Single Fetal Demise Research Articles

Perinatal outcomes of single fetal survivor after fetal intervention for complicated monochorionic twins.

To compare perinatal outcomes between acute single fetal demise following fetoscopic laser photocoagulation to planned selective reduction (SR) in complicated monochorionic twin pregnancies. This was a secondary analysis of prospectively collected data in complicated monochorionic twin pregnancies from 2 fetal centers from 2011 to 2016. Group 1 included women undergoing fetoscopic laser photocoagulation for twin-twin transfusion syndrome (TTTS) who experienced a single fetal demise within 24hours of the procedure. Group 2 consisted of women undergoing planned selective reduction (SR) with TTTS, and Group 3 SR for indications other than TTTS. Survival of the remaining co-twin at birth was highest in Group 1 (n=77 patients; 95%) compared with that in Group 2 (n=15; 80%) and Group 3 (n=32; 78%; P=.047). The preterm premature rupture of membrane rate was higher in Group 1 (47%) compared with that in Group 2 (33%) and Group 3 (7%; P<.001). Group 1 had a lower gestational age at delivery and shorter procedure-to-delivery interval compared with the other 2 groups (P<.01). When single fetal demise occurs following fetoscopic laser photocoagulation, the surviving co-twin is more likely to survive to delivery but has higher PPROM rates and a shorter latency period compared with planned selective reduction for TTTS or other indications.

Intrauterine Single Fetal Demise in Twin Pregnancy

Intrauterine demise of one of the twin fetuses during second or third trimester of pregnancy is an uncommon complication. Fetal death of a twin during the first trimester is not an uncommon event and does not appear to impair the development of the second twin. However, fetal death during second or third trimester may increase the risk of IUGR, microcephaly, cerebral encephalomalacia, pre eclampsia, preterm labour, perinatal mortality. We present two cases with single fetal demise. Death of one of the two fetuses occurred at 23 weeks of gestation in the first case and at 33 weeks in the second case. Both patients were managed conservatively with close fetal monitoring and serial assessment of mother’s clotting profile. Cesarean section was done especially due to patients’ interest at 34 weeks and 35 weeks respectively. A fetus papyraceous was found in the first case. Both the cases were dichorionic diamniotic pregnancies with no maternal and fetal complications during pregnancy or the post partum period.Delta Med Col J. Jan 2018 6(1): 53-57

Large Subchorionic Hematoma: Breus' Mole

A case of large subchorionic hematoma complicated by intrauterine growth retardation and oligohydramnios diagnosed at 32 weeks' gestation with twin pregnancy after ICSI is reported below. The patient was on clexane injection during pregnancy for mitral valve replacement. She was managed with tocolysis using progesterone therapy and antibiotic with followup until delivery. At 34 weeks, a male baby weighing was delivered without complication by caesarean section because of single fetal demise of twin pregnancy.

OP26.05: Differences in prognostic factors of single fetal demise after laser therapy for Twin–twin transfusion syndrome between early and late fetal demise

Single fetal demise (SD) occurs after laser therapy in 15–20% of twin pregnancies, with approximately 60% of cases occurring within a week after laser therapy. However, in some cases, SD occurs later than 14 days after laser therapy. The objective of this study was to elucidate whether the prognostic factors of SD after laser therapy for Twin–twin transfusion syndrome (TTTS) differ depending on the period of SD. We conducted a retrospective study on patients with monochorionic diamniotic (MCDA) twin pregnancies diagnosed with TTTS and treated with laser therapy at a single tertiary centre between 2007 and 2015. SD occurring within 14 days after laser therapy was defined as early SD (E-SD), and SD occurring later than 14 days after laser therapy as late SD (L-SD). In study 1, we defined the group of both twins alive on postoperative day 14 as the control group for E-SD. In study 2, we defined the group of both twins alive at 28 days old after birth as the control group for L-SD. We evaluated the prognostic factors associated with E-SD and L-SD after laser therapy separately, dividing the twins into donors and recipients. Between 2007 and 2015, 145 pregnancies were diagnosed with TTTS and treated with laser therapy. SD occurred in 34 cases (24.1%), involving 26 donors (18.4%) and 8 recipients (5.7%). E-SD and L-SD occurred in 25 (73.5%) and 9 pregnancies (26.5%), respectively. Multivariable logistic regression analysis revealed that the independent risk factors of donor E-SD were the presence of arterioarterial anastomoses (odds ratio [OR], 11.1; 95% confidence interval [CI], 2.7–45.9); p = 0.001) and marginal cord insertion (OR, 4.7; 95% CI, 1.3–17.5); p = 0.022), and that of donor L-SD was postoperative umbilical artery reversed-end diastolic velocity in the donor (OR, 120; 95% CI, 3.9–3687; p = 0.006). We found that the prognostic factors of SD after laser therapy for TTTS differed depending on the period of SD in the donor.

The prognosis of Monochorionic co-twin after single intrauterine fetal demise

Objective: To analyze the prognosis of surviving monochorionic co-twin after single intrauterine fetal demise (sIUFD). Methods: Retrospectively analyzed the twin pregnancy cases admitted in Peking University Third Hospital between Jan 2008 and Feb 2015. We recorded perinatal characteristics, neuroimage in co-twin, and followed up the neonatal outcome. Results: 47 cases were found, including 45 cases of monochorionic diamniotic (MCDA) and 2 cases of monochorionic monoamniotic (MCMA). Median gestational age at sIUFD was 27 weeks.Median interval between sIUFD and birth was 3.3 weeks.Median gestational age at birth was 34.2 weeks.The causes of sIUFD were: MCMA (2/47, 4.3%), sIUGR (11/47, 23.4%), twin-twin transfusion syndrome (TTTS) (16/47, 34.0%) or TTTS complicated with sIUGR (3/47, 6.4%). In the sIUGR pregnancies, sIUFD occurred all in the growth-restricted fetus.In the TTTS pregnancies, sIUFD always occurred in donors (15/16, 93.8%). There were 41 (87.2%) live-born co-twins.Among the live births, fetal cranial ultrasound showed that 7 neonatus got intraventricular hemorrhage.There were 6 neonatus dead in first 28 days.All of the 35 survivors whose follow up from 12 to 70 months, responses were all received and nobody had cerebral palsy. Conclusion: sIUFD always occurred in the growth-restricted fetus and the donor-twins. There was nobody had cerebral palsy in the survivors.

OC09.05: Fetal brain injury in co‐twin survivors after single fetal demise in monochorionic twin pregnancies: a large series at a single centre

OC09.05: Fetal brain injury in co‐twin survivors after single fetal demise in monochorionic twin pregnancies: a large series at a single centre

Fetal Brain Injury in Survivors of Twin Pregnancies Complicated by Demise of One Twin: A Review.

Perinatal mortality is increased considerably in multiple pregnancies compared to singleton pregnancies, with single intrauterine fetal demise (sIUFD) presenting a rare but unique perinatal problem. Monochorionic pregnancies are at particular risk of sIUFD due to bidirectional inter-twin placental vascular anastomoses. The resulting inter-twin blood flow can become unbalanced, causing acute and chronic inter-twin transfusion and profound anemia secondary to fetal exsanguination into the low-pressure circulation of the dead fetus. If the sIUFD occurs after 14 weeks' gestation it is believed to have the most significant effect on the continuing pregnancy as the co-twin is at increased risk of preterm delivery, long-term neurological complications, and death. This article will focus on fetal brain injury in the surviving co-twin in the case of sIUFD, as it is the most common kind of injury in sIUFD, and one which concerns parents and may be the basis for terminating the pregnancy. We will outline how these brain injuries are thought to occur and describe potential pathophysiological mechanisms. We will discuss risk factors for brain injury in cases of sIUFD, including: chorionicity, cause of the sIUFD (spontaneous or secondary to an underlying pathological process such as twin-to-twin transfusion syndrome), gestation of delivery and how to prevent brain injury in the co-twin. We also review modes of imaging, discuss the difficulties in predicting the long-term outcome for co-twin survivors, and highlight the dearth of research in this area.

North American Fetal Therapy Network: intervention vs expectant management for stage I twin-twin transfusion syndrome

Stage I twin-twin transfusion syndrome presents amanagement dilemma. Intervention may lead to procedure-related complications while expectant management risks deterioration. Insufficient data exist to inform decision-making. The aim of this retrospective observational study was to describe the natural history of stage I twin-twin transfusion syndrome, to assess for predictors of disease behavior, and to compare pregnancy outcomes after intervention at stage I vs expectant management. Ten North American Fetal Therapy Network centers submitted well-documented cases of stage I twin-twin transfusion syndrome for analysis. Cases were retrospectively divided into 3 management strategies: those managed expectantly, those who underwent amnioreduction at stage I, and those who underwent laser therapy at stage I. Outcomes were categorized as no survivors, 1 survivor, 2 survivors, or at least 1 survivor to live birth, and good (twin live birth ≥30.0 weeks), mixed (single fetal demise or delivery between 26.0-29.9 weeks), and poor (double fetal demise or delivery <26.0 weeks) pregnancy outcomes. Outcomes were analyzed by initial management strategy. A total of 124 cases of stage I twin-twin transfusion syndrome were studied. In all, 49 (40%) cases were managed expectantly while 30 (24%) underwent amnioreduction and 45 (36%) underwent laser therapy at stage I. The overall fetal mortality rate was 20.2% (50 of 248 fetuses). Of those managed expectantly, 11 patients regressed (22%), 4 remained stage I (8%), 29 advanced in stage (60%), and 5 experienced spontaneous previable preterm birth (10%) during observation. The mean number of days from diagnosis of stage I to a change in status (progression, regression, loss, or delivery) was 11.1 (SD 14.3) days. Intervention by amniocentesis or laser therapy was associated with a lower risk of fetal loss (P= .01) than expectant management. The unadjusted odds of poor outcome were 0.33 (95% confidence interval, 0.09-01.20), for amnioreduction and 0.26 (95% confidence interval, 0.09-0.77) for laser therapy vs expectant management. Adjusting for nulliparity, recipient maximum vertical pocket, gestational age at diagnosis, and placenta location had negligible effect. Both amnioreduction and laser therapy at stage I decreased the likelihood of no survivors (odds ratio, 0.11; 95% confidence interval, 0.02-0.68 and odds ratio, 0.07; 95% confidence interval, 0.01-0.37, respectively). Only laser therapy, however, was protective against poor outcome in our data (odds ratio, 0.29; 95% confidence interval, 0.07-1.30 for amnioreduction vs odds ratio, 0.12, 95% confidence interval, 0.03-0.44 for laser), although the estimate for amnioreduction suggests a protective effect. Stage I twin-twin transfusion syndrome was associated with substantial fetal mortality. Spontaneous resolution was observed, although the majority of expectantly managed cases progressed. Progression was associated with a worse prognosis. Both amnioreduction andlaser therapy decreased the chance of no survivors, and laser was particularly protective against poor outcome independent of multiple factors. Further studies are justified to corroborate these findings and to further define risk stratification and surveillance strategies for stage I disease.

Prediction of single fetal demise after laser therapy for twin-twin transfusion syndrome.

Single fetal demise (SFD) occurs in up to 20% of monochorionic pregnancies treated with laser coagulation for twin-twin transfusion syndrome (TTTS). We aimed to determine the independent factors associated with SFD to improve outcome in the care of TTTS pregnancies in the future. This was a case-control study on twin pregnancies treated for TTTS between 2007 and 2013. Data on ultrasound, laser surgery and outcome were retrieved from our monochorionic twin database. We analyzed separately cases of SFD in donor and recipient twins, and compared them with treated pregnancies that resulted in two live births. Of the 273 TTTS pregnancies treated with laser coagulation, SFD occurred in 30 donors (11.0%) and 27 recipients (9.9%). In 67% of pregnancies with SFD, the death occurred within 1 week after laser treatment. For SFD in donors, absent/reversed end-diastolic flow in the umbilical artery was the strongest predictor (odds ratio (OR), 3.0 (95% CI, 1.1-8.0); P = 0.01), followed by the presence of an arterioarterial anastomosis (OR, 4.2 (95% CI, 1.4-13.1); P = 0.03) and discordance in estimated fetal weight (OR, 1.0 (95% CI, 1.0-1.1); P = 0.04). For SFD in recipients, independent predictors were absent/reversed A-wave in the ductus venosus (OR, 3.6 (95% CI, 1.2-10.5); P = 0.02) and the absence of recipient-to-donor arteriovenous anastomoses (OR, 10.6 (95% CI, 1.8-62.0); P < 0.01). Our findings confirm earlier reports that suggest that abnormal blood flow is associated with SFD after laser treatment for TTTS. The association of SFD with the type of anastomoses is a new finding. We speculate that the type of anastomoses present determines the degree of hemodynamic change during laser therapy. Future strategies should aim at stabilizing fetal circulation before laser therapy to decrease the vulnerability to acute preload and afterload changes. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

ISUOG Practice Guidelines: role of ultrasound in twin pregnancy.

ISUOG Practice Guidelines: role of ultrasound in twin pregnancy.

Single Fetal Demise at 10 - 14 Weeks of Monochorionic and Dichorionic Twin Pregnancy.

BackgroundWe examined the perinatal outcomes in cases of at least one fetal demise in monochorionic and diamniotic twin pregnancies.MethodsWe reviewed the obstetric records of all Japanese twin pregnancies managed beyond 9 weeks’ gestation at Japanese Red Cross Katsushika Maternity Hospital between 2008 and 2014.ResultsThe incidence in the monochorionic twin pregnancies was significantly higher than that in the dichorionic twin pregnancies (8.3% vs. 2.6%, odds ratio: 3.40, 95% confidence interval: 1.5 - 7.6, P < 0.01). Of these, 60.0% were diagnosed as fetal demise of both fetuses at the same time (vs. dichorionic twin pregnancy: odds ratio: 12.0, 95% confidence interval: 1.3 - 120, P = 0.04). The rate of “vanishing twin” in cases of at least one fetal demise at 10 - 14 weeks’ gestation in the monochorionic twin pregnancies was significantly lower than that in the diamniotic twin pregnancies (30.0% vs. 88.9%, odds ratio: 0.05, 95% confidence interval: 0.01 - 0.53, P = 0.01).ConclusionThe incidence of fetal demise and the influence on the co-twin in monochorionic twin pregnancy is greater than those in dichorionic twin pregnancy.

EP07.07: Frequency of discordancy in twins from Padre Hurtado Hospital

Significant discordancy in twins has to be defined, as it has been published 20 to 25%. The objective was to study the local incidence. Retrospective study of all twins from Padre Hurtado Hospital during an 8 year period of study, corresponding to 42,879 births. Fetal mortality > 24 weeks, birthweight discordancy and birthweight z-score was calculated. Fetal mortality in singletons was 5.1/1,000 and raised to 33/1,000 in all multiple pregnancies. From 198 dichorionic and 118 monochorionic twins correctly classified, fetal mortality > 24 weeks was 7.1 times (1.9–25.3) in the latter. Neonatal weight discordancy was 10.4 + −8% and 13.7 + −14% respectively. Birthweight z-score was −0.37 + 0.83 and −0.47 + −0.86, supporting that monochorionic twins have greater discordancy and lower weight than dichorionic twins. To study normal discordancy, only liveborn twins were considered: 15% of all twin pregnancies had > 20% weight discordancy and only 5% presented more than 25% of weight discordancy. Because the moment of single fetal demise is hard to determine and the alive twin may continue growing, the limit of acceptable discordancy is hard to define. Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Fetal brain injury in survivors of twin pregnancies complicated by demise of one twin as assessed by in utero MR imaging.

The aim of this study was to quantify the risk of brain abnormalities in single-twin demise of monochorionic pregnancies and to describe the type of brain injuries using ultrasound and in utero magnetic resonance (iuMR) imaging. Monochorionic twin pregnancies complicated by the demise of one twin referred between 2004 and 2013 were reviewed. Ultrasound was performed in a tertiary centre prior to iuMR. The cases were subdivided into those associated with co-twin loss following fetoscopic laser ablative treatment for twin-twin transfusion syndrome (TTTS) and those associated with spontaneous fetal demise. Sixty-eight cases were identified, 27/68 following treatment for TTTS and 41/68 with spontaneous fetal demise. Nine (13.2%) had brain abnormalities on iuMR, and the rate of brain abnormalities was similar in the two groups. Expert ultrasound and iuMR findings agreed in three out of nine of those cases, and in six out of nine cases, ultrasound underestimated or missed the pathology. Monochorionic twin pregnancies with single fetal demise are complex pregnancies with increased risk of acquired brain pathology, although the rate of brain abnormalities in our study is lower than that of other publications. iuMR in such complicated pregnancies is a useful adjuvant imaging technique that appears to detect brain pathologies better than prenatal ultrasonography.

Single fetal demise in monochorionic pregnancies: incidence and patterns of cerebral injury.

To evaluate the incidence, type and severity of cerebral injury in the surviving monochorionic (MC) cotwin after single fetal demise in twin pregnancies. All MC pregnancies with single fetal demise that were evaluated at the Leiden University Medical Center between 2002 and 2013 were included. Perinatal characteristics, neonatal outcome and the presence of cerebral injury, observed on neuroimaging, were recorded for all cotwin survivors. A total of 49 MC pregnancies with single fetal demise, including one MC triplet, were included in the study (n = 50 cotwins). Median gestational age at occurrence of single fetal demise was 25 weeks and median interval between single fetal demise and live birth was 61 days, with a median gestational age at birth of 36 weeks. Severe cerebral injury was diagnosed in 13 (26%) of the 50 cotwins and was detected antenatally in 4/50 (8%) and postnatally in 9/50 (18%) cases. Cerebral injury was mostly due to hypoxic-ischemic injury resulting in cystic periventricular leukomalacia, middle cerebral artery infarction or injury to basal ganglia, thalamus and/or cortex. Risk factors associated with severe cerebral injury were advanced gestational age at the occurrence of single fetal demise (odds ratio (OR), 1.14 (95% CI, 1.01-1.29) for each week of gestation; P = 0.03), twin-twin transfusion syndrome developing prior to single fetal demise (OR, 5.0 (95% CI, 1.30-19.13); P = 0.02) and a lower gestational age at birth (OR, 0.83 (95% CI, 0.69-0.99) for each week of gestation; P = 0.04). Single fetal demise in MC pregnancies is associated with severe cerebral injury occurring in 1 in 4 surviving cotwins. Routine antenatal and postnatal neuroimaging, followed by standardized long-term follow-up, is mandatory.

Mono Fetal Demise in Twin Gestation and Outcome

ABSTRACT We present two cases of dichorionic diamniotic (DCDA) twin and one monochorionic diamniotic (MCDA) twin during their third trimester with single intrauterine fetal demise (IUFD) and their outcomes. These cases were not found to be associated with any of the high-risk factor for fetal demise in twin like abruption placenta, velamentous insertion of cord or cord entanglement.1 Between the DCDA twins, one case developed coagulation disorder, the other case developed acute fatty liver of pregnancy after 2 weeks of diagnosing IUFD and emergency termination was done. Whereas the MCDA twin showed, hypoxic ischemic encephalopathy (HIE) changes in fetal magnetic resonance imaging (MRI) and emergency termination of pregnancy was done. How to cite this article Sinduja TP, Sadique N, Pavithra. Mono Fetal Demise in Twin Gestation and Outcome. J South Asian Feder Obst Gynae 2015;7(3):199-201.

OC26.04: Single intrauterine fetal demise after laser therapy for twin–twin transfusion syndrome: room for improvement?

Unexpected single intrauterine fetal death (sIUFD) occurs in up to 20% of monochorionic pregnancies treated with laser for twin-to-twin-transfusion syndrome (TTTS). We aimed to determine independent factors associated with sIUFD after laser for TTTS, to identify ways to improve outcome. Prospectively collected data on ultrasound, surgery, placental injection studies and outcome were used to find associations between candidate factors (including number and type of anastomes, preoperative Doppler, ultrasound and echocardiographic findings) and sIUFD before the onset of labour. Twins after laser with two live-births were used as controls. Out of 279 treated twin pregnancies, sIUFD occurred in 30 donors (10.8%) and 27 recipients (9.8%). In 67.7%, sIUFD occurred within a week after laser. In sIUFD of donors, the presence of arterio-arterial (AA) anastomoses was the strongest independent factor (OR 4.65 (1.63-13.25)), followed by absent/reversed end diastolic flow in the umbilical artery (AREDF UA) (OR 3.60 (1.29-10.05)) and estimated fetal weight (EFW) discordance (OR 1.04 (1.00-1.09)). In sIUFD of recipients, only AREDF UA was an independent factor (OR 4.08 (1.18-14.15)). Although AA anastomoses are thought to equalize blood flow between both fetuses and protecting against TTTS, we found that the presence of AA anastomoses were strongly associated with sIUFD of the donor. Our findings confirm earlier reports suggesting that abnormal umbilical flow and EFW discordance is associated with sIUFD. We hypothesize that acute hemodynamic changes during and shortly after laser surgery are more profound in the presence of AA anastomoses, possibly causing sIUFD in some cases. Future strategies should aim to stabilize the fetal circulation before or during laser to decrease the vulnerability for acute pre- and afterload changes.

Single-twin demise: Pregnancy outcome

Single-twin demise can pose substantial risks for the surviving co-twin, including increased risk of fetal loss, preterm delivery, neurovascular injury, and end-organ damage. In this chapter, we summarise recently published research on the causes of single twin demise, the pathophysiology of injury to the surviving co-twin, and the evidence for current management strategies. The gestation at which single intrauterine fetal demise occurs, and the chorionicity of the multiple pregnancies, are the two most important factors when considering the risks to the surviving twin. Management should include fortnightly ultrasound scans for growth, umbilical artery Doppler studies, and liquor volume. In monochorionic twins, more complex Doppler assessment with middle cerebral artery Doppler velocimetry and a magnetic resonance imaging of the survivor's brain at least 3 weeks after single intrauterine fetal demise occurs should be carried out to look for evidence of neurological morbidity. With no other obstetric complications, dichorionic pregnancies can be delivered at term. Monochorionic pregnancies are more difficult to manage, and are often delivered between 34 and 36 weeks.

Perinatal complications of monochorionic diamniotic twin gestations with discordant crown–rump length determined at mid‐first trimester

The aim of this study was to investigate the value of discordance of crown-rump length (DCRL) at mid-first trimester to predict adverse outcomes in monochorionic diamniotic twin gestations (MD). This was a retrospective cohort study of the perinatal outcome in MD pregnancies managed from the first trimester onward. DCRL was evaluated between 8 and 10 weeks of gestation. The association between DCRL and perinatal complications, including fetal death, twin-twin transfusion syndrome, severe discordant birthweight (DB), and twin anemia-polycythemia sequence, was assessed. Among 126 cases, a single fetal demise occurred in two (2%) and demise of both fetuses occurred in eight (6%). Five pregnancies (4%) were complicated with twin-twin transfusion syndrome; one case (1%) was twin anemia-polycythemia sequence and 13 (10%) were DB. Neonatal death occurred in one pair. At 28 days of age, in 115 cases (91%) both twins were alive. In 117 cases (93%), at least one twin survived until 28 days of age. DCRL >12.0% was not related to any perinatal complications but DB (P < 0.01; relative risk: 1.40; 95% confidence interval: 1.06-1.84). DCRL in MD during the mid-first trimester might be useful for predicting DB.

Embryonic growth discordance and early fetal loss: the STORK multiple pregnancy cohort and systematic review

Is there an association between discordance in embryonic growth and fetal loss at the time of the 11-14-week scan in twin pregnancies? Regardless of the chorionicity, crown rump length (CRL) discordance at 7(+0)-9(+6) weeks is predictive of subsequent single fetal demise in the first trimester. Previous small studies have reported a variable association between discordance in embryonic growth and subsequent fetal loss. Retrospective study of all twin pregnancies of known chorionicity from a large regional cohort over a 10-year period. A total of 1356 twin pregnancies (288 monochorionic and 1068 dichorionic) were included in the study. Women presenting to the early pregnancy unit were included in the study. Logistic regression, ROC curve and Kaplan-Meier analyses were performed to evaluate the association between CRL discordance at 7(+0)-9(+6) weeks and spontaneous single fetal loss diagnosed at the 11-14-week scan. A systematic review was also performed using MEDLINE, EMBASE, Cinahl and the Cochrane Library in order to explore the relationship between early growth discordance and single fetal loss in twin pregnancies. There were 111 (8.2%) single fetal losses diagnosed at 11-14 weeks in this cohort. At multivariate analysis, CRL discordance percentile [odds ratio (OR) 1.20; 95% confidence interval (CI), 1.12-1.63, P < 0.0001] and CRL <5th centile of at least one twin (OR, 2.21; 95% CI 1.23-4.24, P = 0.023), but not chorionicity (P = 0.486) or maternal age (P = 0.283) was independently associated with the loss of one fetus at the 11-14-week scan. The predictive accuracy of CRL discordance for single fetal loss was high (AUC = 0.93; 95% CI = 0.91-0.94). A significant association was found between the increase in the degree of embryonic discordance and the likelihood of early fetal loss (P < 0.0001). Only a high-risk population was analysed. Therefore, the patients studied were not a representative sample from the population of women pregnant with twins. Twin pregnancies, in particular those resulting from assisted conception, are scanned frequently, particularly during the early stages of pregnancy. The findings of this study are likely to prove important in counselling parents about the short-term outcome of the pregnancy when an embryonic discordance is present. No external funding was sought for this study. None of the authors has any conflicts of interest to declare.

Single fetal death in twin gestations

Twin pregnancies are at higher risk for fetal mortality when compared with singleton pregnancies. Single fetal demise occurs in 3.7 – 6.8 % of all twin pregnancies and considerably increases the complication rate in the co-twin including fetal loss, premature delivery, and end-organ damage. In this review, we summarize the current information on the etiology of single twin demise, the pathophysiology of injury to the surviving twin, and the preventive and secondary management strategies.