Monochorionic Diamniotic Pregnancies Research Articles

Twin reversed arterial perfusion sequence in monochorionic diamniotic pregnancy: A rare occurrence

Twin reversed arterial perfusion is a rare complication occurring in monochorionic multifetal pregnancies. This condition is characterized by a malformed fetus being perfused by a normal twin through an artery-to-artery anastomosis in the reverse direction. Herein, we report a case of a multigravida female with a twin pregnancy at 27 weeks 5 days of gestation referred in view of twin pregnancy with the intra-uterine demise of one twin. Gray scale and color Doppler imaging revealed a monochorionic diamniotic pregnancy with a viable, normal twin, and an amorphously developed acardiac twin. The patient was monitored with weekly ultrasonography, echocardiography, and Doppler ultrasound examination to ascertain the well-being of the pump twin. She delivered a normal live baby at term and an acardius acephalus fetus. The perinatal mortality of the pump twin is significantly high. Therefore, it is necessary to diagnose this entity at an early gestational age through improved imaging techniques, so that timely intervention can be planned.

Pregnancy outcomes of monochorionic diamniotic and dichorionic diamniotic twin pregnancies conceived by assisted reproductive technology and conceived naturally: a study based on chorionic comparison

ObjectiveTo evaluate monochorionic diamniotic (MCDA) and dichorionic diamniotic (DCDA) twin pregnancies conceived by assisted reproductive technology (ART) and conceived naturally.MethodsWe retrospectively analyzed the data on twin pregnancies conceived by ART from January 2015 to January 2022,and compared pregnancy outcomes of MCDA and DCDA twins conceived by ART with those of MCDA and DCDA twins conceived naturally, pregnancy outcomes between MCDA and DCDA twins conceived by ART, and pregnancy outcomes of DCT and TCT pregnancies reduced to DCDA pregnancies with those of DCDA pregnancies conceived naturally.ResultMCDA pregnancies conceived by ART accounted for 4.21% of the total pregnancies conceived by ART and 43.81% of the total MCDA pregnancies. DCDA pregnancies conceived by ART accounted for 95.79% of the total pregnancies conceived by ART and 93.26% of the total DCDA pregnancies. Women with MCDA pregnancies conceived by ART had a higher premature delivery rate, lower neonatal weights, a higher placenta previa rate, and a lower twin survival rate than those with MCDA pregnancies conceived naturally (all p < 0.05). Women with DCDA pregnancies conceived naturally had lower rates of preterm birth, higher neonatal weights, and higher twin survival rates than women with DCDA pregnancies conceived by ART and those with DCT and TCT pregnancies reduced to DCDA pregnancies (all p < 0.05).ConclusionOur study confirms that the pregnancy outcomes of MCDA pregnancies conceived by ART are worse than those of MCDA pregnancies conceived naturally. Similarly, the pregnancy outcomes of naturally-conceived DCDA pregnancies are better than those of DCDA pregnancies conceived by ART and DCT and TCT pregnancies reduced to DCDA pregnancies.

Maternal and fetal outcomes after planned cesarean or vaginal delivery in twin pregnancy: a comparison between 2 third level birth centers

Background Twin pregnancy is associated with higher risks of adverse perinatal outcomes for both the mother and the babies. Among the many challenges in the follow-up of twin pregnancies, the mode of delivery is the last but not the least decision to be made, with the main influencing factors being amnionicity and fetal presentation. The aim of the study was to compare perinatal outcomes in two European centers using different protocols for twin birth in case of non-cephalic second twin; the Italian patients being delivered mainly by cesarean section with those in Belgium being routinely offered the choice of vaginal delivery (VD). Methods This was a dual center international retrospective observational study. The population included 843 women with a twin pregnancy ≥ 32 weeks (dichorionic or monochorionic diamniotic pregnancies) and a known pregnancy outcome. The population was stratified according to chorionicity. Demographic and pregnancy data were reported per pregnancy, whereas neonatal outcomes were reported per fetus. We used multiple logistic regression models to adjust for possible confounding variables and to compute the adjusted odds ratio (adjOR) for each maternal or neonatal outcome. Results The observed rate of cesarean delivery was significantly higher in the Italian cohort: 85% for dichorionic pregnancies and 94.4% for the monochorionic vs 45.2% and 54.4% respectively in the Belgian center (p-value < 0.001). We found that Belgian cohort showed significantly higher rates of NICU admission, respiratory distress at birth and Apgar score of < 7 after 5 min. Despite these differences, the composite severe adverse outcome was similar between the two groups. Conclusion In this study, neither the presentation of the second twin nor the chorionicity affected maternal and severe neonatal outcomes, regardless of the mode of delivery in two tertiary care centers, but VD was associated to a poorer short-term neonatal outcome.

885 Outcomes in monochorionic diamniotic pregnancies with proximate placental cord insertions

885 Outcomes in monochorionic diamniotic pregnancies with proximate placental cord insertions

1150 Risk factors for preterm delivery in monochorionic diamniotic pregnancies undergoing selective cord occlusion

1150 Risk factors for preterm delivery in monochorionic diamniotic pregnancies undergoing selective cord occlusion

Genetic evaluation for twin pregnancies using karyotyping and single nucleotide polymorphism array analysis

The study aimed to assess chromosomal abnormalities in twin pregnancies using karyotyping and SNP array analysis. The research involved 530 twin pregnancies from two prenatal diagnosis centers between October 2012 and October 2022. Two types of twin pregnancies were considered: monochorionic diamniotic (MCDA) and dichorionic diamniotic (DCDA), with a total of 177 MCDA and 353 DCDA cases. Chromosomal abnormalities were examined based on chorionic and amniotic sac properties and clinical indications. Among 42 twin pregnancies, 50 fetuses showed chromosomal abnormalities by karyotyping, with 35 cases of aneuploidy in DCDA and 10 in MCDA. Trisomy 21 was the most common aberration, affecting 15 fetuses in DCDA and 4 in MCDA. The rate of discordant karyotypes in MCDA and DCDA groups was 1.1% and 8.8%, respectively. Ultrasound abnormalities and advanced maternal age were frequent indications (55.3% and 39.2%, respectively). Aneuploidy frequencies in DCDA and MCDA pregnancies with advanced maternal age were 10.6% and 4.5%. Cardiac defects and increased nuchal translucency were common anomalies, with higher incidences of chromosomal abnormalities in DCDA (12.5% and 6.9%) and MCDA groups (23.5% and 3.7%). SNP array identified 1.6% clinically significant copy number variants in DCDA fetuses with ultrasound abnormalities, while no significant CNVs were found in MCDA pregnancies. Chromosomal aneuploidies were the primary abnormalities in twin pregnancies, with detectable abnormalities and clinically significant CNVs more likely in DCDA pregnancies, especially those with ultrasound abnormalities.

Perinatal Outcomes of Monochorionic Twin Pregnancies Conceived Naturally Versus through Assisted Reproductive Techniques.

Objective: It has been reported that monochorionic twin pregnancies conceived through assisted reproductive techniques (ART) display a higher risk of second-trimester miscarriage, cesarean delivery, and neonatal death than those conceived naturally. The aim of this study was to compare the perinatal outcomes of monochorionic diamniotic (MCDA) twin pregnancies conceived naturally and through ART in a tertiary hospital. Methods: This was a retrospective cohort study of all MCDA twin pregnancies that received obstetric care and delivered at La Fe University and Polytechnic Hospital between 2015 and 2021. MCDA pregnancies that were referred to the tertiary hospital for specialized management, follow-up, and delivery were also included. The study was approved by The Health Research Institute Hospital La Fe (IIS La Fe). Results: Among the 184 MCDA pregnancies, 149 (81%) had a natural conception, and 35 (19%) were conceived through ART. Patients with an MCDA pregnancy who conceived through ART had a significantly older maternal age (38.0 [35.5-42.5] vs. 32.0 [29.0-36.0], p < 0.001) and an elevated rate of nulliparity (80.0% vs. 50.3%, p = 0.001). Regarding pregnancy complications, MCDA pregnancies through ART were associated with a significantly higher incidence of gestational diabetes (22.9% vs. 2.7%, p < 0.001), hypertensive disorders during pregnancy (22.9% vs. 9.4%, p = 0.04), and other pregnancy complications such as threatened labor or preterm prelabor rupture of membranes (14.3% vs. 36.2%, p = 0.015), than naturally conceived MCDA pregnancies. No differences were found in the incidence of twin-to-twin transfusion syndrome (20% vs. 33.6%, p = 0.155). MCDA pregnancies through natural conception had a greater rate of vaginal delivery than MCDA through ART (16.8% vs. 2.9%, p = 0.032). When adjusted for confounding factors, MCDA pregnancies through ART were only more likely to develop gestational diabetes than those naturally conceived (aOR 7.86, 95% CI 1.55-39.87). No differences were found regarding neonatal outcomes between groups. Conclusions: Compared with naturally conceived MCDA twin pregnancies, those conceived through ART displayed a significantly higher risk of developing gestational diabetes. No differences regarding other pregnancy complications, mode of delivery, or neonatal outcomes were found between groups.

Placental differences between uncomplicated and complicated monochorionic diamniotic pregnancies on diffusion and multicompartment Magnetic Resonance Imaging

IntroductionTwin-twin transfusion syndrome (TTTS) and selective fetal growth restriction (sFGR) are common complications in monochorionic diamniotic (MCDA) pregnancies. The Diffusion-rElaxation Combined Imaging for Detailed Placental Evaluation (DECIDE) model, a placental-specific model, separates the T2 values of the fetal and maternal blood from the background tissue and estimates the fetal blood oxygen saturation. This study investigates diffusion and relaxation differences in uncomplicated MCDA pregnancies and MCDA pregnancies complicated by TTTS and sFGR in mid-pregnancy. MethodsThis prospective monocentric cohort study included uncomplicated MCDA pregnancies and pregnancies complicated by TTTS and sFGR. We performed MRI with conventional diffusion-weighted imaging (DWI) and combined relaxometry – DWI-intravoxel incoherent motion. DECIDE analysis was used to quantify different parameters within the placenta related to the fetal, placental, and maternal compartments. ResultsWe included 99 pregnancies, of which 46 were uncomplicated, 12 were complicated by sFGR and 41 by TTTS. Conventional DWI did not find differences between or within cohorts. On DECIDE imaging, fetoplacental oxygen saturation was significantly lower in the smaller member of sFGR (p = 0.07) and in both members of TTTS (p = 0.01 and p = 0.004) compared to the uncomplicated pairs. Additionally, average T2 relaxation time was significantly lower in the smaller twin of the sFGR (p = 0.004) compared to the uncomplicated twins (p = 0.03). ConclusionMulticompartment functional MRI showed significant differences in several MRI parameters between the placenta of uncomplicated MCDA pregnancies and those complicated by sFGR and TTTS in mid-pregnancy.

Outcome following laser surgery of twin-twin transfusion syndrome complicated by selective fetal growth restriction: systematic review and meta-analysis.

The published literature reports mostly on the outcome of twin pregnancies complicated by twin-twin transfusion syndrome (TTTS) without considering whether the pregnancy is also complicated by another pathology, such as selective fetal growth restriction (sFGR). The aim of this systematic review was to report on the outcome of monochorionic diamniotic (MCDA) twin pregnancies undergoing laser surgery for TTTS that were complicated by sFGR and those not complicated by sFGR. MEDLINE, EMBASE and Cochrane databases were searched. The inclusion criteria were studies reporting on MCDA twin pregnancies with TTTS undergoing laser therapy that were complicated by sFGR and those not complicated by sFGR. The primary outcome was the overall fetal loss following laser surgery, defined as miscarriage and intrauterine death. The secondary outcomes included fetal loss within 24 h after laser surgery, survival at birth, preterm birth (PTB) prior to 32 weeks of gestation, PTB prior to 28 weeks, composite neonatal morbidity, neurological and respiratory morbidity, and survival free from neurological impairment. All outcomes were explored in the overall population of twin pregnancies complicated by sFGR vs those not complicated by sFGR in the setting of TTTS and in the donor and recipient twins separately. Random-effects meta-analysis was used to combine data and the results are reported as pooled odds ratios (OR) with 95% CI. Five studies (1710 MCDA twin pregnancies) were included in the qualitative synthesis and four in the meta-analysis. The overall risk of fetal loss after laser surgery was significantly higher in MCDA twin pregnancies with TTTS complicated by sFGR (20.90% vs 14.42%), with a pooled OR of 1.6 (95% CI, 1.3-1.9) (P < 0.001). The risk of fetal loss was significantly higher in MCDA twin pregnancies with TTTS and sFGR for the donor but not for the recipient twin. The rate of live twins was 79.1% (95% CI, 72.6-84.9%) in TTTS pregnancies with sFGR and 85.6% (95% CI, 81.0-89.6%) in those without sFGR (pooled OR, 0.6 (95% CI, 0.5-0.8)) (P < 0.001). There was no significant difference in the risk of PTB prior to 32 weeks of gestation (P = 0.308) or prior to 28 weeks (P = 0.310). Assessment of short- and long-term morbidity was affected by the small number of cases. There was no significant difference in the risk of composite (P = 0.506) or respiratory (P = 0.531) morbidity between twins complicated by TTTS with vs those without sFGR, while the risk of neurological morbidity was significantly higher in those with TTTS and sFGR (pooled OR, 1.8 (95% CI, 1.1-2.9)) (P = 0.034). The risk of neurological morbidity was significantly higher for the donor twin (pooled OR, 2.4 (95% CI, 1.1-5.2)) (P = 0.029) but not for the recipient twin (P = 0.361). Survival free from neurological impairment was observed in 70.8% (95% CI, 45.0-91.0%) of twin pregnancies with TTTS complicated by sFGR and in 75.8% (95% CI, 51.9-93.3%) of those not complicated by sFGR, with no difference between the two groups. sFGR in MCDA pregnancies with TTTS represents an additional risk factor for fetal loss following laser surgery. The findings of this meta-analysis may be useful for individualized risk assessment of twin pregnancy complicated by TTTS and tailored counseling of the parents prior to laser surgery. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Two Year Neurodevelopmental Outcome after Fetoscopic Laser Therapy for Twin-Twin Transfusion Syndrome: Comparison with Uncomplicated Monochorionic Diamniotic Twins.

Twin-twin Transfusion Syndrome (TTTS) represents a significant complication in monochorionic twin pregnancies, caused by an unbalanced shunting of blood through intertwin placental vascular anastomoses. Despite advances in fetoscopic laser surgery, TTTS is still associated with a high rate of cerebral injury. However, there are no studies comparing these pregnancies with uncomplicated monochorionic diamniotic (MCDA) twin pregnancies, establishing the baseline risk of neurodevelopmental impairment. The aim of this study is to evaluate the odds of neurodevelopmental impairment in MCDA twins who undergo fetoscopic laser surgery for twin-twin transfusion syndrome, in comparison to a cohort of uncomplicated MCDA twin pregnancies. This is a retrospective cohort study of children born from MCDA twin pregnancies at a single center between 2008 and 2019. A routine, standardized follow-up assessment was conducted at a minimum of 2 years after delivery. The primary outcome of this was a 2 year neurodevelopmental impairment. Neurological, motor, and cognitive development was assessed by using the revised Brunet-Lézine scale. 176 children met the enrolment criteria. Of these, 42 (24%; TTTS group) underwent fetoscopic laser surgery for TTTS during pregnancy, and 134 (76%; uncomplicated MCDA group) were uncomplicated MCDA pregnancies. The primary outcome was found in four children (9.52%) in the TTTS group and ten children (7.46%) in the uncomplicated MCDA group (p = 0.67, aOR 2.82, 95% CI 0.49-16.23). Major neurologic impairment was found in 2.38% after fetoscopic laser surgery and 1.49% in uncomplicated MCDA twins (p = 0.70, aOR 0.97, 95% CI 0.22-4.24). The data were adjusted by birth order, birth weight, and gestational age at birth. The outcome in MCDA twins who underwent fetoscopic laser surgery for TTTS is comparable to the outcome in uncomplicated MCDA twins. Our findings emphasize the need for long-term neurodevelopmental follow-ups in all children from monochorionic twin gestations.

Velamentous cord insertion in monochorionic twin pregnancies: a step forward in screening for twin to twin transfusion syndrome and birthweight discordance?

Two major complications of monochorionic diamniotic (MCDA) twin pregnancies are twin to twin transfusion syndrome (TTTS) and birthweight discordance. The current screening ultrasound test for these pathologies combines the detection of nuchal translucency discrepancy and abnormal ductus venosus in at least one twin, in the first trimester. We aim to determine whether combining the presence of velamentous cord insertion in at least one twin increases screening efficiency. This was a retrospective cohort with a sample of 136 MCDA twin pregnancies followed at Centro Hospitalar Universitário São João, during a 16-year period. The combination of abnormal ductus venosus in at least one twin and nuchal translucency discrepancy is associated with the development of TTTS with an OR of 10.455, but not with birthweight discordance. The combination of these first trimester markers with velamentous cord insertion is not associated with the development of either outcome. The presence of velamentous cord insertion in MCDA pregnancies is not associated to TTTS development. Therefore, the addition of this marker to the first trimester screening would not effectively predict the development of birthweight discordance or TTTS. However, a positive currently used screening test increases the risk of developing TTTS by about ten times.

Congenital heart defects in monochorionic twin pregnancy complicated by selective fetal growth restriction.

To evaluate the prevalence, subtypes and postnatal outcomes of congenital heart defects (CHD) in a cohort of monochorionic diamniotic (MCDA) twin pregnancies complicated by selective fetal growth restriction (sFGR), and to compare this population with a cohort of uncomplicated MCDA pregnancies evaluated during the same period. This was a retrospective analysis of all consecutive MCDA pregnancies referred between 2009 and 2018, including those complicated by sFGR (Group A) and those without complications (Group B). All neonates delivered in our center were screened for CHD before discharge. Discharge letters for all those delivered elsewhere were retrieved. Pregnancies with complications other than sFGR and those without perinatal follow-up were excluded. Pregnancies in Group A were divided into three types according to the Gratacós system of sFGR classification. A total of 870 MCDA twin pregnancies were included: 296 in Group A and 574 in Group B. In Group A, the prevalence of CHD was 3.7% (22/592 twins), with no significant difference in CHD frequency between the three types of sFGR (Type I, 3.7%; Type II, 3.2%; Type III, 4.2%; P = 0.55). Of four Type-III sFGR pregnancies with CHD, one had pulmonary stenosis (PS) in the larger twin and isolated coarctation of the aorta in the smaller cotwin, and three had PS in the larger twin only. No Type-III sFGR pregnancies in which only the smaller twin was affected by CHD were observed. Of 11 CHD cases in the larger twin, 10 (91%) were right ventricular outflow tract abnormalities (RVOTA), and one (9%) was a ventricular septal defect. In the smaller twins, 11 cases of CHD were observed, covering a broad spectrum of cardiac abnormalities. In Group B, the CHD prevalence was 1.1% (13/1148 twins), which was similar to that in the general population, according to the EUROCAT registry for the same period and geographical area of the study (0.96%; P = 0.579). The CHD prevalence was significantly higher in Group A compared with Group B (3.7% vs 1.1%; P = 0.0002; odds ratio, 3.57 (95% CI, 1.78-7.22)). In all pregnancies with CHD in the study population, the anomaly was discordant. In MCDA twin pregnancy, sFGR was associated with a three-fold higher prevalence of CHD. Women with such pregnancies should be referred to a tertiary care hospital for pre- and postnatal cardiac evaluation, treatment and long-term follow-up. In larger twins, the only major CHD observed was RVOTA, while a broad spectrum of CHD was noted in smaller twins. The higher risk of CHD in MCDA pregnancies appears to be due to the typical complications of the monochorionic pregnancy, rather than to the monochorionic nature of the pregnancy itself. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

First-trimester biomarkers and ultrasound biometries in relation to growth discordance in monochorionic diamniotic twins

Objective The aim of this study was to investigate the association and predictive value between intertwin discordance in first trimester biometries crown-rump length (CRL) and nuchal translucency (NT), and the first trimester biochemical markers PAPP-A and free β-hCG in relation to birth weight discordance (BWD) ≥25% in monochorionic diamniotic (MCDA) twin pregnancies. Methods First trimester screening information and pregnancy outcome data on MCDA twin pregnancies with delivery from July 2008 to July 2017 were retrieved from the Danish Fetal Medicine Database. CRL discordance was divided into: <10% (reference group) and ≥10%. NT discordance was divided into: <20% (reference group) and ≥20%. The twin pregnancies were classified according to BWD into the following groups: <10% (reference group), 10–24.9%, and ≥25% including cases undergoing umbilical cord occlusion due to selective fetal growth restriction (sFGR). The twin pregnancies with the most severe BWD (BWD ≥25%) were subdivided into three groups including cases with only one growth-restricted (<10th centile) infant defined as sFGR, and cases where both twins were <10th centile. Median multiples of the median (MoM) values of PAPP-A and free ß-hCG were compared with the group with BWD <10% using the Wilcoxon two-sample test. The ability of CRL discordance and NT discordance to predict BWD ≥25% was examined by the area under the receiver operator characteristic (ROC) curve. Results A total of 762 MCDA pregnancies were included. The proportion of pregnancies with CRL discordance ≥10% and NT discordance ≥20% was significantly higher in the group with severe BWD discordance (27.0% vs. 4.7% (p < 0.001) and 40.9% vs. 23.9% (p = 0.001), respectively). When examining the three subgroups of severe BWD, we found a significantly higher percentage of pregnancies with CRL discordance ≥10% in the group where umbilical cord occlusion was performed (52.6% vs. 4.7% in the group with BWD <10% (p < 0.001)) and in the group of BWD ≥25% with sFGR (21.7% vs. 4.7% (p < 0.001)). Additionally, a significantly higher percentage of pregnancies with NT discordance ≥20% was found in the group where umbilical cord occlusion was performed (52.6% vs. 23.9% (p = 0.005)) and in the group with both twins <10th centile (66.7% vs. 23.9% (p = 0.003)). No statistically significant differences were found when comparing levels of PAPP-A and free β-hCG MoMs with the group with BWD <10%. In ROC curves, CRL discordance yielded an AUC for prediction of BWD ≥25% of 0.70 (95% CI 0.63–0.76), and for NT discordance AUC was 0.59 (95% CI 0.52–0.66)). OR for any BWD ≥ 25% was 6.7 (95% CI 3.8–12.0) for pregnancies with a CRL discordance ≥10% compared to pregnancies with a CRL discordance <10%. Conclusions This study shows that a discordance in CRL and NT in MCDA twins are both significantly associated with development of BWD. The most important predictor remains CRL discordance ≥10%, thereby suggesting the unequal growth pattern in many cases with BWD is evident already in the first trimester of the pregnancy. No association was found between first trimester biochemical markers and severe BWD.

The incidence and timing of abnormal ultrasound findings in monochorionic-diamniotic twin pregnancies

Monochorionic-diamniotic (MCDA) twin pregnancies impart an increased risk of complications. Current guidelines recommend routine screening ultrasounds from 16 weeks gestation onward. We sought to investigate the incidence of abnormal ultrasound findings in this population and evaluate the timing at which abnormalities were most commonly noted. This was a retrospective study of MCDA pregnancies who delivered at a single academic medical center from June 2013-December 2021. The primary outcome was the frequency of abnormal ultrasound findings. The secondary outcomes included type of abnormal ultrasound finding and gestational age at which it was recognized. Anomalies were characterized into 5 categories: structural, amniotic fluid-related, growth, placental, or TTTS. 116 MCDA pregnancies were included in our sample. 51 patients (44%) had at least one abnormal ultrasound finding documented. However, some of these patients had multiple abnormal findings, for a total of 59 abnormal ultrasound findings in our sample. 73% of these findings (43/59) were noted during the second trimester (Figure 1). All 11 cases of TTTS in our sample were noted prior to 24 weeks gestation. Of the 16 abnormal ultrasound findings in the third trimester, 12 of these (75%) were growth discordance or fetal growth restriction. Of these patients, all delivered late preterm. More than half of patients with MCDA gestations in our sample had normal routine screening ultrasounds throughout pregnancy. After the second trimester, the risk of encountering new abnormalities substantially decreased. Most findings necessitating immediate intervention and counseling by a Maternal Fetal Medicine specialist, specifically TTTS and congenital anomalies, were noted prior to 28 weeks gestation. Of third trimester findings, most were growth related and resulted in late preterm delivery. Thus, it is reasonable for patients with MCDA pregnancies to resume care with their primary obstetrician for routine surveillance after 28 weeks gestation, particularly for those patients who live far from a subspecialist.

Amniotic fluid biomarkers of fetal stress response to cardiac dysfunction in twin-twin transfusion syndrome

Recipient twin (RT) cardiovascular changes in twin-twin transfusion syndrome (TTTS) are associated with increased mortality. This relationship is likely related to a cascade of pathophysiologic changes in the RT progressing to multisystem organ failure. We sought to evaluate biomarkers of inflammation, stress, and tissue injury within amniotic fluid (AF) of RTs undergoing selective fetoscopic laser photocoagulation (SFLP) for TTTS and examine their relationship with fetal echocardiographic findings. AF samples from RTs were obtained from 39 monochorionic-diamniotic pregnancies complicated by TTTS. Those without preoperative fetal echocardiograms or evidence of selective intrauterine growth restriction were excluded from analysis with 24 remaining samples. 15 commonly utilized clinical biomarkers for inflammation, stress, and tissue injury were assessed using a flow-cytometry based multiplex immunoassay. Fetal echocardiograms were performed prior to SFLP with myocardial performance index (MPI) utilized as a measure of cardiac dysfunction. Pearson’s correlation was used for data analysis. RT Left ventricular MPI (LV-MPI) ranged from 0.28-0.74, with 11/24 RTs demonstrating abnormal MPI for GA (Z-score > 2). RT AF cortisol (r = 0.4527, p = 0.020), IL-6 (r = 0.44, p = 0.025), CRP (r = 0.431, p = 0.028), and myoglobin (r = 0.401, p = 0.042) levels correlated with recipient left ventricular MPI (LV-MPI). AF cortisol strongly correlated with AF myoglobin (r = 0.576, p < 0.001). RT with abnormal LV-MPI exhibited significantly higher AF cortisol levels compared to those with normal LV-MPI (p = 0.029). RT amniotic fluid demonstrates markers of inflammation, stress and cardiac injury in recipient twins with cardiac dysfunction. These markers may be indicators of disease progression in TTTS secondary to cardiac dysfunction. The presence of these markers implicate stress and the immune response in the pathophysiologic response to cardiac dysfunction in TTTS.

The Role of Fetal Brain Magnetic Resonance Imaging in Current Fetal Medicine.

In open spina bifida we studied the use of MRI for the assessment of the posterior fossa and prevalence of supratentorial anomalies before and after in utero repair. New postprocessing techniques were applied to evaluate fetal brain development in this population compared to controls. In fetuses with congenital diaphragmatic hernia, we evaluated the brain development in comparison to controls. Diffusion weighted imaging was applied to study difference between fetuses with proven first trimester cytomegalovirus infection and controls. Finally, we investigated the value of third trimester fetal brain MRI after treatment for complicated monochorionic diamniotic pregnancies.

Monochorionic monoamniotic twin pregnancies.

Monochorionic monoamniotic (MCMA) twin pregnancy is rare and associated with increased complication rates when compared with singletons, dichorionic and monochorionic diamniotic pregnancy in general. Monoamnionicity presents an enormous challenge following its accurate diagnosis, where the absence of an inter-twin membrane subsequently results in cord entanglement and consistently fluctuating foetal position. Furthermore, the detection of twin-twin transfusion syndrome (TTTS) in MCMA pregnancy can be challenging in the absence of amniotic fluid volume discordance without the presence of the inter-twin dividing membrane. Early surveillance of foetal anatomy permits early recognition of foetal structural anomalies, the twin reversed arterial perfusion (TRAP) sequence and conjoined twins. However, the evidence on how best to monitor MCMA pregnancies remains inadequate, though observational studies have demonstrated that once surveillance is initiated, the potential risk of foetal death decreases significantly. In-utero foetal demise can be acute and unpredictable in MCMA pregnancies, despite close surveillance. Elective preterm delivery is usually advocated when the risk of foetal loss upon continuing the pregnancy outweighs the risk of prematurity - around 33 weeks' gestation by caesarean section. Nevertheless, the optimal prenatal surveillance regimen and prompts for delivery have yet to be defined.

Hepatic arterial buffer response in monochorionic diamniotic pregnancies with twin-to-twin transfusion syndrome.

Hepatic arterial buffer response (HABR) is animportant regulatory process for hepatic blood flow. Itsactivity has been described in some fetal adverse conditions but in twin-to-twin transfusion syndrome (TTTS) it is unknown if such response is present. The aim of this study is to test the hypothesis that HABR operates in monochorionic diamniotic twins (MCDA) with TTTS. Hepatic artery pulsatility index (PI) and peak systolic velocity (PSV) were measured prospectively in 64 MCDA pregnancies. 43 without TTTS (group 1) and in 21 pregnancies with TTTS (group 2). We calculated ratios for PI (HAPI-ratio) and PSV (HAV-ratio) between recipient and donor in group 2 or bigger and smaller fetus in group 1 and compared groups. The association of HAV-ratio and HAPI ratio with TTTS, relation with other fetal Dopplers and reliability of measurement by a single operator were investigated. HAV-ratio and HAPI-ratio appears to be independent from fetal Dopplers, estimated weight and gestational age. In group 2, HAV-ratio is lower than group 1 (p<0.001, 95% CI 0.443-0.643). In group 1 the mean HAV-ratio is 1.014 (±0.021) while in group 2 is 0.47 (±0.035). HAPI-ratio is lower in group 2 than in group 1 although this difference was not significant (p=0.066, 95% CI-0.007-0.231). A good reliability of measurements of hepatic artery PSV and PI was demonstrated by intraclass correlation coefficient analysis (ICC 0.971 95% CI 0.963-0.977, p<0.001 and ICC 0.694 95% CI 0.596-0.772, p<0.001, respectively). Monochorionic pregnancies with TTTS are associated with lower HAV-ratios. This could be explained by an active HABR.

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.

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.