Monochorionic Diamniotic Twin Pregnancies Research Articles

Efficacy of Long-Term Indomethacin Therapy in Prolonging Pregnancy After Fetoscopic Laser Surgery for Twin-to-Twin Transfusion Syndrome: A Collaborative Cohort Study

(Abstracted from BJOG 2022;129:597–606) Approximately 10% to 15% of monochorionic diamniotic twin pregnancies are affected by twin-to-twin transfusion syndrome (TTTS). Fetoscopic laser surgery is recognized as the standard for treating such pregnancies.

Outcomes of Monoamniotic Twin Pregnancies from the First Trimester Onward

Introduction: Monochorionic monoamniotic (MCMA) twins are rare, and information is lacking on pregnancy outcomes from the first trimester onward. This study compares the pregnancy and neonatal outcomes between MCMA and monochorionic diamniotic (MCDA) twin pregnancies from the first trimester onward. We also report on the outcomes of MCMA twin pregnancies continuing after 28 weeks and on the neurodevelopmental outcomes of MCMA twins. Methods: A retrospective single-center cohort study of MCMA and MCDA twin pregnancies followed from the first trimester with a fortnightly ultrasound scan. We excluded pregnancies with a major anomaly diagnosed on the first-trimester ultrasound scan. MCMA twin pregnancies were offered inpatient monitoring from 28 weeks onward, and an elective cesarean section was advised between 32 and 33 weeks. MCDA pregnancies were managed as inpatients only if medically indicated, and an elective birth between 36 and 37 weeks was recommended. Results: We analyzed the outcomes of 52 MCMA and 671 MCDA twin pregnancies. In MCMA twins, the fetal and neonatal survival rate was 81/104 (78%) versus 1,192/1,342 (89%) in MCDA twins (p = 0.016). Double intrauterine demise (IUD) was more common in MA than in DA pairs (13% vs. 3%) (p = 0.002). No IUD occurred in the 40 MCMA pregnancies that continued after 28 weeks, but five women (13%) required an urgent cesarean section for fetal distress. Thirty-eight of 52 eligible infants (73%) underwent a neurodevelopmental assessment. Thirty-three (87%) had cognitive and motor development scores within normal limits. Four infants had mild cognitive or motor impairment, and one infant was diagnosed with spastic diplegia. Conclusion: MCMA twins are associated with decreased survival rates compared to MCDA due to increased rates of double IUD. After 28 weeks, about one in eight women required an urgent delivery for fetal distress. Most infants had normal neurodevelopmental outcomes.

Association of amniotic fluid natriuretic peptide levels with ductus venosus Doppler flow in recipient twins with twin-to-twin transfusion syndrome

This study examined the relationships between fetal quantitative Doppler parameters and amniotic fluid N-terminal prohormone brain natriuretic peptide (afNT-proBNP) levels as a biomarker of the increased cardiac load in recipient twins with twin-to-twin transfusion syndrome (TTTS). This single-center, prospective study included all monochorionic diamniotic (MD) twin pregnancies that were diagnosed with TTTS and underwent fetoscopic laser surgery. Doppler flow was used to measure the pulsatility index (PI) of the umbilical artery (UA), ductus venosus (DV), and middle cerebral artery (MCA) of each recipient and donor twins. The afNT-proBNP levels of recipient twins were examined at the time of surgery. The Spearman or Pearson correlation coefficients were used to assess the relationships between afNT-proBNP levels and Doppler parameters. A total of 150 MD twin pregnancies were included. The afNT-proBNP levels of the recipient twins showed a stronger correlation with the DV-PI (r = 0.637; P < 0.001) of recipient twins than with the UA-PI and MCA-PI of recipient twins. The Doppler parameters of donor twins were scarcely correlated with the afNT-proBNP levels of the recipient twins. A positive correlation between the DV-PI and afNT-proBNP levels of recipient twins with TTTS was observed. The recipient twin with an increased DV-PI is expected to be under a high cardiac load; therefore, DV-PI is a useful parameter for assessing increased NT-proBNP levels consecutively and noninvasively. This study was registered with Japanese Clinical Trial Registry "UMIN-CTR" ( http://www.umin.ac.jp/ctr/index-j.htm ; trial ID numbers UMIN000024486 and 000037702).

Are there differences between monochorionic twin placentas after spontaneous and assisted conception?

IntroductionNo data are available on the placental characteristics of monochorionic twin pregnancies conceived by in vitro fertilization (IVF). This study investigates the differences between placentas from monochorionic diamniotic (MCDA) twin pregnancies conceived spontaneously and those conceived after IVF. MethodsThis is a retrospective analysis of placental data from a consecutive series of MCDA twin pregnancies followed from the first trimester. The following placental characteristics were compared between IVF versus spontaneous MCDA pregnancies: placental sharing and birth weight discordance relative to placental sharing, the placental angioarchitecture (number, type, and size of anastomoses), and the umbilical cord insertion types. ResultsOf the 256 MCDA placentas included in this analysis, 32 (12%) were conceived through IVF and 224 (88%) spontaneously. MCDA twin placentas after IVF did not differ significantly from MCDA twin placentas after spontaneous conception regarding placental sharing, birthweight discordance relative to sharing discordance, and angioarchitecture. There was a trend toward more discordant cord insertions (combination eccentric and velamentous) in IVF (25%) than in spontaneously conceived placentas (12%) (P = 0.05). DiscussionNo differences could be demonstrated between MCDA placentation after spontaneous conception and IVF. Any differences in pregnancy outcome between spontaneous and IVF conceived MCDA twins may not be related to differences in placental sharing, angioarchitecture and cord insertion type.

Retrospective validation of ultrasound characteristics at 19-24 weeks as predictive tools for selective intrauterine growth restriction in monochorionic diamniotic twin pregnancies: a diagnostic study.

BackgroundSeeking an optimal time point for ultrasound examination is important for the diagnosis of late selective intrauterine growth restriction (sIUGR) at birth in monochorionic diamniotic (MCDA) twin pregnancies. We aimed to assess the role of ultrasound characteristics at 19–24 weeks as predictive tools for late sIUGR at birth in MCDA twin pregnancies.MethodsWe retrospectively recruited 32 sIUGR and 56 normal patients with MCDA twin pregnancies. Ultrasound indexes of these included subjects at 19–24 weeks, including the middle cerebral artery peak systolic velocity (MCA-PSV), umbilical artery pulsatility index (UA-PI), middle cerebral artery pulsatility index (MCA-PI), and cerebroplacental ratio (CPR) were assessed. Receiver operating characteristic (ROC) curves were used to ascertain the predictive value of ultrasound characteristics discrepancy for such complications, and the relationship between the ultrasound characteristics and sIUGR was assessed by a logistic regression analysis.ResultsDifferences were found in the MCA-PI, UA-PI, and CPR discordances between the normal MCDA and sIUGR subjects. CPR discordance was the most effective characteristic for predicting sIUGR [area under the ROC curve (AUC) =0.883; 95% CI: 0.795–0.948], followed by UA-PI discordance (AUC =0.772; 95% CI: 0.685–0.829), and MCA-PI discordance (AUC =0.746; 95% CI: 0.681–0.823), respectively. Additionally, the optimal cutoff value of CPR discordance was 21.65, and the corresponding sensitivity and specificity were 0.750 and 0.929, respectively. The correlation analysis revealed that gestational age (GA) at ultrasound scan but not at delivery was significantly correlated with the MCA-PSV (r=0.55, P<0.01), UA-PI (r=0.55, P<0.01), MCA-PI (r=0.49, P<0.01), and CPR (r=0.55, P<0.01) in sIUGR, while GA at both ultrasound scan and birth was significantly correlated with MCA-PSV (r=0.65, P<0.01), UA-PI (r=0.49, P<0.01), MCA-PI (r=0.48, P<0.01), and CPR (r=0.63, P<0.01) in normal MCDA.ConclusionsIncreased MCA-PI, UA-PI, and CPR discordances were found in fetuses with sIUGR. CPR discordance could serve as a predictive index for sIUGR. An early ultrasound examination may be more accurate than biochemical modality for sIUGR prediction.

Monochorionic-Diamniotic Twin Pregnancy Complicated by Spontaneous Septostomy and Cord Entanglement: A Systematic Review, Evaluation of Complication Rates and Presentation of an Additional Case

Background: Our purpose is to describe the ultrasound findings, both with bi-dimensional and three-dimensional imaging, suggestive of spontaneous septostomy in monochorionic-diamniotic twin pregnancies. Methods: PubMed, Medline and reference lists were searched using “Spontaneous septostomy and twin pregnancy” as keywords. Seventeen articles reporting a total of 25 cases, adding our own, were included in the systematic review. Only English full text articles, the main purpose of which was to describe spontaneous septostomy in twin pregnancies, were included. Results: In our sample the major ultrasound sign arousing suspicion of spontaneous septostomy was found to be an absent or disrupted inter-twin membrane (79% of cases). Twins close to each-other were described in 33% of cases, while cord entanglement was suspected only in 27% of cases. We reported a lower antenatal detection of entanglement when compared with intrapartum evaluation (27% vs 59%). Adverse fetal outcomes occurred in 12% of cases, while 88% of cases were born alive. Conclusions: Spontaneous septostomy represents a diagnostic and clinical challenge for obstetrics providers. Clinicians must focus on ultrasound findings to close surveil fetal wellness and reduce both fetal and neonatal impairment.

Obstetric perinatal and maternal outcomes of monochorionic diamniotic twins following assisted reproductive techniques. Retrospective observational study

IntroductionMultiple and specifically monochorionic diamniotic (MCDA) pregnancies are related to maternal and foetal complications. The aim of this study is to evaluate obstetric and perinatal outcomes of MCDA after assisted reproductive techniques (ART). MethodsThis is a case-control study comparing 23 MCDA twin pregnancies after ART (ART-MCDA) and 75 spontaneous MCDA (sMCDA). Maternal, obstetric, foetal, and perinatal outcomes variables including maternal age, prematurity, TTTS, sIUGR, TAPS, PROM, and neonatal weight were compared. Resultsmean maternal age is higher in the ART-MCDA pregnancies, 38.0±.6 (OR=1.32(1.13–1.53)). Neonates weighing between 1500 and 2500g are more frequent in the sMCDA group and those weighing >2500g in the ART group (OR=0.47(0.22–0.97)). Foetuses born at between 32 and 37 weeks are more frequent in sMCDA pregnancies and those born >37 in the TRA group (OR=0.27(0.09–0.80)). These differences are lost when we adjust the results by maternal age. There were no differences in maternal, obstetric, or foetal complications. ConclusionsART-MCDA are not associated with a higher number of maternal, obstetric or foetal complications if they are adjusted by maternal age. When they are not adjusted by maternal age, there would be better outcomes such as premature and neonatal weight in the ART group.

Impact of Preoperative Cervical Length on Pregnancy Outcome in Twin-Twin Transfusion Syndrome.

To evaluate the impact of preoperative cervical length on pregnancy outcome in monochorionic diamniotic twin pregnancies complicated by twin-twin transfusion syndrome that underwent laser surgery or cord occlusion. Retrospective study of 330 patients stratified by preoperative cervical length (≥25 mm, 16-24 mm,≤15 mm). Maternal characteristics, operative data, and pregnancy outcomes were compared between the cervical length groups as well as between the subgroups of patients with a cervical length≤15 mm according to management (expectant vs. cerclage). A preoperative cervical length≥25 mm was observed in 82% (n=271) of cases, 16-24 mm in 9% (n=29), and≤15 mm in 9% (n=30). Patients with a preoperative cervical length≤15 mm showed shorter median procedure-to-delivery interval (5.5 weeks vs. 11.6 (16-24 mm) vs. 13.0 (≥25 mm); p<0.001); lower median gestational age at delivery (29.5 weeks vs. 34.3 (16-24 mm) vs. 33.4 (≥25 mm); p<0.001); higher rate of preterm delivery<32 weeks (78 vs. 20% (16-24 mm) vs. 31% (≥25 mm); p<0.001); and lower neonatal survival rate of at least one twin (70 vs. 88% (16-24 mm) vs. 93% (≥25 mm); p<0.001). Outcome of patients with a preoperative cervical length≤15 mm was similar regardless of management. Monochorionic diamniotic twin pregnancies complicated by twin-twin transfusion syndrome with a preoperative cervical length≤15 mm showed a higher rate of preterm delivery<32 weeks and lower neonatal survival. The role of a cervical cerclage remains unclear.

Monochorionic Diamniotic Twins with Bordering Cord Insertions: Images and Outcome.

Twin pregnancy contributes to perinatal mortality, particularly monochorionic diamniotic twin pregnancy. Placental abnormalities are much more common in twin pregnancies than in singletons. In MCDA pregnancy, vascular anastomoses are always present and are accountable for severe complications such as Twin-to-Twin transfusion syndrome (TTTS). In TTTS, umbilical cords are usually inserted at a distance from each other. We present a rare type of MCDA pregnancy, TTTS gr 1 case with bordering umbilical cord insertions.

Sonographic evaluation of umbilical cord thickness in monochorionic diamniotic twin pregnancies.

To develop a nomogram of the thickness of the umbilical cord (UC) and its components in monochorionic diamniotic (MCDA) twin pregnancies. This prospective longitudinal study involved 47 MCDA twin pregnancies (94 fetuses) between 18 and 33weeks of gestation. Ultrasound assessments of UC cross-sections and measurements of the umbilical cord area (UCA), the umbilical vein area (UVA), the umbilical artery area (UAA), and the Wharton jelly area (WJA) were made. The UC measurements were correlated with gestational ages. Reference values for the gestational ages of MCDA pregnancies were determined and compared with those of dichorionic twins and singletons. The cases which developed selective intrauterine growth restriction were contrasted with normal cases. A positive correlation was found between all UC components and gestational age and fetal weight. The UCA of MCDA fetuses was significantly larger than that of DC fetuses (p<0.001) at the expense of a larger WJA (p<0.001) and similar to that of singleton pregnancies. The MCDA fetuses with an estimated fetal weight below the 10th percentile had a smaller UCA than fetuses with a normal estimated weight (p<0.001). The MCDA twins exhibited a thicker UC than that of dichorionic twins.

The Metabolic Signatures of Surviving Cotwins in Cases of Single Intrauterine Fetal Death During Monochorionic Diamniotic Pregnancy: A Prospective Case-Control Study.

Introduction: Single intrauterine fetal death (sIUFD) in monochorionic diamniotic (MCDA) twin pregnancy may be associated with adverse clinical outcomes and possible metabolic changes in the surviving co-twin. Metabolomic profiling has not been undertaken before in these complex twin pregnancies. Methods: In this prospectively collected case-control study, three cross-cohort comparisons were made between sIUFD MCDA (n = 16), uncomplicated MCDA (n = 16, eight pairs), and uncomplicated singleton pregnancies (n = 8). To identify major sources of variation within the sIUFD MCDA cohort, a secondary comparison was conducted between spontaneous sIUFD (n = 8) and sIUFD in MCDA twins due to selective termination of a single abnormal fetus by radiofrequency ablation (RFA) (n = 8). Metabolomics analysis of placental tissue and umbilical cord plasma was performed using LC-MS profiling. The underlying metabolic networks and pathways were analyzed by web-based platforms. Associations and statistical correlations of all identified differential metabolites with neonatal birthweight and birth length were assessed by multivariable linear regression, adjusted for maternal age and gestation. Results: Across four comparisons, 131 and 111 differential metabolites were identified in placental tissue and cord plasma, respectively, with the highest variation seen between the spontaneous vs. single-induced IUFD in MCDA twins by RFA in the cord plasma. Conversely, the number of viable fetuses and the presence of sIUFD in MCDA twins had the highest impact on metabolite variation in placental tissue. Compounds correlated with fetal growth including placental acylcarnitines and gangliosides, along with specific amino acids (e.g., histidinyl-hydroxyproline), xenobiotics and biliverdin in cord plasma. Conclusion: sIUFD in MCDA twin pregnancy correlates with distinctive metabolic signatures, mostly in fatty acyls and complex lipids, in placental tissue and cord plasma of the surviving cotwin. Some metabolites are also associated with fetal growth.

Iatrogenic chorioamniotic separation and septostomy following fetoscopic laser photocoagulation for twin-twin transfusion syndrome.

To compare the perinatal outcomes of pregnancies complicated by chorioamniotic separation (CAS) vs septostomy following fetoscopic laser photocoagulation (FLP) for twin-twin transfusion syndrome (TTTS). This was a retrospective cohort analysis of monochorionic diamniotic twin pregnancies with TTTS that underwent FLP at one of two university-affiliated tertiary medical centers between January 2012 and December 2020. CAS and septostomy were diagnosed either during the procedure or by ultrasonography within 24-48 h after FLP. Data on procedure and postprocedure parameters, pregnancy outcomes and survival were collected from the patients' electronic medical records. Pregnancies were stratified according to the presence of CAS, septostomy or neither. Patients diagnosed with both CAS and septostomy were analyzed separately. Of the 522 women included in the cohort, 38 (7.3%) were diagnosed with CAS, 68 (13.0%) with septostomy and 23 (4.4%) with both CAS and septostomy. The remaining 393 (75.3%) women comprised the control group. Groups did not differ in demographic characteristics. The septostomy group had a lower rate of selective fetal growth restriction than did the CAS and control groups (24.2% vs 36.8% vs 42.7%, respectively; P = 0.017). Moreover, intertwin size discordance was lower in the septostomy group (15.1% vs 23.4% in the CAS group and 25.5% in the control group; P = 0.001). Median gestational age at FLP was significantly lower in the CAS group (19.3 weeks vs 20.4 weeks in controls and 20.9 weeks in the septostomy group; P = 0.049). The rate of delivery prior to 34 weeks was significantly higher in the CAS group (89.2%), followed by the septostomy group (80.9%), compared with the control group (69.0%) (P = 0.006). A secondary analysis demonstrated that patients with both CAS and septostomy presented the highest rates of delivery prior to 34 weeks (100%) and 32 weeks (68.2%). CAS and septostomy following laser surgery for TTTS are independently associated with higher rates of preterm delivery. The presence of these two findings in the same patient enhances the risk of prematurity. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

How to Better Distinguish between Type II and III Selective Fetal Growth Restriction in Monochorionic Twin Pregnancies?

Objectives: The objective of this study is to determine additional variables, next to umbilical artery (UA) Doppler, to help differentiate between Type II and III selective fetal growth restriction (sFGR). Methods: Retrospective analysis categorizing monochorionic diamniotic twin pregnancies with sFGR and abnormal UA Doppler as either Type II or III sFGR based on the diameter of the artery-to-artery (AA) anastomosis of ≤2 or >2 mm, respectively on placental examination after birth. This exploratory study compared maternal characteristics, pregnancy outcome, placental characteristics, and ultrasound features between the two groups. Results: We included 40 sFGR placentas, 13 were classified as Type II and 27 as Type III. Maternal age was higher in Type II. Small Type II twins had lower birth weights (BWs) for gestational age and BW discordance was higher in Type II. Type III placentas were more unevenly divided, but Type III pairs differed less in BW than expected relative to their placental discordance. Type III placentas more commonly had a vein-to-vein anastomosis and larger artery-to-vein anastomoses than Type II placentas, and proximate cord insertions were only observed in Type III. On the ultrasound scan at first diagnosis, small Type II twins were more growth-restricted. An AA anastomosis was detected in half of the Type III cases and in none of the Type II group. Signs of high-output cardiac strain were observed only in large Type III twins. In contrast, placental dichotomy was detected in nearly half of the Type II cases and only one Type III case. Conclusions: The presence of an AA anastomosis, signs of cardiac strain in the large twin, and proximate cord insertions suggested Type III sFGR, whereas placental dichotomy and a severe growth restriction were typically present in Type II. Prospective studies need to validate if these markers help prenatal differentiation between Type II and III sFGR.

New ultrasonographic midtrimester scoring method for predicting spontaneous preterm birth in uncomplicated asymptomatic twin pregnancies.

The aim of the present study was to evaluate a new ultrasonographic scoring method that could predict spontaneous preterm birth (sPTB) in uncomplicated twin pregnancies during routine anomaly screening in the midtrimester. This prospective study included women with a monochorionic diamniotic (MCDA) or dichorionic diamniotic (DCDA) twin pregnancy gestational ages from 170/7 through 226/7. A new ultrasonographic score between 0 and 5 points was calculated using cervical length (CL), uterocervical angle (UCA), and cervical dilatation status during routine anomaly screening in the midtrimester. The primary outcome of the study was the prediction of sPTB < 32 and <34 gestational weeks. A total of 118 pregnant women with twins were evaluated, 31 of whom delivered before 34 gestational weeks an 87 of whom delivered after 34 gestational weeks. The sensitivity and specificity values were separately calculated for scores of 3.5 and 2.5 for predicting sPTB < 32 gestational weeks. The cut-off value of 3.5 provided a sensitivity of 80% and a specificity of 82%. When the score was 2.5, the sensitivity and specificity were 86 and 71%, respectively. To determine a score for predicting sPTB < 34 gestational week cut-off value of 3.5 provided a sensitivity of 80% and a specificity of 90%. When the score value was 2.5, the sensitivity and specificity of the method were 83 and 81%, respectively. Our results indicated that the midtrimester new scoring is a simple technique that can be easily used as an improved tool for predicting the risk of sPTB in women with a twin pregnancy.

The association between vein-to-vein anastomoses and birth weight discordance in relation to placental sharing in monochorionic twin placentas.

This study aims to examine the association between the presence and size of a vein-to-vein (VV) anastomosis and birth weight discordance relative to placental discordance in monochorionic diamniotic twin pregnancies. Placentas of two previous prospective studies were included in this retrospective analysis. After injection with color dye, we measured the placental surface of each twin and VV, artery-to-artery (AA), and artery-to-vein (AV) anastomoses on a digital photograph. We calculated the birth weight ratio (BWR), placental ratio (PR), and birth weight ratio/placenta ratio (BWR/PR), as well as total AV size and net AV transfusion. Placental characteristics were compared between placentas with and without VV anastomoses. We performed univariate analyses to assess the following predictors for BWR/PR: VV size, AA size, total AV size, and net AV transfusion. Multivariate analysis was then performed, including the variables significant in univariate analysis. We analyzed 247 placentas: 58 (23%) with VV anastomoses and 189 without (77%). The BWR and PR were higher in the group with VV. In contrast, BWR/PR was lower in the group with VV anastomoses than in those without. The size of AA anastomoses was larger in placentas with VV anastomoses than in those without. In univariate analysis, VV size and AA size were significantly associated with BWR/PR. However, in multivariate regression, only VV size remained significantly associated with the BWR/PR. VV anastomoses are associated with a decreased birth weight discordance relative to the placental sharing discordance, independent of the AA anastomoses.

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.

Twin-to-twin transfusion syndrome and coronavirus disease 2019: impact on diagnosis, referral, eligibility for fetoscopic laser therapy, and outcomes

BACKGROUNDBecause of the progressive nature of twin-to-twin transfusion syndrome, difficulties in healthcare access during the COVID-19 pandemic may lead to delayed diagnosis and referral to fetal surgery centers, which may have repercussions on outcomes.OBJECTIVEThis study aimed to assess the clinical impact of the COVID-19 pandemic on pregnancies complicated with twin-to-twin transfusion syndrome.STUDY DESIGNA retrospective cohort study of consecutive monochorionic diamniotic twin pregnancies complicated with twin-to-twin transfusion syndrome evaluated in our national referral fetal surgery center at Queretaro, Mexico, for possible surgical fetoscopy was conducted. Maternal-fetal characteristics and perinatal outcomes of cases evaluated during the first year of the World Health Organization's COVID-19 pandemic declaration (March 11, 2020 to March 10, 2021) were retrospectively compared with outcomes of cases evaluated during the same period in the previous year (March 11, 2019 to March 10, 2020).RESULTSOverall, 109 consecutive twin-to-twin transfusion syndrome cases were evaluated during the 2-year study period, 54 during the COVID-19 pandemic and 55 in the previous year. In the former group, a higher proportion of cases with fetal surveillance interval longer than 2 weeks (70.4% vs 47.3%; P=.01); twin-to-twin transfusion syndrome complications precluding laser therapy, such as intrauterine fetal demise, preterm rupture of membranes, or cervical dilatation with prolapsed amniotic membranes (18.5% vs 1.8%; P<.01); advanced twin-to-twin transfusion syndrome (53.7% vs 36.4%; P=.07); preoperative short cervix (25.9% vs 10.9%; P<.05); and lower overall perinatal survival (56.9% vs 80.0% [P=.01; at least 1 twin] and 39.2% vs 56.4% [P=.08; both twins], respectively) were observed. A significantly lower number of cases were selected for fetoscopic laser therapy during the pandemic (75.9% vs 92.7%; P=.01), with similar postoperative outcomes seen in both study periods.CONCLUSIONIn pregnancies with twin-to-twin transfusion syndrome, the COVID-19 pandemic has shown an adverse impact involving suboptimal fetal surveillance, advanced stages at diagnosis, poorer survival rates, and higher number of complications that preclude fetoscopic laser therapy.

Proximate umbilical cord insertion in a monochorionic diamniotic twin pregnancy with spontaneous septostomy：Two case reports and a review of literature

Proximate umbilical cord insertion in a monochorionic diamniotic twin pregnancy with spontaneous septostomy：Two case reports and a review of literature

Perinatal Outcomes of Using Ursodeoxycholic Acid to Treat Monochorionic and Dichorionic Twin Pregnancy Complicated by Intrahepatic Cholestasis of Pregnancy

To study the effect of using ursodeoxycholic acid (UDCA) to treat monochorionic and dichorionic twin pregnancies complicated by intrahepatic cholestasis of pregnancy (ICP) and to examine the differences in perinatal outcomes. A total of 406 twin-carrying pregnant women who had ICP and received care at West China Second Hospital, Sichuan University between January 1, 2015 and November 1, 2018 were included in the study. The clinical data of monochorionic diamniotic (MCDA) and dichorionic diamniotic (DCDA) twins with ICP were analyzed. Analysis was done to compare the treatment effect for lowering serum total bile acid (TBA) and the perinatal outcomes with simple UDCA medication or combination medication. There were no statistically significant differences in TBA levels, early-onset ICP, simple UDCA medication or combination medication, neonatal Apgar score, birth weight, length of hospital stay, C-section rate, and perinatal mortality between the MCDA and the DCDA twin groups with ICP. However, maternal age, BMI, scarred uterus, in vitro fertilization-embryo transfer, preeclampsia, twin comorbidity rate of the two groups showed statistical differences. Further comparison between twin pregnancies with mildly-elevated TBA and those with severely-elevated TBA showed significant difference in preterm birth rate ( P<0.05). Simple UDCA medication or combination medication may have the same therapeutic effect on MCDA and DCDA twin pregnancies with ICP. Monochorionic twin pregnancy, twin comorbidities and pregnancy complications were still important factors affecting pregnancy outcomes of twin pregnancies with ICP. Twin pregnancies with slightly elevated TBA have been managed as severe ICP, which may be associated with increased iatrogenic preterm births.

Patient-Reported Monochorionic-Diamniotic Twin Pregnancy Management and Experiences During the COVID-19 Pandemic: A Mixed-Methods Cross-Sectional Survey.

Monochorionic-diamniotic (MCDA) pregnancies are high-risk necessitating ongoing screening for serious complications and quick decision-making. COVID-19 pandemic protocols introduced unique challenges to pregnancy management and patient experience. In late 2021, an online, mixed-methods, cross-sectional survey recruited 561 participants who experienced an MCDA pregnancy within five years. Analyses included descriptive and bivariate statistics and thematic analysis. Findings suggest the pandemic did not negatively affect screening/diagnosis for these participants. Care consistent with guidelines was received by most, with care slightly better during the pandemic. Almost 80% (79.0%) received an MCDA diagnosis by gestational week 14 before the pandemic, 87.8% during. Most received biweekly ultrasounds, 88.0% prior to the pandemic, 88.9% during. Experiences were affected in other ways for almost 44% of participants pregnant during COVID-19; in ways likely shared by other high-risk pregnancies. Thematic analysis revealed management during COVID-19 impacted self-advocacy and emotions (eg, alienation, anxiety), made care seem impersonal, and resulted in delayed or canceled appointments. Policies should be considered, so future healthcare disruptions do not impact patients and preserve in-person health care with access to a support person.