin E in the fetal brain and liver and the placenta, but these levels were significantly lower than those in the E-supplemented group.

[The anemic gap in depressed newborn infants]

Thirty cesarean section-delivered newborn were studied. Fifteen of them scored from 0 to 3 and, 8 and greater on the Apgar scale when measured at one and five minutes, respectively. The other 15 scored 8 or more at one minute and 9 at five minutes. Arterial electrolyte and blood gases were measured in samples obtained from the umbilical cord. The anion gap formula was then applied. The average weight of the depressed newborns was found to be less than for those of the control group. The mean gestational age for both groups was 39 weeks. The average values for electrolyte, bicarbonate and the anion gap were found to be practically the same in both groups. No correlation was found between the pH and the gap nor for the gap and the hydrogen ion concentration [H+]. The correlation between the gap and the bicarbonate was 0.78. No differences were seen between anion gap values for the newborn with lactic acidosis or hyperlactemia when compared to those of the control group. It is therefore concluded that the anion gap is not useful for the detection of newborns suffering from metabolic acidosis. Anion gap; bicarbonate; Apgar score; depressed neonates; metabolic acidosis.

The ontogeny of the metabolic and endocrine stress response in the human fetus, neonate and child

Evidence of an endocrine and metabolic response to stress is evident from the mid trimester of fetal life. The ontogeny of this response is seen in the different patterns of response evident in the fetus, neonate, infant and child. These data raise important issues concerning the management of pain and stress in early life.

Hypoxic alterations in neonatal neurons: an acridine orange fluorochromic study of nucleic acids

Acridine orange, a fluorochromic stain of nucleic acids, was used to study tissue sections of brain and spinal cord in 22 premature and full-term neonates who died within a week after severe fetal distress or birth asphyxia. Neurons suffering hypoxic injury may show either a centrifugal or a centripetal pattern of redistribution of cytoplasmic RNA. Severely involved cells show almost complete loss of orange RNA fluorescence, as well as decreased or condensed DNA fluorescence of nuclear chromatin. The most pronounced changes are observed in motor neurons and in pyramidal cells of the hippocampus. It appears likely that the centrifugal redistribution of ribosomes (chromatolysis) is associated with cell injury, while the centripetal pattern indicates a recovery process or regeneration. Acridine orange provides a convenient supplementary method of assessing the extent of hypoxic encephalopathy in neonates at autopsy. Alterations in RNA distribution may correlate with impairment of neurotransmitter synthesis, but normal maturational differences also must be considered in interpretation.

There is evidence that amniotic fluid arginine vasopressin is a marker for foetal stress in rhesus erythroblastosis

In response to different stress stimuli the foetal neurohypophysis releases arginine vasopressin (AVP). Part of the AVP is cleared from circulation by urinary excretion into the amniotic fluid (AF). Increased AF AVP levels may therefore indicate foetal stress, all the more because AF AVP solely is of foetal origin. We therefore studied AF AVP levels in 13 patients with rhesus erythroblastosis from 22 to 34 weeks of gestation. Twenty-eight patients from 14 to 34 weeks of gestation served as controls. The AVP levels were measured by RIA. Spectral absorption curves were performed and delta/E values determined at 450 nm. Mean AF AVP levels in controls were 2.39 pg/ml and were not normally distributed. There was no significant change in AF AVP levels with different gestational age. If in rhesus erythroblastosis patients the delta/E value was low (n = 7; x = 0.048 +/- 0.007 SE), the AF AVP values were not increased. If the delta/E values were within zone III (n = 6; x = 0.22 +/- 0.035 SE), indicating severe haemolysis, the AF AVP levels were significantly elevated (4.7 pg/ml +/- 0.51 SE; P = 0.001). Linear regression analysis showed a significant correlation between delta/E and AF AVP values (P = 0.05; y = 1.94 +/- 10.88 x). We conclude that there is evidence for the role of AF AVP as a marker for foetal stress in rhesus erythroblastosis.

Catecholamines in amniotic fluid as indicators of intrapartum fetal stress

Catecholamines were measured in the amniotic fluid and in the first voided newborn urine obtained from appropriate-for-date infants of term deliveries. Catecholamine values in the amniotic fluid and urine were nearly equal when expressed in terms of creatinine. Significant positive correlations were observed between the amniotic fluid and urine of norepinephrine and epinephrine. In normal cases (n = 32) that underwent uneventful vaginal delivery, the 95% confidence limits for norepinephrine and epinephrine in the amniotic fluid were 1.53 to 2.33 ng/ml and 0.16 to 0.30 ng/ml, respectively. In cases of moderate stress (n = 12), only norepinephrine showed significantly higher values than the normal cases, while in cases of severe stress (n = 12), norepinephrine became more significantly high, and epinephrine was found to be elevated significantly. A significant difference was noted in the incidence of fetal stress between the infants with more than and those with less than 2.30 ng/ml of norepinephrine, the upper limits of the normal 95% confidence limits. However, for epinephrine such a significant difference was not noted. It was concluded that amniotic fluid catecholamines are of fetal origin and reflect fetal sympathoadrenal activity directly, even during labor, and that their level may be a good indicator of fetal condition and stress.

Trends in continuous metabolic monitoring during experimental fetal distress

Intermittent, progressive maternal aortic occlusions were used to produce fetal distress in the fetuses of six pregnant dogs at term. Fetal heart rate and fetal tissue surface pH were continuously recorded and were compared to fetal blood pH, pCO2, pO2 and lactic acid values determined from intermittent sampling. Baseline fetal heart rate was an insensitive indicator of fetal blood pH, tissue surface pH, or of fetal blood lactic acid concentrations. "Delayed" decelerations in fetal heart rate following an occlusive episode were uniformly produced after minimal stress and also did not correlate well with these variables. On the other hand, fetal blood lactic acid concentrations remained elevated even after occlusive episodes were discontinued and other variables had returned to baseline values.

A prospective study of three biochemical fetoplacental tests: serum human placental lactogen, pregnancy-specific beta 1-glycoprotein, and urinary estrogens, and their relationship to placental insufficiency

The relationship between abnormal biochemical fetoplacental test results and placental insufficiency was studied in a group of high-risk obstetric patients. The urinary estrogen: creatinine ratio and serum human placental lactogen (hPL) and pregnancy-specific beta 1-glycoprotein (SP1) were measured in more than 1,600 patients. Fifty-one patients were found to have abnormal biochemical results, and the placentas from these patients were sent for the assessment of placental insufficiency by pathologic examination, which was expressed as a placental insufficiency score. Low hPL was found to be the best biochemical indicator of placental insufficiency, and 84% of the patients with a low level of hPL had an elevated placental insufficiency score. The combination of low levels of hPL and urinary estrogen was found to be the best indicator of placental insufficiency associated with retarded intrauterine growth, and 83% of the patients who had low results in both of these tests had elevated placental insufficiency scores and were delivered of light-for-dates infants. The measurement of SP1 was found to be of limited value in detecting retarded growth, but patients with low SP1 values showed an increased incidence of fetal hypoxia. Attention is drawn to the fact that the discrepancies that occur in the various estimations are not necessarily due to artifact, and specific pathologic processes which could account for some of the anomalous results are identified.

Concentrations of hypoxanthine, xanthine, uridine and urate in amniotic fluid at caesarean section and the association of raised levels with prenatal risk factors and fetal distress

Samples of amniotic fluid were obtained at caesarean section from 33 of 80 consecutive unselected patients in whom the membranes were intact. Concentrations of the ATP metabolites, hypoxanthine and xanthine, as well as uridine and urate were determined using high pressure liquid chromatography. Independent 'clinical' factors associated with reduced fetal growth and well-being were identified and the patients were assigned to one of three groups: those with no recognized risk, those with moderate risk and a small group of four patients with high risk. The mean hypoxanthine concentration was higher in the moderate-risk group than in the group with no risk. Two of the three patients with proteinuric hypertension in the high-risk group had normal hypoxanthine concentrations. There were seven patients with fetal distress, and concentrations of hypoxanthine, xanthine, uridine and urate were significantly higher in the three patients who had meconium stained amniotic fluid in addition to abnormal fetal heart rate tracings than in the remaining four who had fetal heart rate abnormalities only. It is suggested that fetal distress at emergency caesarean sections might be quantitated by such analysis.

Human chorionic gonadotropin levels in maternal blood in late pregnancy: relation to birthweight, sex and condition of the infant at birth

A total of 527 blood samples was obtained from an unselected population of women between 36 and 40 weeks gestation. Serum human chorionic gonadotropin (hCG) levels were measured using a specific radioimmunoassay for the beta 1-subunit of hCG. Serum hCG levels were higher in primigravidae and in women carrying female fetuses. They were also related to the birthweight of the child and to the occurrence of fetal distress.

The influence of asphyxia on fetal lidocaine toxicity

Local anesthetics have played an important role in modern obstetrics. Although reasonably safe, these agents have been shown to have detrimental effects in some fetuses. In the present study we examined the influence of acute asphyxia in the fetal lamb on the distribution and cerebral uptake of maternally infused lidocaine. Results demonstrate that asphyxia is associated with higher lidocaine concentrations in the fetal plasma, increased presentation of the drug to the fetal brain, and increased cerebral lidocaine uptake. These findings underscore the importance of evaluation of fetal status when considering the risks and benefits of maternal drug use.

Presence of immunoassayable beta-endorphin in human amniotic fluid: elevation in cases of fetal distress

Immunoassayable beta-endorphin is present in samples of amniotic fluid obtained in the last two weeks of pregnancy. Average concentration is approximately 300 pg. per milliliter. In all cases of suspected or recognized fetal distress, striking elevations of the beta-endorphin concentrations (twofold to 20-fold) were observed. The degree of elevation correlated with the degree of fetal distress.

Amniotic fluid adenosine 3',5' - monophosphate in prostaglandin-induced midtrimester abortions

Cyclic adenosine 3'5-monophosphate (cAMP) was serially measured in the amniotic fluid (AF) of 9 patients undergoing midtrimester abortions induced by intraamniotic prostaglandins. The results demonstrate an increase in AF cAMP ranging from 2- to 7-fold within the 6 hours of observation. The fetal heart tones were closely monitored by a Doppler instrument and the time from injection of abortifacient to fetal demise (IDT) and to fetal expulsion (IAT) was accurately recorded. No correlation between the rate of AF cAMP increase and IDT or IAT could be demonstrated. The concentration of cAMP in amniotic fluid obtained from patients with fetal demise in utero was lower than that found in AF of fetuses of corresponding gestational age where the fetus was alive. The significance of AF cAMP as a potential indicator of fetal distress is discussed.

Toxemia of pregnancy: assessment of fetal distress by urinary estriol and circulating human placental lactogen and alpha-fetoprotein levels

The efficacy of three biochemical methods for the detection of fetal distress was assessed in a prospective study of 224 singleton pregnancies complicated by toxemia. Fetal distress was diagnosed in 65 cases (29 per cent). Abnormally low urinary estriol (E3) excretion pointed out 63 per cent, low serum levels of human placental lactogen (HPL) 27 per cent, and elevated maternal serum alpha fetoprotein (AFP) 10 per cent of distressed fetuses. The efficacy of each test increased with the severity of maternal disease. The frequencies of false pathologic levels were: E3 19 per cent, HPL 0 per cent, and AFP 1 per cent of the cases with a normal fetal outcome. Although E3 was by far the most effective marker, abnormal levels of HPL and AFP provided supportive evidence for fetal distress by pointing out those cases in which E3 reading was not a false positive.

Alpha-fetoprotein levels in maternal plasma and amniotic fluid during prostaglandin-induced mid-trimester abortions: the relation to fetal distress and death

Alpha-fetoprotein (AFP) levels were measured in both plasma and amniotic fluid during 43 abortions induced with prostaglandin F2alpha (PGF2alpha) and their relationship to the induction-abortion interval and signs of fetal distress or intrauterine death examined. The mean plasma AFP levels showed a progressive rise after PGF2alpha administration but abnormally high levels were found infrequently until the time of delivery. Feto-maternal bleeding could explain the abnormally high plasma AFP levels which occurred early in a few cases. A shorter induction-abortion interval was found in patients with normal plasma AFP levels. Neither fetal distress nor intrauterine death were associated with abnormally high plasma AFP levels. No change in AFP levels in amniotic fluid was found.

Placental insufficiency in relation to postterm pregnancy and fetal postmaturity. Evaluation of fetoplacental function; management of the postterm gravida

As pregnancy extends post term, incidence of placental insufficiency, fetal postmaturity (dysmaturity), and fetal perinatal death increases rapidly as a consequence of reduced respiratory and nutritive placental function. Despite a compensatory fetoplacental respiratory reserve capacity, fetal distress is observed in about one third of postterm pregnancies. On a biochemical level, placental pathophysiology in postterm-postmaturity pregnancies is not well understood. Postmaturity is correlated with increased incidence of placental lesions, fetal hypoxia-asphyxia, intrauterine growth retardation, increased perinatal death, and neonatal morbidity. Early diagnosis of fetal postmaturity is difficult because currently applied test methods allow recognition only when placental insufficiency is far progressed. Therefore, in postterm gravidas with a favorable cervix, induction of labor should be considered; in older primigravidas, in whom fetal losses may be sevenfold increased, or in multiparas with a history of obstetric complications, pregnancy may require termination by cesarean section. Pregnancy may be allowed to continue under close supervision in cases of uncertainty of duration of gestation, in gravidas carrying small babies, in young primigravidas, and in multigravidas in whom placentofetal function tests are normal. As long as fetal scalp blood sampling during labor does not show fetal acidosis, despite abnormal fetal heart rate pattern and meconium release, vaginal delivery may be attempted when deemed possible within a few hours. In parturients attention must be paid to the extent of uterine activity and type of medication; lateral positioning of the gravida and maternal oxygen breathing, facilitating fetal oxygen supply, are important features. Because during bearing-down efforts placentofetal respiratory reserves of postterm gravidas may become further compromised, immediate delivery by forceps or vacuum extraction may be considered. After delivery the umbilical cord should not be clamped immediately in order to allow increased fetal blood supply and to counteract fetal hypovolemia. Dysmature newborn infants require special care by the neonatologist.