New possibilities for ST analysis - A post-hoc analysis on the Dutch STAN RCT

BACKGROUND

The diagnostic value of ST analysis of the fetal electrocardiogram (fECG) during labor is uncertain. False alarms (ST events) may be explained by physiological variation of the fetal electrical heart axis. Adjusted ST events, based on a relative rather than an absolute rise from baseline, correct for this variation and may improve the diagnostic accuracy of ST analysis.

AIMS

Determine the optimal cut-off for relative ST events in fECG to detect fetal metabolic acidosis.

STUDY DESIGN

Post-hoc analysis on fECG tracings from the Dutch STAN trial (STAN+CTG branch).

SUBJECTS

1328 term singleton fetuses with scalp ECG tracing during labor, including 10 cases of metabolic acidosis.

OUTCOME MEASURES

Cut-off value for relative ST events at the point closest to (0,1) in the receiver operating characteristic (ROC) curve with corresponding sensitivity and specificity.

RESULTS

Relative baseline ST events had an optimal cut-off at an increment of 85% from baseline. Relative ST events had a sensitivity of 90% and specificity of 80%.

CONCLUSIONS

Adjusting the current definition of ST events may improve ST analysis, making it independent of CTG interpretation.

Cost-effectiveness of induction of labour at term with a Foley catheter compared to vaginal prostaglandin E₂ gel (PROBAAT trial)

OBJECTIVE

To assess the economic consequences of labour induction with Foley catheter compared to prostaglandin E2 gel.

DESIGN

Economic evaluation alongside a randomised controlled trial.

SETTING

Obstetric departments of one university and 11 teaching hospitals in the Netherlands.

POPULATION

Women scheduled for labour induction with a singleton pregnancy in cephalic presentation at term, intact membranes and an unfavourable cervix; and without previous caesarean section.

METHODS

Cost-effectiveness analysis from a hospital perspective.

MAIN OUTCOME MEASURES

We estimated direct medical costs associated with healthcare utilisation from randomisation to 6 weeks postpartum. For caesarean section rate, and maternal and neonatal morbidity we calculated the incremental cost-effectiveness ratios, which represent the costs to prevent one of these adverse outcomes.

RESULTS

Mean costs per woman in the Foley catheter group (n = 411) and in the prostaglandin E₂ gel group (n = 408), were €3297 versus €3075, respectively, with an average difference of €222 (95% confidence interval -€157 to €633). In the Foley catheter group we observed higher costs due to longer labour ward occupation and less cost related to induction material and neonatal admissions. Foley catheter induction showed a comparable caesarean section rate compared with prostaglandin induction, therefore the incremental cost-effectiveness ratio was not informative. Foley induction resulted in fewer neonatal admissions (incremental cost-effectiveness ratio €2708) and asphyxia/postpartum haemorrhage (incremental cost-effectiveness ratios €5257) compared with prostaglandin induction.

CONCLUSIONS

Foley catheter and prostaglandin E2 labour induction generate comparable costs.

Is intrapartum fever associated with ST-waveform changes of the fetal electrocardiogram? A retrospective cohort study

OBJECTIVE

To investigate the association between maternal intrapartum fever and ST-waveform changes of the fetal electrocardiogram.

DESIGN

Retrospective cohort study.

SETTING

Three academic and six non-academic teaching hospitals in the Netherlands.

POPULATION

Labouring women with a high-risk singleton pregnancy in cephalic position beyond 36 weeks of gestation.

METHODS

We studied 142 women with fever (≥38.0°C) during labour and 141 women with normal temperature who had been included in two previous studies. In both groups, we counted the number and type of ST-events and classified them as significant (intervention needed) or not significant, based on STAN(®) clinical guidelines.

MAIN OUTCOME MEASURES

Number and type of ST-events.

RESULTS

Both univariable and multivariable regression analysis showed no association between the presence of maternal intrapartum fever and the number or type of ST-events.

CONCLUSIONS

Maternal intrapartum fever is not associated with ST-segment changes of the fetal electrocardiogram. Interpretation of ST-changes in labouring women with fever should therefore not differ from other situations.

Delivery of healthy babies after natalizumab use for multiple sclerosis: a report of two cases

BACKGROUND

In current literature, no data on safety in pregnancy for new drugs in the treatment of multiple sclerosis (MS) like natalizumab (Tysabri®), a humanized monoclonal antibody against α4 integrins, are yet available. In the management of MS, natalizumab is the first monoclonal antibody approved to the market.

METHODS

We describe the pregnancy and outcome in two women with MS using natalizumab. The first patient used it in the periconceptional period, and the second patient used it in both the periconceptional period and throughout gestation.

RESULTS

The antenatal course of the first patient was complicated by an exacerbation of MS. The second patient did not experience MS relapses during pregnancy, while still using natalizumab. The newborns did not show any abnormalities postnatal and at 6 weeks' follow-up.

CONCLUSIONS

This is the first detailed report on pregnancy and delivery of two babies after maternal treatment of MS with natalizumab. From the small number of cases on the usage of natalizumab during pregnancy in literature, we cannot conclude whether the use of natalizumab is safe, and long-term effects are not known. Further research is needed to establish the exact effects on pregnancy and intrauterine development as well as the long-term effects. Prenatal counseling with thorough explanation of the risks and careful decision making is advisable.

[Alpha-foetoprotein assessment in amniotic fluid for the detection of neural tube defects: limited added value beyond week 20 ultrasound; retrospective study]

OBJECTIVE

To evaluate the diagnostic additional value of routine alpha-foetoprotein (AFP) assessment in amniotic fluid for the detection of neural tube defects (NTDs), compared with week 20 ultrasonographic examination.

DESIGN

Retrospective.

METHOD

We retrospectively determined AFP concentrations in amniotic fluid obtained from 7981 women who had undergone amniocentesis for karyotyping and AFP assessment. An AFP concentration greater than 2.5 times the median was considered abnormal. Women were categorised into 4 groups based on the indication for invasive prenatal diagnostic assessment: advanced maternal age (group I; n = 6179), increased risk of foetal NTDs (group II; n = 258), ultrasonographically confirmed foetal NTDs (group III; n = 55) or other indications (group IV; n = 1489).

RESULTS

In group I, 18 of 6179 samples had increased AFP levels (0.3%), 2 of which were associated with NTDs. In group II, 2 of 258 samples had increased AFP levels (0.8%); both were associated with NTDs. Increased AFP levels were found in 44 of 55 samples from group III (80%), and 223 of 1489 samples from group IV (15.0%).

CONCLUSION

Routine assessment of AFP in amniotic fluid based on advanced maternal age provides little additional value in the detection of NTDs beyond that of week 20 ultrasound.

Earliest gestational age for fetal sexing in cell-free maternal plasma

OBJECTIVES

To evaluate at what gestational age fetal DNA can reliably be detected at the earliest in maternal plasma.

METHODS

We performed consecutive blood sampling in the first trimester of pregnancy in 17 women who were pregnant after in vitro fertilization (IVF) or intrauterine insemination (IUI). DNA was isolated and the Y-chromosome specific SRY was amplified by real-time polymerase chain reaction (PCR). We likewise studied 31 women prior to invasive prenatal diagnosis procedures for test validation purposes. All test results were compared to cytogenetic sex or sex at birth.

RESULTS

The earliest SRY detection was at a gestational age of 5 weeks and 2 days. In none of 4 pregnancies ending in a miscarriage was SRY detected. We detected SRY in maternal plasma in 1 of 2 patients (50%) carrying a male fetus at a gestational age of 5 weeks, in 4 of 5 (80%) at a gestational age of 7 weeks, in 4 of 4 (100%) at a gestational age of 9 weeks. In all 7 women pregnant with a male fetus, the correct fetal sex was detected by 10 weeks. In none of the 6 patients who delivered a girl was SRY detected. In the validation group, SRY was detected in 13 of the 13 male, and none of the 18 female fetuses.

CONCLUSIONS

We conclude that real-time PCR of the SRY gene promises to be a reliable technique for early fetal sexing in maternal plasma.

Is the correlation between fetal oxygen saturation and blood pH sufficient for the use of fetal pulse oximetry?

OBJECTIVES

Fetal pulse oximetry was performed during labor in high-risk cases for fetal distress to determine the diagnostic value of this method.

METHODS

The fetal SpO2 values were blinded from the obstetrician so that these values did not influence clinical decisions. Mean and lowest SpO2 measurements for the last 30 min prior to either fetal scalp blood sampling or delivery were correlated with scalp pH or pH from the umbilical artery.

RESULTS

No significant correlation was found between pH and mean fetal oxygen saturation (correlation coefficient -0.02, p = 0.9). There was no significant correlation between pH and lowest fetal oxygen saturation (correlation coefficient 0.04, p = 0.84). Concerning the feasibility of the method, we found that only 23 of 65 included patients were suitable for analysis; in 20% of cases, we were not able to perform a SpO2 measurement.

CONCLUSIONS

None of three cases with pH below 7.05 would have been detected using mean SpO2 over the last 30 min prior to fetal scalp blood sampling or delivery. Only one case would have been detected using the lowest SpO2 measurement over this period. We conclude that fetal SpO2 measurements during labor are of poor diagnostic value, with a disappointing feasibility and therefore are not ready for implementing into daily clinical practice.