Spontaneous regression of a large intrathoracic fetal lesion before birth

All fetal intrapulmonary lesions diagnosed antenatally reported in the literature to date have persisted as an ultrasound finding for the remainder of the pregnancy, although spontaneous improvement in utero has been reported recently. We describe a case of a large intrathoracic lesion diagnosed at 24 weeks' gestation by ultrasound that became indistinguishable from the rest of the lungs as the pregnancy approached term. Although the frequency with which this process occurs cannot yet be assessed, the possibility of significant spontaneous regression must now be considered when counseling the parents on an affected fetus.     

Maternal and fetal catecholamines and uterine incision-to-delivery interval during elective cesarean

The fetal sympathoadrenal system is activated during periods of intrauterine stress such as inadequate uterine perfusion. During cesarean, the period of interruption of utero-placental blood flow is extended as the time interval from uterine incision to delivery increases. An increasing uterine incision-to-delivery interval with spinal or general anesthesia has been associated with a poorer neonatal outcome. This association has not been demonstrated previously in patients undergoing cesarean delivery under epidural anesthesia. We investigated the correlation between prolonged uterine incision-to-delivery intervals, fetal catecholamine concentrations, and fetal blood gas values at delivery in 25 parturients undergoing cesarean under epidural anesthesia and in 28 under spinal anesthesia. Infants delivered after prolonged uterine incision-to-delivery intervals had significantly lower pH values in both the epidural and spinal groups. With longer uterine incision-to-delivery intervals, umbilical arterial norepinephrine concentrations were increased significantly. Umbilical arterial pH values were significantly lower in infants with higher umbilical arterial catecholamine concentrations. The importance of minimizing the uterine incision-to-delivery interval, regardless of the type of anesthetic selected, is demonstrated.     

The study of maternal and fetal plasma catecholamines levels during pregnancy and delivery.

BACKGROUND: To study maternal and fetal plasma levels of catecholamines (CA) during pregnancy and delivery, especially changes in CA levels during fetal distress and conditions of different modes of delivery. METHODS: Maternal and fetal plasma NE, E and DA levels were determined by high performance liquid chromatography (HPLC) for 16 non-pregnant women, 19 cases of early pregnancy, 17 cases of mid pregnancy, late pregnancy, spontaneous vaginal delivery and 53 cases of cesarean section. RESULTS: Plasma NE and DA levels decreased gradually with the advance of gestational weeks, and levels of plasma NE were significantly lower than those of non-pregnant women (P < 0.05). The levels of plasma CA in patients who had elective cesarean section were significantly lower than those who had vaginal delivery and emergency cesarean section (P < 0.01). However, CA levels of the cord artery in the vaginal delivery group were significantly higher than those in the cesarean section group (P < 0.01). CONCLUSION: Vaginal delivery is better than cesarean section for the newborn. If cesarean section is necessary, it is best for the newborn after onset of labor.     

Bubbles before birth

When a spa bath was installed in the maternity unit of Osborne Park Hospital, a Quality Assurance survey was undertaken to try to identify any potential problems. At the same time a client satisfaction survey was conducted. The study highlighted many benefits to the client as an alternative method of pain management. At the same time no obvious problems were identified. However, due to lack of control of the many variables, and the absence of statistical analysis, no definite conclusions can be drawn from the study. Positive responses from clients encourage us to continue to offer the spa bath as a method of pain management. This is an area which begs research.Water has long been recognised as an effective form of pain relief (Odent 1983, Lines 1993, Enkin et al 1995). However, little literature was found on the use of a spa bath for pain management during labour.Some maternity units in Western Australia installed spa baths in their birth suite only to realise that residual water was left in the pipe after each bath, creating an infection control hazard. These spa units were subsequently removed.Bearing this in mind, when renovating the birth suite at Osborne Park Hospital, we purchased a Senex air-driven spa bath. This bath leaves no residual water. The spa can be used as a conventional bath or as a spa with two levels of water modulation. Controls are within easy reach of the bather. The bath is to be used solely for pain management. No water births are contemplated. However, the bath is installed in the centre of the room away from the walls allowing easy access all around in case of an emergency.The spa bath is cleaned with soap and water after and, as an added precaution, prior to each use. At least once per week, a strong mixture of vinegar and water is agitated with high modulation for ten minutes. This has been successful in removing any crusty build-up around the air jets.     

The relationship between circulating catecholamines and ST waveform in the fetal lamb electrocardiogram during hypoxia

Previous studies from this laboratory have shown that changes in the ST waveform in the fetal electrocardiogram are a sign of fetal asphyxia. In the present study, seven chronically instrumented fetal lambs between 117 and 143 days' gestation were studied during 16 one-hour periods of maternally induced hypoxia. The aim was to test the hypothesis of a relationship between the concentration of circulating catecholamines and T-wave amplitude. The response to hypoxia was aged-dependent. Fetuses below 126 days of gestation did not react with electrocardiographic changes and output of epinephrine unless acidosis occurred. In more mature fetuses, hypoxia per se would induce a surge of epinephrine and changes in the ST waveform. Overall there was a strong correlation between the T/QRS ratio and the level of circulating epinephrine. During normoxia, epinephrine was undetectable (less than 0.1 nmol/L) in most fetuses; norepinephrine showed an increase at term. The analysis showed one fetus with chronic changes in the ST waveform (T/QRS ratio greater than 0.30) related to a marked increase in the plasma level of epinephrine in spite of normal blood gas values. These findings complement previous results in the acute and chronically instrumented fetal lamb and suggest that changes in the ST waveform expressed as T/QRS ratio identify a change to anaerobic myocardial metabolism mediated by beta-adrenergic stimulation.     

Lymphocyte beta-2-adrenoceptors and plasma catecholamines in fetal hypoxia

Conclusive evidence has been furnished that the beta 2-adrenoceptor density in circulating lymphocytes is related to that of beta 2-adrenoceptors in tissues from the same subjects. This study was designed to evaluate the effect of fetal hypoxia on lymphocyte beta 2-adrenoceptor density. The material consisted of 8 hypoxic newborns, 4 delivered by vacuum extraction and 4 by Caesarean section, after approximately 10 h parturition. The control group consisted of 8 vaginally delivered newborns without hypoxia. Umbilical plasma adrenaline and noradrenaline were significantly elevated in the hypoxic newborns. Their lymphocyte beta 2-adrenoceptor density was lower (p less than 0.01) than that in the controls. A plausible explanation for this finding might be downregulation of beta 2-adrenoceptors because of elevated plasma catecholamine level.     

Indicated preterm birth for fetal anomalies

Between 2% and 3% of pregnancies are complicated by fetal anomalies. For most anomalies, there is no advantage to late preterm or early-term delivery. The risks of maternal or fetal complication are specific for each anomaly. Very few anomalies pose potential maternal risk. Some anomalies carry ongoing risks to the fetus, such as an increased risk of fetal death, hemorrhage, or organ damage. In a limited number of select cases, the advantages of late preterm or early-term birth may include avoiding an ongoing risk of fetal death related to the anomaly, allowing delivery in a controlled setting with availability of subspecialists and allowing direct care for the neonate with organ injury. The optimal gestational age for delivery cannot be determined for all pregnancies complicated by fetal anomalies. For most pregnancies complicated by anomalies, there is no change to obstetrical management regarding timing of delivery. For those that may benefit from late preterm or early-term delivery, variability exists such that each management plan should be individualized.     

Low fetal oxygen saturation at birth and acidosis

OBJECTIVE: To measure umbilical cord blood oxygen saturation, to calculate preductal oxygen saturation at birth, and to assess its predictive value for acidosis. METHODS: Umbilical cord blood samples of 1537 live-born singleton neonates were analyzed. Oxygen saturation was measured by spectrophotometry; pH and base excess were measured by a pH and blood gas analyzer. Preductal oxygen saturation was calculated with an empirical equation. Acidosis was defined as 2 standard deviations (SDs) below the mean of umbilical artery (UA) pH or base excess (7.09 and -10.50 mmol/L, respectively). The predictive value for acidosis of UA and umbilical vein (UV) oxygen saturation and calculated preductal oxygen saturation was determined with receiver operating characteristic curves. RESULTS: The mean values (+/-SD) of UV, UA, and calculated preductal oxygen saturation were 52 +/- 18%, 26 +/- 17%, and 31 +/- 16%, respectively. Forty-seven neonates had UA pH less than 7.09 and 60 had UA base excess less than -10.50 mmol/L. The UV, UA, and calculated preductal oxygen saturation showed considerably weaker relations to UA base excess (multiple r(2) =.056,.003, and.017, respectively; P <.001) than to UA pH (multiple r(2) =.112,.126, and.148, respectively; P <. 001). Receiver operating characteristic areas under the curve were higher when predicting low pH compared with low base excess (for UV, UA, and calculated preductal oxygen saturation: 0.716 versus 0.699, 0.747 versus 0.586, and 0.765 versus 0.628, respectively). The difference was significant for UA oxygen saturation (P <.05). All tests showed high sensitivity and negative predictive values, but low specificity and positive predictive values. CONCLUSION: Low fetal oxygen saturation measured at birth seemed to be associated with low fetal pH and base excess values, but its predictive value for acidosis in an unselected population was limited, particularly if acidosis was metabolic.