FERN: is it possible to conduct a randomised controlled trial of intervention or expectant management for early-onset selective fetal growth restriction in monochorionic twin pregnancy - protocol for a prospective multicentre mixed-methods feasibility study.

INTRODUCTION: Selective fetal growth restriction (sFGR) in monochorionic twin pregnancy, defined as an estimated fetal weight (EFW) of one twin <10th centile and EFW discordance ≥25%, is associated with stillbirth and neurodisability for both twins. The condition poses unique management difficulties: on the one hand, continuation of the pregnancy carries a risk of death of the smaller twin, with a high risk of co-twin demise (40%) or co-twin neurological sequelae (30%). On the other, early delivery to prevent the death of the smaller twin may expose the larger twin to prematurity, with the associated risks of long-term physical, emotional and financial costs from neurodisability, such as cerebral palsy.When there is severe and early sFGR, before viability, delivery is not an option. In this scenario, there are currently three main management options: (1) expectant management, (2) selective termination of the smaller twin and (3) placental laser photocoagulation of interconnecting vessels. These management options have never been investigated in a randomised controlled trial (RCT). The best management option is unknown, and there are many challenges for a potential RCT. These include the rarity of the condition resulting in a small number of eligible pregnancies, uncertainty about whether pregnant women will agree to participate in such a trial and whether they will agree to be randomised to expectant management or active fetal intervention, and the challenges of robust and long-term outcome measures. Therefore, the main objective of the FERN study is to assess the feasibility of conducting an RCT of active intervention vs expectant management in monochorionic twin pregnancies with early-onset (prior to 24 weeks) sFGR. METHODS AND ANALYSIS: The FERN study is a prospective mixed-methods feasibility study. The primary objective is to recommend whether an RCT of intervention vs expectant management of sFGR in monochorionic twin pregnancy is feasible by exploring women's preference, clinician's preference, current practice and equipoise and numbers of cases. To achieve this, we propose three distinct work packages (WPs). WP1: A Prospective UK Multicentre Study, WP2A: a Qualitative Study Exploring Parents' and Clinicians' Views and WP3: a Consensus Development to Determine Feasibility of a Trial. Eligible pregnancies will be recruited to WP1 and WP2, which will run concurrently. The results of these two WPs will be used in WP3 to develop consensus on a future definitive study. The duration of the study will be 53 months, composed of 10 months of setup, 39 months of recruitment, 42 months of data collection, and 5 months of data analysis, report writing and recommendations. The pragmatic sample size for WP1 is 100 monochorionic twin pregnancies with sFGR. For WP2, interviews will be conducted until data saturation and sample variance are achieved, that is, when no new major themes are being discovered. Based on previous similar pilot studies, this is anticipated to be approximately 15-25 interviews in both the parent and clinician groups. Engagement of at least 50 UK clinicians is planned for WP3. ETHICS AND DISSEMINATION: This study has received ethical approval from the Health Research Authority (HRA) South West-Cornwall and Plymouth Ethics Committee (REC reference 20/SW/0156, IRAS ID 286337). All participating sites will undergo site-specific approvals for assessment of capacity and capability by the HRA. The results of this study will be published in peer-reviewed journals and presented at national and international conferences. The results from the FERN project will be used to inform future studies. TRIAL REGISTRATION NUMBER: This study is included in the ISRCTN Registry (ISRCTN16879394) and the NIHR Central Portfolio Management System (CPMS), CRN: Reproductive Health and Childbirth Specialty (UKCRN reference 47201).

Diagnosis and management of selective fetal growth restriction in monochorionic twin pregnancies: A cross-sectional international survey.

OBJECTIVE: To identify current practices in the management of selective fetal growth restriction (sFGR) in monochorionic diamniotic (MCDA) twin pregnancies. DESIGN: Cross-sectional survey. SETTING: International. POPULATION: Clinicians involved in the management of MCDA twin pregnancies with sFGR. METHODS: A structured, self-administered survey. MAIN OUTCOME MEASURES: Clinical practices and attitudes to diagnostic criteria and management strategies. RESULTS: Overall, 62.8% (113/180) of clinicians completed the survey; of which, 66.4% (75/113) of the respondents reported that they would use an estimated fetal weight (EFW) of <10th centile for the smaller twin and an inter-twin EFW discordance of >25% for the diagnosis of sFGR. For early-onset type I sFGR, 79.8% (75/94) of respondents expressed that expectant management would be their routine practice. On the other hand, for early-onset type II and type III sFGR, 19.3% (17/88) and 35.7% (30/84) of respondents would manage these pregnancies expectantly, whereas 71.6% (63/88) and 57.1% (48/84) would refer these pregnancies to a fetal intervention centre or would offer fetal intervention for type II and type III cases, respectively. Moreover, 39.0% (16/41) of the respondents would consider fetoscopic laser surgery (FLS) for early-onset type I sFGR, whereas 41.5% (17/41) would offer either FLS or selective feticide, and 12.2% (5/41) would exclusively offer selective feticide. For early-onset type II and type III sFGR cases, 25.9% (21/81) and 31.4% (22/70) would exclusively offer FLS, respectively, whereas 33.3% (27/81) and 32.9% (23/70) would exclusively offer selective feticide. CONCLUSIONS: There is significant variation in clinician practices and attitudes towards the management of early-onset sFGR in MCDA twin pregnancies, especially for type II and type III cases, highlighting the need for high-level evidence to guide management.

High-Sensitivity Cardiac Troponin I Enhances Preeclampsia Prediction Beyond Maternal Factors and the sFlt-1/PlGF Ratio.

BACKGROUND: Preeclampsia shares numerous risk factors with cardiovascular diseases. Here, we aimed to assess the potential utility of high-sensitivity cardiac troponin I (hs-cTnI) values during pregnancy in predicting preeclampsia occurrence. METHODS: This study measured hs-cTnI levels in 3721 blood samples of 2245 pregnant women from 4 international, prospective cohorts. Three analytical approaches were used: (1) a cross-sectional analysis of all women using a single blood sample, (2) a longitudinal analysis of hs-cTnI trajectories in women with multiple samples, and (3) analyses of prediction models incorporating hs-cTnI, maternal factors, and the sFlt-1 (soluble fms-like tyrosine kinase 1)/PlGF (placental growth factor) ratio. RESULTS: Women with hs-cTnI levels in the upper quarter had higher odds ratios for preeclampsia occurrence compared with women with levels in the lower quarter. Associations were driven by preterm preeclampsia (odds ratio, 5.78 [95% CI, 2.73-12.26]) and remained significant when using hs-cTnI as a continuous variable adjusted for confounders. Between-trimester hs-cTnI trajectories were independent of subsequent preeclampsia occurrence. A prediction model incorporating a practical hs-cTnI level of detection cutoff (≥1.9 pg/mL) alongside maternal factors provided comparable performance with the sFlt-1/PlGF ratio. A comprehensive model including sFlt-1/PlGF, maternal factors, and hs-cTnI provided added value (cross-validated area under the receiver operator characteristic, 0.78 [95% CI, 0.73-0.82]) above the sFlt-1/PlGF ratio alone (cross-validated area under the receiver operator characteristic, 0.70 [95% CI, 0.65-0.76]; P=0.027). As assessed by likelihood ratio tests, the addition of hs-cTnI to each prediction model significantly improved the respective prediction model not incorporating hs-cTnI, particularly for preterm preeclampsia. Net reclassification improvement analyses indicated that incorporating hs-cTnI improved risk prediction predominantly by correctly reclassifying women with subsequent preeclampsia occurrence. CONCLUSIONS: These exploratory findings uncover a potential role for hs-cTnI as a complementary biomarker in the prediction of preeclampsia. After validation in prospective studies, hs-cTnI, alongside maternal factors, may either be considered as a substitute for angiogenic biomarkers in health care systems where they are sparce or unavailable, or as an enhancement to established prediction models using angiogenic markers.

The Arabin cervical pessary for the prevention of preterm birth in twin-to-twin transfusion syndrome treated by fetoscopic laser coagulation: a multicenter randomized controlled trial.

BACKGROUND: Miscarriage and preterm birth are leading causes of loss and disability in monochorionic twins after laser treatment of twin-twin transfusion syndrome. OBJECTIVE: This study aimed to investigate the use of cervical pessary to reduce preterm birth before 32 weeks of gestation in monochorionic diamniotic twin pregnancies after fetal surgery for twin-twin transfusion syndrome. STUDY DESIGN: In this open-label multicenter randomized trial, pregnant women carrying monochorionic diamniotic twins requiring fetoscopic laser coagulation for twin-twin transfusion syndrome were randomly assigned in a 1:1 ratio to pessary placement or conservative management. The primary outcome was birth before 32 weeks of gestation. The secondary outcomes were birth before 28, 30, 34, or 37 weeks of gestation; preterm premature rupture of membranes; fetal and neonatal survival; and a composite of maternal and neonatal complications. The estimated sample size was 364 patients, with 182 cases in each arm of the study. The analysis was performed according to the intention-to-treat principle. Moreover, 2 interim analyses were planned. RESULTS: The trial was stopped prematurely after the first planned interim analysis for futility. Overall, 137 women were included in the analysis, 67 in the pessary group and 70 in the conservative management group. Preterm birth before 32 weeks of gestation occurred in 27 of 67 women (40.3%) in the pessary group and in 25 of 70 women (35.7%) in the conservative management group (adjusted odds ratio, 1.19; 95% confidence interval, 0.58-2.47; P=.63). No differences between groups was observed in the rate of deliveries before 28, 30, 34, and 37 weeks of gestation. Overall survival to delivery was 91.2% (125/137) for at least 1 twin, and 70.8% (97/137) for both twins, with no difference between groups. Neonatal survival at 30 days was 76.5% (208/272). There was no difference between the groups in maternal or neonatal morbidity. CONCLUSION: In monochorionic diamniotic twin pregnancies requiring fetal therapy for twin-twin transfusion syndrome, routine use of cervical pessary did not reduce the rate of preterm birth before 32 weeks of gestation.

Maternal PlGF and umbilical Dopplers predict pregnancy outcomes at diagnosis of early-onset fetal growth restriction.

BACKGROUNDSevere, early-onset fetal growth restriction (FGR) causes significant fetal and neonatal mortality and morbidity. Predicting the outcome of affected pregnancies at the time of diagnosis is difficult, thus preventing accurate patient counseling. We investigated the use of maternal serum protein and ultrasound measurements at diagnosis to predict fetal or neonatal death and 3 secondary outcomes: fetal death or delivery at or before 28+0 weeks, development of abnormal umbilical artery (UmA) Doppler velocimetry, and slow fetal growth.METHODSWomen with singleton pregnancies (n = 142, estimated fetal weights [EFWs] below the third centile, less than 600 g, 20+0 to 26+6 weeks of gestation, no known chromosomal, genetic, or major structural abnormalities) were recruited from 4 European centers. Maternal serum from the discovery set (n = 63) was analyzed for 7 proteins linked to angiogenesis, 90 additional proteins associated with cardiovascular disease, and 5 proteins identified through pooled liquid chromatography and tandem mass spectrometry. Patient and clinician stakeholder priorities were used to select models tested in the validation set (n = 60), with final models calculated from combined data.RESULTSThe most discriminative model for fetal or neonatal death included the EFW z score (Hadlock 3 formula/Marsal chart), gestational age, and UmA Doppler category (AUC, 0.91; 95% CI, 0.86-0.97) but was less well calibrated than the model containing only the EFW z score (Hadlock 3/Marsal). The most discriminative model for fetal death or delivery at or before 28+0 weeks included maternal serum placental growth factor (PlGF) concentration and UmA Doppler category (AUC, 0.89; 95% CI, 0.83-0.94).CONCLUSIONUltrasound measurements and maternal serum PlGF concentration at diagnosis of severe, early-onset FGR predicted pregnancy outcomes of importance to patients and clinicians.TRIAL REGISTRATIONClinicalTrials.gov NCT02097667.FUNDINGThe European Union, Rosetrees Trust, Mitchell Charitable Trust.

Twin-to-twin transfusion syndrome: Controversies in the diagnosis and management.

In twin-to-twin transfusion syndrome (TTTS) communicating placental vessels on the chorionic plate between the donor and recipient twins are responsible for the chronic imbalance of blood flow. Evidence demonstrates that fetoscopic laser ablation is superior to serial amnioreductions in terms of survival and neurological outcome for stages II-IV TTTS. However, the optimal management of stage I TTTS remains poorly understood. It is well established that all chorionic plate anastomoses should be closed by laser ablation. Compared to the selective laser method, the Solomon technique yields a significant reduction of recurrent TTTS and post-laser twin anemia polycythemia sequence (TAPS). Over the past 25 years, survival rates after fetoscopic laser surgery have significantly increased. High volume centers report up to 70% double survival and at least one survivor in >90% cases. In this review, we discuss the controversies in the diagnosis and management of TTTS, especially, the optimal management in stage I cases, very early or late diagnosis, and the optimal laser technique. Furthermore, we will discuss a stage-related outcome after laser surgery and examine whether it is necessary at all to distinguish between stages I and II. Finally, the optimal timing as well as mode of delivery after TTTS laser treatment will be discussed.

Fetoscopic techniques for prenatal covering of gastroschisis in an ovine model are technically demanding and do not lead to permanent anchoring on the fetus until the end of gestation.

INTRODUCTION: This is the cumulative technical report on the operative procedures and limitations of fetoscopic bag insertion, intestinal bag placement, and bag fixation to the fetus in a series of pilot studies in an ovine model for prenatal treatment of gastroschisis. MATERIAL AND METHODS: In 24 German blackhead sheep, a surgically created gastroschisis was managed by fetoscopic placement of the extruded intestines into a bag. The bag was then fastened onto the fetal abdominal wall. Different materials (sterile gloves, latex condoms, laparosopic retrieval bags) and different fixation techniques (laparoscopic staplers, interrupted and continuous sutures) have been examined. The fetuses were retrieved and evaluated at the end of gestation. RESULTS: Uterine bag insertion was successful in 15 of 24 (62.5%) and intestinal bag placement in 10 of 15 available fetuses (66.6%). The main factor limiting fetoscopic procedures was chorioamniotic separation (CAS). Sterilized condoms provided the most appropriate type of bags and the V-Loc™ running suture, the most expedient type of fixation, which was achieved in 9 of the 10 fetuses (complete = 2, partially = 7) by using a three port access (5 mm and 2 × 3 mm). All bags were encountered completely or partially dislocated from the fetus at the end of gestation. CONCLUSIONS: Fetoscopic intestinal bag placement and fixation in gastroschisis technically demanding. None of the evaluated techniques led to permanent anchorage of the bag to the fetus. The development of specially designed instruments, bags and fixation methods is required to optimize this approach.

Intrauterine fetoscopic laser surgery versus expectant management in stage 1 twin-to-twin transfusion syndrome: an international randomized trial.

BACKGROUND: Selective fetoscopic laser coagulation of the intertwin anastomotic chorionic vessels is the first-line treatment for twin-twin transfusion syndrome. However, in stage 1 twin-twin transfusion syndrome, the risks of intrauterine surgery may be higher than those of the natural progression of the condition. OBJECTIVE: This study aimed to compare immediate surgery and expectant follow-up in stage 1 twin-twin transfusion syndrome. STUDY DESIGN: We conducted a multicentric randomized trial, which recruited from 2011 to 2018 with a 6-month postnatal follow-up. The study was conducted in 9 fetal medicine centers in Europe and the Unites States. Asymptomatic women with stage 1 twin-twin transfusion syndrome between 16 and 26 weeks' gestation, a cervix of >15 mm, and access to a surgical center within 48 hours of diagnosis were randomized between expectant management and immediate surgery. In patients allocated to immediate laser treatment, percutaneous laser coagulation of anastomotic vessels was performed within 72 hours. In patients allocated to expectant management, a weekly ultrasound follow-up was planned. Rescue fetoscopic coagulation of anastomoses was offered if the syndrome worsened as seen during a follow-up, either because of progression to a higher Quintero stage or because of the maternal complications of polyhydramnios. The primary outcome was survival at 6 months without severe neurologic morbidity. Severe complications of prematurity and maternal morbidity were secondary outcomes. RESULTS: The trial was stopped at 117 of 200 planned inclusions for slow accrual rate over 7 years: 58 women were allocated to expectant management and 59 to immediate laser treatment. Intact survival was seen in 84 of 109 (77%) expectant cases and in 89 of 114 (78%) (P=.88) immediate surgery cases, and severe neurologic morbidity occurred in 5 of 109 (4.6%) and 3 of 114 (2.6%) (P=.49) cases in the expectant and immediate surgery groups, respectively. In patients followed expectantly, 24 of 58 (41%) cases remained stable with dual intact survival in 36 of 44 (86%) cases at 6 months. Intact survival was lower following surgery than for the nonprogressive cases, although nonsignificantly (78% and 71% following immediate and rescue surgery, respectively). CONCLUSION: It is unlikely that early fetal surgery is of benefit for stage 1 twin-twin transfusion syndrome in asymptomatic pregnant women with a long cervix. Although expectant management is reasonable for these cases, 60% of the cases will progress and require rapid transfer to a surgical center.

Post-Laser Twin Anemia Polycythemia Sequence: Diagnosis, Management, and Outcome in an International Cohort of 164 Cases.

The aim of this study was to investigate the management and outcome in the post-laser twin anemia polycythemia sequence (TAPS). Data of the international TAPS Registry, collected between 2014 and 2019, were used for this study. The primary outcomes were perinatal mortality and severe neonatal morbidity. Secondary outcomes included a risk factor analysis for perinatal mortality and severe neonatal morbidity. A total of 164 post-laser TAPS pregnancies were included, of which 92% (151/164) were diagnosed antenatally and 8% (13/164) postnatally. The median number of days between laser for TTTS and detection of TAPS was 14 (IQR: 7-28, range: 1-119). Antenatal management included expectant management in 43% (62/151), intrauterine transfusion with or without partial exchange transfusion in 29% (44/151), repeated laser surgery in 15% (24/151), selective feticide in 7% (11/151), delivery in 6% (9/151), and termination of pregnancy in 1% (1/151). The median gestational age (GA) at birth was 31.7 weeks (IQR: 28.6-33.7; range: 19.0-41.3). The perinatal mortality rate was 25% (83/327) for the total group, 37% (61/164) for donors, and 14% (22/163) for recipients (p < 0.001). Severe neonatal morbidity was detected in 40% (105/263) of the cohort and was similar for donors (43%; 51/118) and recipients (37%; 54/145), p = 0.568. Independent risk factors for spontaneous perinatal mortality were antenatal TAPS Stage 4 (OR = 3.4, 95%CI 1.4-26.0, p = 0.015), TAPS donor status (OR = 4.2, 95%CI 2.1-8.3, p < 0.001), and GA at birth (OR = 0.8, 95%CI 0.7-0.9, p = 0.001). Severe neonatal morbidity was significantly associated with GA at birth (OR = 1.5, 95%CI 1.3-1.7, p < 0.001). In conclusion, post-laser TAPS most often occurs within one month after laser for TTTS, but may develop up to 17 weeks after initial surgery. Management is mostly expectant, but varies greatly, highlighting the lack of consensus on the optimal treatment and heterogeneity of the condition. Perinatal outcome is poor, particularly due to the high rate of perinatal mortality in donor twins.

In-depth characterization of monocyte subsets during the course of healthy pregnancy.

Pregnancy represents an immunological challenge for the maternal immune system. Pregnancy augments innate immune responses, and particularly monocytes contribute to maintaining the balance between pro- and anti-inflammatory immune responses required for the successful sequence of distinct immunological phases throughout pregnancy. Nonetheless, studies that focus on the heterogeneity of monocytes and analyze the alteration of monocyte subsets in a longitudinal approach throughout healthy pregnancies have remained scarce. In this study, we characterized the gradual phenotypic changes of monocyte subsets and the secretory potential of bulk monocytes in peripheral blood mononuclear cells of healthy pregnant women from a population-based prospective birth cohort study. Blood samples at predefined time points were analyzed using flow cytometry for in-depth characterization of monocyte subsets, which confirmed a shift from classical towards intermediate monocytes throughout pregnancy. Principal component analysis revealed characteristic phenotypic changes on monocyte subsets, especially on the intermediate monocyte subset, throughout pregnancy. Pregnancy-related hormones were measured in serum and ß-human chorionic gonadotropin levels were significantly associated with expression of CD11b, CD116 and CCR2 on monocyte subsets. TLR4 and TLR7/8 stimulation of monocytes furthermore showed reduced polycytokine production towards the end of pregnancy. These data provide a comprehensive overview of phenotypic changes and secretory potential of monocytes in healthy pregnant women and establish a selective contribution of different monocyte subsets to healthy pregnancy. The results from this study therefore build a basis for future comparisons and evaluation of women with adverse pregnancy outcomes.

Marfan Syndrome Versus Bicuspid Aortic Valve Disease: Comparative Analysis of Obstetric Outcome and Pregnancy-Associated Immediate and Long-Term Aortic Complications.

Pregnancy poses a threat to women with aortopathy. Conclusive data on the obstetric and aortic outcome in this risk collective, especially when it comes to aortic complications in the long term, are still missing. This study offers a comparative analysis of pregnancy-associated outcome in 113 consecutive women with Marfan syndrome or bicuspid aortic valve disease, including 46 ever-pregnant and 37 never-pregnant women with Marfan syndrome, and 23 ever-pregnant and 7 never-pregnant females with bicuspid aortic valve disease. The overall obstetric outcome was comparable between ever-pregnant women with Marfan syndrome and with bicuspid aortic valve disease (p = 0.112). Pregnancy-associated aortic dissection occurred in two women with Marfan syndrome (3%) during a total of 62 completed pregnancies, whereas no single case of aortic event occurred in women with bicuspid aortic valve disease during a total of 36 completed pregnancies (p = 0.530). In the long-term follow-up, aortic dissection occurred in 21% of ever-pregnant women with Marfan syndrome, but in none of the women with bicuspid aortic valve disease (p = 0.022). Proximal aortic surgery was performed with similar frequency in ever-pregnant women with Marfan syndrome and with bicuspid aortic valve disease in the long term (p = 0.252). However, ever-pregnant women with Marfan syndrome were younger when surgery was performed (44 ± 9 vs. 59 ± 7 years; p = 0.041). In Marfan syndrome, long-term growth of the aorta was comparable between ever-pregnant and never-pregnant women. Pregnancy thus exhibited an increased immediate aortic risk only in women with Marfan syndrome, but not in women with bicuspid aortic valve disease. Previous pregnancy did not relate to an increased long-term risk of adverse aortic events in women with Marfan syndrome or with bicuspid aortic valve disease.

Interleukin-6 elevation in healthy neonates.

OBJECTIVE: This study aimed to identify peripartum and neonatal factors associated with elevated Interleukin-6 levels in the cord blood of neonates without clinical signs of an infection. STUDY DESIGN: We conducted a prospective single-center study with healthy term and preterm neonates between March and November 2017. We investigated correlations between 21 peripartum factors and neonatal IL-6 concentrations. RESULTS: Four hundred and seventy-one infants (GA: 32.9-42.3 weeks) were included. The risk for elevated neonatal IL-6 levels was 3.1 to 4.5-fold increased in the presence of either peripartum maternal temperature >37.5 °C (p = 0.012), duration of labor >12 h (p < 0.001), vaginal delivery (p < 0.001), or neonatal neutrophils >8 × 109 cells/L (p < 0.001). CONCLUSION: The results indicate that a considerable number of neonates with elevated IL-6 levels can sufficiently cope with an exposition to substantial perinatal stress or intrauterine inflammation and do not require postnatal antibiotic treatment.

[Chorangioma of the Placenta - A Rare Placental Cause of Fetal High Output Cardiac Failure]. / Chorioangiom der Plazenta ­ eine seltene Ursache fetaler High-Output-Herzinsuffizienz.

Chorangiomas of the placenta, benign tumors of chorionic tissue, are a rare placental cause of adverse fetal and maternal outcomes. We describe the case of a large placental chorangioma leading to polyhydramnios as well as consecutive preterm birth and high output cardiac failure of the newborn. Derived from a literature review, we suggest instructions for diagnosis and optimal prenatal care in case of a a suspected placental chorangioma.

Update on twin-to-twin transfusion syndrome.

Twin-to-twin transfusion syndrome (TTTS) is a serious complication that affects 10-15% of monochorionic multiple pregnancies. Communicating placental vessels on the chorionic plate between the donor and recipient twin are responsible for the imbalance of blood flow. There is evidence for the superiority of fetoscopic laser ablation over serial amnioreductions regarding survival and neurological outcome for stages II-IV TTTS. However, the optimal management of stage I is still debated. The "Solomon" technique showed a significant reduction in recurrent TTTS and post laser twin anemia-polycythemia sequence (TAPS) in comparison to the selective laser method without improvement in perinatal mortality or neonatal morbidity. Survival rates after fetoscopic laser surgery have significantly increased over the last 25 years. High volume centers report up to 70% double survival and at least one survivor in >90%. Long-term neurodevelopmental impairment occurs in about 10% of children after laser surgery. In this review we discuss the optimal management, innovations in laser technique, long-term neurodevelopmental outcome, and future aspects of TTTS treatment.

Long-term outcomes for monochorionic twins after laser therapy in twin-to-twin transfusion syndrome.

Twin-to-twin transfusion syndrome typically occurs in the second trimester in 10-15% of monochorionic twin pregnancies. Vascular anastomoses of monochorionic placentae are the underlying cause of the development of the syndrome. If a blood flow imbalance occurs, one fetus becomes the so-called donor twin and the other the recipient. If untreated, perinatal mortality is 80-90%. Fetoscopic laser coagulation of the vascular anastomoses destroys the cause of the syndrome and leads to dual twin survival rates of around 70% and more than 90% of pregnancies with at least one survivor. However, unequal placental sharing, intrauterine death, and severe prematurity are still limiting factors for further improvement of survival rates and decreases in long-term morbidity. Prematurity and neurodevelopmental impairment affect the donor and recipient twins, whereas cardiovascular failure and obstruction of the right ventricular outflow tract are typical complications of recipients, which can lead to long-term morbidity. In this Review, we summarise the literature on follow-up data for survivors of twin-to-twin-transfusion syndrome after laser therapy, including neurodevelopmental outcomes, cardiovascular outcomes, growth, renal function, and ischaemic events, as well as the potential effects of intrauterine programming on later life.

Innate immune responses to toll-like receptor stimulation are altered during the course of pregnancy.

During pregnancy the maternal immune system has to develop tolerance towards the developing fetus. These changes in maternal immunity can result in increased severity of certain infections, but also in amelioration of autoimmune diseases. Pregnancy-related hormones have been suggested to play a central role in the adaptation of the maternal immune system, but their specific effects on innate immune function is not well understood. In a longitudinal study of pregnant women, we investigated innate immune cell function in response to toll-like receptors (TLR) 4 and 7 stimulation, two TLR pathways playing a critical role in early innate immune recognition of bacteria and viruses. IFNα production by TLR7-stimulated pDCs was decreased in early pregnancy, and increased towards the end of pregnancy. In contrast, pro-inflammatory TLR4-induced TNFα production by monocytes was increased during early pregnancy, but declined after the first trimester. Changes in cytokine production were associated with changes in pregnancy-related hormones and monocyte subpopulations over the course of pregnancy. These data demonstrating a significant association between pregnancy-related hormones and modulation of innate immune responses mediated by TLRs provide novel insights into the immunological adaptations occurring during pregnancy.

Paracetamol Medication During Pregnancy: Insights on Intake Frequencies, Dosages and Effects on Hematopoietic Stem Cell Populations in Cord Blood From a Longitudinal Prospective Pregnancy Cohort.

BACKGROUND: Paracetamol is the first choice for antipyretic or analgesic treatment throughout pregnancy. Products with Paracetamol are readily available over the counter and therefore easily accessible for self-medication. Epidemiological data on Paracetamol intake pattern during pregnancy and its potential immunological effects are sparse. We aimed to analyze a possible association between Paracetamol medication and numbers of hematopoietic stem cells (HSC) in cord blood. METHODS: The objective was addressed in the PRINCE (PRENATAL DETERMINANTS OF CHILDREN'S HEALTH) study, a population-based prospective pregnancy cohort study initiated in 2011 at the University Medical Center in Hamburg, Germany. 518 healthy pregnant women with singleton pregnancies were recruited during the first trimester. Three examinations were scheduled at the end of the 1st (gestational week 12-14), the 2nd (gestational week 22-24) and the 3rd trimester (gestational week 34-36). For 146 of these women, cord blood flow cytometry data were available. Paracetamol intake was assessed for each trimester of pregnancy. FINDINGS: Among the 518 enrolled women, 40% took Paracetamol as main analgesic treatment during pregnancy. The intake frequency and dosage of Paracetamol varied between the women and was overall low with a tendency towards higher frequencies and higher dosages in the third trimester. Paracetamol intake, particularly during the third trimester, resulted in decreased relative numbers of HSCs in cord blood, independent of maternal age, first-trimester BMI, parity, gestational age and birth weight (-0.286 (95% CI -0.592, 0.021), p=0.068). INTERPRETATION: Prenatal Paracetamol intake, especially during the third trimester, may be causally involved in decreasing HSCs in cord blood.

Arabin cervical pessary for prevention of preterm birth in cases of twin-to-twin transfusion syndrome treated by fetoscopic LASER coagulation: the PECEP LASER randomised controlled trial.

BACKGROUND: Fetoscopic LASER coagulation of the placental anastomoses has changed the prognosis of twin-twin transfusion syndrome. However, the prematurity rate in this cohort remains very high. To date, strategies proposed to decrease the prematurity rate have shown inconclusive, if not unfavourable results. METHODS: This is a randomised controlled trial to investigate whether a prophylactic cervical pessary will lower the incidence of preterm delivery in cases of twin-twin transfusion syndrome requiring fetoscopic LASER coagulation. Women eligible for the study will be randomised after surgery and allocated to either pessary or expectant management. The pessary will be left in place until 37 completed weeks or earlier if delivery occurs. The primary outcome is delivery before 32 completed weeks. Secondary outcomes are a composite of adverse neonatal outcome, fetal and neonatal death, maternal complications, preterm rupture of membranes and hospitalisation for threatened preterm labour. 352 women will be included in order to decrease the rate of preterm delivery before 32 weeks' gestation from 40% to 26% with an alpha-error of 0.05 and 80% power. DISCUSSION: The trial aims at clarifying whether the cervical pessary prolongs the pregnancy in cases of twin-twin transfusion syndrome regardless of cervical length at the time of fetoscopy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01334489 . Registered 04 December 2011.