MemPrep, a new technology for isolating organellar membranes provides fingerprints of lipid bilayer stress

Biological membranes have a stunning ability to adapt their composition in response to physiological stress and metabolic challenges. Little is known how such perturbations affect individual organelles in eukaryotic cells. Pioneering work has provided insights into the subcellular distribution of lipids in the yeast Saccharomyces cerevisiae, but the composition of the endoplasmic reticulum (ER) membrane, which also crucially regulates lipid metabolism and the unfolded protein response, remains insufficiently characterized. Here, we describe a method for purifying organelle membranes from yeast, MemPrep. We demonstrate the purity of our ER membrane preparations by proteomics, and document the general utility of MemPrep by isolating vacuolar membranes. Quantitative lipidomics establishes the lipid composition of the ER and the vacuolar membrane. Our findings provide a baseline for studying membrane protein biogenesis and have important implications for understanding the role of lipids in regulating the unfolded protein response (UPR). The combined preparative and analytical MemPrep approach uncovers dynamic remodeling of ER membranes in stressed cells and establishes distinct molecular fingerprints of lipid bilayer stress.

Remodeling of yeast vacuole membrane lipidomes from the log (one phase) to stationary stage (two phases)

Upon nutrient limitation, budding yeast of Saccharomyces cerevisiae shift from fast growth (the log stage) to quiescence (the stationary stage). This shift is accompanied by liquid-liquid phase separation in the membrane of the vacuole, an endosomal organelle. Recent work indicates that the resulting micrometer-scale domains in vacuole membranes enable yeast to survive periods of stress. An outstanding question is which molecular changes might cause this membrane phase separation. Here, we conduct lipidomics of vacuole membranes in both the log and stationary stages. Isolation of pure vacuole membranes is challenging in the stationary stage, when lipid droplets are in close contact with vacuoles. Immuno-isolation has previously been shown to successfully purify log-stage vacuole membranes with high organelle specificity, but it was not previously possible to immuno-isolate stationary-stage vacuole membranes. Here, we develop Mam3 as a bait protein for vacuole immuno-isolation, and demonstrate low contamination by non-vacuolar membranes. We find that stationary-stage vacuole membranes contain surprisingly high fractions of phosphatidylcholine lipids (∼40%), roughly twice as much as log-stage membranes. Moreover, in the stationary stage, these lipids have higher melting temperatures, due to longer and more saturated acyl chains. Another surprise is that no significant change in sterol content is observed. These lipidomic changes, which are largely reflected on the whole-cell level, fit within the predominant view that phase separation in membranes requires at least three types of molecules to be present: lipids with high melting temperatures, lipids with low melting temperatures, and sterols.

Cysteine cross-linking in native membranes establishes the transmembrane architecture of Ire1

The ER is a key organelle of membrane biogenesis and crucial for the folding of both membrane and secretory proteins. Sensors of the unfolded protein response (UPR) monitor the unfolded protein load in the ER and convey effector functions for maintaining ER homeostasis. Aberrant compositions of the ER membrane, referred to as lipid bilayer stress, are equally potent activators of the UPR. How the distinct signals from lipid bilayer stress and unfolded proteins are processed by the conserved UPR transducer Ire1 remains unknown. Here, we have generated a functional, cysteine-less variant of Ire1 and performed systematic cysteine cross-linking experiments in native membranes to establish its transmembrane architecture in signaling-active clusters. We show that the transmembrane helices of two neighboring Ire1 molecules adopt an X-shaped configuration independent of the primary cause for ER stress. This suggests that different forms of stress converge in a common, signaling-active transmembrane architecture of Ire1.

Brain volume increase and neuronal plasticity underly predator-induced morphological defense expression in Daphnia longicephala

Predator-induced phenotypic plasticity describes the ability of prey to respond to an increased predation risk by developing adaptive phenotypes. Upon the perception of chemical predator cues, the freshwater crustacean Daphnia longicephala develops defensive crests against its predator Notonecta spec. (Heteroptera). Chemical predator perception initiates a cascade of biological reactions that leads to the development of these morphological features. Neuronal signaling is a central component in this series, however how the nervous system perceives and integrates environmental signals is not well understood. As neuronal activity is often accompanied by functional and structural plasticity of the nervous system, we hypothesized that predator perception is associated with structural and functional changes of nervous tissues. We observe structural plasticity as a volume increase of the central brain, which is independent of the total number of brain cells. In addition, we find functional plasticity in form of an increased number of inhibitory post-synaptic sites during the initial stage of defense development. Our results indicate a structural rewiring of nerve-cell connections upon predator perception and provide important insights into how the nervous system of prey species interprets predator cues and develops cost-benefit optimized defenses.

A Quantitative Analysis of Cellular Lipid Compositions During Acute Proteotoxic ER Stress Reveals Specificity in the Production of Asymmetric Lipids

The unfolded protein response (UPR) is central to endoplasmic reticulum (ER) homeostasis by controlling its size and protein folding capacity. When activated by unfolded proteins in the ER-lumen or aberrant lipid compositions, the UPR adjusts the expression of hundreds of target genes to counteract ER stress. The proteotoxic drugs dithiothreitol (DTT) and tunicamycin (TM) are commonly used to induce misfolding of proteins in the ER and to study the UPR. However, their potential impact on the cellular lipid composition has never been systematically addressed. Here, we report the quantitative, cellular lipid composition of Saccharomyces cerevisiae during acute, proteotoxic stress in both rich and synthetic media. We show that DTT causes rapid remodeling of the lipidome when used in rich medium at growth-inhibitory concentrations, while TM has only a marginal impact on the lipidome under our conditions of cultivation. We formulate recommendations on how to study UPR activation by proteotoxic stress without interferences from a perturbed lipid metabolism. Furthermore, our data suggest an intricate connection between the cellular growth rate, the abundance of the ER, and the metabolism of fatty acids. We show that Saccharomyces cerevisiae can produce asymmetric lipids with two saturated fatty acyl chains differing substantially in length. These observations indicate that the pairing of saturated fatty acyl chains is tightly controlled and suggest an evolutionary conservation of asymmetric lipids and their biosynthetic machineries.

Regulation of lipid saturation without sensing membrane fluidity

Cells maintain membrane fluidity by regulating lipid saturation, but the molecular mechanisms of this homeoviscous adaptation remain poorly understood. We have reconstituted the core machinery for regulating lipid saturation in baker’s yeast to study its molecular mechanism. By combining molecular dynamics simulations with experiments, we uncover a remarkable sensitivity of the transcriptional regulator Mga2 to the abundance, position, and configuration of double bonds in lipid acyl chains, and provide insights into the molecular rules of membrane adaptation. Our data challenge the prevailing hypothesis that membrane fluidity serves as the measured variable for regulating lipid saturation. Rather, we show that Mga2 senses the molecular lipid-packing density in a defined region of the membrane. Our findings suggest that membrane property sensors have evolved remarkable sensitivities to highly specific aspects of membrane structure and dynamics, thus paving the way toward the development of genetically encoded reporters for such properties in the future.

Cells maintain membrane fluidity by regulating lipid saturation, but the molecular mechanisms of this homeoviscous adaptation remain poorly understood. Here authors reconstituted the core machinery for regulating lipid saturation in baker’s yeast to directly characterize its response to defined membrane environments and uncover its mode-of-action.

High-Sensitivity Dry Rehydratable Film Method for Enumeration of Coliforms in Dairy Products: Collaborative Study

A dry-film coliform count plate that is inoculated with 5 mL sample was compared with the Violet Red Bile Agar plate method in a collaborative study by 18 laboratories. Products analyzed were 2% milk, chocolate milk, cream, vanilla ice cream, cottage cheese, and cheese. Collaborators tested blind duplicate uninoculated samples and samples inoculated at low, medium, and high level. Significantly (P< 0.05) higher numbers of coliforms were recovered by the dry-film method from 2% milk samples at the 3 inoculum levels, the chocolate milk at the low- and high-inoculum levels, and the cream at the high-inoculum level. Significantly higher counts were obtained by the agar method for cottage cheese samples at the low-inoculum level. The repeatability standard deviation for the dry-film method was significantly higher for the high-inoculum level chocolate milk sample and the medium-inoculum level cottage cheese. The same statistic was significantly higher for the agar method at all 3 inoculum levels in the 2% milk and the medium-inoculum level cream. The high-sensitivity dry rehydratable film method for enumeration of coliforms in dairy products has been adopted first action by AOAC INTERNATIONAL.

An Emerging Group of Membrane Property Sensors Controls the Physical State of Organellar Membranes to Maintain Their Identity

The biological membranes of eukaryotic cells harbor sensitive surveillance systems to establish, sense, and maintain characteristic physicochemical properties that ultimately define organelle identity. They are fundamentally important for membrane homeostasis and play active roles in cellular signaling, protein sorting, and the formation of vesicular carriers. Here, we compare the molecular mechanisms of Mga2 and Ire1, two sensors involved in the regulation of fatty acid desaturation and the response to unfolded proteins and lipid bilayer stress in order to identify their commonalities and specializations. We will speculate on the cellular significance of membrane property sensors in other organelles and discuss their putative mechanisms. Based on these findings, we propose membrane property sensors as an emerging class of proteins with wide implications for organelle communication and function.

A Modular High-Throughput In Vivo Screening Platform Based on Chimeric Bacterial Receptors

Multidrug resistance (MDR) is a globally relevant problem that requires novel approaches. Two-component systems are a promising, yet untapped target for novel antibacterials. They are prevalent in bacteria and absent in mammals, and their activity can be modulated upon perception of various stimuli. Screening pre-existing compound libraries could reveal small molecules that inhibit stimulus-perception by virulence-modulating receptors, reduce signal output from essential receptors or identify artificial stimulatory ligands for novel SHKs that are involved in virulence. Those small molecules could possess desirable therapeutic properties to combat MDR. We propose that a modular screening platform in which the periplasmic domain of the targeted receptors are fused to the cytoplasmic domain of a well-characterized receptor that governs fluorescence reporter genes could be employed to rapidly screen currently existing small molecule libraries. Here, we have examined two previously created Tar-EnvZ chimeras and a novel NarX-EnvZ chimera. We demonstrate that it is possible to couple periplasmic stimulus-perceiving domains to an invariable cytoplasmic domain that governs transcription of a dynamic fluorescent reporter system. Furthermore, we show that aromatic tuning, or repositioning the aromatic residues at the end of the second transmembrane helix (TM2), modulates baseline signal output from the tested chimeras and even restores output from a nonfunctional NarX-EnvZ chimera. Finally, we observe an inverse correlation between baseline signal output and the degree of response to cognate stimuli. In summary, we propose that the platform described here, a fluorescent Escherichia coli reporter strain with plasmid-based expression of the aromatically tuned chimeric receptors, represents a synthetic biology approach to rapidly screen pre-existing compound libraries for receptor-modulating activities.

Tumour-adapted Reduction Mammoplasty - a New (Old) Breast Conserving Strategy: Review

Today over 70 % of patients treated for primary breast carcinoma in certified breast centres are managed with breast conserving surgery. The classical semicircular incision directly above the tumour, though in many cases easily carried out and associated with good cosmetic results, does have limitations. Unsatisfactory aesthetic results often occur when tumour location is unfavourable or when there is unfavourable tumour size relative to breast size. Distortion of the nipple, changes to breast shape and retraction of skin overlying surgical defects can occur. Tumour-adapted reduction mammoplasty/mastopexy or the "modified B technique" offer excellent chances of combining the oncological demands of breast surgery with satisfactory symmetrical cosmetic results. This article reviews a traditional, old operative technique that has been re-embraced in various new forms.

The expression pattern and inhibitory influence of Tenascin-C on the growth of spiral ganglion neurons suggest a regulatory role as boundary formation molecule in the postnatal mouse inner ear

Sensorineural hearing loss, as a consequence of acoustic trauma, aging, genetic defects or ototoxic drugs, is highly associated with irreversible damage of cochlear hair cells (HCs) and secondary degeneration of spiral ganglion (SG) cells. Cochlear implants (CIs), which bypass the lost HC function by direct electrical stimulation of the remaining auditory neurons, offer an effective therapy option. Several studies imply that components of the extracellular matrix (ECM) have a great impact on the adhesion and growth of spiral ganglion neurons (SGNs) during development. Based on these findings, ECM proteins might act as bioactive CI substrates to optimize the electrode-nerve interface and to improve efficacy of these implants. In the present study, we focused on the ECM glycoproteins Tenascin-C (TN-C), Laminin (LN), and Fibronectin (FN), which show a prominent expression along the growth route of SGNs and the niche around HCs during murine postnatal development in vivo. We compared their influence on adhesion, neurite length, and neurite number of SGNs in vitro. Moreover, we studied the expression of the chondroitin sulfate proteoglycan (CSPG) dermatan sulfate-dependent proteoglycan-1 (DSD-1-PG), an interaction partner of TN-C. In sum, our in vitro data suggest that TN-C acts as an anti-adhesive and inhibitory factor for the growth of SGNs. The DSD-1 carbohydrate epitope is specifically localized to HC stereocilia and SG fibers. Interestingly, TN-C and the DSD-1-PG exhibit a mutually exclusive expression pattern, with the exception of a very restricted region beneath the habenula perforata, where SG neurites grow through the basilar membrane (BM) toward the HCs. The complementary expression of TN-C, LN, FN, and the DSD-1 epitope suggests that TN-C may act as an important boundary formation molecule in the developing postnatal mouse inner ear, which makes it a promising candidate to regulate neurite outgrowth in the light of CIs.

Clinical Study: Change in Outlook Towards Birth After a Midwife Led Antenatal Education Programme Versus Hypnoreflexogenous Self-Hypnosis Training for Childbirth

Aim: To compare the change of maternal outlook towards birth due to a midwife led antenatal education programme versus hypnoreflexogenous self-hypnosis training for childbirth. Method: Before beginning of the classes and after the last class maternal perception on birth was evaluated using Osgood semantic differential questionnaire. The Gießen personality score was evaluated once. Results: 213 patients were enrolled in this study. 155 were in the midwife led education programme and 58 in the self-hypnosis training programme. There was no statistically significant difference between the two groups in regard of participants' characteristics, Gießen personality score and initial Osgood semantic differential scores. After the midwife led course childbirth was emotionally more negatively scored (displeasure, tarnishing, dimension evaluation [p < 0.05]), whereas after the hypnosis course childbirth was emotionally more positively evaluated (pleasure, harmony, dimension evaluation [p < 0.01] and brightness [p < 0.05]). Summary: In this study hypnoreflexogenous self-hypnosis training resulted in a positive maternal outlook towards childbirth, in comparison to the midwife led course. Further prospective randomised studies are required to test these initial results.

[Requirements and current state of birth documentation in Germany]

INTRODUCTION

The partogram is a central record in everyday practice for midwifes and obstetricians. For legal enquiries it is one of the most important documents, however, so far there is no standardised partogram in use in Germany. This study explores the current requirements and develops a standardised partogram.

MATERIAL AND METHODS

In Germany 95 hospitals with a focus on tertiary referral centres were randomly selected to be questioned. Obstetricians and midwifes were asked to answer a questionnaire, which was based on a current literature search and expert interviews.

RESULTS

49 obstetricians (51.6%) and 24 midwives (25.3%) returned the questionnaires. 80% of those regularly cooperate with the other specialty with a partogram. 75% are using a standardised partogram, 8% an empty page and 6% computerised obstetric records. Most responders are using parameters which are defined in the current guidelines of the German Society of Obstetrics and Gynaecology. Variations were especially pronounced in the scoring system of the cardiotocogram and on legal issues. Room for improvement of the current documentation was documented in half of the cases.

DISCUSSION

There is a need for optimising the current birth documentation. With the results of the questionnaire a standardised model for a partogram was developed.

Intrapartum ST segment analyses (STAN) using simultaneous invasive and non-invasive fetal electrocardiography: a report of 6 cases

The objective of this study was to analyze ST segment analyses (STAN) using simultaneous traditional - gold standard invasive (fetal scalp electrode) and newly available non-invasive abdominal fetal electrocardiography (fECG) during delivery.This was a prospective observational study of non-invasive fetal ECG using 5 abdominally sited electrodes (Monica AN24) against the traditional fetal scalp electrodes (STAN S31) on 6 patients. Data were analyzed when the STAN S31 found the baseline and when there was a baseline rise.Successful fECG signal acquisition was achieved in 6/6 (100%) patients. Using the non-invasive fECG, P and QRS waves were seen in all cases, and T waves in 3/6 (50%). ST segment analysis analysis was possible in 6/6 (100%) and 3/6 (50%) using invasive and non-invasive fECG, respectively.This study demonstrates that ST segment analysis is feasible using invasive and non-invasive fECG. Further studies are warranted to confirm the preliminary results and improve ECG morphology of non-invasive fECG.

Neonatal Transfer Rate and Mode of Delivery from 37th Week of Gestation in a German Perinatal Center Level 1

Introduction: Rates for caesarean section are on the rise and the reasons for this are being discussed worldwide. As the data is unclear, the identification of additional predictive factors for caesarean section is important as caesarean sections are closely linked to maternal and neonatal morbidity. The aim of the study was to identify predictive factors for the transfer of the neonate to a neonatal intensive care unit (NICU) depending on the mode of delivery. The study investigated the neonatal transfer rates for singleton and twin pregnancies delivered at ≥ 36 + 0 weeks of gestation. Material and Methods: The data of all singleton (n = 4181) and twin pregnancies (n = 305 neonates), delivered between 1 January 2009 and 31 March 2012 in the OB/Gyn Department of the University Hospital Frankfurt/M, Germany, (perinatal center level 1) were evaluated. The indications for transfer to the NICU and possible predictive factors were evaluated. Results: Our study found a two times lower neonatal transfer rate for vaginal deliveries of pregnant women without risk factors compared to women with risk factors. The following neonatal transfer rates to the NICU were noted for singleton pregnancies: 4.7 % without risk factors, 8.3 % high-risk pregnancy, 6.2 % vaginal breech delivery, 9.3 % forceps delivery, 10 % elective primary caesarean section and 14 % secondary caesarean section. There was a statistically signific.

Outcome in single and twin pregnancies at 20 to 24 weeks gestation: ten years experience in one perinatal center

OBJECTIVE

The aim of this investigation was to evaluate the outcome at 20 to 24 weeks gestation of twin and singleton extremely low birth weight infants.

STUDY DESIGN

The authors conducted a retrospective cohort study of live newborns at 20 to 24 weeks gestation admitted to one neonatal intensive care unit (NICU) from 2000 to 2009. Outcome mortality and predictors of outcome were evaluated. Results were compared for twin and singleton infants.

RESULTS

The cohort of infants consisted of 60 singleton infants and 17 twins. The results suggest an increased risk of death for twins when compared with singletons. A correlation between neonatal C-reactive protein (CRP) and bacterial culture positive results on admission to NICU might be a predictor of neonatal outcome.

CONCLUSION

In extremely low birth weight infants, twin delivery is associated with an independent increased risk of death. Both first- and second-born twins are at increased risk.

Prevalence, Spectrum and Antibiotic Susceptibility of Bacterial and Candida Colonization between the 21st and 33rd Week of Gestation in Women with PPROM - 5 Years' Experience in 1 Perinatal Center

Objective: The aim of this study was to evaluate the prevalence, spectrum and antibiotic susceptibility of bacterial and Candida colonization of the vagina between the 21st and the 33rd week of gestation in women who had preterm premature rupture of membranes (PPROM). Study design: High vaginal swabs from 245 subjects with PPROM were analyzed in a retrospective cohort study using cultivation-dependent methods. Patients were additionally divided into two groups: women with PPROM between the 21st and 27th week of gestation (group A) and women with PPROM between the 28th and 33rd week of gestation (group B). A subgroup analysis comparing the two groups was done. Results: The prevalence of pathological bacterial colonization was similar in both study groups (40.8 vs. 41.4 %; p > 0.05), however, a difference in antibiotic susceptibility was noted, which did not reach statistical significance (resistance to ampicillin 71.4 vs. 52.5 %; cefuroxime 9.5 vs. 11.7 %; gentamicin 28.6 vs. 16.4 %; ciprofloxacin 5.0 vs. 5.4 %). In group A there was a statistically significant lower rate of Candida colonization (11.1 vs. 24.3 %; p = 0.04). Conclusion: In patients with early PPROM, the rate of Candida colonization (group A) is lower and there are indications of a difference in antibiotic susceptibility of the colonizing bacteria depending on gestational age. Larger study groups are required to confirm these preliminary results.

Conservative Management of Placenta Accreta/Increta after Vaginal Birth

Aim: Aim of the study was to show that conservative management with preservation of the uterus and of fertility is possible in patients with placenta accreta/increta after vaginal delivery. Method: A retrospective analysis of patients with placental attachment disorders after vaginal delivery was done in a perinatal centre between November 2009 and April 2011. The patient collective was identified using the ICD-10 codes for placenta accreta/increta/percreta, and patient records were analysed for risk factors, maternal morbidity, preservation of the uterus and of fertility, and neonatal outcome. Results: Three cases of placenta increta were identified in the last 1.5 years out of a total of 1457 vaginal deliveries, and all 3 cases were treated conservatively. Mean maternal age was 35.3 years; gestational age ranged from 39 to 41 weeks, and mean duration between delivery of the child and delivery of the placenta was 44.67 days (range: 14-100 days). Two patients developed symptoms of endomyometritis, including fever, leukocytosis and increased CRP levels. All 3 women were successfully managed with preservation of the uterus. Conclusion: In selected cases with placenta accreta/increta after vaginal delivery, it is possible to avoid surgical procedures, particularly hysterectomy procedures, and successfully manage these patients conservatively with preservation of the uterus.

Prenatal Foetal Non-invasive ECG instead of Doppler CTG - A Better Alternative?

Introduction: This study aimed to evaluate foetal signal quality obtained using an antenatal foetal ECG system (Monica 24™) and compare it with Doppler ultrasound CTG monitoring (Corometrics® 250 series). Material and Methods: Seventy pregnant women (gestational age: between 20 + 0 weeks and 40 + 0 weeks) were examined using the Monica AN24™ system and also underwent Doppler CTG. The signal quality of both methods was compared and correlated with gestational age and pre-pregnancy body mass index (BMI). Results: Overall, ECG had a signal quality of 77.4 % and CTG had a signal quality of 73.1 % (p > 0.05). In gestational weeks (GW) 20-26, the signal quality of ECG was significantly better compared to that obtained with CTG (75.5 vs. 45.3 %; p = 0.003), while in GW 27-36, the signal quality was better with CTG (72.3 vs. 83.0 %, p = 0.001). No difference in signal quality was found between the two methods after the 37th GW (87.7 vs. 86.1 %; p > 0.05). CTG showed a statistically significant correlation with BMI (rho 0.25, p < 0.05) while ECG showed no such correlation. Conclusion: The use of non-invasive ECG is particularly indicated in the early weeks of pregnancy, while CTG offers superior results during the vernix period. There was no difference in signal quality after the vernix period. The signal quality with ECG was found to be independent of BMI, while the signal quality of CTG deteriorated with increasing BMI.

Change of Spectral Analysis of Fetal Heart Rate During Clinical Hypnosis: a Prospective Randomised Trial from the 20th Week of Gestation Till Term

Objective: To investigate the functional adaptive process of the fetal autonomic nervous system during hypnosis from the 20th week of gestation till term. Are there changes in the power spectrum analysis of fetal heart rate when the mother is having a clinical hypnosis or control period? Study Design: Fourty-nine FHR recordings were analysed. Included recordings were from singletons and abdominal fetal ECG-monitored pregnancies. All women were randomised to receive clinical hypnosis followed by a period with no intervention or vice versa. Statistical analyses were performed with the Wilcoxon signed ranks and Spearman rho correlation tests. Results: There was a significant difference found between fetal heart rate at baseline (144.3 ± 6.0) and hypnosis (142.1 ± 6.4). A difference was also detected between the standard deviation of the heart rate between baseline (6.7 ± 1.9) and hypnosis (6.8 ± 3.5). LFnu was smaller during baseline (80.2 ± 5.3) than during hypnosis (82.1 ± 5.7), whereas HFnu was significantly larger (19.8 ± 5.3 vs. 17.9 ± 5.7). There was no correlation between the gestation age and the change in LFnu, HFnu or ratio LF/HF due to the hypnosis intervention. Conclusion: The functional adaptive process of the fetal autonomic system during hypnosis is reflected by a sympathovagal shift towards increased sympathetic modulation.

Non-invasive Foetal ECG - a Comparable Alternative to the Doppler CTG?

This review discusses the alternative of using the non-invasive foetal ECG compared with the conventionally used Doppler CTG. Non-invasive abdominal electrocardiograms (ECG) have been approved for clinical routine since 2008; subsequently they were also approved for antepartum and subpartum procedures. The first study results have been published. Non-invasive foetal ECG is especially indicated during early pregnancy, while the Doppler CTG is recommended for the vernix period. Beyond the vernix period no difference has been recorded in the success rate of either approach. The foetal ECG signal quality is independent of the BMI, whereas the success rate of the Doppler CTG is diminished with an increased BMI. During the first stage of labour, non-invasive foetal ECG demonstrates better signal quality; however during the second stage of labour no difference has been identified between the methods.