Alan Cameron

Effect of direct fetal opioid analgesia on fetal hormonal and hemodynamic stress response to intrauterine needling

BackgroundWhether the fetus can experience pain remains controversial. During the last half of pregnancy, the neuroanatomic connections for nociception are in place, and the human fetus mounts sizable stress responses to physical insults. Analgesia has been recommended for intrauterine procedures or late termination, but without evidence that it works. The authors investigated whether fentanyl ablates the fetal stress response to needling using the model of delayed interval sampling during intrahepatic vein blood sampling and transfusion in alloimmunized fetuses undergoing intravascular transfusion between 20 and 35 weeks. MethodsIntravenous fentanyl (10 &mgr;g/kg estimated fetal weight × 1.25 placental correction) was given once at intrahepatic vein transfusion in 16 fetuses, and changes (posttransfusion − pretransfusion) in &bgr; endorphin, cortisol, and middle cerebral artery pulsatility index were compared with intrahepatic vein transfusions without fentanyl and with control transfusions at the placental cord insertion. ResultsFentanyl reduced the &bgr; endorphin (mean difference in changes, −70.3 pg/ml; 95% confidence interval, −121 to −19.2;P = 0.02) and middle cerebral artery pulsatility index response (mean difference, 0.65; 95% confidence interval, 0.26–1.04;P = 0.03), but not the cortisol response (mean difference, −10.9 ng/ml, 95% confidence interval, −24.7 to 2.9;P = 0.11) in fetuses who had paired intrahepatic vein transfusions with and without fentanyl. Comparison with control fetuses transfused without fentanyl indicated that the &bgr; endorphin and cerebral Doppler response to intrahepatic vein transfusion with fentanyl approached that of nonstressful placental cord transfusions. ConclusionsThe authors conclude that intravenous fentanyl attenuates the fetal stress response to intrahepatic vein needling.

Management of fetal alloimmune thrombocytopenia-a less invasive option?

Fetal alloimmune thrombocytopenia (FAITP) is a condition associated with significant infant morbidity and mortality. We report on the West of Scotland experience of 30 pregnancies complicated by FAITP over a 17-year period (1982-98). Management options included serial cordocentesis together with platelet transfusion, and maternal intravenous gammaglobulin (IVIgG) therapy. Of those pregnancies managed by serial cordocentesis all had poor outcomes. Weekly IVIgG was administered to the remaining pregnancies, all of which had a good outcome although four infants were thrombocytopenic at birth. None of these cases had previously been complicated by intracranial haemorrhage. In the milder end of the spectrum of FAITP we would suggest that IVIgG is an alternative treatment option.

Short term outcomes following intrauterine transfusion in Scotland

Aim To describe neonatal outcomes following intrauterine transfusion (IUT) for severe Rhesus isoimmunisation from 1993 to 2004. Results 116 neonates who had undergone 457 IUTs (median 4, range 1–9) were identified. Three neonates died, all before 1995 (two because of hypoxic ischaemic multiorgan failure and one because of overwhelming Escherichia coli sepsis). 13 neonates (11%) were delivered by emergency Caesarean section following either IUT complication or spontaneous onset of preterm labour. They were more likely to require intubation (p<0.0001), on-going respiratory support (p=0.0007) and an exchange transfusion (p=0.007). 23 (20%) required an exchange transfusion and 63 (54%) at least one top-up transfusion. Conclusions Management of severe Rhesus disease is associated with encouraging neonatal outcomes and most infants can be managed with phototherapy and a few top-up transfusions. IUT complications are rare but significantly increase neonatal mortality and morbidity. Antenatal counselling should address the likely postnatal course for these infants.

The observed to expected lung head ratio as a predictor of outcome in antenatal congenital diaphragmatic hernia

Introduction Congenital diaphragmatic hernia (CDH) has an incidence of 1 in 2500 and around 30% of babies with isolated CDH die from pulmonary hypoplasia. There have been several techniques describing prediction of postnatal outcome in antenatally diagnosed isolated CDH based on the estimation of residual lung capacity by US and MRI. Recently, the observed to expected lung head ratio (O/E LHR) has been validated as a reliable method of lung estimation by 2D ultrasound and is a marker of postnatal morbidity and mortality.1 The authors sought to determine if the O/E LHR predicts survival in our West of Scotland population. Methods The authors conducted a retrospective analysis of antenatally diagnosed isolated left-sided CDH cases referred to the Ian Donald Fetal Medicine unit, Queen Mothers Hospital, Glasgow from 2002 to 2009. Results 58 patients had an antenatal diagnosis of isolated fetal left-sided CDH, lung head ratios were available for 25 cases. The mortality was 29%, none of these patients underwent in utero fetal tracheal occlusion. There was no significant difference in conventional LHRs between the neonates that survived (n=18) and those that did not (n=7), p=0.11. Using the O/E LHRs however the neonates that survived had a significantly higher O/E ratio than those that did not (p=0.03). The liver position (being in the fetal chest or abdomen) did not affect the O/E ratios in the group of survivors (p=0.26) or non-survivors (p=0.44). Conclusion The authors have shown that the O/E LHR is a good predictor of mortality in our population of antenatally diagnosed CDH.