Preterm Birth In Twin Pregnancies Research Articles

Cervical elastography using E-Cervix™ for prediction of preterm birth in twin pregnancies with threatened preterm labor

ObjectiveTo evaluate the prediction performance of E-Cervix™ for preterm birth in twin pregnancies with threatened preterm labor. MethodsThis was a single-center retrospective cohort study of twin pregnancies presenting to obstetrics triage for threatened preterm labor (PTL) between 23 0/7 – 33 6/7 weeks who received screening for PTL with transvaginal ultrasound cervical length (TVU CL) and cervical elastography with E-Cervix™ at the time of triage. Cervical elastography parameters were examined and compared between women who delivered preterm and those who did not. The quantification of cervical strain was calculated by a data analysis system that directly analyzes raw data from the region of interest (ROI) and described as hardness ratio (HR), mean strain level within 1 cm from internal (IOS) and external (EOS) os. Results63 twin gestations without prior preterm birth and with threatened PTL between 23 0/7 – 33 6/7 weeks of gestation were included in the study. 27 (42.9 %) had cervical length < 25 mm, and were admitted for true PLT. Out of the 36 women with cervical length ≥ 25 mm, 6 (16.7 %) were admitted. Women with threatened PTL had significantly higher HR compared to those with true PTL (p < 0.01), and significantly lower IOS and EOS. Women who delivered preterm had significantly higher HR compared to those who did not delivery preterm and significantly lower IOS and EOS, in overall cohort, and in the subset of women with true PTL. Incidences of HR < 50 % and < 35 % were statistically significantly higher in women who delivered preterm compared to those who did not (p < 0.01). ConclusionCervical elastography with E-Cervix™ may be useful for assessment of twin gestations presenting to obstetrics triage for threatened PTL.

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

IntroductionTwin pregnancies have a high risk of extreme preterm birth (PTB) at less than 28 weeks of gestation, which is associated with increased risk of neonatal morbidity and mortality. Currently...

Development and validation of a prediction model on spontaneous preterm birth in twin pregnancy: a retrospective cohort study

BackgroundThis study was conducted to develop and validate an individualized prediction model for spontaneous preterm birth (sPTB) in twin pregnancies.MethodsThis a retrospective cohort study included 3845 patients who gave birth at the Chongqing Maternal and Child Health Hospital from January 2017 to December 2022. Both univariable and multivariable logistic regression analyses were performed to find factors associated with sPTB. The associations were estimated using the odds ratio (OR) and the 95% confidence interval (CI). Model performance was estimated using sensitivity, specificity, accuracy, area under the receiver operating characteristic curve (AUC) and decision curve analysis (DCA).ResultsA total of 1313 and 564 cases were included in the training and testing sets, respectively. In the training set, univariate and multivariate logistic regression analysis indicated that age ≥ 35 years (OR, 2.28; 95% CI 1.67–3.13), pre-pregnancy underweight (OR, 2.36; 95% CI 1.60–3.47), pre-pregnancy overweight (OR, 1.67; 95% CI 1.09–2.56), and obesity (OR, 10.45; 95% CI, 3.91–27.87), nulliparity (OR, 0.58; 95% CI 0.41–0.82), pre-pregnancy diabetes (OR, 5.81; 95% CI 3.24–10.39), pre-pregnancy hypertension (OR, 2.79; 95% CI 1.44–5.41), and cervical incompetence (OR, 5.12; 95% CI 3.08–8.48) are independent risk factors for sPTB in twin pregnancies. The AUC of the training and validation set was 0.71 (95% CI 0.68–0.74) and 0.68 (95% CI 0.64–0.73), respectively. And then we integrated those risk factors to construct the nomogram.ConclusionsThe nomogram developed for predicting the risk of sPTB in pregnant women with twins demonstrated good performance. The prediction nomogram serves as a practical tool by including all necessary predictors that are readily accessible to practitioners.

Reduction in spontaneous and iatrogenic preterm births in twin pregnancies during COVID-19 lockdown in Melbourne, Australia: a multicenter cohort study

BackgroundMelbourne, Australia, recorded one of the longest and most stringent pandemic lockdowns in 2020, which was associated with an increase in preterm stillbirths among singleton pregnancies. Twin pregnancies may be particularly susceptible to the impacts of pandemic disruptions to maternity care due to their higher background risk of adverse perinatal outcomes.MethodsMulticenter retrospective cohort study of all twin pregnancies birthing in public maternity hospitals in Melbourne. Multivariable log-binomial regression models were used to compare perinatal outcomes between a pre-pandemic group to women in whom weeks 20+0 to 40+0 of gestation occurred entirely during one of two lockdown-exposure periods: exposure 1 from 22 March 2020 to 21 March 2021 and exposure 2 from 22 March 2021 to 27 March 2022.ResultsTotal preterm births < 37 weeks were significantly lower in exposure 1 compared with the pre-pandemic period (63.1% vs 68.3%; adjusted risk ratio 0.92 95% CI 0.87–0.98, p = 0.01). This was mainly driven by fewer spontaneous preterm births (18.9% vs 20.3%; adjusted risk ratio 0.95 95% CI 0.90–0.99, p = 0.04). There were also lower rates of preterm birth < 34 weeks (19.9% vs 23.0%, adjusted risk ratio 0.93 95% CI 0.89–0.98 p = 0.01) and total iatrogenic births for fetal compromise (13.4% vs 20.4%; adjusted risk ratio 0.94 95% CI 0.89–0.98, p = 0.01). There were fewer special care nursery admissions (38.5% vs 43.4%; adjusted risk ratio 0.91 95% CI 0.87–0.95, p < 0.001) but no significant changes in stillbirth (1.5% vs 1.6%; adjusted risk ratio 1.00 95% CI 0.99–1.01, p = 0.82). Compared with the pre-pandemic period, there were more preterm births < 28 weeks and neonatal intensive care unit admissions in exposure 2.ConclusionsMelbourne’s first lockdown-exposure period was associated with lower preterm births in twins without significant differences in adverse newborn outcomes. Our findings provide insights into the influences on preterm birth and the optimal timing of delivery for twins.

OP11.05: Cervical cerclage for prevention of preterm birth in twin pregnancies: systematic review and meta‐analysis

OP11.05: Cervical cerclage for prevention of preterm birth in twin pregnancies: systematic review and meta‐analysis

Screening and Prevention of Preterm Birth in Twin Pregnancies.

Twins represent 3.2% of all live births. However, they account for 20% of all preterm deliveries, 60% delivering <37 weeks, 10.7% <32 weeks, and 5 times higher risk of infant death. Risk factors for preterm birth (PTB) include the history of preterm delivery, monochorionic twins, short cervical length, and cervical surgery. Transvaginal cervical length <24 weeks is the best tool to predict PTB. Only vaginal progesterone in women with transvaginal cervical length <25mm and physical exam indicated cerclage in women with cervical dilation >1cm have shown a significant decrease in PTB and improvement in neonatal outcomes.

The association of preconceptional folic acid supplementation with gestational age and preterm birth risk in twin pregnancies: a prospective cohort study in China.

This study aims to explore the association of maternal preconceptional folic acid (FA) supplementation with gestational age and preterm birth in twin pregnancies, and whether the association varies by chorionicity or conception mode. From November 2018 to December 2021, the information of FA supplementation and pregnancy outcomes were collected in twin pregnant women. The linear regression models and the logistic regression were used to test the association of preconceptional FA supplementation with gestational age at delivery and preterm birth and premature rupture of membranes (PROM). A total of 416 twin pregnancies were included. Compared with no use in twins, maternal preconceptional FA use was associated with a 0.385-week longer gestational age (95% CI 0.019-0.751) and lower risk of preterm birth < 36weeks (adjusted OR 0.519; 95% CI 0.301-0.895) and PROM (adjusted OR 0.426; 95% CI 0.215-0.845). The protective effect on preterm birth < 36weeks and PROM is similar whether taking FA supplements alone or multivitamins. However, the associations varied by chorionicity and conception mode of twins or compliance with supplementation. The positive associations between preconceptional FA use and gestational age only remained significant among twins via assisted reproductive technology or dichorionic diamniotic twins. Significant protective effects on preterm birth < 36weeks and PROM were only found among women who took FA at least 4 times a week before conception. Maternal preconceptional FA supplementation was associated with longer gestation duration and lower risk of preterm birth < 36weeks and PROM in twin pregnancies. To improve the success of their pregnancies, reproductive women should start taking FA supplements well before conception and with good compliance.

Cervical sliding sign at second trimester in the prediction of early preterm birth in twin pregnancy.

To examine the cervical sliding sign (CSS) alongside cervical length (CL) in twin pregnancies to predict preterm birth (PB). Twin pregnancies (n = 37) with no known risk factor for PB were included in this prospective study. CSS was defined as the ultrasonographic finding in which the anterior lip of the cervix slides over the posterior lip with gentle and continuous pressure application. The CSS and CL measurements were held in the second trimester. Early PB was defined as the birth of the fetus before 32 weeks of gestation. The patients were divided into two groups as CSS-positive and CSS-negative. Whereas 11 (29.7%) of the twin pregnancies were CSS-positive, 26 (70.3%) were CSS-negative. CSS positivity had a sensitivity of 75.0%, a specificity of 82.2%, a positive predictive value of 54.5%, and a negative predictive value of 92.3% to predict early PB. Multivariate logistic regression analysis revealed that CSS positivity was the only significant independent factor related to early PB. CSS was shown to be superior to CL in providing a better insight to predict early PB. CSS evaluation should be performed in twin pregnancies.

Effect of prior spontaneous preterm birth on delivery timing in subsequent twin pregnancy

People pregnant with twins who had a prior, singleton preterm birth are known to be at risk for preterm birth; however, prior data did not distinguish between spontaneous and iatrogenic births in the prior singleton pregnancy. We aimed to investigate the recurrence risk for preterm birth in a subsequent twin pregnancy in those who had prior spontaneous preterm birth (PSPTB) compared to those without PSPTB in a modern obstetric cohort. This is a secondary analysis of data from a retrospective cohort aimed to evaluate cell-free DNA screening performance in patients with twin pregnancies from 12/2011- 2/2020. We included twin pregnancies >20 weeks gestation and excluded those with nulliparity, unknown pregnancy outcome in twin pregnancy and unknown prior pregnancy history. Presence or absence of PSPTB was confirmed by medical record review. Baseline characteristics, gestational age of twin pregnancy and preterm birth in twin pregnancy were compared between those with history of PSPTB versus those without PSPTB. Multivariable logistic regression was used to assess adjusted odds ratio and adjust for confounders. Of the 958 twin pregnancies, 877 had no PSPTB and 81 had PSPTB. Those with twin pregnancies and prior PSPTB had a higher incidence of preterm birth (PTB) overall (77.8% vs 55.2%, OR 2.84 95%CI 1.66-4.87) and lower gestational age at delivery (34.7 vs 36.6 weeks, p< 0.001) than those with twin pregnancies without PSPTB. However, the rate of spontaneous PTB was not significantly different (46.8% vs 41.7%, OR 1.28 95% CI 0.75-2.17). For patients with PSPTB the adjusted odds ratio for PTB was 3.14 (95% CI 1.72,5.72) after controlling for Black race, body mass index, tobacco use, assisted reproductive technology, chronic hypertension and pregestational diabetes. Pregnant persons who have PSPTB are at increased risk for preterm birth in a subsequent twin pregnancy, and this information may be useful for risk counseling.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Different pathways for preterm birth between singleton and twin pregnancies: a population-based registry study of 481 176 nulliparous women.

To explore the contribution of pregnancy-related complications on the prevalence of extremely, very and late preterm births in singleton and twin pregnancies. To study the risk of spontaneous preterm birth in twin pregnancies compared with singleton pregnancies. Population-based registry study. Medical birth registry of Norway and Statistics Norway. Nulliparous women with singleton (n=472 449) or twin (n=8727) births during 1999-2018. Prevalence rates of pregnancy-related complications for extremely, very and late preterm birth in twin and singleton pregnancies were calculated with 95% confidence intervals. Multivariable logistic regression was applied to assess odds ratios for preterm birth, adjusted for obstetric and socio-economic factors. Extremely preterm (<28+0 weeks of gestation), very preterm (28+0 -33+6 weeks of gestation) and late preterm (34+0 -36+6 weeks of geatation) birth. Preterm birth was significantly more prevalent in twin pregnancies than in singleton pregnancies in all categories: all preterm (54.7% vs 6.1%), extremely preterm (3.6% vs 0.4%), very preterm (18.2% vs 1.4%) and late preterm (33.0% vs 4.3%) births. Stillbirth, congenital malformation and pre-eclampsia were more prevalent in twin pregnancies than in singleton pregnancies, but the prevalence of complications differed in the three categories of preterm birth. Pre-eclampsia was more prevalent in singleton than in twin pregnancies ending in extremely and very preterm birth. The adjusted odds of spontaneous preterm live birth were between 19- and 54-fold greater in twin pregnancies than in singleton pregnancies. Singleton and twin pregnancies seem to have different pathways leading to extremely, very and late preterm birth.

Screening and prevention of preterm birth in twin pregnancies.

Preterm birth (PTB) is commonest cause of perinatal mortality and morbidity in multiple pregnancies with significant long-term sequelae. The etiology of PTB is multifactorial. Universal screening by a transvaginal assessment of cervical length (CL) at midtrimester scan is recommended for all women with twin pregnancies. Women with CL≤25mm should be offered prophylactic vaginal progesterone to mitigate the risk of PTB. Other modalities like home uterine activity monitoring, digital cervical examination, fetal fibronectin (FFN) assessment, and screening for infections are not recommended. History-indicated cerclage is not advised in unselected twin pregnancies, but a combination of physical examination-indicated cerclage, tocolytics, and antibiotics may be considered in twin pregnancies with a dilated cervix prior to 24 weeks' gestation. Routine use of cervical pessary is not advised and should be limited to research settings. Neither transvaginal CL nor FFN assessment is supported by evidence to predict the risk of PTB in symptomatic women with multiple pregnancies. More research is warranted to develop and validate algorithms to predict PTB to provide individualized care to these high-risk pregnancies.

Prenatal exposure to fine particulate matter and the risk of spontaneous preterm birth: A population-based cohort study of twins.

Studies in singletons have suggested that prenatal exposure to fine particulate matter (PM2.5) and some of its chemical components is associated with an increased risk of preterm birth (PTB). However, no study has been conducted in twins. To examine the associations of maternal exposure to total PM2.5 mass and its carbonaceous components with PTB in twin pregnancies. A total of 1,515 pairs of twins and their mothers were enrolled from a previous twin birth cohort that had been conducted at the Shanghai First Maternity and Infant Hospital School of Medicine of Tongji University in China. Participants who had iatrogenic PTBs were excluded. Maternal exposure to total PM2.5 mass and two carbonaceous components, namely, organic carbon (OC) and black carbon (BC), was estimated by a satellite-based model. The associations between PM2.5 exposure and the risk of spontaneous PTB were evaluated by logistic regression analysis. This study found that exposure to total PM2.5 mass and OC during the second trimester of pregnancy was significantly associated with an increased risk of spontaneous PTB. An interquartile range (IQR) increase in total PM2.5 mass and OC exposure during the second trimester was associated with 48% (OR = 1.48, 95% CI, 1.06, 2.05) and 50% (OR = 1.50, 95% CI, 1.00, 2.25) increases in the odds of PTB, respectively. However, no significant association was found between BC exposure during any exposure window and the risk of PTB. The findings suggest that exposure to ambient air pollution with fine particles may be a risk factor for spontaneous PTB in twin pregnancies. The middle stage of pregnancy seems to be a critical window for the impacts of PM2.5 exposure on PTB in twin pregnancies.

The effectiveness of the Dr. Arabin cervical pessary in the prevention of extreme preterm birth and very preterm birth in twins

BACKGROUND: Multiple pregnancy remains a serious obstetrical problem, as it is a high risk factor for miscarriage/preterm birth at any gestational age. On average, in 54% of patients with twins, pregnancy ends in preterm birth, regardless of the economic situation and the level of perinatal care in the state, and is characterized by high childhood morbidity and mortality.&#x0D; AIM: The aim of this study was to identify risk factors for spontaneous preterm birth and to evaluate the effectiveness of a cervical pessary in pregnant women with twins and a short cervix.&#x0D; MATERIALS AND METHODS: This prospective, open, randomized cohort study included 91 women with twins, a short cervix (25 according to the L.J. Salomon scale) and a threatened miscarriage / preterm birth in the second and third trimesters of pregnancy, who received the Dr. Arabin cervical pessary. We analyzed pregnancy outcomes and identified risk factors for spontaneous preterm birth.&#x0D; RESULTS: Based on the pregnancy outcomes, all patients were categorized into two main groups after 16 pregnant women with induced preterm birth were excluded from further study. The study was continued by 75 pregnant women, with term birth in 40 (53.3%) women in group I and spontaneous preterm birth in 35 (46.7%) women in group II.&#x0D; The average period of pregnancy prolongation was statistically different between groups II and I (8.86 4.86 and 12.32 4.38 weeks, p 0.01). The average gestational age of labor initiation was 37.73 0.62 weeks in group I and 34.24 2.08 weeks in group II (p 0.001). We found no extreme preterm birth (22-27 6/7 weeks) in group II, the perinatal mortality of newborns being the highest at this gestational age. Labor at a gestational age of 28-33 6/7 weeks was in 14 (18.67%) women and of 34-36 6/7 weeks in 21 (28.00%) women. The detailed analysis of the course and outcomes of pregnancy and labor in high-risk groups identified two factors that affect the occurrence of spontaneous preterm birth in twin pregnancies: the Bishop score 5 points (p = 0.03579; odds ratio 4.93, 95% confidence interval 1.2319.74) and cervical length on bimanual vaginal examination 20 mm (p = 0.014; odds ratio 4.67, 95% confidence interval 1.4714.82).&#x0D; CONCLUSIONS: The use of a cervical pessary in the group of pregnant women with twins and at a high risk of spontaneous preterm birth not only allows for prolonging pregnancy and excluding the birth of extremely premature babies, but also reduces the number of spontaneous extreme and very preterm births.

Interventions to prevent preterm delivery in women with short cervix before fetoscopic laser surgery for twin-twin transfusion syndrome.

Preoperative short cervical length (CL) remains a major risk factor for preterm birth after laser surgery for twin-twin transfusion syndrome (TTTS), but the optimal intervention to prolong pregnancy remains elusive. The objective of this study was to compare secondary methods for the prevention of preterm birth in twin pregnancies with TTTS undergoing fetoscopic laser photocoagulation (FLP), in the setting of a short cervix at the time of FLP, in five North American Fetal Treatment Network (NAFTNet) centers. This was a secondary analysis of data collected prospectively at five NAFTNet centers, conducted from January 2013 to March 2020. Inclusion criteria were a monochorionic diamniotic twin pregnancy complicated by TTTS, undergoing FLP, with preoperative CL < 30 mm. Management options for a short cervix included expectant management, vaginal progesterone, pessary (Arabin, incontinence or Bioteque cup), cervical cerclage or a combination of two or more treatments. Patients were not included if the intervention was initiated solely on the basis of having a twin gestation rather than at the diagnosis of a short cervix. Demographics, ultrasound characteristics, operative data and outcomes were compared. The primary outcome was FLP-to-delivery interval. Propensity-score matching was performed, with each treatment group matched (1:1) to the expectant-management group for CL, in order to estimate the effect of each treatment on the FLP-to-delivery interval. A total of 255 women with a twin pregnancy complicated by TTTS and a short cervix undergoing FLP were included in the study. Of these, 151 (59%) were managed expectantly, 32 (13%) had vaginal progesterone only, 21 (8%) had pessary only, 21 (8%) had cervical cerclage only and 30 (12%) had a combination of treatments. A greater proportion of patients in the combined-treatment group had had a prior preterm birth compared with those in the expectant-management group (33% vs 9%; P = 0.01). Mean preoperative CL was shorter in the pessary, cervical-cerclage and combined-treatment groups (14-16 mm) than in the expectant-management and vaginal-progesterone groups (22 mm for both) (P < 0.001). There was no significant difference in FLP-to-delivery interval between the groups, nor in gestational age at delivery or the rate of live birth or neonatal survival. Vaginal progesterone was associated with a decrease in the risk of delivery before 28 weeks' gestation compared with cervical cerclage and combined treatment (P = 0.03). Using propensity-score matching for CL, cervical cerclage was associated with a reduction in FLP-to-delivery interval of 13 days, as compared with expectant management. A large proportion of pregnancies with TTTS and a short maternal cervix undergoing FLP were managed expectantly for a short cervix, establishing a high (62%) risk of delivery before 32 weeks in this condition. No treatment that significantly improved outcome was identified; however, there were significant differences in potential confounders and there were also likely to be unmeasured confounders. Cervical cerclage should not be offered as a secondary prevention for preterm birth in twin pregnancies with TTTS and a short cervix undergoing FLP. A large randomized controlled trial is urgently needed to determine the effects of treatments for the prevention of preterm birth in these pregnancies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Clinical analysis on the influencing factors related to preterm twin pregnancy.

The aim of this study was to explore the influencing factors of preterm twin pregnancy. In total, 602 twin-pregnant women delivered from February 2016 to February 2020 were analyzed retrospectively. According to whether the pregnant women were preterm or not, they were divided into preterm group (n=363) and term group (n=239). Baseline information, such as maternal age, address, and education level of the pregnant women, were collected. The clinical information of pregnant women, such as chorionic, preeclampsia, gestational diabetes, premature rupture of membranes, abnormal fetal position, and fetal weight, were analyzed. Logistic regression analysis was used to analyze the risk factors. p-value <0.05 was considered statistically significant. In the preterm group, monochorionic diamniotic comorbidities were significantly higher compared with the control group (p<0.05). Higher risks of preterm group have lower education (p<0.05). Multiple logistic regression analysis demonstrated that education, preeclampsia, and premature rupture of membranes were risk factors for preterm twin pregnancy. Preterm birth in twin pregnancy is associated with many risk factors, such as education, preeclampsia, and premature rupture of membranes. Pregnancy supervision and prenatal guidance for twin pregnancy should be strengthened. Furthermore, early detection and diagnosis of comorbidities can improve maternal and neonatal outcomes.

Perinatal outcome of pregnancy complicated by twin anemia-polycythemia sequence: systematic review and meta-analysis.

To report the perinatal outcome of monochorionic diamniotic (MCDA) twin pregnancies complicated by twin anemia-polycythemia sequence (TAPS), according to the type of TAPS (spontaneous or postlaser) and the management option adopted. MEDLINE, EMBASE and The Cochrane Library databases were searched for studies reporting on the outcome of twin pregnancies complicated by TAPS. Inclusion criteria were non-anomalous MCDA twin pregnancies with a diagnosis of TAPS. The primary outcome was perinatal mortality; secondary outcomes were neonatal morbidity and preterm birth (PTB). The outcomes were stratified according to the type of TAPS (spontaneous or following laser treatment for twin-twin transfusion syndrome) and the management option adopted (expectant, laser surgery, intrauterine transfusion (IUT) or selective reduction (SR)). Random-effects meta-analysis of proportions was used to analyze the data. Perinatal outcome was assessed according to whether TAPS occurred spontaneously or after laser treatment in 506 pregnancies (38 studies). Intrauterine death (IUD) occurred in 5.2% (95% CI, 3.6-7.1%) of twins with spontaneous TAPS and in 10.2% (95% CI, 7.4-13.3%) of those with postlaser TAPS, while the corresponding rates of neonatal death were 4.0% (95% CI, 2.6-5.7%) and 9.2% (95% CI, 6.6-12.3%), respectively. Severe neonatal morbidity occurred in 29.3% (95% CI, 25.6-33.1%) of twins after spontaneous TAPS and in 33.3% (95% CI, 17.4-51.8%) after postlaser TAPS, while the corresponding rates of severe neurological morbidity were 4.0% (95% CI, 3.5-5.7%) and 11.1% (95% CI, 6.2-17.2%), respectively. PTB complicated 86.3% (95% CI, 77.2-93.3%) of pregnancies with spontaneous TAPS and all cases with postlaser TAPS (100% (95% CI, 84.3-100%)). Iatrogenic PTB was more frequent than spontaneous PTB in both groups. Perinatal outcome was assessed according to the management option adopted in 417 pregnancies (21 studies). IUD occurred in 9.8% (95% CI, 4.3-17.1%) of twins managed expectantly and in 13.1% (95% CI, 9.2-17.6%), 12.1% (95% CI, 7.7-17.3%) and 7.6% (95% CI, 1.3-18.5%) of those treated with laser surgery, IUT and SR, respectively. Severe neonatal morbidity affected 27.3% (95% CI, 13.6-43.6%) of twins in the expectant-management group, 28.7% (95% CI, 22.7-35.1%) of those in the laser-surgery group, 38.2% (95% CI, 18.3-60.5%) of those in the IUT group and 23.3% (95% CI, 10.5-39.2%) of those in the SR group. PTB complicated 80.4% (95% CI, 59.8-94.8%), 73.4% (95% CI, 48.1-92.3%), 100% (95% CI, 76.5-100%) and 100% (95% CI, 39.8-100%) of pregnancies after expectant management, laser surgery, IUT and SR, respectively. The present meta-analysis provides pooled estimates of the risks of perinatal mortality, neonatal morbidity and PTB in twin pregnancies complicated by TAPS, stratified by the type of TAPS and the management option adopted. Although a direct comparison could not be performed, the results from this systematic review suggest that spontaneous TAPS may have a better prognosis than postlaser TAPS. No differences in terms of mortality and morbidity were observed when comparing different management options for TAPS, although these findings should be interpreted with caution in view of the limitations of the included studies. Individualized prenatal management, taking into account the severity of TAPS and gestational age, is currently the recommended strategy. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Are two children at once better than one? Risk analysis of twin pregnancies and births after assisted reproduction

ObjectivesPregnancies and births following assisted reproductive treatment (ART) are related to an increased risk for adverse perinatal outcomes. The aim of this retrospective cohort study at a University Hospital with a tertiary perinatal center was the combined risk analysis of singleton and twin pregnancies after ART in comparison to spontaneously conceived pregnancies. Study designMaternal and fetal risks were analyzed in subgroups after spontaneous conception (N = 14,233) and ART (N = 785) during the 6-year study period from 2014 to 2019. Odds ratios for perinatal risks between the groups were calculated and adjusted for maternal age and gestational week at birth using a matched control analysis. Subgroups of preterm delivery were compared. ResultsThe overall maternofetal risks after ART are higher than after spontaneous conception. Maternal risks after ART are mainly related to higher maternal age (p < 0.001). Preterm delivery and neonatal complications are more frequent in twins than in singletons (p < 0.001), but no statistically significant differences were seen in comparison in the subgroup of twins due to conception. Higher maternal age and body mass index did not increase the risk of preterm birth in twin pregnancies. ConclusionsMaternal risks in pregnancies after ART are mainly influenced by maternal age. The strongest risk factor in ART pregnancies is a multiple pregnancy. Every 5th pregnancy after ART was a twin pregnancy with higher risks for preterm delivery, maternal hospitalization and adverse neonatal outcome (p < 0.001). Advanced maternal age in ART cannot be altered, but twin pregnancies can be actively avoided using the single embryo transfer strategy.

Perinatal Outcomes and Risk Factors for Preterm Birth in Twin Pregnancies in a Chinese Population: A Multi-center Retrospective Study.

Background: Twin pregnancies are associated with an increased risk of adverse maternal and neonatal outcomes, mainly owing to prematurity. Few studies have evaluated the risk factors for preterm birth (PTB) in Chinese population. The objective of this study is to present the short-term maternal-neonatal outcomes, investigating the potential risk factors associated with preterm birth in Chinese twin pregnancies.Methods: A multi-center retrospective study of women pregnant with twins ≥28 weeks of gestation was conducted. Maternal and neonatal outcomes were analyzed. Logistic regression was used to identify potential risk factors for PTB before 37, 34, and 32 weeks, respectively.Results: A total of 3,288 twin pregnancies and 6,576 neonates were included in 99,585 pregnancies. The rate of twin pregnancy was 3.3%, while the PTB rate before 37, 34, and 32 weeks among this population were 62.1, 18.8, and 10.4%, respectively. Logistic regression revealed that monochorionicity [Odds ratio (OR) 3.028, 95% confident interval (CI) 2.489–3.683, P < 0.001], gestational weight gain (GWG) <10 kg (OR 2.285, 95% CI 1.563–3.339, P < 0.001) and GWG between 10 and 15 kg (OR 1.478, 95% CI 1.188–1.839, P < 0.001), preeclampsia (PE) (OR 3.067, 95% CI 2.142–4.390, P < 0.001), and intrahepatic cholestasis of pregnancy (ICP) (OR 3.122, 95% CI 2.121–4.596, P < 0.001) were the risk factors for PTB before 37 weeks. Monochorionicity (OR 2.865, 95% CI 2.344–3.501, P < 0.001), age < 25 years (OR 1.888, 95% CI 1.307–2.728, P = 0.001), and GWG <10 kg (OR 3.100, 95% CI 2.198–4.372, P < 0.001) were risk factors for PTB before 34 weeks. Monochorionicity (OR 2.566, 95% CI 1.991–3.307, P < 0.001), age younger than 25 years (OR 1.964, 95% CI 1.265–3.048, P = 0.003), and GWG <10 kg (OR 4.319, 95% CI 2.931–6.364, P < 0.001) were the risk factors for PTB before 32 weeks.Conclusions: Monochorionicity and GWG <10 kg were two major risk factors for PTB before 32, 34, and 37 weeks, whereas maternal age, PE, and ICP were also risk factors for PTB in specific gestational age.

Uterocervical angle at 20 weeks: A promising predictor of spontaneous preterm birth in twin pregnancies

ObjectiveTo compare the performance of uterocervical angle (UCA) and cervical length (CL) measurement at 20 weeks of pregnancy for prediction of spontaneous preterm birth (sPTB) in twin pregnancies. Study designWe conducted a retrospective cohort study of 424 twin pregnancies who delivered in our center from October 2014 to December 2018 and who underwent transvaginal ultrasound between 19+0–22+0 weeks to measure CL during routine second trimester scan. Recorded ultrasound images of CL were reassessed to evaluate UCA. Medical and obstetric data were also collected for statistical analysis. ResultsA total of 424 women were included. The rates of sPTB rate below 28, 32 and 34 weeks of gestation were 2.8 %, 5.4 % and 10.4 %, respectively. ROC curves showed a better area under the curve (AUC) for UCA at all gestational ages compared with CL (AUC for sPTB <28 weeks 0.902 (p < 0.001) vs 0.620 (p 0.175); AUC for sPTB <32 weeks 0.740 (p 0.001) vs 0.620 (p 0.058); AUC for sPTB <34 weeks 0.676 (p 0.001) vs 0.632 (p 0.047). UCA > 120 degrees was significantly associated with sPTB <28 weeks (p < 0.001; OR 39.17; CI 4.81–319.23; NPV, 99.65 %), <32 weeks (OR 4.23; p 0.002) and <34 weeks of gestation (OR 2.66; p 0.01). ConclusionIn our study, an UCA > 120 degrees allowed to identify those women with twin pregnancies at risk of sPTB and performed better than CL measurement.

Prevention of preterm birth in multiples.

Multifetal pregnancy carries increased risk of preterm delivery, and consensus on management options to prevent early birth in this population has not been reached. This review serves to summarize the most contemporary findings on this controversial topic. Examination-indicated cerclage is effective in reducing preterm birth in twin pregnancies, whereas cerclages for other indications are less convincing. Cervical pessary may be beneficial for patients with a short cervix and in those who have had threatened preterm labor. Progesterone supplementation for multifetal gestation alone is not beneficial, but it can be considered in those with a history of prior singleton preterm birth. Interventions for preterm birth prevention in multiple gestations remain under investigation, and further data is required in order to reach consensus for this high-risk population.