Fetal Scalp Research Articles

Fetal pulse oximetry for fetal assessment in labour.

The use of conventional cardiotocographic (CTG) monitoring of fetal well-being during labour is associated with an increased caesarean section rate, compared with intermittent auscultation of the fetal heart rate, resulting in a reduction in neonatal seizures, although no differences in other neonatal outcomes. To improve the sensitivity of this test and therefore reduce the number of caesarean sections performed for nonreassuring fetal status, several additional measures of evaluating fetal well-being have been considered. These have demonstrated some effect on reducing caesarean section rates, for example, fetal scalp blood sampling for pH estimation/lactate measurement. The adaptation of pulse oximetry for use in the unborn fetus could potentially contribute to improved evaluation during labour and therefore lead to a reduction in caesarean sections for nonreassuring fetal status, without any change in neonatal outcomes. To compare the effectiveness and safety of fetal intrapartum pulse oximetry with other surveillance techniques. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2014), contacted experts in the field and searched reference lists of retrieved studies. In previous versions of this review, we performed additional searches of MEDLINE, Embase and Current Contents. These searches were discontinued for this review update, as they consistently failed to identify any trials that were not shown in the Cochrane Pregnancy and Childbirth Group's Trials Register. All published and unpublished randomised controlled trials that compared maternal and fetal outcomes when fetal pulse oximetry was used in labour, (i) with or without concurrent use of conventional fetal surveillance, that is, cardiotocography (CTG), compared with using CTG alone or (ii) with or without concurrent use of both CTG and other method(s) of fetal surveillance, such as fetal electrocardiography (ECG) plus CTG. At least two independent review authors performed data extraction. We sought additional information from the investigators of three of the reported trials. We included seven published trials: six comparing fetal pulse oximetry and CTG with CTG alone (or when fetal pulse oximetry values were blinded) and one comparing fetal pulse oximetry plus CTG with fetal ECG plus CTG. The published trials, with some unpublished data, were at high risk of bias in terms of the impractical nature of blinding participants and clinicians, as well as high risk or unclear risk of bias for outcome assessor for all but one report. Selection bias, attrition bias, reporting bias and other sources of bias were of low or unclear risk. The trials reported on a total of 8013 pregnancies. Differing entry criteria necessitated separate analyses, rather than meta-analysis of all trials.Systematic review of four trials from 34 weeks not requiring fetal blood sampling (FBS) prior to study entry showed no evidence of differences in the overall caesarean section rate between those monitored with fetal oximetry and those not monitored with fetal pulse oximetry or for whom the fetal pulse oximetry results were masked (average risk ratio (RR) 0.99 using random-effects, 95% confidence intervals (CI) 0.86 to 1.13, n = 4008, I² = 45%). There was evidence of a higher risk of caesarean section in the group with fetal oximetry plus CTG than in the group with fetal ECG plus CTG (one study, n = 180, RR 1.56, 95% CI 1.06 to 2.29). Neonatal seizures and neonatal encephalopathy were rare in both groups. No studies reported details of long-term disability.There was evidence of a decrease in caesarean section for nonreassuring fetal status in the fetal pulse oximetry plus CTG group compared to the CTG group, gestation from 34 weeks (average RR (random-effects) 0.65, 95% CI 0.46 to 0.90, n = 4008, I² = 63%). There was no evidence of differences between groups in caesarean section for dystocia, although the overall incidence rates varied between the trials. The addition of fetal pulse oximetry does not reduce overall caesarean section rates. One study found a higher caesarean section rate in the group monitored with fetal pulse oximetry plus CTG, compared with fetal ECG plus CTG. The data provide limited support for the use of fetal pulse oximetry when used in the presence of a nonreassuring CTG, to reduce caesarean section for nonreassuring fetal status. A better method than pulse oximetry is required to enhance the overall evaluation of fetal well-being in labour.

Hepatitis B and C in pregnancy: a review and recommendations for care.

Our objective was to provide a comprehensive review of the current knowledge regarding pregnancy and hepatitis B virus (HBV) or hepatitis C virus (HCV) infection as well as recent efforts to reduce the rate of mother-to-child transmission (MTCT). Maternal infection with either HBV or HCV has been linked to adverse pregnancy and birth outcomes, including MTCT. MTCT for HBV has been reduced to approximately 5% overall in countries including the US that have instituted postpartum neonatal HBV vaccination and immunoprophylaxis with hepatitis B immune globulin. However, the rate of transmission of HBV to newborns is nearly 30% when maternal HBV levels are greater than 200 000 IU ml(-1) (>6 log10 copies ml(-1)). For these patients, new guidelines from the European Association for the Study of the Liver (EASL) and the Asian Pacific Association for the Study of the Liver (APASL) indicate that, in addition to neonatal vaccination and immunoprophylaxis, treating with antiviral agents such as tenofovir disoproxil fumarate or telbivudine during pregnancy beginning at 32 weeks of gestation is safe and effective in preventing MTCT. In contrast to HBV, no therapeutic agents are yet available or recommended to further decrease the risk of MTCT of HCV, which remains 3 to 10%. HCV MTCT can be minimized by avoiding fetal scalp electrodes and birth trauma whenever possible. Young women with HCV should be referred for treatment post delivery, and neonates should be closely followed to rule out infection. New, better-tolerated treatment regimens for HCV are now available, which should improve outcomes for all infected individuals.

Introducing routine fetal scalp blood analysis (FSBA) for suspicious or pathologic fetal heart rate – effect on mode of delivery, fetal and maternal outcome

Introduction: Despite a good sensitivity (80 – 91%) for fetal hypoxia or acidosis, specificity of fetal heart rate (FHR) analysis is low (9 – 63%). Fetal scalp blood analysis (FSBA) is a complementary tool for the interpretation of pathologic FHR. However FSBA is an invasive procedure and could lead to complications.

Comparison of the Nova StatStrip(R) Lactate versus the Arkray Lactate Pro(R) meters for fetal scalp lactate measurement

Comparison of the Nova StatStrip(R) Lactate versus the Arkray Lactate Pro(R) meters for fetal scalp lactate measurement

Principal component model for maternal ECG extraction in fetal QRS detection

Fetal cardiac monitoring using noninvasive abdominal leads can provide important information on fetal well-being. However, extraction of fetal electrocardiogram (fECG) from abdominal signals is often problematic because of the higher amplitude maternal ECG (mECG). The aim of this study was to introduce a principal component model for removing the maternal ECG from abdominal signals. The proposed method removes mECG waveforms with high accuracy even though abdominal movements cause morphological deviation to mECG complexes. The method can be used for single or multi-lead measurements. The proposed method was tested using 175 1 min long abdominal measurements with fetal QRS annotation markers acquired from a fetal scalp electrode. Using the presented mECG removing algorithm and matched filtering based fQRS detector, 95% sensitivity for fQRS detection and 4.84 ms RMS error for fetal RR-interval estimation were acquired.

Safe Prevention of the Primary Cesarean Delivery

Safe Prevention of the Primary Cesarean Delivery

Perinatal aspects of haemophilia.

Haemophilia is an X-linked recessive genetic disease of haemostasis. Women carriers may present with a bleeding tendency similar to milder forms of the disease. Haemophilic newborns present risk factors and patterns of bleeding that are challenging. Identification of carriers and genetic counselling before conception is considered optimal to help decide on available conception options and during pregnancy to help minimise bleeding risks for both carrier mother and affected baby. Preimplantation genetic diagnosis is attractive to many couples at risk of having a child with haemophilia and relevant technology is becoming more available although it has both practical and ethical limitations. Pregnancy in carriers should be managed by a multidisciplinary team in a comprehensive treatment centre. The optimal mode of delivery for carriers expecting a baby known to have or being at risk of haemophilia is an issue of great debate. The general consensus among authors is avoidance of instrumental delivery, foetal scalp electrodes and blood sampling in pregnancies at risk of carrying an affected foetus, as well as early recourse to Caesarean section as guided by obstetric indications. Intracranial haemorrhage, although infrequent, is one the most devastating types of bleeding in haemophilic newborns and can occur regardless of the mode of delivery or the severity of haemophilia. Early screening is proposed for all infants with severe or moderate haemophilia who have had traumatic delivery and/or have evidence of extracranial haemorrhage. Women with postpartum haemorrhage should have a bleeding work-up.

Cardiotocography patterns and risk of intrapartum fetal acidemia.

To identify cardiotocography (CTG) patterns associated with increased risk of intrapartum fetal acidemia. A prospective observational cohort study of 1070 women with fetal scalp blood sampling (FBS) during labor was conducted at Karolinska University Hospital, Stockholm, Sweden. Women with a nonreassuring CTG pattern underwent FBS, and lactate concentration was measured at the bedside. Lactate concentrations >4.8 mmol/L were defined as fetal acidemia. A senior obstetrician, blinded to the lactate concentration at FBS, visually interpreted the CTG tracings that had prompted FBS. There were 2134 FBSs performed on 1070 laboring women, constituting 11% of all deliveries at this labor ward. The CTG patterns with the highest frequency of lactacidemia at FBS were late or severe variable decelerations combined with tachycardia (20%-25% at first FBS and 33%-49% at last FBS). With a normal baseline fetal heart rate, normal variability, and absence of serious decelerations, the fetal scalp blood lactate concentration at the first FBS was normal in 97.5% of cases. The group with isolated reduced variability had no increased prevalence of acidemia and median lactate concentration did not differ from the normal group. Isolated reduced variability is in most cases not a sign of hypoxia. If development of hypoxia is ruled out with one FBS, this pattern does not require monitoring with repetitive FBSs throughout labor. Late decelerations and severe variable decelerations increase the risk for intrapartum fetal metabolic acidemia to the same extent. The combination of these decelerations and tachycardia was associated with the highest rate of fetal metabolic acidemia.

The Risks and Benefits of Internal Monitors in Laboring Patients

Objective The purpose of this study was to estimate the impact of internal monitors (fetal scalp electrode [FSE] and intrauterine pressure catheter [IUPC]) on maternal and neonatal outcomes. Study Design The study comprised a retrospective cohort of all women who were admitted for labor from 2004-2008. Women with internal monitors (FSE, IUPC, or both) were compared with women without internal monitors. Maternal outcomes were maternal fever and cesarean delivery. Neonatal outcomes were a composite of 5-minute Apgar score of ≤3, cord pH Results Of 6445 subjects, 3944 women (61.2%) had internal monitors. Women with internal monitors were more likely to have a fever than women without internal monitors (11.7% vs 4.5%; adjusted odds ratio [AOR], 2.0; 95% confidence interval [CI], 1.6–2.5). FSE alone was not associated with an increased risk of fever (AOR, 1.5; 95% CI, 1.0–2.1), but IUPC alone was (AOR, 2.4; 95% CI, 1.8–3.2). The risk of cesarean delivery was higher in women with internal monitors (18.6% vs 9.7%; AOR, 1.3; 95% CI, 1.0–1.5). Risk of cesarean delivery was lower in women with an FSE alone (AOR, 0.5; 95% CI, 0.4–0.7) but higher in women with both an FSE and an IUPC (AOR, 1.6; 95% CI, 1.4–2.0). Risk of the composite neonatal outcome was not higher in women with internal monitors (3.3% vs 3.6%; AOR, 0.8; 95% CI, 0.6–1.1). Conclusion Routine use of an IUPC in laboring patients should be avoided because of an increased risk of maternal fever.

PFM.32 Third trimester amniocentesis for the diagnosis of haemophilia A and B

Haemophilia A and B are bleeding disorders inherited in an X linked recessive manner. Female carriers of these conditions have a 50% chance of delivering an affected infant when pregnant...

PLD.27 Fetal Blood Sampling in the Operating Theatre – Advised or Indefensible?

There is a body of opinion within expert witnesses that suggests that the undertaking of fetal scalp blood sampling (FBS) in a theatre setting prior to performing a perceived difficult...

PMM.03 The management of patients with primary immune thrombocytopenia during pregnancy in Leeds

Introduction and objectivesPrimary immune thrombocytopenia (ITP) is a rare autoimmune condition that affects women of child bearing age and accounts for around 3% of thrombocytopenias at delivery.1 It can lead...

Fetal scalp blood sampling during labor: an appraisal of the physiological basis and scientific evidence.

Fetal cardiotocography is characterized by low specificity; therefore, in an attempt to ensure fetal well-being, fetal scalp blood sampling has been recommended by most obstetric societies in the case of a non-reassuring cardiotocography. The scientific agreement on the evidence for using fetal scalp blood sampling to decrease the rate of operative delivery for fetal distress is ambiguous. Based on the same studies, a Cochrane review states that fetal scalp blood sampling increases the rate of instrumental delivery while decreasing neonatal acidosis, whereas the National Institute of Health and Clinical Excellence guideline considers that fetal scalp blood sampling decreases instrumental delivery without differences in other outcome variables. The fetal scalp is supplied by vessels outside the skull below the level of the cranial vault, which is likely to be compressed during contractions. The self-regulated redistribution of oxygenated blood from peripheral to central organs causes peripheral ischemia, thus theoretically bringing into question the scalp capillary bed as representative of the central circulation.

A critical appraisal of the evidence for using cardiotocography plus ECG ST interval analysis for fetal surveillance in labor. Part II: the meta-analyses.

We appraised the methodology, execution and quality of the five published meta-analyses that are based on the five randomized controlled trials which compared cardiotocography (CTG)+ST analysis to cardiotocography. The meta-analyses contained errors, either created de novo in handling of original data or from a failure to recognize essential differences among the randomized controlled trials, particularly in their inclusion criteria and outcome parameters. No meta-analysis contained complete and relevant data from all five randomized controlled trials. We believe that one randomized controlled trial excluded in two of the meta-analyses should have been included, whereas one randomized controlled trial that was included in all meta-analyses, should have been excluded. After correction of the uncovered errors and exclusion of the randomized controlled trial that we deemed inappropriate, our new meta-analysis showed that CTG+ST monitoring significantly reduces the fetal scalp blood sampling usage (risk ratio 0.64; 95% confidence interval 0.47–0.88), total operative delivery rate (0.93; 0.88–0.99) and metabolic acidosis rate (0.61; 0.41–0.91).

Fetal scalp blood sampling in labor--a review.

During the 1970s and 1980s, electronic fetal monitoring and fetal scalp blood sampling were introduced without robust evidence. With a methodical review of the published literature, and using one randomized controlled trial, seven controlled studies, nine randomized studies of various surveillance methods and data from the Danish National Birth Registry, we have assessed the usefulness of fetal scalp blood sampling as a complementary tool to improve the specificity and sensitivity of electronic cardiotocography. Based on heterogeneous studies of modest quality with somewhat inconsistent results, we conclude that fetal scalp blood sampling in conjunction with cardiotocography can reduce the risk of operative delivery. Fetal scalp blood sampling can provide additional information on fetal wellbeing and fetal reserves at a time before decisions are made concerning the need for and timing of operative delivery and the choice of anesthesia, and be an adjunct in the interpretation of cardiotocography patterns.

Influence of maternal body mass index on accuracy and reliability of external fetal monitoring techniques

To evaluate the performance of external electronic fetal heart rate and uterine contraction monitoring according to maternal body mass index. Secondary analysis of prospective equivalence study. Three US urban teaching hospitals. Seventy-four parturients with a normal term pregnancy. The parent study assessed performance of two methods of external fetal heart rate monitoring (abdominal fetal electrocardiogram and Doppler ultrasound) and of uterine contraction monitoring (electrohystero-graphy and tocodynamometry) compared with internal monitoring with fetal scalp electrode and intrauterine pressure transducer. Reliability of external techniques was assessed by the success rate and positive percent agreement with internal methods. Bland-Altman analysis determined accuracy. We analyzed data from that study according to maternal body mass index. We assessed the relationship between body mass index and monitor performance with linear regression, using body mass index as the independent variable and measures of reliability and accuracy as dependent variables. There was no significant association between maternal body mass index and any measure of reliability or accuracy for abdominal fetal electrocardiogram. By contrast, the overall positive percent agreement for Doppler ultrasound declined (p=0.042), and the root mean square error from the Bland-Altman analysis increased in the first stage (p=0.029) with increasing body mass index. Uterine contraction recordings from electrohysterography and tocodynamometry showed no significant deterioration related to maternal body mass index. Accuracy and reliability of fetal heart rate monitoring using abdominal fetal electrocardiogram was unaffected by maternal obesity, whereas performance of ultrasound degraded directly with maternal size. Both electrohysterography and tocodynamometry were unperturbed by obesity.

Scientific and clinical evidence for the use of fetal ECG ST segment analysis (STAN)

Fetal electrocardiogram waveform analysis has been studied for many decades, but it is only in the last 20years that computerization has made real-time analysis practical for clinical use. Changes in the ST segment have been shown to correlate with fetal condition, in particular with acid-base status. Meta-analysis of randomized trials (five in total, four using the computerized system) has shown that use of computerized ST segment analysis (STAN) reduces the need for fetal blood sampling by about 40%. However, although there are trends to lower rates of low Apgar scores and acidosis, the differences are not statistically significant. There is no effect on cesarean section rates. Disadvantages include the need for amniotic membranes to be ruptured so that a fetal scalp electrode can be applied, and the need for STAN values to be interpreted in conjunction with detailed fetal heart rate pattern analysis.

Comparison of outcomes between operative vaginal deliveries and spontaneous vaginal deliveries in southeast Nigeria

ObjectiveTo evaluate the incidence of, indications for, and outcome of operative vaginal deliveries compared with spontaneous vaginal deliveries in southeast Nigeria. MethodsA retrospective cohort study was conducted involving cases of operative vaginal delivery performed at Ebonyi State University Teaching Hospital over a 10-year period. Data on the procedures were abstracted from the operation notes of the medical records of parturients. ResultsAn incidence of 4.7% (n=461) was recorded. The most common indications for vacuum and forceps delivery were prolonged second stage of labor (44.9%) and poor maternal effort (27.8%). The only indication for destructive operation was intrauterine fetal death (3.7%). The risk ratio (RR) for hemorrhage/vulvar hematoma was 1.14 (95% confidence interval [CI], 0.53–2.48) for vacuum-assisted delivery and 5.49 (95% CI, 0.82–36.64) for forceps delivery. The RR for genital laceration was 1.21 (95% CI, 0.44–3.30) for vacuum-assisted delivery and 9.41 (95% CI, 1.33–66.65) for forceps delivery. The risk of fetal scalp bruises and caput succedaneum was higher for operative vaginal delivery than for spontaneous vaginal delivery, with no significant difference in maternal morbidity. The perinatal mortality rate was 0.9 per 1000 live births. ConclusionOperative vaginal delivery by experienced healthcare providers is associated with good obstetric outcomes with minimal risk.

Fetal scalp blood sampling during labour: is it a useful diagnostic test or a historical test that no longer has a place in modern clinical obstetrics?

Fetal scalp blood sampling during labour: is it a useful diagnostic test or a historical test that no longer has a place in modern clinical obstetrics?

Complete involution of prenatally-diagnosed fetal scalp hemangioma

ObjectiveScalp hemangioma is a rare benign fetal tumor. Here, we describe the detailed imaging features and natural course of a fetal scalp hemangioma until 1 year of age. Case reportWe encountered a case of scalp hemangioma at 23 weeks’ gestation by prenatal ultrasonography and magnetic resonance imaging. The mass persisted postnatally, but spontaneously regressed after birth. ConclusionProper diagnosis with prenatal ultrasonography and magnetic resonance imaging is important when a scalp mass is suspected in utero. Continuation of the pregnancy after appropriate counseling is prudent, considering the favorable prognosis and the rate of spontaneous regression of uncomplicated cases.