Longitudinal Cervical Length Measurements and Spontaneous Preterm Birth in Singleton and Twin Pregnancies.

Importance: Changes in cervical length in twin pregnancies exhibit various patterns, but it is unclear whether the mechanism underlying spontaneous preterm birth (sPTB) is consistent. The existence of detailed phenomena in singleton pregnancies is also unclear. Objectives: To explore the different patterns in cervical length trajectories in singleton and twin pregnancies and to analyze whether the immunological mechanisms of sPTB are consistent among these cervical length patterns. Design, Setting, and Participants: This cohort study recruited pregnant individuals who received antenatal care and delivered at Peking University Third Hospital in Beijing, China, between January 1, 2014, and December 31, 2022. Individuals with singleton and twin pregnancies were included. Exposures: Cervical length measurements and white blood cell (WBC) indicators. Main Outcomes and Measures: The primary outcome was sPTB. Longitudinal trajectory cluster analysis was used to identify patterns of changes in cervical length in singleton and twin pregnancies. A random-effects model with cubic spline was used to fit and compare the longitudinal trajectory of WBC indicators among early preterm birth, moderate to late preterm birth, and term birth. Results: A total of 43 559 pregnant individuals were included; of these, 41 706 had singleton pregnancies (mean [SD)] maternal age, 33.0 [4.0] years) and 1853 had twin pregnancies (mean [SD] maternal age, 33.3 [3.6] years). Two distinct patterns of cervical length changes were observed in both singleton and twin pregnancies: shortened (21 366 singletons and 546 twins) and stable (20 340 singletons and 1307 twins). In singleton pregnancies, WBC count was associated with early sPTB in individuals with both shortened cervix (odds ratio [OR], 1.35; 95% CI, 1.00-1.82) and stable cervix (OR, 1.64; 95% CI, 1.07-2.50). However, for twin pregnancies, the association of WBC count (OR, 3.13; 95% CI, 1.58-6.18) with the risk of early sPTB was observed only in individuals with a shortened cervix. Conclusions and Relevance: This study identified 2 distinct cervical length patterns: shortened and stable. These patterns revealed 2 preterm birth mechanisms in twin pregnancies, with the immunopathogenesis of sPTB found only in the shortened cervix pattern; in singleton pregnancies, maternal immune response was associated with a higher risk of sPTB regardless of a shortened or stable cervix.

The changing Doppler patterns and perinatal outcomes of monochorionic diamniotic twins with selective fetal growth restriction.

OBJECTIVES: To investigate the clinical outcomes and Doppler patterns changes in monochorionic diamniotic (MCDA) twins with selective fetal growth restriction (sFGR). METHODS: We retrospectively analyzed 362 sFGR cases from January 2010 to May 2016 at a single tertiary referral center. The Doppler waveforms of umbilical artery end-diastolic flow were collected, and all neonates were subjected to an early neonatal brain scan. RESULTS: A total of 66/100 (66 %) type I cases were stable, whereas 25/100 (25 %) cases changed to type II and 9/100 (9 %) changed to sFGR complicated twin-twin transfusion syndrome (TTTS). A total of 48.9 % (22/45) sFGR cases were complicated with polyhydramnios and 30.4 % (7/23) sFGR cases were complicated with oligohydramnios, both of which were progressed to sFGR with TTTS. Mild cerebral injury was significantly associated with Doppler flow abnormalities, earlier gestational age at delivery and type of sFGR diagnosis. Severe cerebral injury was significantly associated with gestational age at delivery (31.6 vs. 34.1, p=0.002) and larger birthweight discordance (43.9 vs. 29.3 %, p=0.011). CONCLUSIONS: Doppler patterns in sFGR can gradually change, with important consequences with regard to management and outcomes. Along with abnormal Doppler findings, earlier occurrence of sFGR and delivery are associated with subsequent neonatal cerebral injury.

Association of Paternal Age Alone and Combined with Maternal Age with Perinatal Outcomes: A Prospective Multicenter Cohort Study in China.

Maternal and paternal age at birth is increasing globally. Maternal age may affect perinatal outcomes, but the effect of paternal age and its joint effect with maternal age are not well established. This prospective, multicenter, cohort analysis used data from the University Hospital Advanced Age Pregnant Cohort Study in China from 2016 to 2021, to investigate the separate association of paternal age and joint association of paternal and maternal age with adverse perinatal outcomes. Of 16,114 singleton deliveries, mean paternal and maternal age (± SD) was 38.0 ± 5.3 years and 36.0 ± 4.1 years. In unadjusted analyses, older paternal age was associated with increased risks of gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy, preeclampsia, placenta accreta spectrum disorders, placenta previa, cesarean delivery (CD), and postpartum hemorrhage, preterm birth (PTB), large-for-gestational-age, macrosomia, and congenital anomaly, except for small-for-gestational-age. In multivariable analyses, the associations turned to null for most outcomes, and attenuated but still significant for GDM, CD, PTB, and macrosomia. As compare to paternal age of < 30 years, the risks in older paternal age groups increased by 31-45% for GDM, 17-33% for CD, 32-36% for PTB, and 28-31% for macrosomia. The predicted probabilities of GDM, placenta previa, and CD increased rapidly with paternal age up to thresholds of 36.4-40.3 years, and then plateaued or decelerated. The risks of GDM, CD, and PTB were much greater for pregnancies with younger paternal and older maternal age, despite no statistical interaction between the associations related to paternal and maternal age. Our findings support the advocation that paternal age, besides maternal age, should be considered during preconception counseling.Trial Registration NCT03220750, Registered July 18, 2017-Retrospectively registered, https://classic.clinicaltrials.gov/ct2/show/NCT03220750 .

Association of maternal age with adverse pregnancy outcomes: A prospective multicenter cohort study in China.

Background: Although maternal age might affect pregnancy outcomes, it remains unclear whether this relationship is linear or curvilinear and if it differs between nulliparous and multiparous women. We aimed to characterize the relationship between maternal age and risks of pregnancy outcomes in a diverse sample of Chinese singleton pregnant women and to evaluate whether the relationship varied by parity. Methods: We based this prospective multicenter cohort study on data from 18 495 singleton pregnant women who participated in the University Hospital Advanced Age Pregnant Cohort Study, conducted in eight Chinese public hospitals from 2016 to 2021. We used restricted cubic splines to model nonlinear relationships between maternal age continuum and adverse outcomes, and performed multivariable log-binomial regression to estimate the adjusted relative risk (RR) and 95% confidence interval (CI). Results: Among 18 495 singleton pregnant women (mean age 35.7, standard deviation (SD) = 4.2 years), maternal age was not related to postpartum hemorrhage or small for gestational age, but showed a positive, nonlinear relationship to gestational diabetes mellitus, hypertensive disorders of pregnancy, preeclampsia, placenta accreta spectrum, placenta previa, cesarean delivery, preterm birth, large for gestational age, macrosomia, and fetal congenital anomaly, with inflection points around 35.6-40.4 years. Compared to women younger than 35 years, older women had higher risks of adverse pregnancy outcomes, except for postpartum hemorrhage and small for gestational age. The risks of placenta accreta spectrum, placenta previa, large for gestational age, and macrosomia were highest for women aged 40-44 years, and risks of gestational diabetes mellitus, hypertensive disorders of pregnancy, preeclampsia, cesarean delivery, preterm birth and congenital anomaly were highest for those aged ≥45 years. Most risks were more pronounced in nulliparous than multiparous women (P for interaction <0.02). Conclusions: Delayed childbirth was related to increased risks of adverse pregnancy outcomes, especially for nulliparous women. Appropriate childbearing age, generally before 35 years, is recommended for optimising pregnancy outcomes.

A study on the correlation of placental anastomosis and superficial vascular branches of selective fetal growth restriction in monochorionic diamniotic twins.

INTRODUCTION: The main purpose of the present study was to investigate the correlation between placental anastomosis and superficial vascular branches in selective fetal growth restriction (sFGR) in monochorionic diamniotic twins. MATERIALS AND METHODS: This was a retrospective analysis of the pregnancy data and placental perfusion of 395 patients with monochorionic diamniotic (MCDA) twin pregnancies delivered at our hospital from April 2013 to April 2020. We divided the patients into two groups and compared the number of placental superficial vascular branches in sFGR twins and normal MCDA twins. The correlation between the placental anastomosis and the number of superficial vascular branches in sFGR and normal MCDA twins was also investigated. RESULTS: The number of umbilical arterial branches and umbilical venous branches was less than larger twins in sFGR, larger twins in normal MCDA and smaller twins in normal MCDA. (11.83 [4-44], 21.82 [7-50], 19.72 [3-38], 14.85 [0-31], p < 0.001, 6.08 [1-18], 9.60 [3-22], 9.96 [2-22], 8.38 [1-20], p < 0.00) For smaller twins in the sFGR group, the number of umbilical venous branches was positively associated with AA anastomosis overall diameter, AV anastomosis overall diameter and all anastomosis overall diameter. (r = 0.194, 0.182 and 0.211, p < 0.05) CONCLUSIONS: The risk of sFGR may arise when the placenta from MCDA twins shows a poor branching condition of placental superficial vessels. For the smaller twin of sFGR, regular ultrasound examination of the number of the umbilical venous branches may help to predict artery-to-artery (AA) overall diameter, artery-to-vein (AV) overall diameter and all anastomosis overall diameter.

Thick artery-artery anastomoses delay the onset of selective fetal growth restriction in monochorionic diamniotic twins: a 7-year single-center cohort study.

Objective: This study aimed to investigate differences in placental characteristics between early- and late-onset selective fetal growth restriction (sFGR) in monochorionic diamniotic twins. Methods: A total of 253 patients with sFGR between April 2013 and April 2020 were retrospectively analyzed. Placental characteristics of early- and late-onset sFGR were compared. Results: The gestational age at diagnosis and delivery in the early-onset group was significantly less than that in the late-onset group [22.0 (16.9-23.9) and 28.4 (24.0, 36.3) weeks, P < 0.001; 33.1 ± 2.2 and 33.7 ± 2.5 weeks, P = 0.025]. The birth weight of normal growth and growth-restricted fetuses in the early-onset group was less than the late-onset group [1,990 ± 422 and 2,162 ± 525 g, P = 0.044; 1,320 ± 409 and 1,595 ± 519 g, P = 0.001]. The birthweight discordance ratio in the early-onset group was greater than the late-onset group (0.34 ± 0.12 and 0.29 ± 0.13, P = 0.001). The early-onset group had a significantly lower prevalence of sFGR type I than the late-onset group (37.5 and 62.0%, P = 0.018). The early-onset group had a significantly higher prevalence of sFGR type III than the late-onset group (30.4 and 12.7%, P = 0.048). The early-onset group had a lower prevalence of thick artery-artery anastomoses than the late-onset group (37.5 and 62.0%, P = 0.006). The placental territory discordance ratio in the early-onset group was higher than in the late-onset group [0.60 (0.01, 0.80) and 0.50 (0.01, 0.88), P = 0.018]. Conclusion: Unequal placental territory is the cause for most of the late-onset sFGR. Thick artery-artery anastomoses may delay the onset time of these cases of sFGR.

Metabolic dynamics and prediction of sFGR and adverse fetal outcomes: a prospective longitudinal cohort study.

BACKGROUND: Selective fetal growth restriction (sFGR) is an extreme complication that significantly increases the risk of perinatal mortality and long-term adverse neurological outcomes in offspring, affecting approximately 15% of monochorionic diamniotic (MCDA) twin pregnancies. The lack of longitudinal cohort studies hinders the early prediction and intervention of sFGR. METHODS: We constructed a prospective longitudinal cohort study of sFGR, and quantified 25 key metabolites in 337 samples from maternal plasma in the first, second, and third trimester and from cord plasma. In particular, our study examined fetal growth and brain injury data from ultrasonography and used the Ages and Stages Questionnaire-third edition subscale (ASQ-3) to evaluate the long-term neurocognitive behavioral development of infants aged 2-3 years. Furthermore, we correlated metabolite levels with ultrasound data, including physical development and brain injury indicators, and ASQ-3 data using Spearman's-based correlation tests. In addition, special combinations of differential metabolites were used to construct predictive models for the occurrence of sFGR and fetal brain injury. RESULTS: Our findings revealed various dynamic patterns for these metabolites during pregnancy and a maximum of differential metabolites between sFGR and MCDA in the second trimester (n = 8). The combination of L-phenylalanine, L-leucine, and L-isoleucine in the second trimester, which were closely related to fetal growth indicators, was highly predictive of sFGR occurrence (area under the curve [AUC]: 0.878). The combination of L-serine, L-histidine, and L-arginine in the first trimester and creatinine in the second trimester was correlated with long-term neurocognitive behavioral development and showed the capacity to identify fetal brain injury with high accuracy (AUC: 0.94). CONCLUSIONS: The performance of maternal plasma metabolites from the first and second trimester is superior to those from the third trimester and cord plasma in discerning sFGR and fetal brain injury. These metabolites may serve as useful biomarkers for early prediction and promising targets for early intervention in clinical settings.

Outcomes of fetal reduction versus expectant management in dichorionic triamniotic triplets.

OBJECTIVE: To compare the outcomes of dichorionic triamniotic (DCTA) triplets who underwent fetal reduction (FR) to singletons or twins with those managed expectantly. METHODS: We conducted a retrospective study of DCTA triplets with three living fetuses at 11-14 weeks over a 7-year period. Pregnancy outcomes were compared following different management strategies. RESULTS: Of 108 included patients, 22 underwent expectant management (EM), 28 were reduced to dichorionic diamniotic twins, and 58 to singletons. The median gestational age at birth for EM, FR to twins, and singletons was 33.1 weeks, 37.0 weeks, and 38.6 weeks, respectively (P < 0.001). Prematurity before 37 and 34 weeks was less common following FR to singletons and twins than in ongoing triplets (18.9%, 46.2% and 90.5%, P < 0.001; 13.2%, 26.9% and 57.1%, P < 0.001). Neonatal birth weight was higher in triplets reduced to singletons and twins compared with EM cases (3140g, 2315g, and 1860g, P < 0.001). However, rates of miscarriage, pregnancies with ≥1 survivor, maternal complications, and adverse neonatal outcomes were comparable among the three groups. CONCLUSIONS: In our experience, FR in DCTA triplets could reduce prematurity risk compared to EM, but it confers no survival advantage. Fetal reduction to singletons may result in more favorable outcomes than those reduced to dichorionic twins.

Reduced-visit antenatal care model combined with telemedicine for low-risk pregnant women: protocol for a randomised controlled trial.

INTRODUCTION: Antenatal care (ANC) is a critical measure to reduce maternal and perinatal morbidity and mortality. However, there are issues of too many visits and cumbersome procedures of ANC in many maternity hospitals of China. In the past 2 years, reduced-visit ANC models combined with remote monitoring have been recommended and implemented at most hospitals in China during the COVID-19 pandemic. Nevertheless, due to limited evaluations of the cost-effectiveness, policy-makers remain confused on how to appropriately integrate online delivery strategies with routine models to improve ANC quality and efficiency sustainably at scale. This trial aims to evaluate the effectiveness, acceptability and cost of a reduced-visit ANC model combined with telemedicine. METHODS AND ANALYSIS: A single-blind, randomised controlled trial will be conducted among low-risk pregnant women at Peking University Third Hospital in Beijing. 1476 patients (738 in each group) would be required, and they will be randomly assigned in a 1:1 ratio to receive the reduced-visit ANC combined with telemedicine services or the routine ANC. The primary outcome is the composite rate of adverse maternal and perinatal outcomes which will be extracted from the medical records. Secondary outcomes include acceptability of ANC models, which is assessed by satisfaction with ANC, pregnancy-related stress and ANC costs measured from the perspectives of both service providers and demanders. Both intention-to-treat and per-protocol analyses will be performed. Non-inferiority tests will be used to compare the two ANC models for the primary outcome. A cost-effectiveness analysis comparing the two ANC models will be conducted by estimating the incremental cost-effectiveness ratios. ETHICS AND DISSEMINATION: This study was approved by the ethical review committee of the Peking University Third Hospital (Beijing, China). The results of this study will be published in peer-reviewed scientific journals and presented at relevant academic conferences. TRIAL REGISTRATION NUMBER: NCT05290467.

Hospital variations in caesarean delivery rates: An analysis of national data in China, 2016-2020.

Background: The impact of China's use of caesarean delivery on global public health has been a long-term concern. The number of private hospitals is increasing in China and likely driving up caesarean delivery rates, yet specifics remain unknown. We aimed to investigate variations in caesarean delivery rates across and within hospital types in China. Methods: We retrieved data on hospital characteristics and national hospital-level annually aggregated data on the number of deliveries and caesarean deliveries from 2016-2020, covering 7085 hospitals in 31 provinces of mainland China, from the National Clinical Improvement System. We categorized hospitals as public-non-referral (n = 4103), public-referral (n = 1805) and private (n = 1177). Among the private hospitals, 89.1% (n = 1049) were non-referral regarding obstetrical services for uncomplicated pregnancies. Results: Among 38 517 196 deliveries, 16 744 405 were caesarean, giving an overall rate of 43.5% with a minor range of 42.9%-43.9% over time. Median rates differed across hospital types, from 47.0% (interquartile range (IQR) = 39.8%-55.9%) in public-referral, 45.8% (36.2%-55.8%) in private, and 40.3% (30.6%-50.6%) in public-non-referral hospitals. The stratified analyses corroborated the results, except for the northeastern region, where the median rates did not differ across the public-non-referral (58.9%), public-referral (59.3%), and private (58.8%) hospitals, while all ranked higher than the other regions, regardless of hospital type and urbanization levels. The rates within hospital types differed as well, especially in the rural areas of the western region of China, where the difference of rates between the 5th and 95th percentiles was 55.6% (IQR = 4.9%-60.5%) in public-non-referral, 51.5% (IQR = 19.6%-71.1%) in public-referral, and 64.6% (IQR = 14.8%-79.4%) in private hospitals. Conclusions: Variation across hospital types in China was pronounced, with the highest rates either in public-referral or private hospitals, except in the northeastern region, where no variation was observed among the high rates of caesarean deliveries. Variation within each hospital type was pronounced, especially in rural areas of the western region.

The Proteome Landscape of Human Placentas for Monochorionic Twins with Selective Intrauterine Growth Restriction.

In perinatal medicine, intrauterine growth restriction (IUGR) is one of the greatest challenges. The etiology of IUGR is multifactorial, but most cases are thought to arise from placental insufficiency. However, identifying the placental cause of IUGR can be difficult due to numerous confounding factors. Selective IUGR (sIUGR) would be a good model to investigate how impaired placentation affects fetal development, as the growth discordance between monochorionic twins cannot be explained by confounding genetic or maternal factors. Herein, we constructed and analyzed the placental proteomic profiles of IUGR twins and normal cotwins. Specifically, we identified a total of 5481 proteins, of which 233 were differentially expressed (57 up-regulated and 176 down-regulated) in IUGR twins. Bioinformatics analysis indicates that these differentially expressed proteins (DEPs) are mainly associated with cardiovascular system development and function, organismal survival, and organismal development. Notably, 34 DEPs are significantly enriched in angiogenesis, and diminished placental angiogenesis in IUGR twins has been further elaborately confirmed. Moreover, we found decreased expression of metadherin (MTDH) in the placentas of IUGR twins and demonstrated that MTDH contributes to placental angiogenesis and fetal growth in vitro. Collectively, our findings reveal the comprehensive proteomic signatures of placentas for sIUGR twins, and the DEPs identified may provide in-depth insights into the pathogenesis of placental dysfunction and subsequent impaired fetal growth.

Evaluation of Cesarean Rates for Term, Singleton, Live Vertex Deliveries in China in 2020 Among Women With No Prior Cesarean Delivery.

Importance: Substantial regional variation in cesarean delivery rates has been reported in China, but there is a lack of reports on hospital-level variation in these rates among low-risk deliveries. Objectives: To evaluate hospital variation in cesarean rates in China for term, singleton, live vertex deliveries among women with no prior cesarean delivery and to estimate contributions of individual and hospital factors. Design, Setting, and Participants: This nationwide cross-sectional study used data from maternal patient discharge records collected by the Hospital Quality Monitoring System in China from January 1 to December 31, 2020. Pregnant female individuals aged 15 to 49 years (referred to hereafter as women) with at least 1 live birth were included, and low-risk deliveries were defined as term, singleton, live, vertex deliveries with no prior cesarean delivery. Exposures: Birth by cesarean delivery. Main Outcomes and Measures: The main outcome was cesarean delivery rate by hospital. Hierarchical logistic regression analysis was used to calculate the adjusted cesarean rate and to estimate the percentage of hospital variation in low-risk deliveries explained by individual and hospital factors. Results: Among the 7 635 149 deliveries identified from 4359 hospitals in 31 provinces of mainland China, 6 599 468 (86.4%) were considered low risk. Of overall and low-risk deliveries, 3 400 162 and 2 638 097 were cesarean deliveries, corresponding to mean rates of 44.5% and 40.0%, respectively. The mean (SD) maternal age for overall and low-risk deliveries was 29.1 (4.0) and 28.8 (4.8) years, respectively, and mothers were more likely to be of Han ethnicity (89.5%). Cesarean rates varied widely among hospitals, with absolute differences between the 5th and 95th percentiles of 53.5% (19.4%-72.9%) for overall deliveries and 56.8% (14.3%-71.1%) for low-risk deliveries. Large absolute differences remained after adjusting for maternal characteristics, with rates of 47.4% (19.1%-66.5%) for overall deliveries and 52.6% (15.0%-67.6%) for low-risk deliveries. Among low-risk deliveries, hospital factors (eg, hospital province location) explained 31.3% of the hospital variation in cesarean rate and individual factors explained an additional 2.0%. Conclusions and Relevance: The findings of this cross-sectional study suggest that cesarean rates varied markedly among hospitals in China in 2020, which may be attributable to hospital rather than individual factors. Future work is needed to design hospital-level initiatives to optimize cesarean use, particularly among low-risk deliveries.

Serum hsCRP in early pregnancy and preterm delivery in twin gestations: a prospective cohort study.

BACKGROUND: Systemic inflammation during pregnancy may be associated with preterm delivery (PTD), but data for twin gestations are lacking. The aim of this study was to examine the association of serum high-sensitivity C-reactive protein (hsCRP), a marker of inflammation, in early pregnancy of twin gestations with risk of PTD, including spontaneous (sPTD) and medical-induced preterm delivery (mPTD). METHODS: A prospective cohort study involved 618 twin gestations was conducted in a tertiary hospital in Beijing, from 2017 to 2020. Serum samples collected in early pregnancy were analyzed for hsCRP using particle-enhanced immunoturbidimetric method. Unadjusted and adjusted geometric means (GM) of hsCRP were estimated using linear regression, and compared between PTD before 37 weeks of gestation and term delivery at 37 or more weeks of gestation using Mann-Whitney rank sum test. The association between hsCRP tertiles and PTDs was estimated using logistic regression, and further converted overestimated odds ratios into relative risks (RR). RESULTS: A total of 302 (48.87%) women were classified as PTD, with 166 sPTD and 136 mPTD. The adjusted GM of serum hsCRP was higher in PTDs (2.13 mg/L, 95% confidence interval [CI] 2.09 -2.16) compared to term deliveries (1.84 mg/L, 95% CI 1.80 -1.88) (P < 0.001). Compared with the lowest tertile of hsCRP, the highest tertile was associated with increased risk of PTD (adjusted relative risks [ARR] 1.42; 95% CI: 1.08-1.78). Among twin pregnancies, the adjusted association between high values of serum hsCRP in early pregnancy and preterm delivery was only observed in the subgroup of spontaneous preterm deliveries (ARR 1.49, 95%CI:1.08-1.93). CONCLUSIONS: Elevated hsCRP in early pregnancy was associated with increased risk of PTD, particular the risk of sPTD in twin gestations.

Effect of fetoscopic laser surgery on the placental characteristics and birth-weight discordance of twins with twin-to-twin transfusion syndrome.

Objective: This study explored the effect of fetoscopic laser surgery on the placental structure and birth-weight discordance of twin-to-twin transfusion syndrome (TTTS). Methods: A retrospective cohort study was conducted in TTTS patients who were admitted to the Peking University Third Hospital between April 2014 and April 2020. The patients were divided into two groups: laser group and control group. Placentas with twin survival were injected, and pregnancy outcomes and placental characteristics of the two groups were compared. The correlation between the birth-weight discordance and placental characteristics in each group was analyzed. Results: The gestational age at first diagnosis in the laser group was significantly smaller than that in the control group (21.6 ± 2.8 weeks vs. 27.7 ± 3.0 weeks, p < 0.001). The proportion of patients with TTTS stage-I in the laser group was significantly lower than the control group (9.4 vs. 64.0%, p < 0.001). The gestational age at delivery in the laser group was significantly larger than that in the control group (33.6 ± 2.1 weeks vs. 31.4 ± 2.5 weeks, p = 0.001). In the laser group, the birth-weight discordance ratio was positively correlated with the placental territory discordance ratio (Spearman coefficient = 0.556; p = 0.001). Conclusion: The birth-weight discordance is positively correlated with placental territory discordance in TTTS patients after FLS.

Risk of preeclampsia by gestational weight gain in women with varied prepregnancy BMI: A retrospective cohort study.

Introduction: Despite the important clinical significance, limited data on the joint contribution of prepregnancy body mass index (BMI) and gestational weight gain (GWG) to preeclampsia, the second leading cause of maternal mortality worldwide. This study aimed to estimate the risk of preeclampsia by GWG among women with varied prepregnancy BMI. Methods: We conducted a retrospective cohort study using data of 117 738 singleton pregnant women aged 18-49 years from 150 maternity hospitals in China between 2015 and 2018. GWG was calculated as the measured weight at the time of preeclampsia assessment minus prepregnancy weight; GWG velocity was calculated as the GWG divided by the gestational age at weighing. The non-linear associations of GWG with preeclampsia were examined by restricted cubic spline regression analysis according to prepregnancy BMI. The association of the GWG categories with preeclampsia was further examined by performing robust Poisson regression stratified by the prepregnancy BMI categories. Results: Among participants, 2426 (2.06%) were diagnosed with preeclampsia. Compared to women with normal BMI, those who were overweight and obese had 1.92- fold (95%CI, 1.73-2.14) and 5.06- fold (95%CI, 4.43-5.78) increased risks for preeclampsia, respectively. The association of GWG velocity with preeclampsia was presented as a J-shaped curve with the varied inflexion point (where the rate of preeclampsia was 2%), which was 0.54, 0.38, and 0.25 kg/week in women with normal BMI, overweight, and obesity, respectively; a steep risk rise was observed along with GWG velocity beyond the inflexion points. The overall adjusted relative risk for preeclampsia was calculated among women with the different GWG categories of GWG. Conclusions: The findings highlight that high prepregnancy BMI and exceed GWG contributed to increased risk of preeclampsia with a superimposed effect and underscore the need to optimize the recommendations for GWG for women with different prepregnancy BMI.

Association of Gestational Vitamin E Status With Pre-eclampsia: A Retrospective, Multicenter Cohort Study.

Introduction: Pre-eclampsia is the second leading cause of maternal mortality worldwide. The controversy for the association of vitamin E with pre-eclampsia has raged unabated for two decades. We aimed to determine the association of vitamin E level in the first trimester and the gestational change with pre-eclampsia. Materials and Methods: A retrospective cohort study was conducted among singleton pregnant women aged 15-49 years at 137 hospitals in China. Serum vitamin E concentrations in the first trimester and at pre-eclampsia assessment time were uniformly quantified in a laboratory by high performance liquid chromatography. Logistic regression models with restricted cubic splines were performed to reveal a non-linear association of vitamin E concentrations in the first trimester and the gestational change with pre-eclampsia. Results: We included 73 317 participants (47.8% aged 25-29 years) and 2.28% were diagnosed with pre-eclampsia. Higher risk was observed in those with lower concentration in the first trimester and greater gestational decrease, with a range from 0.81 to 80.60%. A non-linear L-shaped association was observed between vitamin E concentrations in the first trimester and pre-eclampsia, suggesting a threshold at 7.3 mg/L and a ceiling effect: the risk saw a steep rise when the concentrations in the first trimester were < 7.3 mg/L but was relatively flat beyond the inflection point. Sharply increased pre-eclampsia risk was also found in those with gestational vitamin E decrease after accounting for the baseline status in the first trimester. However, gestational vitamin E increase was associated with decreased pre-eclampsia risk when the baseline concentrations were < 7.3 mg/L but did not confer additional benefits when it was above the threshold. Conclusion: We demonstrated alarmingly high pre-eclampsia risk in women with vitamin E concentrations of < 7.3 mg/L in the first trimester and gestational vitamin E decrease. These findings underscore the need to supplement vitamin E among pregnant women with low baseline status.

Comparison of pregnancy outcomes and placental characteristics for monochorionic diamniotic twins with and without proximate umbilical cord insertion.

INTRODUCTION: This study was developed to evaluate the relative placental characteristics and pregnancy outcomes associated with monochorionic diamniotic (MCDA) twins with and without proximate umbilical cord insertion (PCI). METHODS: All MCDA twins delivered with complete placentas for whom placental characteristics were assessed via dye injection between April 1, 2013 and April 1, 2021 were included in the present cohort study. Cases were separated into PCI and non-PCI groups, and pregnancy outcomes and placental characteristics were then compared between these groups. RESULTS: Birthweight discordance rates were significantly lower in the PCI group relative to the non-PCI group (7.3 ± 7.5% vs 29.9 ± 16.8%, P＜0.001), while relative to the non-PCI group, rates of artery-artery (AA), vein-vein (VV), thick AA, and thick VV anastomoses were significantly higher in the PCI group (95.5% vs 67.0%, P = 0.008, 59.1% vs 16.4, P＜0.001,90.5% vs 34.9%, P＜0.001, 54.5% vs 10.5%, P＜0.001). Significantly more anastomoses were observed in the PCI group (7 (3,11) vs 6 (3,15), P = 0.015), and they were significantly larger on average than those in the non-PCI group 12.8 (6.7,21.3) mm vs 11.9 (3.4, 24.6) mm, P = 0.009). Significantly lower placental territory discordance and UCI ratios were evident in the PCI group relative to the non-PCI group (23.5 (15.0,51.0) % vs 60.0 (2.0,80.0) %, P＜0.001, 13.3 ± 5.8% vs 56.1 ± 18.0%, P < 0.001). Marginal cord insertion rates were lower in the PCI group relative to the non-PCI group (13.6% vs 77.5%, P < 0.001). DISCUSSION: The placental structure of MCDA twins with PCI is distinct from that of twins without PCI, and these results suggest PCI may be indicative of the more even distribution of placental territory between MCDA fetuses.

Correction: Fast label-free recognition of NRBCs by deep-learning visual object detection and single-cell Raman spectroscopy.

Correction for 'Fast label-free recognition of NRBCs by deep-learning visual object detection and single-cell Raman spectroscopy' by Teng Fang et al., Analyst, 2022, https://doi.org/10.1039/D2AN00024E.

Fast label-free recognition of NRBCs by deep-learning visual object detection and single-cell Raman spectroscopy.

Nucleated red blood cells (NRBCs) as a type of rare cell present in an adult's peripheral blood is a concern in hematology, intensive care medicine and prenatal diagnostics. However, it is labor-intensive to screen such rare cells from real complex cell mixtures especially in a label-free way. Herein, we report a new label-free method that incorporates image recognition and Raman spectroscopy for fast recognition of the rare cells in blood. First, we identified unlabeled NRBCs based on both Raman signals of hemoglobin and nucleated morphology, and recorded their microscopic image characteristics which were different enough from other blood cells in unlabeled morphology. Then, two deep-learning algorithms of visual object detection, Faster RCNN and YOLOv3, were investigated for cell morphological recognition on a low-cost computer configuration, and YOLOv3 was demonstrated to be more competent for real-time detection despite slightly lower precision. Finally, several NRBCs were successfully found in maternal blood using this method, which verified the methodological feasibility. Thus, we believe such a labor-saving approach might inspire a new idea for detecting rare cells from complex cell mixtures in a label-free and computer-assisted way.

Outcome of monochorionic triamniotic triplet pregnancies: Expectant management versus fetal reduction.

OBJECTIVE: To compare the outcomes of monochorionic triamniotic (MCTA) triplets managed expectantly with those reduced to twins. METHOD: This was a retrospective cohort study comparing expectant management (EM) with fetal reduction (FR) to twins in 43 consecutive MCTA triplets with 3 live fetuses at 11-14 weeks between 2012 and 2021. RESULTS: Nineteen patients managed expectantly and 24 triplets reduced to twins were included. The rate of pregnancy with at least one survivor was 84.2% in the EM group and 66.7% in the FR group (P = 0.190). Compared to the EM cases, triplets reduced to twins had a higher median gestational age at delivery (36.0 vs. 33.3 weeks; P < 0.001), a higher mean birth weight (2244.3 ± 488.6 g vs. 1751.1 ± 383.2 g; P < 0.001) and a lower risk of preterm birth before 34 weeks (11.8% vs. 64.7%; P = 0.001). There were no significant differences in the risk of miscarriage, pregnancy complications and composite adverse neonatal outcomes. CONCLUSION: In MCTA triplets, FR to twins could reduce the risk of preterm birth, whereas EM seems to be a reasonable choice when the priority is at least one survivor. However, due to the small sample size of this study, these findings must be interpreted with great caution.