Assessment of Sleep Quality in Spanish Twin Pregnancy: An Observational Single-Center Study.

Women with twin pregnancies experience greater sleep disturbance compared to women with singleton pregnancies. The aims of this study were to explore the sleep quality in women with twin pregnancies and to compare their sleep dimensions with coetaneous single pregnancies. This was an observational study in which women were enrolled at the end of pregnancy in the Obstetric Service of Hospital La Paz (Spain). The women were classified as single (n = 143) or twin pregnancy (n = 62). Pregnant women responded to the Pittsburgh Sleep Quality Index to evaluate sleep quality, latency, duration, efficiency, perturbance, use of medication, and daytime dysfunction. The higher the index, the greater the alteration of sleep quality. Without statistical differences, a poor sleep quality was higher in women with single (66.7%) than women with twin pregnancies (22.8%). The good sleeper slept 6.8 h/day in single pregnancy and 7.3 h/day in twin pregnancy. The sleep perturbation and dysfunctionality were higher in women with twin than single pregnancies. The use of medication to sleep was significantly lower in women with twin than single pregnancies. In women with twin pregnancy, the body weight gain during first trimester had a positive correlation with worse sleep quality and sleep perturbations. Twin pregnancy needed more than 7 h/day to have a high sleep quality, showing greater sleep perturbations and daytime dysfunction than single pregnancies. The control of gestational body weight can improve the sleep quality, disturbances, and duration in twin gestations. Sleep screening during pregnancy would be necessary to handle sleep issues and increase benefits in twin gestational outcomes.

Can growth in dichorionic twins be monitored with individualized growth assessment?

OBJECTIVE: To characterize fetal growth in dichorionic twins using individualized growth assessment (IGA), a method based on individual growth potential estimates. METHODS: This secondary analysis included 286 fetuses/neonates from 143 dichorionic twin pregnancies that were part of the ESPRiT (Evaluation of Sonographic Predictors of Restricted Growth in Twins) study. The sample was subcategorized according to birth weight into appropriate-for-gestational-age (AGA) (n = 243) and small-for-gestational-age (SGA) (n = 43) cohorts. Serial biometric scans evaluating biparietal diameter, head circumference (HC), abdominal circumference, femur diaphysis length and estimated weight at 2-week intervals were used to evaluate fetal growth, while measurements of birth weight, crown-heel length and HC determined neonatal growth outcome. Six abnormalities (hypoxic ischemic encephalopathy, periventricular leukomalacia, necrotizing enterocolitis, respiratory distress, sepsis and death) constituted the evaluated adverse neonatal outcomes (ANO). IGA was used to: evaluate differences in second-trimester growth velocities between singletons (from a published dataset) and dichorionic twins (138 AGA twins with normal third-trimester growth); describe the degree to which actual third-trimester growth in twins followed expected growth (111 AGA twins, normal fetal growth and neonatal growth outcomes); determine if the fetal growth pathology score 1 (-FGPS1) could detect, quantify and classify twin growth pathology (224 AGA, 42 SGA); and assess the relationship between -FGPS1 and ANO (24 SGA twins with progressive growth restriction confirmed by abnormal neonatal growth outcome). RESULTS: The differences in second-trimester growth velocity between singletons and twins (means and variances) were small and not statistically significant. Percent deviations from the expected third-trimester size trajectories were within the 95% reference ranges derived from singletons at 95.7% (1677/1752) of timepoints studied. Abnormal growth was detected in 37.9% of AGA twins and 85.7% of SGA twins. Growth restriction was more heterogeneous in AGA twins, while in SGA twins progressive growth restriction was the principal type (66.7%). -FGPS1 patterns previously defined in singletons classified 97.5% of pathological twin cases. In our most severe form of growth restriction (progressive), there were only three (12.5%) ANOs related to growth abnormalities, all in cases with -FGPS1 values more negative than -2.0%. Using these criteria, the frequency of ANO was 33%. CONCLUSIONS: With respect to growth, dichorionic twins can be considered as two singletons in the same uterus. Normally growing dichorionic twins have the same growth potential as singletons with normal growth outcome. These twins also follow expected third-trimester growth trajectories with the same precision as do singletons. Third-trimester growth pathology can be detected, quantified and classified using -FGPS1 as in singletons. Limited evidence of a relationship between fetal growth abnormalities and adverse neonatal outcome was found. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Twin Vaginal Deliveries in Labor Rooms: A Cost-Effectiveness Analysis.

OBJECTIVE: Twin vaginal deliveries (VDs) are often performed in the operating room (OR) given the theoretical risk of conversion to cesarean delivery (CD) for the aftercoming twin. We aim to evaluate the cost-effectiveness of performing VDs for twin gestations in the labor and delivery room (LDR) versus OR. STUDY DESIGN: We conducted a cost-effectiveness analysis using a decision-analysis model that compared the costs and effectiveness of two strategies of twin deliveries undergoing a trial of labor: (1) intended delivery in the LDR and 2) delivery in the OR. Sensitivity analyses were performed to assess strength and validity of the model. Primary outcome was incremental cost-effectiveness ratio (ICER) defined as cost needed to gain 1 quality-adjusted life year (QALY). RESULTS: In the base-case scenario, where 7% of deliveries resulted in conversion to CD for twin B, attempting to deliver twins in the LDR was the most cost-effective strategy. For every QALY gained by delivering in the OR, 243,335 USD would need to be spent (ICER). In univariate sensitivity analyses, the most cost-effective strategy shifted to delivering in the OR when the following was true: (1) probability of successful VD was less than 86%, (2) probability of neonatal morbidity after emergent CD exceeded 3.5%, (3) cost of VD in an LDR exceeded 10,500 USD, (4) cost of CD was less than 10,000 USD, or (5) probability of neonatal death from emergent CD exceeded 2.8%. Assuming a willingness to pay of 100,000 USD per neonatal QALY gained, attempted VD in the LDR was cost effective in 51% of simulations in the Monte Carlo analysis. CONCLUSION: Twin VDs in the LDR are cost effective based on current neonatal outcome data, taking into account gestational age and associated morbidity. Further investigation is needed to elucidate impact of cost and outcomes on optimal utilization of resources. KEY POINTS: · Cost effectiveness of twin VDs in the LDR versus OR was assessed.. · Twin VDs in the LDR are cost effective based on current neonatal outcome data.. · Attempted VD in the LDR was cost effective in 51% of simulations in the Monte Carlo analysis..

Disparities in Trial of Labor among Women with Twin Gestations in the United States.

OBJECTIVE: The aim of the study is to examine clinical and demographic factors associated with trial of labor (TOL) among women with twin gestations eligible for a vaginal delivery. STUDY DESIGN: This was a population-based cohort study of women giving birth to twin gestations in the United States (2012-2014). Inclusion criteria for the analysis included live births greater than 23 weeks' gestation and a cephalic presenting twin. Women with prior cesarean delivery were excluded. Women were categorized by whether they underwent a TOL. Clinical and demographic characteristics associated with TOL status were evaluated using multivariable logistic regression analyses. Secondary analyses with stratification by parity and by second twin presentation were performed. RESULTS: Of 90,000 women eligible for inclusion, a minority (39.3%) underwent TOL. Women who had a greater gestational age at delivery were more likely to have a TOL. In contrast, several demographic factors were associated with decreased likelihood of TOL, including maternal age >35 years and identifying as Hispanic or Asian compared with non-Hispanic White. No differences in odds of TOL were observed for women who were identified as non-Hispanic Black versus non-Hispanic White, nor were other demographic factors such as marital status, insurance status, or educational attainment associated with undergoing TOL. Clinical factors associated with decreased odds of TOL included nulliparity, obesity, and hypertensive disorders of pregnancy. Results did not substantively change when stratified by parity or second twin presentation, nor did findings differ in the subgroup who delivered at 32 weeks of gestation or greater. CONCLUSION: In this large population of women with twins who were eligible for a TOL, a minority of individuals attempted a vaginal delivery. Demographic and clinical factors such as older maternal age, Asian or Hispanic racial or ethnic identification, nulliparity, and obesity are associated with decreased odds of undergoing TOL. KEY POINTS: · Understanding disparities in trial of labor among patients with twins is key to promoting equity.. · Older maternal age and identifying as Hispanic or Asian were associated with lower odds of TOL.. · Nulliparity, obesity, and hypertension were associated with decreased odds of TOL..

Female fertility treatment and adverse birth outcomes: a multistate analysis of pregnancy risk assessment monitoring system data.

OBJECTIVE: The popularity of fertility treatments has continued to rise, however, the potential health risks of these treatments for both mother and infant are not fully known. Our objective was to determine the association between fertility treatments and adverse birth outcomes of intended pregnancies using the Pregnancy Risk Assessment Monitoring System (PRAMS) data. METHODS: Data from 27,018 intended pregnancies, collected from 2009 to 2018 in the United States, were included in our analysis. PRAMS data consisted of questionnaire and birth certificate data. SAS 9.4 was used for analyses accounting for complex survey weights. All analyses were conducted separately for singleton and twin births. Weighted percentages with 95% confidence intervals (CIs) were estimated for maternal characteristics and birth outcomes. Multivariable logistic regression was used to determine adjusted odds ratios (OR) and 95% CIs for associations of fertility treatment use and adverse birth outcomes. RESULTS: Close to 12% of women reported the use of any fertility treatment. Among those using fertility treatments, the most common type was assisted reproductive technology (ART) for both twin (68.7%, 95% CI: 62.3, 75.2) and singleton births (45.1%, 95% CI: 42.0, 48.1). Use of any type of fertility treatment for singleton births was associated with increased odds of a cesarean delivery (OR: 1.31, 95% CI: 1.16, 1.47), preterm birth (OR: 1.42, 95% CI: 1.20, 1.67), a small-for-gestational age infant (OR: 1.20, 95% CI: 1.00, 1.44), and an infant hospital stay >5 days (OR: 1.34, 95% CI: 1.11, 1.62). Use of fertility treatment for twin births was associated with cesarean delivery only. In analyses examining associations for specific types of treatment (medication alone, ART, insemination) with birth outcomes, results varied by treatment type. CONCLUSIONS: In this large population-based sample of women who intended to become pregnant and had a live birth, fertility treatment was associated with adverse birth outcomes. Patients seeking fertility treatment should be appropriately counseled on the risks of adverse maternal and infant birth outcomes overall and by treatment type. Maternal support and resources to prevent adverse birth outcomes among women using fertility treatments are warranted.

Selective Fetoscopic Laser Photocoagulation or Expectant Management for Stage I Twin-Twin Transfusion: A Cost-Effectiveness Analysis.

BACKGROUND: Selective fetoscopic laser photocoagulation (SFLP) is the preferred intervention for stage II-IV twin-twin transfusion syndrome (TTTS); however, there is no consensus on whether SFLP or expectant management (EM) is the preferred strategy to manage Quintero stage I TTTS. OBJECTIVE: The objective of this study is to estimate whether SFLP or EM is the cost-effective strategy for management of Quintero stage I TTTS. STUDY DESIGN: A decision-analysis (DA) model compared SFLP to EM for 1,000 pregnant people with monochorionic-diamniotic twins affected by stage I TTTS. All subjects were assumed to be appropriate candidates for either SFLP or EM. Probabilities, costs, and utilities were derived from the literature. The DA was conducted from a healthcare payor perspective, and the analytic horizon was over the course of an offspring's lifetime, with primary outcomes of survivorship (i.e., no intrauterine fetal demise or neonatal death) and long-term neurodevelopmental impairment. The model incorporated Markov processes with 4-week cycles throughout pregnancy. Incremental cost-effectiveness ratios (ICER) for each strategy were calculated and compared to estimate marginal cost effectiveness. An ICER of USD 100,000 per quality-adjusted life year was used to define the cost-effectiveness threshold. One-way sensitivity and Monte Carlo analyses (MCA), as well as microsimulations, were performed. RESULTS: For base-case estimates, SFLP was found to be cost-effective compared to EM in the management of stage I TTTS. In one-way sensitivity analysis, varying each variable along pre-specified ranges did not result in changes in the conclusion. MCA projects SFLP as the cost-effective strategy in 100% of runs. CONCLUSIONS: With base-case estimates, SFLP is estimated to be the cost-effective strategy for the treatment of Quintero stage I TTTS when compared with EM. This remained true across a wide range of inputs.

Assessment of fetal growth in twins: Which method to use?

Fetal growth restriction contributes to the excess perinatal mortality and morbidity associated with twin pregnancies. Regular ultrasound monitoring for fetal growth restriction is an essential component of antenatal care of twin gestations. It is accepted that twins have divergent growth trajectories around 28-30 weeks' gestation and are born smaller compared to singletons. Despite this well-established difference in fetal growth, twin pregnancies have been traditionally managed using growth standards developed for singleton pregnancies. Numerous recent studies have demonstrated a strong case supporting the use of twin-specific growth standards, but clinical implementation has been lacking. In this paper, we will review the evidence on factors affecting fetal growth, the rationale for twin-specific reference charts, clinical evidence for their use, and future direction of research. Applying singleton growth standards to twin pregnancies inflates the abnormal growth rate, and recent clinical evidence from several studies suggests that they are too stringent for classification of twins. The association of adverse perinatal and maternal outcomes such as perinatal death, preterm birth, neonatal care unit admission, hypertensive disorders of pregnancy, and composite neonatal morbidity is stronger when classification is made using twin-specific standards compared to singletons.

Ultrasound assessment of twin reversed arterial perfusion sequence for the prediction of adverse pregnancy outcomes in the first trimester.

OBJECTIVE: To investigate twin reversed arterial perfusion (TRAP) sequence for the prediction of TRAP-related adverse pregnancy outcomes at the gestational age of 11-14 weeks. METHODS: Pregnant women in the first trimester diagnosed with TRAP were recruited at West China Second University Hospital from January 2015 to June 2018. Systematic screening for the pump twin's crown-rump length (CRL) and acardiac twin's upper pole-rump length (URL) was conducted using ultrasonic detection. The (CRL - URL)/CRL and URL/CRL ratios were used to assess the pregnancy outcomes for the pump twin. Twenty-one pregnant women aged 21-39 years with a gestation of 11-14 weeks were recruited. RESULTS: TRAP was diagnosed on average (± standard deviation (SD)) at pregnancy week 13.1 ± 0.18. The pump twins' mean (± SD) CRL was 6.65 ± 1.1 cm. The incidence of intrauterine death for the pump twins was 19.0% (n = 4), the miscarriage rate was 14.3% (n = 3), and the live birth rate was 66.7% (n = 14). The (CRL - URL)/CRL ratios between the nonsurvival (intrauterine death and miscarriage) and survival groups significantly differed (0.33 ± 0.08 vs. 0.58 ± 0.08, p < 0.05). Similarly, the URL/CRL ratios between the nonsurvival and survival groups significantly differed (0.67 ± 0.08 vs. 0.42 ± 0.08, p < 0.05). CONCLUSION: The (CRL - URL)/CRL and URL/CRL ratios were valuable indicators for determining pregnancy outcomes of pump twins with TRAP at an early gestational age.

Glycemic profile assessment during betamethasone administration in women with twin pregnancies after IVF with or without gestational diabetes.

BACKGROUND AND AIMS: Betamethasone's effect on glycemia in twin pregnancies, with or without gestational diabetes mellitus, has not been adequately investigated. METHODS: We assessed the glycemic profile of 30 women with twin pregnancies after in-vitro-fertilization who were given betamethasone. RESULTS: The majority of women were treated eventually with insulin to maintain glycemia. In insulin-treated women the increase in insulin dosage was of 61.1%. Insulin use/dosage was not associated with betamethasone dose, age, gestational age, weight gain in pregnancy, or duration of hyperglycemia. CONCLUSION: Post-betamethasone, twin pregnancies seem to follow the same glycemia pattern as singleton pregnancies.

Delivery timing in dichorionic diamniotic twin pregnancies complicated by preeclampsia: a decision analysis.

OBJECTIVE: To determine the optimal timing of delivery in Dichorionic-diamniotic (DCDA) pregnancies complicated by preeclampsia without severe features. METHODS: A decision-analytic model was created to compare outcomes of expectant management vs. delivery from 34 to 37w0d. Outcomes included quality-adjusted life years (QALYs), development of severe preeclampsia, maternal mortality, maternal stroke, small for gestational age (SGA) due to fetal growth restriction (FGR) detected antenatally, stillbirth, cerebral palsy (CP), and neonatal mortality. Probabilities, utilities, and life expectancies were derived from the literature. Univariate analysis was used to evaluate the impact of delivery at various gestational ages. Maternal and neonatal outcomes were calculated for a theoretical cohort of 10,000 DCDA pregnancies with preeclampsia. RESULTS: The optimal gestational age for delivery was 36w0d when the total QALYs (868,112) were highest. Delivery at 34w0d resulted in the fewest cases of severe preeclampsia, maternal mortality, and maternal stroke (0, 4, and 15 cases per 10,000, respectively). The incidence of each of these adverse outcomes increased with gestational age, with the greatest number of adverse outcomes at 37w0d (2452 cases of severe preeclampsia, eight maternal deaths, and 31 cases of maternal stroke per 10,000). Delivery at 34w0d resulted in the fewest cases of severe preeclampsia (0), maternal stroke (15), maternal mortality (4), stillbirth (0), and SGA (1183). However, this strategy was also associated with most cases of neonatal CP (91) and neonatal mortality (87). CONCLUSION: DCDA twin pregnancies complicated by preeclampsia without severe features appear to have the best outcomes when delivered at 36w0d. Specifically, when compared to delivery at 37w0d, this strategy reduced maternal and neonatal morbidity and mortality.

Assessment of Twin Fetal Exposure to Environmental Magnetic and Electromagnetic Fields.

Fetal development is vital in the human lifespan. Therefore, it is essential to characterize exposure by a series of typical environmental magnetic and electromagnetic fields. In particular, there has recently been a sharp increase in the twin birth rate. However, lack of appropriate models has prohibited dosimetric evaluation, restricting characterization of the impact of these environmental factors on twins. The present study developed two whole-body pregnant models of 31 and 32 weeks of gestation with twin fetuses and explored several typical exposure scenarios, including 50-Hz uniform magnetic field exposure, local 125-kHz magnetic field (MF), and 13.56-MHz electromagnetic field exposure, as well as wideband planewave radiofrequency (RF) exposure from 20 to 6000 MHz. Finally, dosimetric results were derived. Compared to the singleton pregnancy with similar weeks of gestation, twin fetuses were overexposed at 50-Hz uniform MF, but they were probably underexposed in the RF scenarios with frequencies for wireless communications. Furthermore, the twin fetuses manifested large dosimetric variability compared to the singleton, which was attributed to the incident direction and fetal position. Based on the analysis, the dosimetric results over the entire gestation period were estimated. The results can be helpful to estimate the risk of twin-fetal exposure to electromagnetic fields and examine the conservativeness of the international guidelines.© 2022 Bioelectromagnetics Society.

Assessment of different thresholds of birthweight discordance for early neonatal outcomes: retrospective analysis of 2348 twin pregnancies.

BACKGROUND: The optimal threshold of birthweight discordance (BWD) remains controversial. This study aimed to evaluate the associations between BWD at different thresholds and early neonatal outcomes and to assess their predictive accuracy. METHODS: This was a retrospective cohort study using a birthweight data with the chorionicity information of 2348 liveborn twin pairs at a gestational age of ≥26 weeks, from 2012 to 2018. The percentage of BWD was calculated by dividing the actual birthweight difference by the weight of the larger twin and multiplying by 100. Outcomes of interest included neonatal intensive care unit (NICU) admission, neonatal respiratory distress syndrome (NRDS), ventilator support and a composite outcome combining major morbidities and neonatal death. Logistic regression models were performed to estimate the association between neonatal outcomes and BWD with different thresholds (≥15.0%, ≥20.0%, ≥25% and ≥ 30%). Generalized estimated equation (GEE) models were used to address intertwin correlation. Restrictive cubic spline (RCS) models were established to draw the dose-response relationship between BWD and the odds ratios of outcomes. Clustered receiver operating characteristic (ROC) curve analyses were performed to assess the predictive accuracy. RESULTS: Of 2348 twin pairs, including 1946 dichorionic twin pairs and 402 monochorionic twin pairs, BWD was significantly associated with NICU admission, regardless of the thresholds used. The incidence of NRDS, ventilator support and the composite outcome were significantly higher when a threshold of ≥20% or greater was chosen. The dose-response relationship showed nonlinear growth in the risk of adverse neonatal outcomes with increasing BWD. ROC analyses showed a low significant AUROC of 0.569 (95% CI: 0.526-0.612) for predicting NICU admission but no significant AUROCs for predicting other outcomes. A BWD of ≥30% provided a moderate increase in the likelihood of NICU admission [positive likelihood ratio (LR+) = 5.77]. CONCLUSION: Although BWD is independently associated with adverse neonatal outcomes, it is not a single predictor for neonatal outcomes given the weak discriminative ability to predict neonatal outcomes. A cutoff of 30% is more practical for risk stratification among twin gestations.

Diagnosis-Related Group Weight and Derived Case Mix Index to Assess the Complexity among Twins.

OBJECTIVE: Diagnosis-related groups (DRGs) are used to summarize hospital morbidity and mortality. Each DRG has a weight which is important in calculating the case mix index (CMI), a numeric summary of disease complexity in a population of patients. We utilized DRG weight and resultant CMI to compare postnatal outcomes among singletons versus monochorionic and monoamniotic, monochorionic diamniotic, and dichorionic diamniotic twins. STUDY DESIGN: This single-center and retrospective cohort study evaluated DRGs assigned by the investigators, birth weight, gestational age, length of stay (LOS), NICU admission rate, and mortality in twin births between 2014 and 2016. Twins were analyzed depending on chorionicity and amnionicity. Overall, 3 months of singleton births served as the control. The CMI derived from DRG weights were compared across groups. RESULTS: Twins (n = 288) had lower gestational ages and birth weights and higher mortality, LOS, NICU admission rates and DRG weights/CMI compared with singletons (n = 327; p < 0.001 for each). The LOS was no different between twin subtypes; monochorionic monoamniotic twins had the highest mortality and DRG weight (p < 0.001). CONCLUSION: DRG weight and CMI values summarize in-hospital complexity and can be a useful tool to evaluate differences in care complexity among groups of patients. KEY POINTS: · Using diagnosis-related group and case mix index to assess morbidities.. · Morbidities of twins are monochorionic-monoamniotic versus monochorionic-diamniotic versus dichorionic-diamniotic twins.. · Only seven diagnosis-related group in neonatology make it a valuable tool for clinicians..

Routine ultrasound for fetal assessment before 24 weeks' gestation.

BACKGROUND: Ultrasound examination of pregnancy before 24 weeks gestation may lead to more accurate dating and earlier diagnosis of pathology, but may also give false reassurance. It can be used to monitor development or diagnose conditions of an unborn baby. This review compares the effect of routine or universal, ultrasound examination, performed before 24 completed weeks' gestation, with selective or no ultrasound examination.  OBJECTIVES: To assess the effect of routine pregnancy ultrasound before 24 weeks as part of a screening programme, compared to selective ultrasound or no ultrasound, on the early diagnosis of abnormal pregnancy location, termination for fetal congenital abnormality, multiple pregnancy, maternal outcomes and later fetal compromise. To assess the effect of first trimester (before 14 weeks) and second trimester (14 to 24 weeks) ultrasound, separately. SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, and the World Health Organization's International Clinical Trials Registry Platform (ICTRP) on 11 August 2020. We also examined the reference lists of retrieved studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs), quasi-RCTs, cluster-RCTs and RCTs published in abstract form. We included all trials with pregnant women who had routine or revealed ultrasound versus selective ultrasound, no ultrasound, or concealed ultrasound, before 24 weeks' gestation. All eligible studies were screened for scientific integrity and trustworthiness. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for eligibility and risk of bias, extracted data and checked extracted data for accuracy. Two review authors independently used the GRADE approach to assess the certainty of evidence for each outcome MAIN RESULTS: Our review included data from 13 RCTs including 85,265 women. The review included four comparisons. Four trials were assessed to be at low risk of bias for both sequence generation and allocation concealment and two as high risk. The nature of the intervention made it impossible to blind women and staff providing care to treatment allocation.  Sample attrition was low in the majority of trials and outcome data were available for most women. Many trials were conducted before it was customary for trials to be registered and protocols published. First trimester routine versus selective ultrasound: four studies, 1791 women, from Australia, Canada, the United Kingdom (UK) and the United States (US). First trimester scans probably reduce short-term maternal anxiety about pregnancy (risk ratio (RR) 0.80, 95% confidence interval (CI) 0.65 to 0.99; moderate-certainty evidence). We do not have information on whether the reduction was sustained.  The evidence is very uncertain about the effect of first trimester scans on perinatal loss (RR 0.97, 95% CI 0.55 to 1.73; 648 participants; one study; low-certainty evidence) or induction of labour for post-maturity (RR 0.83, 95% CI 0.50 to 1.37; 1474 participants; three studies; low-certainty evidence). The effect of routine first trimester ultrasound on birth before 34 weeks or termination of pregnancy for fetal abnormality was not reported. Second trimester routine versus selective ultrasound: seven studies, 36,053 women, from Finland, Norway, South Africa, Sweden and the US. Second trimester scans probably make little difference to perinatal loss (RR 0.98, 95% CI 0.81 to 1.20; 17,918 participants, three studies; moderate-certainty evidence) or intrauterine fetal death (RR 0.97, 95% CI 0.66 to 1.42; 29,584 participants, three studies; low-certainty evidence). Second trimester scans may reduce induction of labour for post-maturity (RR 0.48, 95% CI 0.31 to 0.73; 24,174 participants, six studies; low-certainty evidence), presumably by more accurate dating. Routine second trimester ultrasound may improve detection of multiple pregnancy (RR 0.05, 95% CI 0.02 to 0.16; 274 participants, five studies; low-certainty evidence). Routine second trimester ultrasound may increase detection of major fetal abnormality before 24 weeks (RR 3.45, 95% CI 1.67 to 7.12; 387 participants, two studies; low-certainty evidence) and probably increases the number of women terminating pregnancy for major anomaly (RR 2.36, 95% CI 1.13 to 4.93; 26,893 participants, four studies; moderate-certainty evidence). Long-term follow-up of children exposed to scans before birth did not indicate harm to children's physical or intellectual development (RR 0.77, 95% CI 0.44 to 1.34; 603 participants, one study; low-certainty evidence). The effect of routine second trimester ultrasound on birth before 34 weeks or maternal anxiety was not reported. Standard care plus two ultrasounds and referral for complications versus standard care: one cluster-RCT, 47,431 women, from Democratic Republic of Congo, Guatemala, Kenya, Pakistan and Zambia. This trial included a co-intervention, training of healthcare workers and referral for complications and was, therefore, assessed separately. Standard pregnancy care plus two scans, and training and referral for complications, versus standard care probably makes little difference to whether women with complications give birth in a risk appropriate setting with facilities for caesarean section (RR 1.03, 95% CI 0.89 to 1.19; 11,680 participants; moderate-certainty evidence).  The intervention also probably makes little to no difference to low birthweight (< 2500 g) (RR 1.01, 95% CI 0.90 to 1.13; 47,312 participants; moderate-certainty evidence). The evidence is very uncertain about whether the community intervention (including ultrasound) makes any difference to maternal mortality (RR 0.92, 95% CI 0.55 to 1.55; 46,768 participants; low-certainty evidence). Revealed ultrasound results (communicated to both patient and doctor) versus concealed ultrasound results (blinded to both patient and doctor at any time before 24 weeks): one study, 1095 women, from the UK. The evidence was very uncertain for all results relating to revealed versus concealed ultrasound scan (very low-certainty evidence). AUTHORS' CONCLUSIONS: Early scans probably reduce short term maternal anxiety.  Later scans may reduce labour induction for post-maturity. They may improve detection of major fetal abnormalities and increase the number of women who choose termination of pregnancy for this reason. They may also reduce the number of undetected twin pregnancies. All these findings accord with observational data.  Neither type of scan appears to alter other important maternal or fetal outcomes, but our review may underestimate the effect in modern practice because trials were mostly  from relatively early in the development of the technology, and many control participants also had scans. The trials were also underpowered to show an effect on other important maternal or fetal outcomes.

The Arabin pessary to prevent preterm birth in women with a twin pregnancy and a short cervix: the STOPPIT 2 RCT.

BACKGROUND: Preterm birth is common in twins and accounts for significant mortality and morbidity. There are no effective preventative treatments. Some studies have suggested that, in twin pregnancy complicated by a short cervix, the Arabin pessary, which fits around the cervix and can be inserted as an outpatient procedure, reduces preterm birth and prevents neonatal morbidity. OBJECTIVE: STOPPIT 2 aimed to evaluate the clinical utility of the Arabin cervical pessary in preventing preterm birth in women with a twin pregnancy and a short cervix. DESIGN: STOPPIT 2 was a pragmatic, open label, multicentre randomised controlled trial with two treatment group - the Arabin pessary plus standard care (intervention) and standard care alone (control). Participants were initially recruited into the screening phase of the study, when cervical length was measured. Women with a measured cervical length of ≤ 35 mm were then recruited into the treatment phase of the study. An economic evaluation considered cost-effectiveness and a qualitative substudy explored the experiences of participants and clinicians. SETTING: Antenatal clinics in the UK and elsewhere in Europe. PARTICIPANTS: Women with twin pregnancy at < 21 weeks' gestation with known chorionicity and gestation established by scan at ≤ 16 weeks' gestation. INTERVENTIONS: Ultrasound scan to establish cervical length. Women with a cervical length of ≤ 35 mm at 18+ 0-20+ 6 weeks' gestation were randomised to standard care or Arabin pessary plus standard care. Randomisation was performed by computer and accessed through a web-based browser. MAIN OUTCOME MEASURES: Obstetric - all births before 34+ 0 weeks' gestation following the spontaneous onset of labour; and neonatal - composite of adverse outcomes, including stillbirth or neonatal death, periventricular leukomalacia, early respiratory morbidity, intraventricular haemorrhage, necrotising enterocolitis or proven sepsis, all measured up to 28 days after the expected date of delivery. RESULTS: A total of 2228 participants were recruited to the screening phase, of whom 2170 received a scan and 503 were randomised: 250 to Arabin pessary and 253 to standard care alone. The rate of the primary obstetric outcome was 18.4% (46/250) in the intervention group and 20.6% (52/253) in the control group (adjusted odds ratio 0.87, 95% confidence interval 0.55 to 1.38; p = 0.54). The rate of the primary neonatal outcome was 13.4% (67/500) and 15.0% (76/506) in the intervention group and control group, respectively (adjusted odds ratio 0.86, 95% confidence interval 0.54 to 1.36; p = 0.52). The pessary was largely well tolerated and clinicians found insertion and removal 'easy' or 'fairly easy' in the majority of instances. The simple costs analysis showed that pessary treatment is no more costly than standard care. LIMITATIONS: There was the possibility of a type II error around smaller than anticipated benefit. CONCLUSIONS: In this study, the Arabin pessary did not reduce preterm birth or adverse neonatal outcomes in women with a twin pregnancy and a short cervix. The pessary either is ineffective at reducing preterm birth or has an effect size of < 0.4. FUTURE WORK: Women with twin pregnancy remain at risk of preterm birth; work is required to find treatments for this. TRIAL REGISTRATION: Current Controlled Trials ISRCTN98835694 and ClinicalTrials.gov NCT02235181. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 44. See the NIHR Journals Library website for further project information.

Women who are pregnant with twins have a much higher risk of going into labour early and having an early (preterm) birth than women who are pregnant with only one baby. For this reason, babies who are twins are much more likely to die or to have serious health complications in the first months of life. Although we know that women with twin pregnancy are at risk, there are no treatments that are recommended to prevent early births. Some studies have suggested that the Arabin pessary can help. The Arabin pessary is a silicone ring that fits around the cervix (neck of the womb). The pessary can be put in place in a clinic without any need for an anaesthetic. Some studies have suggested that the Arabin pessary helps and others have suggested that it does not. It appears to be most helpful when the cervix (neck of the womb) is already shortening. Shortening of the neck of the womb is a sign that early birth is even more likely. We asked women with twin pregnancy to take part in STOPPIT 2. Women who agreed had an ultrasound scan of the neck of the womb, which measured its length. Those with a short cervix were randomised to be offered the Arabin pessary (in addition to standard care) or standard care alone. This allocation was carried out 'at random' by a computer. We followed women up until the end of their pregnancy and collected information on the babies' health after birth. We found that the Arabin pessary did not reduce the risk of an early birth; nor did it reduce the risk of health complications for the baby. We conclude that the Arabin pessary should not be used for this purpose.

The role of umbilical artery velocities in the clinical assessment of twin-twin transfusion syndrome at stage.

OBJECTIVE: To analyze the discordances of the umbilical artery velocities between pregnancies with twin-twin transfusion syndrome (TTTS) at stage I and those with normal monochorionic-diamniotic (MCDA) twins, and investigate the value of their discordances in predicting TTTS at stage I. METHODS: We recruited 58 twin pregnancies with TTTS at stage I and 60 normal MCDA twin pregnancies in a tertiary referral center retrospectively. The umbilical artery velocities and their discordances were compared between the normal and TTTS twins. RESULTS: The discordances of umbilical artery mean diastolic velocity (UA-MDV), umbilical artery time-averaged maximum velocity (UA-TAmax), umbilical artery peak systolic velocity (UA-PSV), and umbilical artery end-diastolic velocity (UA-EDV) were higher in the TTTS group than in the normal group. In TTTS co-twins, the UA-MDV, UA-TAmax, UA-PSV, and UA-EDV in recipients were higher than those in donors. The discordances of UA-TAmax and UA-PSV were found to be independent predicting factors for TTTS at stage I. CONCLUSION: Co-twin umbilical artery velocity discordances were significantly associated with stage I TTTS. The results suggest that UA-TAmax and UA-PSV might be new parameters for predicting TTTS at stage I.

Sonographic Assessment of Fetal Growth Abnormalities.

Fetal growth abnormalities have significant consequences for pregnancy management and maternal and fetal well-being. The accurate diagnosis of fetal growth abnormalities contributes to optimal antenatal management, which may minimize the sequelae of inadequate or excessive fetal growth. An accurate diagnosis of abnormal fetal growth depends on accurate pregnancy dating and serial growth measurements. The fetal size at any given stage of pregnancy is either appropriate or inappropriate for the given gestational age (GA). Pregnancy dating is most accurate in the first trimester, as biologic variability does not come into play until the second and third trimesters. The authors describe the determination of GA with use of standard US measurements and how additional parameters can be used to confirm dating. Once dates are established, serial measurements are used to identity abnormal growth patterns. The sometimes confusing definitions of abnormal growth are clarified, the differentiation of a constitutionally small but healthy fetus from a growth-restricted at-risk fetus is described, and the roles of Doppler US and other adjunctive examinations in the management of growth restriction are discussed. In addition, the definition of selective growth restriction in twin pregnancy is briefly discussed, as is the role of Doppler US in the classification of subtypes of selective growth restriction in monochorionic twinning. The criteria for diagnosing macrosomia and the management of affected pregnancies also are reviewed. The importance of correct pregnancy dating in the detection and surveillance of abnormal fetal growth and for prevention of perinatal maternal and fetal morbidity and mortality cannot be overstated. The online slide presentation from the RSNA Annual Meeting is available for this article. ©RSNA, 2020.

Monozygotic dichorionic-diamniotic pregnancies following single frozen-thawed blastocyst transfer: a retrospective case series.

BACKGROUND: The primary aim of the study is to report cases of monozygotic dichorionic-diamniotic (DC-DA) pregnancies after single frozen-thawed blastocyst transfer. METHODS: This is a retrospective case series. All single frozen-thawed blastocyst transfer cycles performed between June 2013 and December 2018 at the Shanghai Ji Ai Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China, were reviewed retrospectively. We included frozen embryo transfer (FET) cycles which clinical pregnancy was confirmed with multiple gestational sacs showed on ultrasonography at around 6 to 7 weeks of gestation. We then conducted an in-depth analysis to further exclude cases which contained newborns of different genders or natural FET cycles. RESULTS: Five thousand four hundred fifteen frozen-thawed single blastocyst transfer cycles were preformed between June 2013 and December 2018 at the Shanghai Ji Ai Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China. Of these, fourteen women underwent a single blastocyst transfer and then achieved clinical pregnancy with an ultrasound diagnosis of multi-chorionic pregnancy. With one natural cycle FET excluded, we finally included thirteen single blastocyst transfer cycles performed in down-regulated controlled FET or hormone replacement FET, in which the possibility of concurrently spontaneous pregnancy was extremely small. These included 13 cases reveal the phenomenon of monozygotic DC-DA twinning after single blastocyst transfer, which challenges the classical theory that only monochorionic pregnancy could happen after 3 days of fertilization. CONCLUSION: This case series suggest that single blastocyst transfer could result DC-DA pregnancies during IVF treatment.

Renal artery Doppler studies in the assessment of monochorionic, diamniotic twin pregnancies with and without twin-twin transfusion syndrome.

BACKGROUND: In monochorionic, diamniotic twin pregnancies complicated by twin-twin transfusion syndrome, imbalanced fetofetal blood shunting and discordant activation of the renin-angiotensin system result in a hypovolemic, oliguric donor twin and a hypervolemic, polyuric recipient twin. Renal artery Doppler assessments have been reported to predict oligohydramnios in singleton pregnancies; however, their value in assessing monochorionic, diamniotic twin gestations, including pregnancies complicated by twin-twin transfusion syndrome, remains unstudied. OBJECTIVE: This investigation evaluated whether renal artery Doppler parameters are different between sets of monochorionic, diamniotic twins with and without twin-twin transfusion syndrome. STUDY DESIGN: We conducted a prospective study of women with monochorionic, diamniotic twin pregnancies complicated by twin-twin transfusion syndrome and women with gestational-age matched monochorionic, diamniotic twin control pregnancies without twin-twin transfusion syndrome. For each twin, renal artery Doppler assessment was performed from a coronal view of the fetus, and pulsatility index, resistive index, and peak systolic velocity were measured. In twin pairs complicated by twin-twin transfusion syndrome, renal artery Doppler pulsatility index, resistive index, and peak systolic velocity intertwin ratios were calculated by comparing paired recipient-to-donor values. Similar ratios were calculated for control twin pairs. We compared each measurement between donors and controls and between recipients and controls. Intertwin ratios were compared between twin-twin transfusion syndrome cases and monochorionic, diamniotic controls. Our primary outcome was a comparison of renal artery Doppler pulsatility index measurement between donor fetuses in twin-twin transfusion syndrome cases and matched control twins. Secondary outcomes included comparisons of other renal artery Doppler parameters between twin-twin transfusion syndrome donor twins and controls and between twin-twin transfusion syndrome recipients and controls and comparisons of the renal artery Doppler parameter ratios between twin-twin transfusion syndrome and non-twin-twin transfusion syndrome twin pair groups. Finally, we performed a subgroup analysis involving pregnancies with twin-twin transfusion syndrome that underwent fetoscopic laser therapy and resulted in twin survivors to evaluate if laser therapy influenced renal artery Doppler findings. RESULTS: We recruited 12 donors and 12 controls. Renal artery Doppler pulsatility index and resistive index did not differ between donors and controls. However, donor renal artery Doppler peak systolic velocity (median, 14.24 [11.51-15.36]) was significantly lower than that of controls (median, 24.79 [22.46-27.03]; P<.0004). When recipient twins were compared with controls, there was no difference in renal artery Doppler pulsatility index, renal artery Doppler resistive index, or renal artery Doppler peak systolic velocity. Renal artery Doppler peak systolic velocity ratios were significantly higher among cases with twin-twin transfusion syndrome (median, 1.70 [1.53-2.02]) than controls (median, 1.06 [1.03-1.15]; P=.002). Applying a renal artery Doppler peak systolic velocity ratio cutoff of >1.35 for the diagnosis of twin-twin transfusion syndrome correctly classified 11 of 12 cases with twin-twin transfusion syndrome and all 12 controls without twin-twin transfusion syndrome (92% sensitivity and 100% specificity). Among donors with twin-twin transfusion syndrome with double survivors after undergoing laser therapy (n=4), prelaser renal artery Doppler peak systolic velocity ratios (mean, 1.46; standard deviation, 0.37) were significantly higher than postlaser renal artery Doppler peak systolic velocity ratios (mean, 0.87; standard deviation=0.37; P=.02). Postlaser intertwin renal artery Doppler peak systolic velocity ratios did not differ from control twin pairs (P=.125). CONCLUSION: Renal artery Doppler peak systolic velocity ratios differ between monochorionic, diamniotic twins with twin-twin transfusion syndrome and those without twin-twin transfusion syndrome. This effect seems to be driven by altered donor twin renal artery Doppler peak systolic velocity. Laser therapy may normalize renal artery Doppler peak systolic velocity ratios and donor twin renal artery Doppler values to those observed in monochorionic, diamniotic twins without twin-twin transfusion syndrome. Further study is warranted to explore whether renal artery Doppler peak systolic velocity has utility as a tool for twin-twin transfusion syndrome prediction, diagnosis, or staging, and fetal response to laser therapy.