Study protocol for two randomised controlled trials evaluating the effects of Cerclage in the reduction of extreme preterm birth and perinatal mortality in twin pregnancies with a short cervix or dilatation: the TWIN Cerclage studies

INTRODUCTION

Twin pregnancies have a high risk of extreme preterm birth (PTB) at less than 28 weeks of gestation, which is associated with increased risk of neonatal morbidity and mortality. Currently there is a lack of effective treatments for women with a twin pregnancy and a short cervix or cervical dilatation. A possible effective surgical method to reduce extreme PTB in twin pregnancies with an asymptomatic short cervix or dilatation at midpregnancy is the placement of a vaginal cerclage.

METHODS AND ANALYSIS

We designed two multicentre randomised trials involving eight hospitals in the Netherlands (sites in other countries may be added at a later date). Women older than 16 years with a twin pregnancy at <24 weeks of gestation and an asymptomatic short cervix of ≤25 mm or cervical dilatation will be randomly allocated (1:1) to both trials on vaginal cerclage and standard treatment according to the current Dutch Society of Obstetrics and Gynaecology guideline (no cerclage). Permuted blocks sized 2 and 4 will be used to minimise the risk of disbalance. The primary outcome measure is PTB of <28 weeks. Analyses will be by intention to treat. The first trial is to demonstrate a risk reduction from 25% to 10% in the short cervix group, for which 194 patients need to be recruited. The second trial is to demonstrate a risk reduction from 80% to 35% in the dilatation group and will recruit 44 women. A cost-effectiveness analysis will be performed from a societal perspective.

ETHICS AND DISSEMINATION

This study has been approved by the Research Ethics Committees in the Netherlands on 3/30/2023. Participants will be required to sign an informed consent form. The results will be presented at conferences and published in a peer-reviewed journal. Participants will be informed about the results.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT05968794.

Changes in Maternal Heart Rate Variability and Photoplethysmography Morphology after Corticosteroid Administration: A Prospective, Observational Study

Background: Owing to the association between dysfunctional maternal autonomic regulation and pregnancy complications, assessing non-invasive features reflecting autonomic activity-e.g., heart rate variability (HRV) and the morphology of the photoplethysmography (PPG) pulse wave-may aid in tracking maternal health. However, women with early pregnancy complications typically receive medication, such as corticosteroids, and the effect of corticosteroids on maternal HRV and PPG pulse wave morphology is not well-researched. Methods: We performed a prospective, observational study assessing the effect of betamethasone (a commonly used corticosteroid) on non-invasively assessed features of autonomic regulation. Sixty-one women with an indication for betamethasone were enrolled and wore a wrist-worn PPG device for at least four days, from which five-minute measurements were selected for analysis. A baseline measurement was selected either before betamethasone administration or sufficiently thereafter (i.e., three days after the last injection). Furthermore, measurements were selected 24, 48, and 72 h after betamethasone administration. HRV features in the time domain and frequency domain and describing heart rate (HR) complexity were calculated, along with PPG morphology features. These features were compared between the different days. Results: Maternal HR was significantly higher and HRV features linked to parasympathetic activity were significantly lower 24 h after betamethasone administration. Features linked to sympathetic activity remained stable. Furthermore, based on the PPG morphology features, betamethasone appears to have a vasoconstrictive effect. Conclusions: Our results suggest that administering betamethasone affects maternal autonomic regulation and cardiovasculature. Researchers assessing maternal HRV in complicated pregnancies should schedule measurements before or sufficiently after corticosteroid administration.

Feasibility and reliability of fetal two dimensional speckle tracking echocardiography at 16 weeks gestational age: A pilot study

BACKGROUND

Fetal two-dimensional speckle tracking echocardiography (2D-STE) is an emerging technique for assessing fetal cardiac function by measuring global longitudinal strain. Alterations in global longitudinal strain may serve as early indicator of pregnancy complications, making 2D-STE a potentially valuable tool for early detection. Early detection can facilitate timely interventions to reduce fetal and maternal morbidity and mortality. Therefore, the aim of this study was to investigate the feasibility of performing 2D-STE at 16 weeks gestational age.

METHODS

This pilot study utilized 50 ultrasound clips of the fetal four-chamber view recorded between 15+5 and 16+2 weeks gestational age from a prospective cohort study. A strict protocol assessed three parameters essential for 2D-STE analysis: fetal four-chamber view ultrasound clip quality, region of interest, and frame rates. Two independent researchers measured global longitudinal strain in all adequate fetal four-chamber view ultrasound clips to determine inter- and intra-operator reliability.

RESULTS

Out of the 50 ultrasound clips, 37 (74%) were feasible for 2D-STE analysis. The inter-operator reliability for global longitudinal strain measurements of the left and right ventricles was moderate (ICC of 0.64 and 0.74, respectively), while the intra-operator reliability was good (ICC of 0.76 and 0.79, respectively).

CONCLUSIONS

Our findings demonstrate that fetal 2D-STE analysis at 16 weeks gestational age is feasible when adhering to a strict protocol. However, further improvements are necessary to enhance the inter- and intra-operator reliability of 2D-STE at this gestational age.

Artificial intelligence based cardiotocogram assessment during labor

OBJECTIVE

To assess whether artificial intelligence, inspired by clinical decision-making procedures in delivery rooms, can correctly interpret cardiotocographic tracings and distinguish between normal and pathological events.

STUDY DESIGN

A method based on artificial intelligence was developed to determine whether a cardiotocogram shows a normal response of the fetal heart rate to uterine activity (UA). For a given fetus and given the UA and previous FHR, the method predicts a fetal heart rate response, under the assumption that the fetus is still in good condition and based on how that specific fetus has responded so far. We hypothesize that this method, when having only learned from fetuses born in good condition, is incapable of predicting the response of a compromised fetus or an episode of transient fetal distress. The (in)capability of the method to predict the fetal heart rate response would then yield a method that can help to assess fetal condition when the obstetrician is in doubt. Cardiotocographic data of 678 deliveries during labor were selected based on a healthy outcome just after birth. The method was trained on the cardiotocographic data of 548 fetuses of this group to learn their heart rate response. Subsequently it was evaluated on 87 fetuses, by assessing whether the method was able to predict their heart rate responses. The remaining 43 cardiotocograms were segment-by-segment annotated by three experienced gynecologists, indicating normal, suspicious, and pathological segments, while having access to the full recording and neonatal outcome. This future knowledge makes the expert annotations of a quality that is unachievable during live interpretation.

RESULTS

The comparison between abnormalities detected by the method (only using past and present input) and the annotated CTG segments by gynecologists (also looking at future input) yields an area under the curve of 0.96 for the distinction between normal and pathological events in majority-voted annotations.

CONCLUSION

The developed method can distinguish between normal and pathological events in near real-time, with a performance close to the agreement between three gynecologists with access to the entire CTG tracing and fetal outcome. The method has a strong potential to support clinicians in assessing fetal condition in clinical practice.

Transferring an extremely premature infant to an extra-uterine life support system: a prospective view on the obstetric procedure

To improve care for extremely premature infants, the development of an extrauterine environment for newborn development is being researched, known as Artificial Placenta and Artificial Womb (APAW) technology. APAW facilitates extended development in a liquid-filled incubator with oxygen and nutrient supply through an oxygenator connected to the umbilical vessels. This setup is intended to provide the optimal environment for further development, allowing further lung maturation by delaying gas exposure to oxygen. This innovative treatment necessitates interventions in obstetric procedures to transfer an infant from the native to an artificial womb, while preventing fetal-to-neonatal transition. In this narrative review we analyze relevant fetal physiology literature, provide an overview of insights from APAW studies, and identify considerations for the obstetric procedure from the native uterus to an APAW system. Lastly, this review provides suggestions to improve sterility, fetal and maternal well-being, and the prevention of neonatal transition.

Fetal electrocardiography and artificial intelligence for prenatal detection of congenital heart disease

INTRODUCTION

This study aims to investigate non-invasive electrocardiography as a method for the detection of congenital heart disease (CHD) with the help of artificial intelligence.

MATERIAL AND METHODS

An artificial neural network was trained for the identification of CHD using non-invasively obtained fetal electrocardiograms. With the help of a Bayesian updating rule, multiple electrocardiographs were used to increase the algorithm's performance.

RESULTS

Using 122 measurements containing 65 healthy and 57 CHD cases, the accuracy, sensitivity, and specificity were found to be 71%, 63%, and 77%, respectively. The sensitivity was however 75% and 69% for CHD cases requiring an intervention in the neonatal period and first year of life, respectively. Furthermore, a positive effect of measurement length on the detection performance was observed, reaching optimal performance when using 14 electrocardiography segments (37.5 min) or more. A small negative trend between gestational age and accuracy was found.

CONCLUSIONS

The proposed method combining recent advances in obtaining non-invasive fetal electrocardiography with artificial intelligence for the automatic detection of CHD achieved a detection rate of 63% for all CHD and 75% for critical CHD. This feasibility study shows that detection rates of CHD might improve by using electrocardiography-based screening complementary to the standard ultrasound-based screening. More research is required to improve performance and determine the benefits to clinical practice.

Evidence and clinical relevance of maternal-fetal cardiac coupling: A scoping review

BACKGROUND

Researchers have long suspected a mutual interaction between maternal and fetal heart rhythms, referred to as maternal-fetal cardiac coupling (MFCC). While several studies have been published on this phenomenon, they vary in terms of methodologies, populations assessed, and definitions of coupling. Moreover, a clear discussion of the potential clinical implications is often lacking. Subsequently, we perform a scoping review to map the current state of the research in this field and, by doing so, form a foundation for future clinically oriented research on this topic.

METHODS

A literature search was performed in PubMed, Embase, and Cochrane. Filters were only set for language (English, Dutch, and German literature were included) and not for year of publication. After screening for the title and the abstract, a full-text evaluation of eligibility followed. All studies on MFCC were included which described coupling between heart rate measurements in both the mother and fetus, regardless of the coupling method used, gestational age, or the maternal or fetal health condition.

RESULTS

23 studies remained after a systematic evaluation of 6,672 studies. Of these, 21 studies found at least occasional instances of MFCC. Methods used to capture MFCC are synchrograms and corresponding phase coherence indices, cross-correlation, joint symbolic dynamics, transfer entropy, bivariate phase rectified signal averaging, and deep coherence. Physiological pathways regulating MFCC are suggested to exist either via the autonomic nervous system or due to the vibroacoustic effect, though neither of these suggested pathways has been verified. The strength and direction of MFCC are found to change with gestational age and with the rate of maternal breathing, while also being further altered in fetuses with cardiac abnormalities and during labor.

CONCLUSION

From the synthesis of the available literature on MFCC presented in this scoping review, it seems evident that MFCC does indeed exist and may have clinical relevance in tracking fetal well-being and development during pregnancy.

The impact of angles of insonation on left and right ventricular global longitudinal strain estimation in fetal speckle tracking echocardiography

OBJECTIVES

Two-dimensional speckle tracking echocardiography has been considered an angle-independent modality. However, current literature is limited and inconclusive on the actual impact of angle of insonation on strain values. Therefore, the primary objective of this study was to assess the impact of angles of insonation on the estimation of fetal left ventricular and right ventricular global longitudinal strain. Secondarily, the impact of different definitions for angles of insonation was investigated in a sensitivity analysis.

METHODS

This is a retrospective analysis of a prospective longitudinal cohort study with 124 healthy subjects. The analyses were based on the four-chamber view ultrasound clips taken between 18+0 and 21+6 weeks of gestation. Angles of insonation were categorized into three groups: up/down, oblique and perpendicular. The mean fetal left and right ventricular and global longitudinal strain values corresponding to these three groups were compared by an ANOVA test corrected for heteroscedasticity.

RESULTS

Fetal left and right ventricular global longitudinal strain values were not statistically different between the three angles of insonation (p-value >0.062 and >0.149, respectively). When applying another definition for angles of insonation in the sensitivity analysis, the mean left ventricular global longitudinal strain value was significantly decreased for the oblique compared to the up/down angle of insonation (p-value 0.041).

CONCLUSIONS

There is no evidence of a difference in fetal left and right ventricular global longitudinal strain between the different angles of insonation in fetal two-dimensional speckle tracking echocardiography.

On the distinct differences in autonomic regulation between pregnant and non-pregnant women - a heart rate variability analysis

Objective &#xD;Appropriate adaptation of the maternal autonomic nervous system to progressing gestation is essential to a healthy pregnancy. This is partly evidenced by the association between pregnancy complications and autonomic dysfunction. Therefore, assessing maternal heart rate variability (HRV) - a proxy measure for autonomic activity - may offer insights into maternal health, potentially enabling the early detection of complications. However, identifying abnormal maternal HRV requires a thorough understanding of normal maternal HRV. While HRV in women of childbearing age has been extensively investigated, less is known concerning HRV during pregnancy. Subsequently, we investigate the differences in HRV between healthy pregnant women and their non-pregnant counterparts. &#xD;&#xD;Approach &#xD;We use a comprehensive suite of HRV features (assessing sympathetic and parasympathetic activity, heart rate (HR) complexity, HR fragmentation, and autonomic responsiveness) to quantify HRV in large groups of healthy pregnant (n=258) and non-pregnant women (n=252). We compare the statistical significance and effect size of the potential differences between the groups. &#xD;&#xD;Main results &#xD;We find significantly increased sympathetic and decreased parasympathetic activity during healthy pregnancy, along with significantly attenuated autonomic responsiveness, which we hypothesize serves as a protective mechanism against sympathetic overactivity. HRV differences between these groups typically had a large effect size (Cohen's d > 0.8), with the largest effect accompanying the significantly reduced HR complexity and altered sympathovagal balance observed in pregnancy (Cohen's d > 1.2).&#xD;&#xD;Significance &#xD;Healthy pregnant women are autonomically distinct from their non-pregnant counterparts. Subsequently, assumptions based on HRV research in non-pregnant women cannot be readily translated to pregnant women. &#xD.

Prognostic model on niche development after a first caesarean section: development and internal validation

OBJECTIVE

To develop and internally validate a prognostic prediction model for development of a niche in the uterine scar after a first caesarean section (CS).

STUDY DESIGN

Secondary analyses on data of a randomized controlled trial, performed in 32 hospitals in the Netherlands among women undergoing a first caesarean section. We used multivariable backward logistic regression. Missing data were handled using multiple imputation. Model performance was assessed by calibration and discrimination. Internal validation using bootstrapping techniques took place. The outcome was 'development of a niche in the uterus', defined as an indentation of ≥ 2 mm in the myometrium.

RESULTS

We developed two models to predict niche development: in the total population and after elective CS. Patient related risk factors were: gestational age, twin pregnancy and smoking, and surgery related risk factors were double-layer closure and less surgical experience. Multiparity and Vicryl suture material were protective factors. The prediction model in women undergoing elective CS revealed similar results. After internal validation, Nagelkerke R² ranged from 0.01 to 0.05 and was considered low; median area under the curve (AUC) ranged from 0.56 to 0.62, indicating failed to poor discriminative ability.

CONCLUSIONS

The model cannot be used to accurately predict the development of a niche after a first CS. However, several factors seem to influence scar healing which indicates possibilities for future prevention such as surgical experience and suture material. The search for additional risk factors that play a role in development of a niche should be continued to improve the discriminative ability.

Cervical cerclage for prevention of preterm birth: the results from A 20-year cohort

Cerclages can be used to prevent preterm birth, although their effectiveness and safety is disputed. We aimed to describe obstetric outcomes after cerclage procedures. We included 156 singleton pregnancies and six multiple pregnancies. In singleton pregnancies with history-indicated, short cervix-indicated and emergency cerclages, respectively 84.6, 76.5 and 43.8% resulted in late preterm or term deliveries. In singletons, the following complications were reported: excessive bleeding in one emergency cerclage procedure and three re-cerclage procedures in the history-indicated cerclage group. No perioperative rupture of membranes occurred in singletons. When comparing results of experienced and less-experienced gynaecologists, a remarkably smaller take home child rate was observed for singletons treated by less-experienced gynaecologists: 90.7% and 94.4% for the two experienced gynaecologist as compared to 85.0% for the group of less-experienced gynaecologists. In conclusion, cerclages in singletons result in few cerclage-associated complications and a high take home child rate, when performed by experienced gynaecologists. Impact statementWhat is already known on this subject? Prematurity is the leading cause of perinatal and neonatal mortality and morbidity worldwide. Cervical cerclages can be used to prevent preterm birth, although their effectiveness and safety is disputed.What the results of this study add? In our cohort study, singleton pregnancies with cerclages seem to have satisfactory obstetric outcomes. We found a very low prevalence of cerclage-associated complications in singleton pregnancies, for both history-indicated, short cervix-indicated and emergency cerclages. Additionally, take home child rates in singleton pregnancies were remarkably higher when cerclage procedures were performed by experienced gynaecologists, compared to less experienced gynaecologists.What the implications are of these findings for clinical practice and/or further research? Based on the observed difference in take home child rates, we advise all cerclage procedures to be performed by experienced gynaecologists only. This may mean that women with an indication for cerclage will be referred to a more experienced colleague, either in the same, or in another hospital. To ensure treatment by an experienced gynaecologist, simulation-based training could also provide a solution.

Depression, anxiety, and post-traumatic stress disorder symptoms after hyperemesis gravidarum: a prospective cohort study

OBJECTIVE

To determine the prevalence of depression, anxiety, and posttraumatic stress disorder (PTSD) years after hyperemesis gravidarum (HG) and its association with HG severity.

MATERIAL AND METHODS

This prospective cohort study consisted of a follow-up of 215 women admitted for HG, who were eligible to participate in a randomized controlled trial and either declined or agreed to be randomized between 2013 and 2016 in 19 hospitals in the Netherlands. Participants completed the Hospital Anxiety and Depression Scale (HADS) six weeks postpartum and during follow-up and the PTSD checklist for DSM-5 (PCL-5) during follow-up. An anxiety or depression score ≥8 is indicative of an anxiety or depression disorder and a PCL-5 ≥ 31 indicative of PTSD. Measures of HG severity were symptom severity (PUQE-24: Pregnancy Unique Quantification of Emesis), weight change, duration of admissions, readmissions, and admissions after the first trimester.

RESULTS

About 54/215 participants completed the HADS six weeks postpartum and 73/215 participants completed the follow-up questionnaire, on average 4.5 years later. Six weeks postpartum, 13 participants (24.1%) had an anxiety score ≥8 and 11 participants (20.4%) a depression score ≥8. During follow-up, 29 participants (39.7%) had an anxiety score ≥8, 20 participants (27.4%) a depression score ≥8, and 16 participants (21.9%) a PCL-5 ≥ 31.Multivariable logistic regression analysis showed that for every additional point of the mean PUQE-24 three weeks after inclusion, the likelihood of having an anxiety score ≥8 and PCL-5 ≥ 31 at follow-up increased with OR 1.41 (95% CI: 1.10;1.79) and OR 1.49 (95% CI: 1.06;2.10) respectively.

CONCLUSION

Depression, anxiety, and PTSD symptoms are common years after HG occurred.

Longitudinally Tracking Maternal Autonomic Modulation During Normal Pregnancy With Comprehensive Heart Rate Variability Analyses

Changes in the maternal autonomic nervous system are essential in facilitating the physiological changes that pregnancy necessitates. Insufficient autonomic adaptation is linked to complications such as hypertensive diseases of pregnancy. Consequently, tracking autonomic modulation during progressing pregnancy could allow for the early detection of emerging deteriorations in maternal health. Autonomic modulation can be longitudinally and unobtrusively monitored by assessing heart rate variability (HRV). Yet, changes in maternal HRV (mHRV) throughout pregnancy remain poorly understood. In previous studies, mHRV is typically assessed only once per trimester with standard HRV features. However, since gestational changes are complex and dynamic, assessing mHRV comprehensively and more frequently may better showcase the changing autonomic modulation over pregnancy. Subsequently, we longitudinally (median sessions = 8) assess mHRV in 29 healthy pregnancies with features that assess sympathetic and parasympathetic activity, as well as heart rate (HR) complexity, HR responsiveness and HR fragmentation. We find that vagal activity, HR complexity, HR responsiveness, and HR fragmentation significantly decrease. Their associated effect sizes are small, suggesting that the increasing demands of advancing gestation are well tolerated. Furthermore, we find a notable change in autonomic activity during the transition from the second to third trimester, highlighting the dynamic nature of changes in pregnancy. Lastly, while we saw the expected rise in mean HR with gestational age, we also observed increased autonomic deceleration activity, seemingly to counter this rising mean HR. These results are an important step towards gaining insights into gestational physiology as well as tracking maternal health via mHRV.

Evaluation of low-dose aspirin in the prevention of recurrent spontaneous preterm labour (the APRIL study): A multicentre, randomised, double-blinded, placebo-controlled trial

BACKGROUND

Preterm birth is the leading cause of neonatal morbidity and mortality. The recurrence rate of spontaneous preterm birth is high, and additional preventive measures are required. Our objective was to assess the effectiveness of low-dose aspirin compared to placebo in the prevention of preterm birth in women with a previous spontaneous preterm birth.

METHODS AND FINDINGS

We performed a parallel multicentre, randomised, double-blinded, placebo-controlled trial (the APRIL study). The study was performed in 8 tertiary and 26 secondary care hospitals in the Netherlands. We included women with a singleton pregnancy and a history of spontaneous preterm birth of a singleton between 22 and 37 weeks. Participants were randomly assigned to aspirin 80 mg daily or placebo initiated between 8 and 16 weeks of gestation and continued until 36 weeks or delivery. Randomisation was computer generated, with allocation concealment by using sequentially numbered medication containers. Participants, their healthcare providers, and researchers were blinded for treatment allocation. The primary outcome was preterm birth <37 weeks of gestation. Secondary outcomes included a composite of poor neonatal outcome (bronchopulmonary dysplasia, periventricular leukomalacia > grade 1, intraventricular hemorrhage > grade 2, necrotising enterocolitis > stage 1, retinopathy of prematurity, culture proven sepsis, or perinatal death). Analyses were performed by intention to treat. From May 31, 2016 to June 13, 2019, 406 women were randomised to aspirin (n = 204) or placebo (n = 202). A total of 387 women (81.1% of white ethnic origin, mean age 32.5 ± SD 3.8) were included in the final analysis: 194 women were allocated to aspirin and 193 to placebo. Preterm birth <37 weeks occurred in 41 (21.2%) women in the aspirin group and 49 (25.4%) in the placebo group (relative risk (RR) 0.83, 95% confidence interval (CI) 0.58 to 1.20, p = 0.32). In women with ≥80% medication adherence, preterm birth occurred in 24 (19.2%) versus 30 (24.8%) women (RR 0.77, 95% CI 0.48 to 1.25, p = 0.29). The rate of the composite of poor neonatal outcome was 4.6% (n = 9) versus 2.6% (n = 5) (RR 1.79, 95% CI 0.61 to 5.25, p = 0.29). Among all randomised women, serious adverse events occurred in 11 out of 204 (5.4%) women allocated to aspirin and 11 out of 202 (5.4%) women allocated to placebo. None of these serious adverse events was considered to be associated with treatment allocation. The main study limitation is the underpowered sample size due to the lower than expected preterm birth rates.

CONCLUSIONS

In this study, we observed that low-dose aspirin did not significantly reduce the preterm birth rate in women with a previous spontaneous preterm birth. However, a modest reduction of preterm birth with aspirin cannot be ruled out. Further research is required to determine a possible beneficial effect of low-dose aspirin for women with a previous spontaneous preterm birth.

TRIAL REGISTRATION

Dutch Trial Register (NL5553, NTR5675) https://www.trialregister.nl/trial/5553.

The electrical heart axis of the fetus between 18 and 24 weeks of gestation: A cohort study

Introduction

A fetal anomaly scan in mid-pregnancy is performed, to check for the presence of congenital anomalies, including congenital heart disease (CHD). Unfortunately, 40% of CHD is still missed. The combined use of ultrasound and electrocardiography might boost detection rates. The electrical heart axis is one of the characteristics which can be deduced from an electrocardiogram (ECG). The aim of this study was to determine reference values for the electrical heart axis in healthy fetuses around 20 weeks of gestation.

Material and methods

Non-invasive fetal electrocardiography was performed subsequent to the fetal anomaly scan in pregnant women carrying a healthy singleton fetus between 18 and 24 weeks of gestation. Eight adhesive electrodes were applied on the maternal abdomen including one ground and one reference electrode, yielding six channels of bipolar electrophysiological measurements. After removal of interferences, a fetal vectorcardiogram was calculated and then corrected for fetal orientation. The orientation of the electrical heart axis was determined from this normalized fetal vectorcardiogram. Descriptive statistics were used on normalized cartesian coordinates to determine the average electrical heart axis in the frontal plane. Furthermore, 90% prediction intervals (PI) for abnormality were calculated.

Results

Of the 328 fetal ECGs performed, 281 were included in the analysis. The average electrical heart axis in the frontal plane was determined at 122.7° (90% PI: -25.6°; 270.9°).

Discussion

The average electrical heart axis of healthy fetuses around mid-gestation is oriented to the right, which is, due to the unique fetal circulation, in line with muscle distribution in the fetal heart.

[Electrohysterography, a promising alternative for uterine monitoring: 5 years later]

Electrohysterography monitors the electrical activity of the uterine muscle through electrodes on the maternal abdominal wall. It is a non-invasive method for uterine contraction monitoring and has a strong correlation with the invasive intra-uterine pressure catheter. A prospective validation study showed a significant higher sensitivity of electrohysterography compared to external tocodynamometry for uterine contraction detection (p-value < 0.001). Moreover, the sensitivity of electrohysterography appears to be less affected by maternal obesity compared to external tocodynamometry. A clinical pilotstudy comparing electrohysterography and external tocodynamometry during labor, showed no negative effect of electrohysterography on labor outcomes. Recently, technical improvements have been made and electrohysterography has become available in an adhesive electrode patch together with fetal and maternal electrocardiography. Therefore, we expect a successful implementation of electrohysterography in the near future.

Adapted ST analysis during labor: relative versus absolute ST events, a case-control study

BACKGROUND

The value of ST analysis of the fetal electrocardiogram during labor to lower asphyxia and cesarean section rates is uncertain. Physiological variation of the electrical heart axis between fetuses may explain false alarms in conventional ST analysis (absolute ST analysis). ST events (alarms) based on relative T/QRS rises (relative ST analysis) correct for this variation and may improve diagnostic accuracy of ST analysis.

AIMS

To compare the diagnostic accuracy of absolute and relative ST analysis with regard to fetal acidemia.

STUDY DESIGN

Retrospective case-control study.

SUBJECTS

20 healthy women with an uncomplicated pregnancy monitored with ST analysis during labor: 10 cases (umbilical cord artery pH < 7.05) and 10 controls (pH > 7.20).

OUTCOME MEASURES

Sensitivity, specificity, positive and negative likelihood ratio.

RESULTS

In 16 of the 20 patients a total of 54 absolute ST events were reported. Two reviewers classified the cardiotocograms; in cases 29% of the absolute ST events were significant, in the controls it was 19%. Relative ST analysis versus absolute ST analysis showed a sensitivity of 90% (55-100%) vs. 70% (35-93%), a specificity of 100% (69-100%) vs. 70% (35-93%), a positive likelihood ratio of infinity vs. 2.3 (0.8-6.5), a negative likelihood ratio of 0.1 (0.0-0.6) vs. 0.4 (0.2-1.2), and diagnostic odds ratio of infinity vs. 5.4 (0.8-36.9). McNemar showed no statistical significant difference between the sensitivity and specificity of the methods.

CONCLUSIONS

We observed higher positive and lower negative likelihood ratios for relative ST analysis in comparison to absolute ST analysis. In this small study we found no statistical difference. Relative ST analysis should be studied in a larger study.

Recurrence, postponing pregnancy, and termination rates after hyperemesis gravidarum: Follow up of the MOTHER study

Introduction

Hyperemesis gravidarum (HG) complicates 1% of pregnancies and has a major impact on maternal quality of life and well‐being. We know very little about HG’s long‐term impact after an affected pregnancy, including recurrence rates in future pregnancies, which is essential information for women considering subsequent pregnancies. In this study, we aimed to prospectively measure the recurrence rate of HG and the number of postponed and terminated subsequent pregnancies due to HG. We also aimed to evaluate if there were predictive factors that could identify women at increased risk for HG recurrence, and postponing and terminating subsequent pregnancies.

Material and methods

We conducted a prospective cohort study. A total of 215 women admitted for HG to public hospitals in the Netherlands were enrolled in the original MOTHER randomized controlled trial and associated observational cohort. Seventy‐three women were included in this follow‐up study. Data were collected through an online questionnaire. Recurrent HG was defined as vomiting symptoms accompanied by any of the following: multiple medication use, weight loss, admission, tube feeding or if nausea and vomiting symptoms were severe enough to affect life and/or work. Outcome measures were recurrence, postponing, and termination rates due to HG. Univariable logistic regression analysis was used to identify predictive factors associated with HG recurrence, and postponing and terminating subsequent pregnancies.

Results

Thirty‐five women (48%) became pregnant again of whom 40% had postponed their pregnancy due to HG. HG recurred in 89% of pregnancies. One woman terminated and eight women (23%) considered terminating their pregnancy because of recurrent HG. Twenty‐four out of 38 women did not get pregnant again because of HG in the past. Univariable logistic regression analysis identifying possible predictive factors found that having a western background was associated with having weight loss due to recurrent HG in subsequent pregnancies (odds ratio 12.9, 95% CI 1.3–130.5, p = 0.03).

Conclusions

High rates of HG recurrence and a high number of postponed pregnancies due to HG were observed. Women can be informed of a high chance of recurrence to enable informed family planning.

Thyroid-stimulating hormone and free thyroxine fail to predict the severity and clinical course of hyperemesis gravidarum: A prospective cohort study

Introduction

Little is known about the pathophysiology of hyperemesis gravidarum (HG). Proposed underlying causes are multifactorial and thyroid function is hypothesized to be causally involved. In this study, we aimed to assess the utility of thyroid‐stimulating hormone (TSH) and free thyroxine (FT4) as a marker and predictor for the severity and clinical course of HG.

Material and methods

We conducted a prospective cohort study including women admitted for HG between 5 and 20 weeks of gestation in 19 hospitals in the Netherlands. Women with a medical history of thyroid disease were excluded. TSH and FT4 were measured at study entry. To adjust for gestational age, we calculated TSH multiples of the median (MoM). We assessed HG severity at study entry as severity of nausea and vomiting (by the Pregnancy Unique Quantification of Emesis and nausea score), weight change compared with prepregnancy weight, and quality of life. We assessed the clinical course of HG as severity of nausea and vomiting and quality of life 1 week after inclusion, duration of hospital admissions, and readmissions. We performed multivariable regression analysis with absolute TSH, TSH MoMs, and FT4.

Results

Between 2013 and 2016, 215 women participated in the cohort. TSH, TSH MoM, and FT4 were available for, respectively, 150, 126, and 106 of these women. Multivariable linear regression analysis showed that lower TSH MoM was significantly associated with increased weight loss or lower weight gain at study entry (ΔKg; β = 2.00, 95% CI 0.47‐3.53), whereas absolute TSH and FT4 were not. Lower TSH, not lower TSH MoM or FT4, was significantly associated with lower nausea and vomiting scores 1 week after inclusion (β = 1.74, 95% CI 0.36‐3.11). TSH and FT4 showed no association with any of the other markers of the severity or clinical course of HG. Twenty‐one out of 215 (9.8%) women had gestational transient thyrotoxicosis. Women with gestational transient thyrotoxicosis had a lower quality of life 1 week after inclusion than women with no gestational transient thyrotoxicosis (p = 0.03).

Conclusions

Our findings show an inconsistent role for TSH, TSH MoM, or FT4 at time of admission and provide little guidance on the severity and clinical course of HG.

Changes in Maternal Heart Rate Variability in Response to the Administration of Routine Obstetric Medication in Hospitalized Patients: Study Protocol for a Cohort Study (MAMA-Heart Study)

Pregnancy is a period of continuous change in the maternal cardiovascular system, partly mediated by the autonomic nervous system. Insufficient autonomic adaptation to increasing gestation is associated with pregnancy complications, such as hypertensive disorders of pregnancy and preterm birth (both major causes of perinatal morbidity and mortality). Consequently, maternal heart rate variability (mHRV), which is a proxy measure for autonomic activity, is increasingly assessed in these cohorts to investigate the pathophysiology of their complications. A better pathophysiological understanding could facilitate the early detection of these complications, which remains challenging. However, such studies (typically performed in pregnancies leading to hospitalization) have generated conflicting findings. A probable reason for these conflicting findings is that these study cohorts were likely administered routine obstetric medications during the study period of which the effects on mHRV are largely unknown. Subsequently, we design a longitudinal, observational study to quantifying the effect of these medications-particularly corticosteroids, which are known to affect fetal HRV-on mHRV to improve the interpretation of past and future studies. We will enroll 61 women admitted to a tertiary obstetric unit with an indication to receive corticosteroids antenatally. Participants' mHRV will be continuously acquired throughout their hospitalization with wrist-worn photoplethysmography to facilitate a within-patient comparison of the effect of corticosteroids on mHRV.

Ethical Development of Artificial Amniotic Sac and Placenta Technology: A Roadmap

In this paper we present an initial roadmap for the ethical development and eventual implementation of artificial amniotic sac and placenta technology in clinical practice. We consider four elements of attention: (1) framing and societal dialogue; (2) value sensitive design, (3) research ethics and (4) ethical and legal research resulting in the development of an adequate moral and legal framework. Attention to all elements is a necessary requirement for ethically responsible development of this technology. The first element concerns the importance of framing and societal dialogue. This should involve all relevant stakeholders as well as the general public. We also identify the need to consider carefully the use of terminology and how this influences the understanding of the technology. Second, we elaborate on value sensitive design: the technology should be designed based upon the principles and values that emerge in the first step: societal dialogue. Third, research ethics deserves attention: for proceeding with first-in-human research with the technology, the process of recruiting and counseling eventual study participants and assuring their informed consent deserves careful attention. Fourth, ethical and legal research should concern the status of the subject in the AAPT. An eventual robust moral and legal framework for developing and implementing the technology in a research setting should combine all previous elements. With this roadmap, we emphasize the importance of stakeholder engagement throughout the process of developing and implementing the technology; this will contribute to ethically and responsibly innovating health care.

Two-dimensional Speckle tracking echocardiography in Fetal Growth Restriction: a systematic review

Background Fetal growth restriction (FGR), defined as an estimated fetal weight (EFW)<10th percentile, is associated with an increased risk for adverse fetal and neonatal outcome. Early antenatal diagnosis is important and remains challenging. Deformation changes in the fetal myocardium are early signs of myocardial dysfunction. These changes can be measured using two-dimensional speckle tracking echocardiography (2D-STE) to predict impaired placental function in the growth restricted fetus. Aim To review the literature on fetal heart deformation values measured with 2D-STE, in fetuses with an EFW< 10th centile and appropriate for gestational age (AGA) fetuses, and to compare the results in both groups. Methods The EMBASE, Medline, and Cochrane databases were searched from inception until April 2020. Observational studies on evaluating the cardiac deformation values longitudinal strain, strain rate, and/or global dyssynchrony of both ventricles in FGR, using 2D-STE, were included. Methodological quality was assessed using the Newcastle-Ottowa risk of bias scale. Results Four studies met the inclusion criteria. The mean gestational age (GA) varied from 30 to 38 weeks in the FGR group and 20 to 40 weeks in AGA fetuses. The number of included FGR fetuses (with or without Doppler abnormalities), varied from 30 to 50. Longitudinal strain in FGR fetuses was described as comparable (n = 2), increased (n = 1) and>95th percentile (n = 1) compared to AGA fetuses. Strain rate was measured in two studies. One reported an increased strain rate, another showed comparable strain rate. Two studies addressed global left ventricle (LV) and right ventricle (RV) dyssynchrony. Dyssynchrony was increased in FGR compared to AGA fetuses. Conclusion The currently published data is limited and heterogeneous concerning GA and Doppler profiles. The data presentation and the interpretation thereof make qualitative comparisons impossible. Large prospective longitudinal cohort studies looking at the value of deformation measurements of the fetal heart in FGR and AGA fetuses are needed to assess the clinical significance of deformation values measured with 2D-STE.

Right ventricular dysfunction identified by abnormal strain values precedes evident growth restriction in small for gestational age fetuses

OBJECTIVES

Small for gestational age (SGA) fetuses have an increased risk for adverse outcome. Placental insufficiency leads to changes in the circulation, with secondary adaptation of the fetal heart resulting in changed cardiac deformation. This deformation can be measured with 2D speckle tracking echocardiography (2D-STE). SGA is antenatally often undiagnosed. The measurement of deformation changes in the fetal heart might help in the prediction of SGA and identify fetuses in need of more intensive surveillance.

METHODS

In this longitudinal prospective cohort study, global longitudinal strain (GLS) and strain rate (GLSR), measured before 23 weeks gestational age were compared between SGA and appropriate for gestational age (AGA) fetuses, based on birthweight corrected for gestational age at birth.

RESULTS

The fetal heart rate was significantly increased in SGA; 158 beats per minute (146-163) vs 148 (134-156); P = 0.035 in AGA. Right ventricle GLS (RV-GLS) values were significantly increased in SGA; -15.87% (-11.69% to -20.55%) vs -20.24% (-16.29% to -24.28%); p = 0.024, respectively.

CONCLUSION

RV-GLS values, measured with 2D-STE, were significantly increased in SGA, indicating systolic RV dysfunction before 23 weeks gestational age in fetuses who will become SGA later in pregnancy. A large longitudinal prospective cohort study is needed to confirm these findings.

Small bowel intussusception in pregnant women with a history of a Roux-en-Y gastric bypass: a case series and a systematic review of the literature

Intussusception of the small intestine has been described in pregnant women with a history of a laparoscopic Roux-en-Y gastric bypass. This study provides a systematic review on the characteristics of intussusception in this population. MEDLINE, Embase, Cochrane Library, and our own hospital's electronics health records were searched for eligible studies/cases. Fifteen papers were eligible, containing 17 cases. Our hospital search included 6 cases. Seventeen of 23 intussusceptions were retrograde and were mostly (18/23) located at the jejunojejunostomy. Six patients were treated successfully with manual reduction only and 17 patients required surgical resection. Fifteen (65%) patients had an ischemic segment. Six (26%) patients delivered during the same hospital admission. One fetal death (1 of twins) was reported. Awareness of this rare but serious complication by obstetricians and bariatric surgeons is necessary to limit maternal and fetal complications.

Fetal strain and strain rate during pregnancy measured with speckle tracking echocardiography: A systematic review

Establishment of the maturational patterns of the fetal left and right ventricle strain and strain rate by two-dimensional speckle tracking echocardiography is a prerequisite for its routine clinical adaptation in pregnancy. The aim of this study is to review systematically current literature on the development of left and right ventricle strain and strain rate derived by speckle tracking during gestation. EMBASE, Medline and Central were searched, from inception to October 2019, for observational studies of singletons in uncomplicated, non-anomalous pregnancies, measuring global longitudinal strain and strain rate with 2D speckle tracking echocardiography in the fetal heart during gestation. 23 Studies met the inclusion criteria. The gestational age of the included fetuses varied from 12 to 42 weeks. Four studies used a longitudinal study design, with few consecutive measurements at varying gestational ages. 19 Studies performed either cross sectional or both longitudinal and cross sectional measurements. The ultrasound devices and speckle tracking algorithm software used, varied. Strain and strain rate during gestation increased, decreased or remained stable in the left and right fetal ventricle with increasing gestation. Due to considerable variation in the included gestational ages measured and inconsistency in the direction of strain and strain rate development, a meta-analysis could not be performed. Contradictory results concerning the development of strain and strain rate during gestation were shown, probably due to suboptimal study designs and varying algorithms and ultrasound devices used. A large longitudinal cohort study is needed to obtain reference values for fetal cardiac deformation in the uncomplicated, singleton pregnancy.

Feasibility of non-invasive Foetal electrocardiography in a twin pregnancy

Background

Twin pregnancy is associated with increased perinatal mortality. Close foetal monitoring is therefore warranted. Doppler Ultrasound cardiotocography is currently the only available method to monitor both individual foetuses. Unfortunately, the performance measures of this method are poor and erroneous monitoring of the same twin with both transducers may occur, leaving the second twin unmonitored. In this study we aimed to determine the feasibility of monitoring both foetuses simultaneously in twin gestation by means of non-invasive foetal electrocardiography (NI-fECG), using an electrode patch on the maternal abdomen.

Methods

A NI-fECG recording was performed at 25 + 3 weeks of gestation on a multiparous woman pregnant with dichorionic diamniotic twins. An electrode patch consisting of eight adhesive electrodes was applied on the maternal abdomen, yielding six channels of bipolar electrophysiological measurements. The output was digitized and stored for offline processing. The recorded signals were preprocessed by suppression of high-frequency noise, baseline wander, and powerline interference. Secondly, the maternal ECG was subtracted and segmentation into individual ECG complexes was performed. Finally, ensemble averaging of these individual ECG complexes was performed to suppress interferences.

Results

Six different recordings were obtained from each of the six recording channels. Depending on the orientation and distance of the fetal heart with respect to each electrode, a distinction could be made between each fetus based on the morphology of the signals. Yielding of the fetal ECGs was performed manually based on the QRS complexes of each fetus.

Conclusion

NI-fECG with multiple electrodes allows for monitoring of the fetal heart rate and ECG of both individual fetuses in twin pregnancies.

Doppler Ultrasound Technology for Fetal Heart Rate Monitoring: A Review

Fetal well-being is commonly assessed by monitoring the fetal heart rate (fHR). In clinical practice, the de facto standard technology for fHR monitoring is based on the Doppler ultrasound (US). Continuous monitoring of the fHR before and during labor is performed using a US transducer fixed on the maternal abdomen. The continuous fHR monitoring, together with simultaneous monitoring of the uterine activity, is referred to as cardiotocography (CTG). In contrast, for intermittent measurements of the fHR, a handheld Doppler US transducer is typically used. In this article, the technology of Doppler US for continuous fHR monitoring and intermittent fHR measurements is described, with emphasis on fHR monitoring for CTG. Special attention is dedicated to the measurement environment, which includes the clinical setting in which fHR monitoring is commonly performed. In addition, to understand the signal content of acquired Doppler US signals, the anatomy and physiology of the fetal heart and the surrounding maternal abdomen are described. The challenges encountered in these measurements have led to different technological strategies, which are presented and critically discussed, with a focus on the US transducer geometry, Doppler signal processing, and fHR extraction methods.

The diagnostic value of fetal fibronectin testing in clinical practice

AIM

To evaluate the clinical management to withhold treatment for preterm labor in symptomatic women with an intermediate cervical length and negative fetal fibronectin (fFN) testing.

METHODS

A retrospective cohort study was performed in a tertiary care teaching hospital in the Netherlands. Pregnant women with a gestational age between 23⁺⁵ to 34⁺⁰ weeks, with the presence of regular uterine contractions accompanied by a cervical length between 15 and 30 mm and intact membranes, who underwent fFN testing were included to obtain the diagnostic value of fFN testing for preterm delivery within 7 days.

RESULTS

Fetal fibronectin testing has an extremely high negative predictive value (100%) and sensitivity (100%) for delivery within 7 days, in singleton and multiple pregnancies. However, specificity (64%) and positive predictive value (10%) of fFN testing in singleton pregnancies are low. Blood present on the fFN sample does not affect the reliability of the fFN test; the negative predictive value remains 100%.

CONCLUSION

Women with symptoms of early preterm labor, intact membranes, a cervical length between 15 and 30 mm and negative fFN testing do not deliver within 7 days. Administration of corticosteroids and tocolytics can safely be withhold. Furthermore, blood on the fFN sample does not change the reliability of the fFN test.

Non-invasive Fetal Electrocardiography for Intrapartum Cardiotocography

Fetal monitoring is important to diagnose complications that can occur during pregnancy. If detected timely, these complications might be resolved before they lead to irreversible damage. Current fetal monitoring mainly relies on cardiotocography, the simultaneous registration of fetal heart rate and uterine activity. Unfortunately, the technology to obtain the cardiotocogram has limitations. In current clinical practice the fetal heart rate is obtained via either an invasive scalp electrode, that poses risks and can only be applied during labor and after rupture of the fetal membranes, or via non-invasive Doppler ultrasound technology that is inaccurate and suffers from loss of signal, in particular in women with high body mass, during motion, or in preterm pregnancies. In this study, transabdominal electrophysiological measurements are exploited to provide fetal heart rate non-invasively and in a more reliable manner than Doppler ultrasound. The performance of the fetal heart rate detection is determined by comparing the fetal heart rate to that obtained with an invasive scalp electrode during intrapartum monitoring. The performance is gauged by comparing it to performances mentioned in literature on Doppler ultrasound and on two commercially-available devices that are also based on transabdominal fetal electrocardiography.

Determinants of disease course and severity in hyperemesis gravidarum

OBJECTIVE

We aimed to identify determinants that predict hyperemesis gravidarum (HG) disease course and severity.

STUDY DESIGN

For this study, we combined data of the Maternal and Offspring outcomes after Treatment of HyperEmesis by Refeeding (MOTHER) randomized controlled trial (RCT) and its associated observational cohort with non-randomised patients. Between October 2013 and March 2016, in 19 hospitals in the Netherlands, women hospitalised for HG were approached for study participation. In total, 215 pregnant women provided consent for participation. We excluded women enrolled during a readmission (n = 24). Determinants were defined as patient characteristics and clinical features, available to clinicians at first hospital admission. Patient characteristics included i.e. age, ethnicity, socio-economic status, history of mental health disease and HG and gravidity. Clinical features included weight loss compared to pre-pregnancy weight and symptom severity measured with Pregnancy Unique Quantification of Emesis (PUQE-24) questionnaire and the Nausea and Vomiting in Pregnancy specific Quality of Life questionnaire (NVPQoL). Outcome measures were measures of HG disease severity present at 1 week after hospital admission, including weight change, PUQE-24 and NVPQoL scores. Total days of admission hospital admission and readmission were also considered outcome measures.

RESULTS

We found that high PUQE-24 and NVPQoL scores at hospital admission were associated with those 1 week after hospital admission (difference (β) 0.36, 95 %CI 0.16 to 0.57 and 0.70,95 %CI 0.45-1.1). PUQE-24 and NVPQoL scores were not associated with other outcome measures. None of the patient characteristics were associated with any of the outcome measures.

CONCLUSION

Our findings suggest that the PUQE-24 and NVPQoL questionnaires can identify women that maintain high symptom scores a week after admission, but that patient characteristics cannot be used as determinants of HG disease course and severity.

Head orientation and electrode placement potentially influence fetal scalp ECG waveform

BACKGROUND

Fetal monitoring based on electrocardiographic (ECG) morphology is obtained from a single unipolar fetal scalp electrode. Ideally, it should be obtained from multiple leads, as ECG waveform depends on alignment between electrode and electrical heart axis. This alignment is unknown in fetuses. Besides, fetuses are surrounded by conductive media, which may influence ECG waveform. We explored the influence of electrode position and head orientation on ECG waveforms of unipolar and bipolar scalp ECGs recorded in air and in conductive medium.

METHODS

We recorded ECGs in one adult subject at five different scalp positions in five different head orientations both in dry and immersed conditions. The ratio between T-amplitude and QRS-amplitude (T/QRS ratio) of unipolar and bipolar scalp ECGs was determined and compared between all conditions.

RESULTS

In the dry condition, we observed in the unipolar leads little to no difference between different electrode positions (maximal T/QRS difference 0.00-0.01) and minor differences between head orientations (0.02-0.03), whereas bipolar leads showed no recognizable ECG signal at all. During the immersed condition, we found variation in the unipolar leads, both between electrode positions (maximal T/QRS difference 0.02-0.05) and between head orientations (0.03-0.06). Bipolar leads showed different ECG signals in contrasting head orientations.

CONCLUSIONS

Both unipolar and bipolar scalp lead-derived ECG waveforms are influenced by electrode position and head orientation when the subject is submerged in a conductive medium. Fetal monitoring based on single scalp lead ECG waveform might be suboptimal, as it lacks correction for fetal head orientation and electrode position.

[Breech delivery 'on all fours']

Since the publication of the results of the Term Breech Trial (TBT) in 2000 the number of planned Caesarean sections for breech presentation has increased dramatically, at the expense of vaginal breech deliveries. The favourable effect of a planned Caesarean section for breech presentation on perinatal outcomes described in the TBT could not, however, be reproduced in later trials. A planned Caesarean section does carry an increased risk of maternal complications; furthermore, a previous Caesarean section leads to higher risks for both mother and child in any subsequent pregnancy. A recent prospective study advocates vaginal breech delivery 'on all fours', a position in which the mother leans on her hands and knees during delivery. A vaginal breech delivery in this position seems to be just as safe for the child as a planned Caesarean section, while a vaginal delivery is safer for the mother than a Caesarean section. This article describes two uncomplicated vaginal breech deliveries in the all fours position.

SUGAR-DIP trial: oral medication strategy versus insulin for diabetes in pregnancy, study protocol for a multicentre, open-label, non-inferiority, randomised controlled trial

INTRODUCTION

In women with gestational diabetes mellitus (GDM) requiring pharmacotherapy, insulin was the established first-line treatment. More recently, oral glucose lowering drugs (OGLDs) have gained popularity as a patient-friendly, less expensive and safe alternative. Monotherapy with metformin or glibenclamide (glyburide) is incorporated in several international guidelines. In women who do not reach sufficient glucose control with OGLD monotherapy, usually insulin is added, either with or without continuation of OGLDs. No reliable data from clinical trials, however, are available on the effectiveness of a treatment strategy using all three agents, metformin, glibenclamide and insulin, in a stepwise approach, compared with insulin-only therapy for improving pregnancy outcomes. In this trial, we aim to assess the clinical effectiveness, cost-effectiveness and patient experience of a stepwise combined OGLD treatment protocol, compared with conventional insulin-based therapy for GDM.

METHODS

The SUGAR-DIP trial is an open-label, multicentre randomised controlled non-inferiority trial. Participants are women with GDM who do not reach target glycaemic control with modification of diet, between 16 and 34 weeks of gestation. Participants will be randomised to either treatment with OGLDs, starting with metformin and supplemented as needed with glibenclamide, or randomised to treatment with insulin. In women who do not reach target glycaemic control with combined metformin and glibenclamide, glibenclamide will be substituted with insulin, while continuing metformin. The primary outcome will be the incidence of large-for-gestational-age infants (birth weight >90th percentile). Secondary outcome measures are maternal diabetes-related endpoints, obstetric complications, neonatal complications and cost-effectiveness analysis. Outcomes will be analysed according to the intention-to-treat principle.

ETHICS AND DISSEMINATION

The study protocol was approved by the Ethics Committee of the Utrecht University Medical Centre. Approval by the boards of management for all participating hospitals will be obtained. Trial results will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NTR6134; Pre-results.

Relative versus absolute rises in T/QRS ratio by ST analysis of fetal electrocardiograms in labour: A case-control pilot study

Introduction

The additional value of ST analysis during labour is uncertain. In ST analysis, a T/QRS baseline value is calculated from the fetal electrocardiogram and successive T/QRS ratios are compared to this baseline. However, variation in the orientation of the electrical heart axis between fetuses may yield different T/QRS baseline values. In case of a higher T/QRS baseline value more ST events are encountered, although not always related to perinatal outcome. We hypothesised that we can partly correct for this effect by analysing T/QRS rises as a percentage from baseline (relative ST analysis). This study aimed to explore whether relative ST analysis has better diagnostic value for cord acidaemia compared to conventional ST analysis, where predefined fixed T/QRS ratios are used.

Methods and materials

A case-control study was performed in 20 term human fetuses during labour; 10 cases (umbilical cord artery pH <7.05 at birth, defining acidaemia) and 10 controls (pH >7.20) were included. The fetal electrocardiogram was recorded using a STAN monitor. We electronically extracted all T/QRS values, baseline and episodic ST events from the STAN monitor and calculated the relative T/QRS changes. The cut-off for relative ST events was determined in a receiver operator characteristic (ROC) curve at optimal specificity for cord acidaemia. Parameters of interest were area under the curve (AUC) of the ROC curve for relative ST events and test performance of both conventional and relative ST analysis.

Results

Relative ST analysis showed an AUC of 0.99. The optimal cut-off value for relative T/QRS rise was determined at 0.70. Relative vs conventional (absolute) ST analysis showed a specificity of 100% vs 40% (p = 0.031); sensitivity 90% vs 90%; positive likelihood ratio infinity vs 1.5; negative likelihood ratio 0.10 vs 0.25, respectively.

Conclusion

Relative ST analysis seems to be a promising method to detect impending fetal acidaemia during labour. Further studies are required to determine the diagnostic accuracy.

Fetal Heart Rate Monitoring Implemented by Dynamic Adaptation of Transmission Power of a Flexible Ultrasound Transducer Array

Fetal heart rate (fHR) monitoring using Doppler Ultrasound (US) is a standard method to assess fetal health before and during labor. Typically, an US transducer is positioned on the maternal abdomen and directed towards the fetal heart. Due to fetal movement or displacement of the transducer, the relative fetal heart location (fHL) with respect to the US transducer can change, leading to frequent periods of signal loss. Consequently, frequent repositioning of the US transducer is required, which is a cumbersome task affecting clinical workflow. In this research, a new flexible US transducer array is proposed which allows for measuring the fHR independently of the fHL. In addition, a method for dynamic adaptation of the transmission power of this array is introduced with the aim of reducing the total acoustic dose transmitted to the fetus and the associated power consumption, which is an important requirement for application in an ambulatory setting. The method is evaluated using an in-vitro setup of a beating chicken heart. We demonstrate that the signal quality of the Doppler signal acquired with the proposed method is comparable to that of a standard, clinical US transducer. At the same time, our transducer array is able to measure the fHR for varying fHL while only using 50% of the total transmission power of standard, clinical US transducers.

[Abdominal pain in a pregnant patient who had gastric reduction surgery: risks associated with a history of bariatric surgery]

Pregnant women who previously had bariatric surgery may develop acute abdominal pain during pregnancy that may be related to previous operations. Two patients, a 38-year-old twin-primigravida who had a gestation period of 24+6 weeks and a 26-year-old woman who had a gestation period of 24 weeks, both of whom had laparoscopic gastric bypass (RYGB) surgery 2 and 3 years previously, developed abdominal pain. The patients were not ill, but had diffuse abdominal pain in combination with normal blood tests and imaging. Patient B had undergone laparoscopy at another centre after 5 weeks of gestation for internal herniation. After referral to our multidisciplinary Bariatric-Obstetric-Neonatal (MD-BON) team, diagnostic laparoscopy was advised as internal herniation was deemed possible. In both patients, internal herniation was indeed found in Petersen's space and jejunal mesenteric defect, which was closed using laparoscopic surgery. Both women delivered healthy offspring afterwards. The presence of a MD-BON team allows for an increased awareness of potential long-term complications associated with earlier bariatric surgery in pregnancy.

ST waveform analysis for monitoring hypoxic distress in fetal sheep after prolonged umbilical cord occlusion

INTRODUCTION

The inconclusive clinical results for ST-waveform analysis (STAN) in detecting fetal hypoxemia may be caused by the signal processing of the STAN-device itself. We assessed the performance of a clinical STAN device in signal processing and in detecting hypoxemia in a fetal sheep model exposed to prolonged umbilical cord occlusion (UCO).

METHODS

Eight fetal lambs were exposed to 25 minutes of UCO. ECG recordings were analyzed during a baseline period and during UCO. STAN-event rates and timing of episodic T/QRS rise, baseline T/QRS rise and the occurrence of biphasic ST-waveforms, as well as signal loss, were assessed.

RESULTS

During baseline conditions of normoxemia, a median of 40 (IQR, 25-70) STAN-events per minute were detected, compared to 10 (IQR, 2-22) during UCO. During UCO STAN-events were detected in five subjects within 10 minutes and in six subjects after 18 minutes, respectively. Two subjects did not generate any STAN-event during UCO. Biphasic ST event rate was reduced during UCO (median 0, IQR 0-5), compared to baseline (median 32, IQR, 6-55). ST-waveforms could not be assessed in 62% of the recording time during UCO, despite a good quality of the ECG signal.

CONCLUSIONS

The STAN device showed limitations in detecting hypoxemia in fetal sheep after prolonged UCO. The STAN device produced high false positive event rates during baseline and did not detect T/QRS changes adequately after prolonged fetal hypoxemia. During 14% of baseline and 62% of the UCO period, the STAN-device could not process the ECG signal, despite its good quality. Resolving these issues may improve the clinical performance of the STAN device.

Improved ultrasound transducer positioning by fetal heart location estimation during Doppler based heart rate measurements

OBJECTIVE

Doppler ultrasound (US) is the most commonly applied method to measure the fetal heart rate (fHR). When the fetal heart is not properly located within the ultrasonic beam, fHR measurements often fail. As a consequence, clinical staff need to reposition the US transducer on the maternal abdomen, which can be a time consuming and tedious task.

APPROACH

In this article, a method is presented to aid clinicians with the positioning of the US transducer to produce robust fHR measurements. A maximum likelihood estimation (MLE) algorithm is developed, which provides information on fetal heart location using the power of the Doppler signals received in the individual elements of a standard US transducer for fHR recordings. The performance of the algorithm is evaluated with simulations and in vitro experiments performed on a beating-heart setup.

MAIN RESULTS

Both the experiments and the simulations show that the heart location can be accurately determined with an error of less than 7 mm within the measurement volume of the employed US transducer.

SIGNIFICANCE

The results show that the developed algorithm can be used to provide accurate feedback on fetal heart location for improved positioning of the US transducer, which may lead to improved measurements of the fHR.

The electrical heart axis and ST events in fetal monitoring: A post-hoc analysis following a multicentre randomised controlled trial

Objective

Reducing perinatal morbidity and mortality is one of the major challenges in modern health care. Analysing the ST segment of the fetal electrocardiogram was thought to be the breakthrough in fetal monitoring during labour. However, its implementation in clinical practice yields many false alarms and ST monitoring is highly dependent on cardiotocogram assessment, limiting its value for the prediction of fetal distress during labour. This study aims to evaluate the relation between physiological variations in the orientation of the fetal electrical heart axis and the occurrence of ST events.

Methods

A post-hoc analysis was performed following a multicentre randomised controlled trial, including 1097 patients from two participating centres. All women were monitored with ST analysis during labour. Cases of fetal metabolic acidosis, poor signal quality, missing blood gas analysis, and congenital heart disease were excluded. The orientation of the fetal electrical heart axis affects the height of the initial T/QRS baseline, and therefore the incidence of ST events. We grouped tracings with the same initial baseline T/QRS value. We depicted the number of ST events as a function of the initial baseline T/QRS value with a linear regression model.

Results

A significant increment of ST events was observed with increasing height of the initial T/QRS baseline, irrespective of the fetal condition; correlation coefficient 0.63, p<0.001. The most frequent T/QRS baseline is 0.12.

Conclusion

The orientation of the fetal electrical heart axis and accordingly the height of the initial T/QRS baseline should be taken into account in fetal monitoring with ST analysis.

Effect of tocolytic drugs on fetal heart rate variability: a systematic review

INTRODUCTION

Tocolytics may cause changes in fetal heart rate (HR) pattern, while fetal heart rate variability (HRV) is an important marker of fetal well-being. We aim to systematically review the literature on how tocolytic drugs affect fetal HRV.

MATERIALS AND METHODS

We searched CENTRAL, PubMed and EMBASE up to June 2016. Studies published in English, using computerized or visual analysis to describe the effect of tocolytics on HRV in human fetuses were included. Studies describing tocolytics during labor, external cephalic version, pre-eclampsia and infection were excluded. Eventually, we included six studies, describing 169 pregnant women.

RESULTS

Nifedipine, atosiban and indomethacin administration show no clinically important effect on fetal HRV. Following administration of magnesium sulfate decreased variability and cases of bradycardia are described. Fenoterol administration results in a slight increase in fetal HR with no changes in variability. After ritodrine administration increased fetal HR and decreased variability is seen. The effect of co-administration of corticosteroids should be taken into account.

CONCLUSION

In order to prevent iatrogenic preterm labor, the effects of tocolytic drugs on fetal HRV should be taken into account when monitoring these fetuses.

Normal ranges for fetal electrocardiogram values for the healthy fetus of 18-24 weeks of gestation: a prospective cohort study

Background

The fetal anomaly ultrasound only detects 65 to 81 % of the patients with congenital heart disease, making it the most common structural fetal anomaly of which a significant part is missed during prenatal life. Therefore, we need a reliable non-invasive diagnostic method which improves the predictive value for congenital heart diseases early in pregnancy. Fetal electrocardiography could be this desired diagnostic method. There are multiple technical challenges to overcome in the conduction of the fetal electrocardiogram. In addition, interpretation is difficult due to the organisation of the fetal circulation in utero. We want to establish the normal ranges and values of the fetal electrocardiogram parameters in healthy fetuses of 18 to 24 weeks of gestation.

Methods/Design

Women with an uneventful singleton pregnancy between 18 and 24 weeks of gestation are asked to participate in this prospective cohort study. A certified and experienced sonographist performs the fetal anomaly scan. Subsequently, a fetal electrocardiogram recording is performed using dedicated signal processing methods. Measurements are performed at two institutes. We will include 300 participants to determine the normal values and 95 % confidence intervals of the fetal electrocardiogram parameters in a healthy fetus. We will evaluate the fetal heart rate, segment intervals, normalised amplitude and the fetal heart axis. Three months postpartum, we will evaluate if a newborn is healthy through a questionnaire.

Discussion

Fetal electrocardiography could be a promising tool in the screening program for congenital heart diseases. The electrocardiogram is a depiction of the intimate relationship between the cardiac nerve conduction pathways and the structural morphology of the fetal heart, and therefore particularly suitable for the detection of secondary effects due to a congenital heart disease (hypotrophy, hypertrophy and conduction interruption).

Fetal heart rate variability during pregnancy, obtained from non-invasive electrocardiogram recordings

OBJECTIVE

Non-invasive spectral analysis of fetal heart rate variability is a promising new field of fetal monitoring. To validate this method properly, we studied the relationship between gestational age and the influence of fetal rest-activity state on spectral estimates of fetal heart rate variability.

DESIGN

Prospective longitudinal study.

SETTING

Tertiary care teaching hospital.

POPULATION

Forty healthy women with an uneventful singleton pregnancy.

METHODS

Non-invasive fetal electrocardiogram measurements via the maternal abdomen were performed at regular intervals between 14 and 40 weeks of gestation and processed to detect beat-to-beat fetal heart rate. Simultaneous ultrasound recordings were performed to assess fetal rest-activity state.

MAIN OUTCOME MEASURES

Absolute and normalized power of fetal heart rate variability in the low (0.04-0.15 Hz) and high (0.4-1.5 Hz) frequency band were obtained, using Fourier Transform.

RESULTS

14% of all measurements and 3% of the total amount of abdominal data (330 segments) was usable for spectral analysis. During 21-30 weeks of gestation, a significant increase in absolute low and high frequency power was observed. During the active state near term, absolute and normalized low frequency power were significantly higher and normalized high frequency power was significantly lower compared with the quiet state.

CONCLUSIONS

The observed increase in absolute spectral estimates in preterm fetuses was probably due to increased sympathetic and parasympathetic modulation and might be a sign of autonomic development. Further improvements in signal processing are needed before this new method of fetal monitoring can be introduced in clinical practice.

Estimation of internal uterine pressure by joint amplitude and frequency analysis of electrohysterographic signals

Monitoring the uterine contraction provides important prognostic information during pregnancy and parturition. The existing methods employed in clinical practice impose a compromise between reliability and invasiveness. A promising technique for uterine contraction monitoring is electrohysterography (EHG). The EHG signal measures the electrical activity which triggers the contraction of the uterine muscle. In this paper, a non-invasive method for intrauterine pressure (IUP) estimation by EHG signal analysis is proposed. The EHG signal is regarded as a non-stationary signal whose frequency and amplitude characteristics are related to the IUP. After acquisition in a multi-channel configuration, the EHG signal is therefore analyzed in the time-frequency domain. A first estimation of the IUP is then derived by calculation of the unnormalized first statistical moment of the frequency spectrum. The estimation accuracy is finally increased by identification of a second-order polynomial model. The proposed method is compared to root mean squared analysis and optimal linear filtering and validated by simultaneous measurement of the IUP on nine women during labor. The results suggest that the proposed EHG signal analysis provides an accurate estimate of the IUP.