Low-risk Singleton Pregnancies Research Articles

Early Pregnancy Blood Pressure Trajectories Predict Preeclampsia and Gestational Hypertension Among Low Risk Pregnancies

Develop and validate a prediction model for risk of preeclampsia (PE) and gestational hypertension (GH) using early pregnancy blood pressure (BP) patterns plus risk factors (RF) routinely available in clinical settings among low and moderate risk pregnancies. Retrospective cohort of 249,892 low or moderate risk singleton pregnancies delivered at Kaiser Permanente Northern California hospitals in 2009-2019. Electronic health records excluded prior hypertension, heart, kidney or liver disease and history of PE. All BPs were < 140/90 at < 20 weeks gestation. Data were randomly divided into a training dataset (N=174,925;70%) for model development and a validation dataset (n=74,967;30%). We used group-based trajectory modeling of longitudinal clinical systolic BPs to identify early pregnancy BP trajectory (BPT) groups < 20 weeks. We fit multinomial logistic regression models to predict early PE (< 34 weeks), late PE (≥34 weeks) and GH including BPT alone or with multiple RF (BMI, parity, age, race/ethnicity, diabetes) vs. an initial BP alone or with other RF. C-statistics generated from the validation dataset evaluated model predictive performance. The sample of 249,892 low to moderate risk individuals had mean (SD) maternal age of 30.9 y (5.3), BMI of 26.0 kg/m2 (5.8), 57% were nulliparous, and 63% were from Black, Hispanic, or Asian groups, and 100% had all normal BPs < 20 weeks. Overall, 992 (0.4%) developed early PE, 10,612 (4.3%) late PE, and 10,854 (4.3%) GH. BPT group models performed much better (C-statistic:0.664-0.732) than models with initial BP only (0.630-0.700), multiple RF alone, or in combination (Table 1). The best model performance (0.729-0.768) to predict early PE, late PE and GH included BPT groups plus BMI, parity, age, race/ethnicity, and diabetes. Six BP patterns plus RF available in routine clinical care improved prediction of early and late PE, and GH in lower risk pregnancies. Our findings show promise to guide surveillance and strategies to distinguish risk among ostensibly low risk groups.

Accuracy of intrapartum cardiotocography in identifying fetal acidemia by umbilical cord blood analysis in low-risk pregnancies

The aim of this study was to evaluate the accuracy of intrapartum cardiotocography in identifying fetal acidemia by umbilical cord blood analysis in low-risk pregnancies.This is a retrospective cohort study of low-risk singleton pregnancies in labor after performing intrapartum cardiotocography categories I, II, and III. The presence of fetal acidemia at birth was identified by analyzing the pH of umbilical cord arterial blood (pH<7.1).No significant effect of the cardiotocography category on the arterial (p=0.543) and venous (p=0.770) pH of umbilical cord blood was observed. No significant association was observed between the cardiotocography category and the presence of fetal acidemia (p=0.706), 1-min Apgar score <7 (p=0.260), hospitalization in the neonatal intensive care unit (p=0.605), newborn death within the first 48 h, need for neonatal resuscitation (p=0.637), and adverse perinatal outcomes (p=0.373). Sensitivities of 62, 31, and 6.0%; positive predictive values of 11.0, 16.0, and 10.0%; and negative predictive values of 85, 89.0, and 87.0% were observed for cardiotocography categories I, II, and III, respectively.The three categories of intrapartum cardiotocography presented low sensitivities and high negative predictive values to identify fetal acidemia at birth in low-risk pregnancies.

Screening vs. no screening for preterm delivery in low-risk singleton pregnancies: comparison by propensity score analysis

PurposeTo compare the effect of a policy of screening for spontaneous preterm delivery (SPD) by transvaginal cervical length (CL) measurement versus a no screening policy in the prevention of severe prematurity.MethodsRetrospective study on low-risk singleton pregnancies examined at 20–24 weeks. Two cohorts, one with SPD screening and the other without screening, were matched using propensity analysis to create the study groups. Women with short CL were treated with vaginal progesterone and/or cervical cerclage/pessary. The outcomes examined were SPD < 32 weeks (SPD 32) and SPD between 20 and 32 weeks (SPD 20–32).ResultsScreening for SPD was associated with a significant reduction in the rate of SPD at less than 32 weeks (0.3 vs. 0.8%, p = 0.001 in the screened and no screened pregnancies, respectively) and in the rate of SPD 20–32 (0.3 vs. 0.9%, p = 0.005 in the screened and no screened pregnancies, respectively). After adjusting for maternal age, parity, body mass index, smoking and mode of conception, the screening group had significantly lower hazard for SPD 20–32 (HR = 0.36, 95% CI: 0.18–0.75, p = 0.006) and SPD32 (HR = 0.39, 95% CI: 0.19–0.82, p = 0.013).ConclusionScreening for SPD by transvaginal CL measurement in mid-pregnancy may reduce the incidence of severe prematurity in low-risk singleton pregnancies.

Conditional standards for the quantification of foetal growth in an ethnic Chinese population: a longitudinal study

This was an observational study of low-risk singleton pregnancies in an ethnic Chinese population. Foetal biometric variables which included biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL) were measured repeatedly. The standard views for measurement were obtained according to INTERGROWTH‐21st criteria. A linear mixed model with fractional polynomial regression was used to describe the longitudinal design. The study included 1289 foetuses and a total of 5125 ultrasound scans, of which each foetus was scanned at least three times, the intervals between scans being at least two weeks. The parameters of the linear mixed models were estimated by Stata v.16 (College Station, TX). Using these parameters, the equations of the mean and variance for BPD, HC, AC and FL were constructed. The conditional percentiles or Z scores could be calculated based on the above equations and previous measurements of the same foetus. A spreadsheet was provided for implementation. Impact Statement What is already known on this subject? Longitudinal data derived from serial measurements are therefore appropriate for assessing both foetal size and foetal growth. At present, most reference charts of ethnic Chinese foetal biometry are derived from cross-sectional data, which can only assess foetal size. What do the results of this study add? In this study, we have constructed conditional standards for foetal biometry in an ethnic Chinese population and provided a spreadsheet for querying. What are the implications of these findings for clinical practice and/or further research? The conditional standards can be used to assess foetal growth in clinical practice. In the future, we hope that these foetal growth standards can be applied to determine whether abnormal growth increases the risk of adverse outcomes.

Diagnosis of mid-second trimester fetal growth restriction and associated outcomes

Objective To evaluate maternal and neonatal outcomes of low-risk singleton pregnancies, without underlying maternal medical conditions or genetic and fetal anomalies associated with fetal growth restriction, that were diagnosed with fetal growth restriction (FGR) (EFW < 10th %) in the mid-second trimester (between 17 and 22 weeks and 6 days’ gestation). Methods A retrospective cohort study of all women who underwent a routine fetal anatomy ultrasound between 17 and 22 weeks and 6 days’ gestation at a community-based academic hospital was performed to identify subjects with an EFW <10th%. Pregnancies with inadequate dating, multiple gestations, preexisting maternal vascular disease (chronic hypertension and pregestational diabetes), lethal fetal anomalies, and abnormal prenatal genetic screening were excluded. Descriptive statistics were computed to describe the study population. Subjects were stratified into two groups, estimated fetal weight (EFW) <5th% and EFW 5th–9th%. The primary outcome was a small for gestational age neonate (SGA) at delivery. Secondary outcomes included a composite adverse neonatal outcome, perinatal death, hypertensive disorders of pregnancy, medically indicated delivery, and mode of delivery. A comparison of the two groups, EFW <5th% and EFW 5th–9th %, was performed. Continuous variables were compared utilizing Wilcoxon Rank Sum tests and categorical variables were compared using Fisher’s exact test or Chi-squared tests, and a dichotomous composite variable for adverse neonatal outcomes was also calculated. Results In total, 3,868 unique patient records were screened. Thirty-two patient records (0.8% of the total screened records) were eligible for inclusion. The primary outcome, SGA at delivery, occurred in 13/32 (41%) of the subjects. The secondary outcomes of the composite neonatal morbidity occurred in 9/32 (28%), hypertensive disorders of pregnancy in 10/32 (31%), and medically indicated delivery at <28 weeks gestation in 7/32 (22%) of the subjects. When comparing EFW <5th% and EFW 5th–9th%, EFW <5th% had a larger percentage of SGA newborns (66% vs. 25%, p = .02, OR = 8.0 95% CI 1.5–42.5). EFW <5th% was also significantly associated with a greater composite adverse neonatal outcome when compared to EFW 5th–9th% (54% vs. 10%, p = .015). The subgroup with an EFW <5th% also had higher rates of adverse outcomes including preeclampsia (42% vs. 10%, p = .073), abnormal umbilical artery Doppler studies (50% vs. 15%, p = .049), and medically indicated delivery <28 weeks (42% vs. 10%, p = .07). Conclusions Early onset FGR is a associated with high rates of SGA at delivery, as well as several adverse maternal and neonatal outcomes which include hypertensive disorders of pregnancy, a greater composite neonatal morbidity, perinatal death, and medically indicated preterm delivery. EFW <5th% was associated with worse outcomes when compared to those with an EFW 5th%–9th%.

Effect of induction of labor on maternal and perinatal outcomes in low-risk singleton pregnancies: a retrospective case-control study.

The aim of the study was to investigate the effect of induction of labor on maternal and fetal outcomes. This retrospective case-control study included 4386 pregnant women with low-risk singleton pregnancies who underwent regular prenatal examination and successful vaginal delivery at ≥41 weeks and 0 days of gestation in Fujian Maternal and Child Health Hospital between January 2014 and December 2018. Clinical data of women were retrospectively divided into the induction of labor group (2007 cases) and spontaneous onset of labor group (2361 cases) based on the mode of labor initiation. Two-sample independent t-test and χ2 tests were used to analyze the differences in clinical characteristics, such as maternal age and parity between the two groups. The induction of the labor group had a significantly longer total duration of labor (9.37±5.37 vs. 8.82±5.13 h; p<0.001), more postpartum blood loss (219.18±188.32 vs. 199.95±124.69 mL; p=0.01) and a significantly higher incidence of severe postpartum hemorrhage (PPH) comparing to the spontaneous onset of labor group [0.8% (16/2007) vs. 0.33% (8/2361); p=0.041]. However, no significant difference was found in the neonatal outcomes. After adjusting for age, induction of labor in nulliparous women was more likely to lead to PPH than the spontaneous onset of labor [2.74% (55/2007) vs. 1.65% (39/2361); odds ratio=1.557; 95% confidence interval: 1.039-2.332; p<0.05]. Induction of labor increases the duration of labor and postpartum blood loss, especially in primary parturient, leading to an increased risk of PPH. This increase may be related to the overall higher duration of labor, associated with IOL. Therefore, low-risk nulliparous women should try to avoid induction of labor without medical indications.

The safety and immunogenicity of a combined pertussis containing vaccine Tdap for HIV infected pregnant women and their newborns (WoMANPOWER) – A study protocol for a randomized clinical trial

Background: Globally there are an estimated 24.1 million cases and 160,700 deaths from pertussis annually in children under five years. The disease burden is higher in low- and middle-income countries, especially the African region, which contributes the largest proportions of cases and deaths. Immunization against pertussis in pregnancy is a recommended strategy for the prevention of infant pertussis in many high-income countries. However, vaccine immunogenicity and effectiveness may be different in immunocompromised individuals such as women living with HIV. There is a need to generate data on the impact of HIV infection in pregnancy on maternal and infant immunity to vaccines against pertussis. Methods: This is a phase II, randomized controlled observer blind clinical trial of 100 women living with HIV and 100 uninfected women randomized to either standard vaccines (tetanus diphtheria vaccine, Td) or a tetanus diphtheria-pertussis vaccine (Tdap). Participants aged 18-40 years carrying a low-risk singleton pregnancy with a gestational age between 16 and 26 weeks confirmed on ultrasound scan, with no history of receipt of tetanus or pertussis vaccines in the current pregnancy will be recruited. Women will receive either two doses of Td or a first dose of Td and second dose of Tdap vaccine. Participants will complete 14-day diary cards to monitor reactogenicity. Mother-infant dyads will be followed up until the infant is one year old. The outcomes include: safety for the pregnant woman and infant; anti-pertussis toxin (PT) and anti-filamentous haemagglutinin (FHA) IgG concentrations in maternal, cord and infant blood and breastmilk, compared by maternal HIV status. Discussion: This study will investigate whether vaccines given to women living with HIV have similar immunogenicity and reactogenicity to vaccines given to pregnant women without HIV and monitor the effect of Tdap in pregnancy on infant immune responses. clinicalTrials.gov registration: NCT04589312 (19/10/2020)

Association between gestational weight gain and pregnancy outcomes in a Singaporean population: A prospective cohort study

ObjectivesInadequate or excessive gestational weight gain (GWG) is associated with adverse pregnancy outcomes. We aimed to study GWG in a Singaporean population and its association with pregnancy outcomes, including small for gestational age (SGA), macrosomia, and caesarean section secondary to failure to progress (FTP) or cephalopelvic disproportion (CPD). Study Design926 women with low-risk singleton pregnancy were enrolled in a prospective cohort study from 2010 to 2014 in a Singapore tertiary maternity hospital. 704 patients without pre-existing diabetes or hypertension and had maternal weight information till term pregnancy were included in analyses. Participants were categorized according to their first antenatal visit body mass index (BMI) as underweight, normal weight, overweight and obese. Total GWG for each BMI group was calculated and compared to Institute of Medicine (IOM) 2009 GWG guidelines. Logistic regression analyses were performed to assess the association of GWG below or above IOM guidelines with pregnancy outcomes. ResultsGWG below IOM guidelines was associated with an increased risk of SGA (adjusted OR: 2.97 [1.71, 5.15]; p < 0.0001). GWG above IOM guidelines significantly increased the risk of caesarean section due to FTP or CPD (adjusted OR: 2.10 [1.09, 4.01]; p = 0.0275). GWG above IOM guidelines was associated with an increased risk of macrosomia (adjusted odds ratio: 2.27 [1.43, 3.63]; p = 0.0006), while GWG below IOM guidelines was associated with a reduced risk of macrosomia (adjusted odds ratio: 0.18 [0.08, 0.39]; p < 0.0001). ConclusionsGWG not achieving the IOM recommendations has been found to be associated with adverse pregnancy outcomes in Singaporean women. Inadequate GWG is associated with an increased risk of SGA whereas excessive GWG is associated with increased risks of macrosomia and caesarean section due to failure to progress or CPD. Results of the current study add to our understanding on the association of GWG with pregnancy outcomes in the South-East Asia and suggest that appropriate weight management during pregnancy is important.

Effect of metformin on reducing platelet dysfunction in gestational diabetes mellitus: a randomized controlled trial.

Objectives To evaluate the effect of metformin in improving platelet dysfunction in women with gestational diabetes mellitus (GDM).Patients and methods A randomized controlled trial was conducted on pregnant women diagnosed with GDM. Singleton low-risk pregnancies meeting the inclusion criteria were randomly allocated at 27–31 weeks to receive metformin and placebo through the rest of pregnancy. Thirty-seven and 39 cases were recruited into the metformin group and the placebo group, respectively. MPVs, P-selectin, and 8-isoprostane levels were determined at the time of allocation and 6 weeks after treatment. Obstetric and neonatal outcomes were also assessed.Results Most baseline characteristics of the two groups were comparable. The levels of P-selectin after 6 weeks of treatment were significantly higher in the metformin group (68.9 ± 14.4 vs 60.6 ± 11.3; P-value = 0.006), indicating more platelet activation. All of the obstetric and neonatal outcomes were comparable except that birth weight was significantly lower in the metformin group (3018 ± 364 g vs 3204 ± 393 g; P-value = 0.037).Conclusion Metformin, in addition to diet and lifestyle modifications, does not improve or worsen oxidative stress and platelet dysfunction in women with GDM. Nevertheless, metformin significantly reduces fetal weight in women with GDM, theoretically preventing macrosomia.

Feasibility of 4D-Spatio Temporal Image Correlation (STIC) in the Comprehensive Assessment of the Fetal Heart Using FetalHQ®.

Fetal Heart Quantification (FetalHQ®) is a novel speckle tracking software that permits the study of global and regional ventricular shape and function from a 2D four-chamber-view loop. The 4D-Spatio Temporal Image Correlation (STIC) modality enables the offline analysis of optimized and perfectly aligned cardiac planes. We aimed to evaluate the feasibility and reproducibility of 4D-STIC speckle tracking echocardiography (STE) using FetalHQ® and to compare it to 2D STE. We conducted a prospective study including 31 low-risk singleton pregnancies between 20 and 40 weeks of gestation. Four-chamber view volumes and 2D clips were acquired with an apex pointing at 45° and with a frame rate higher than 60 Hz. Morphometric and functional echocardiography was performed by FetalHQ®. Intra- and interobserver reproducibility were evaluated by the intraclass correlation coefficient (ICC). Our results showed excellent reproducibility (ICC > 0.900) for morphometric evaluation (biventricular area, longitudinal and transverse diameters). Reproducibility was also good (ICC > 0.800) for functional evaluation (biventricular strain, Fractional Area Change, left ventricle volumes, ejection fraction and cardiac output). On the contrary, the study of the sphericity index and shortening fraction of the different ventricular segments showed lower reproducibility (ICC < 0.800). To conclude, 4D-STIC is feasible, reproducible and comparable to 2D echocardiography for the assessment of cardiac morphometry and function.

Arterial stiffness throughout pregnancy: Arteriograph device-specific reference ranges based on a low-risk population.

The maternal cardiovascular system undergoes significant adaptation during pregnancy. We aimed to examine the changes in arterial stiffness parameters during normal pregnancy and establish reference ranges for the general population. We performed a prospective cross-sectional observational study at the University Hospitals of Leicester. We included low-risk healthy pregnant women with singleton and viable pregnancies with no evidence of foetal abnormality or aneuploidy. Smokers, women with pre-existing or gestational hypertensive disorders and diabetes, booking BMI at least 30, on medication that could affect cardiac function and/or those who delivered before 37 completed weeks of gestation, and/or a neonate with birthweight less than 10th centile were excluded. Brachial (BrAIx) and aortic augmentation indices (AoAIx), and pulse wave velocity (PWV) were assessed using the Arteriograph. Data were analysed using a linear mixed model. We analysed a total of 571 readings from 259 women across different gestational ages and present the 10th, 25th, 50th, 75th and 90th centiles for BrAIx, AoAIx and PWV from 12+0 to 42+0 weeks' gestation. All haemodynamic variables were significantly associated with maternal heart rate. BrAIx, AoAIx and PWV demonstrated significant change with gestation, with all reaching their lowest value in the second trimester. The current study presents reference ranges for BrAIx, AoAIx and PWV in low-risk singleton pregnancies. Further work is required to establish if women in whom measures of arterial stiffness lie above the 90th centile could be at increased risk of adverse pregnancy outcomes and to identify the optimum time for screening.

Maternal morbidity associated with early preterm birth in low-risk singleton pregnancies

While the increase in neonatal morbidities associated with early preterm birth is well known, the accompanying risks of maternal morbidity, particularly in the absence of medical indications for delivery, remain unclear. Thus, we set out to determine the risk of maternal morbidity with early preterm birth based on a large population-based cohort of low-risk singleton pregnancies.

Ultrasonographic study of fetal mandibular markers during the first trimester in a Chinese population.

To establish reference ranges for fetal mandibular markers in low-risk singleton pregnancies between 11 and 13 + 6 weeks of gestation in a Chinese population. The inferior facial angle (IFA), transverse, and anteroposterior diameters of the mandible, and mandibular length were measured at 11-13 + 6 weeks of gestation. The utility of these sonographic markers for detecting micrognathia was explored in seven fetuses. In healthy fetuses at 11-13 + 6 weeks, there were linear correlations between gestational age and the transverse (Y=-15.615 + 1.987X, r=0.718, p < 0.001) and anteroposterior (Y=-8.557 + 1.101X, r=0.581, p < 0.001) diameters of the mandible; mean ratio of the anteroposterior: transverse diameters of the mandible decreased with gestational age (Y=0.603-0.003X, r=0.018, p=0.755); there was a positive correlation between crown rump length and mandibular length (mandible length=0.861 + 0.137*crown rump length; r=0.723, p < 0.001); and there was a positive correlation between crown rump length and IFA (r=0.234, p < 0.05). Reference ranges were: mean ratio of anteroposterior diameter: transverse diameter of the mandible 0.56; mean mandibular length 9.05 mm; and median IFA 66.5°. The values for these mandibular markers in seven cases of fetal micrognathia were outside the normal range. Evaluations of fetal mandibular markers during first trimester ultrasound screening may contribute to the early detection and diagnosis of micrognathia. We recommend obtaining a subjective impression of the mandible on the mid-sagittal view routinely used to measured nuchal translucency, followed by targeted objective measurements on the mid-sagittal and axial views in suspected cases.

The Risk of Preterm Birth in Low Risk Pregnant Women with Urinary Tract Infections.

Urinary tract infections are among the most common infections during pregnancy. The association between symptomatic lower urinary tract infections during pregnancy and fetal and maternal complications such as preterm birth and low birthweight remains unclear. The aim of this research is to evaluate the association between urinary tract infections during pregnancy and maternal and neonatal outcomes, especially preterm birth. This study is a secondary analysis of a multicenter prospective cohort study, which included patients between October 2011 and June 2013. The population consists of women with low risk singleton pregnancies. We divided the cohort into women with and without a symptomatic lower urinary tract infection after 20 weeks of gestation. Baseline characteristics and maternal and neonatal outcomes were compared between the two groups. Multivariable logistic regression analysis was used to correct for confounders. The main outcome was spontaneous preterm birth at <37 weeks. We identified 4,918 pregnant women eligible for enrollment, of whom 9.4% had a symptomatic lower urinary tract infection during their pregnancy. Women with symptomatic lower urinary tract infections were at increased risk for both preterm birth in general (12 vs. 5.1%, adjusted OR 2.5; 95% CI 1.7-3.5) as well as a spontaneous preterm birth at <37 weeks (8.2 vs. 3.7%, adjusted OR 2.3; 95% CI 1.5-3.5). This association was also present for early preterm birth at <34 weeks. Women with symptomatic lower urinary tract infections during pregnancy are also at increased risk of endometritis (8.9 vs. 1.8%, adjusted OR 5.3; 95% CI 1.4-20) and mastitis (7.8 vs. 1.8%, adjusted OR 4.0; 95% CI 1.6-10) postpartum. Low risk women with symptomatic lower urinary tract infections during pregnancy are at increased risk of spontaneous preterm birth. In addition, an increased risk for endometritis and mastitis postpartum was found in women with symptomatic lower urinary tract infection during pregnancy. · UTIs increase the risk of preterm birth.. · UTIs increase the risk of endometritis postpartum.. · UTIs increase the risk of mastitis postpartum..

Obstetrician involvement in planned midwife-led births: a cohort study in an obstetric department of a University Hospital in Switzerland

BackgroundHealthy women with low risk singleton pregnancies are offered a midwife-led birth model at our department. Exclusion criteria for midwife-led births include a range of abnormalities in medical history and during the course of pregnancy. In case of complications before, during or after labor and birth, an obstetrician is involved. The purpose of this study was 1) to evaluate the frequency of and reasons for secondary obstetrician involvement in planned midwife-led births and 2) to assess the maternal and neonatal outcome.MethodsWe analyzed a cohort of planned midwife-led births during a 14 years period (2006-2019). Evaluation included a comparison between midwife-led births with or without secondary obstetrician involvement, regarding maternal characteristics, birth mode, and maternal and neonatal outcome. Statistical analysis was performed by unpaired t-tests and Chi-square tests.ResultsIn total, there were 532 intended midwife-led births between 2006 and 2019 (2.6% of all births during this time-period at the department). Among these, 302 (57%) women had spontaneous vaginal births as midwife-led births. In the remaining 230 (43%) births, obstetricians were involved: 62% of women with obstetrician involvement had spontaneous vaginal births, 25% instrumental vaginal births and 13% caesarean sections. Overall, the caesarean section rate was 5.6% in the whole cohort of women with intended midwife-led births. Reasons for obstetrician involvement primarily included necessity for labor induction, abnormal fetal heart rate monitoring, thick meconium-stained amniotic fluid, prolonged first or second stage of labor, desire for epidural analgesia, obstetrical anal sphincter injuries, retention of placenta and postpartum hemorrhage. There was a significantly higher rate of primiparous women in the group with obstetrician involvement. Arterial umbilical cord pH < 7.10 occurred significantly more often in the group with obstetrician involvement, while 5′ Apgar score < 7 did not differ significantly. The overall transfer rate of newborns to neonatal intensive care unit was low (1.3%).ConclusionA midwife-led birth in our setting is a safe alternative to a primarily obstetrician-led birth, provided that selection criteria are being followed and prompt obstetrician involvement is available in case of abnormal course of labor and birth or postpartum complications.

Revisions to mid-pregnancy cervical length reference range for preterm birth screening among singleton pregnancies in Taiwan – 10 years’ experiences

ObjectiveOur study aimed to build a normal reference range for routine mid-pregnancy cervical length screening for preterm birth (PTB) based on a large cross-section of Taiwanese singleton pregnancies. Based on our reference range findings, we aim to develop a Z-score and centile calculator. Materials and methodsWe performed a retrospective analysis of the routine mid-trimester cervical length measurement in low-risk singleton pregnancies (without known abnormal growth or karyotype, congenital malformation, history of preterm birth due to preterm premature rupture of the membranes, or history of cervical cerclage treatment). From November 2008 to June 2018, the cervical lengths of 51,644 Taiwanese low-risk pregnant women were measured by experienced sonographers via transvaginal ultrasound during second trimester fetal anatomical screening at 20–24 weeks of gestation. Kolmogorov–Smirnov test was used to assess the normality of the distribution. Cole's lambda, mu, sigma (LMS) method was applied to build mid-pregnancy cervical length reference range and calculate Z-scores. Cut-off values of 2.5, 2.0 and 1.5 cm were used to evaluate the number of pregnancies considered high-risk for PTB. ResultsKolmogorov–Smirnov test showed that the cervical length measurements did not follow a normal distribution (<0.001). Reference range constructed by LMS method was presented in our study. Mean cervical length was 3.82 cm (SD = 0.62 cm). Overall, less than 0.3% of women had a cervical length shorter than 1.5 cm. ConclusionWe are providing an open access calculator for z-score and centile calculation for use in clinical practice for assessing how CL measurement compares in normally developing singleton pregnancies. Further investigation is needed to determine if Z-scores can better assess risk for PTB compared to fixed cut-offs. Since Z-scores are used to assess large deviations from normal development, they may be a useful tool for risk assessment and can be the basis for future standardized screening protocol in Taiwan.

Establishment of nomograms for fetal vermis and brainstem structures in the midsagittal cranial plane by ultrasonography.

To construct nomograms for the fetal cerebellar vermis and brainstem structures obtainable from the midsagittal plane of the brain by two-dimensional sonography. This was a prospective cross-sectional study of 434 healthy fetuses in low-risk singleton pregnancies between 18 and 35 gestational weeks. The following parameters were evaluated in the midsagittal cranial plane; cerebellar vermis anteroposterior diameter (APD), craniocaudal diameter (CCD), pons, midbrain and medulla oblongata APD and tectum length. The measurements were presented as growth charts according to gestational age. The mean ± SD, and 5%, 50%, 95% centile charts according to gestational age for vermis APD and CCD, pons, midbrain and medulla oblongata APD and tectum length were constructed. Pearson's correlation coefficients for vermis CCD and APD, pons, midbrain, medulla oblongata APD and tectum length by gestational week were 0.961, 0.929, 0.918, 0.761, 0.731 and 0.854, respectively (p < 0.0001). The reference data provided in the present study would be helpful in the prenatal diagnosis of challenging fetal conditions with involvement of the brainstem and cerebellum.

Association between gestational PFAS exposure and Children's adiposity in a diverse population

Perfluoroalkyl substances (PFAS) are widely distributed suspected obesogens that cross the placenta. However, few data are available to assess potential fetal effects of PFAS exposure on children's adiposity in diverse populations. To address the data gap, we estimated associations between gestational PFAS concentrations and childhood adiposity in a diverse mother-child cohort. We considered 6 PFAS in first trimester blood plasma, measured using ultra-high-performance liquid chromatography with tandem mass spectrometry, collected from non-smoking women with low-risk singleton pregnancies (n = 803). Body mass index (BMI), waist circumference (WC), fat mass, fat-free mass, and % body fat were ascertained in 4–8 year old children as measures of adiposity. We estimated associations of individual gestational PFAS with children's adiposity and overweight/obesity, adjusted for confounders. There were more non-Hispanic Black (31.7 %) and Hispanic (42.6 %) children with overweight/obesity, than non-Hispanic white (18.2 %) and Asian/Pacific Islander (16.4 %) children (p < 0.0001). Perfluorooctane sulfonate (PFOS; 5.3 ng/mL) and perfluorooctanoic acid (2.0 ng/mL) had the highest median concentrations in maternal blood. Among women without obesity (n = 667), greater perfluoroundecanoic acid (PFUnDA) was associated with their children having higher WC z-score (β = 0.08, 95%CI: 0.01, 0.14; p = 0.02), fat mass (β = 0.55 kg, 95%CI: 0.21, 0.90; p = 0.002), and % body fat (β = 0.01 %; 95%CI: 0.003, 0.01; p = 0.004), although the association of PFUnDA with fat mass attenuated at the highest concentrations. Among women without obesity, the associations of PFAS and their children's adiposity varied significantly by self-reported race-ethnicity, although the direction of the associations was inconsistent. In contrast, among the children of women with obesity, greater, PFOS, perfluorononanoic acid, and perfluorodecanoic acid concentrations were associated with less adiposity (n = 136). Our results suggest that specific PFAS may be developmental obesogens, and that maternal race-ethnicity may be an important modifier of the associations among women without obesity.

Endometrial preparation does not affect the risk of hypertensive disorders of pregnancy in low-risk women undergoing frozen embryo transfer

Objective Frozen embryo transfer (FET) is associated with a higher risk of hypertensive disorders in pregnancy. The objective of the present study is to evaluate the effect of different protocols of endometrial preparation on the risk of these disorders. Methods We conducted a retrospective cohort study on 594 singleton pregnancies achieved by embryo transfer of single frozen-thawed blastocysts. Women with preexisting risk factors for hypertensive disorders were excluded. Women were divided into two groups according to the endometrial preparation protocol: either natural cycle (n = 495) or programming cycle with hormonal replacement therapy (n = 97). The primary outcome was the frequency of hypertensive disorders in pregnancy: specifically, gestational hypertension and preeclampsia. Results No differences emerged between women following the natural cycle and those following the programming cycle in the frequency of gestational hypertension (5 vs. 4%) and preeclampsia (1.1 vs. 1.2%). No impact emerged also after multivariate analyses. Conclusions Women receiving hormonal replacement therapy have the same risk of gestational hypertension and preeclampsia as women following natural cycles when considering low-risk singleton pregnancies.

Safety and acceptance of “Vibwife”, a new moving mattress to support mobilization during labor: Result of a clinical study

ObjectiveTo examine the safety and acceptance “Vibwife”, a new moving mattress to support mobilization of pregnant women during labor. DesignThe study was a prospective medical device clinical study without a control group. The study was designed in intervention phases, with safety evaluation by a safety review board after each intervention phase. SettingThe study took place at the University Hospital of Basel, Switzerland. Participants50 women were included with a low risk singleton pregnancy > 37th weeks during the first stage of labor. InterventionEvaluation of the safety and acceptance of women, midwives and physicians during the first stage of labor. The intervention was carried out in 3 phases. In the first phase five women in labor used the device for 10 minutes, the next 10 women for 20 minutes, and finally the next 35 women for 30 minutes. MeasurementsMeasurement included capturing Adverse Events (AEs) (including Adverse Device Effects (ADEs)), Serious Adverse Events (SAEs) and recording vital parameters before, during, and after intervention, as well as CTG before and after intervention. Acceptance by women, midwives and physicians was measured by questionnaires with a 4-point Likert scale and pain intensity by a discrete Visual Analogue Scale (VAS) from 0-10. FindingsNo SAE occurred during the trial. A total of 32 AEs occurred in 25 women during the intervention or in the 30 minutes follow-up. The most frequently observed AEs were modification of blood pressure and CTG abnormalities. None of the 32 AEs led to sequels of any kind. The relationship between AEs occurrence and the use of the medical device was viewed as certain in 2 cases (6.2%), possible or likely in 8 cases (25%), and unlikely or unrelated in 22 cases (68, 7%). Overall, women, midwives and physicians reported high satisfaction with their use of the device. Key conclusions and implications for practiceThe medical device “Vibwife” was judged as safe for women. Acceptance among women and health personnel was good. Considering the potential benefits of mobilization during labor, this new medical device could be a very interesting adjunct to other obstetrical tools. Particularly, women whose mobility is restrained by epidural anesthesia while giving birth could be very suitable candidates. To answer the question of efficacy, a randomized-controlled trial is required.