Feasibility for non-invasive prenatal fetal blood group and platelet genotyping by massively parallel sequencing: A single test system for multiple atypical red cell, platelet and quality control markers.

Non-invasive prenatal tests (NIPT) to predict fetal red cell or platelet antigen status for alloimmunised women are provided for select antigens. This study reports on massively parallel sequencing (MPS) using a red cell and platelet probe panel targeting multiple nucleotide variants, plus individual identification single nucleotide polymorphisms (IISNPs). Maternal blood samples were provided from 33 alloimmunised cases, including seven with two red cell antibodies. Cell-free and genomic DNA was sequenced using targeted MPS and bioinformatically analysed using low-frequency variant detection. The resulting maternal genomic DNA allele frequency was subtracted from the cell-free DNA counterpart. Outcomes were matched against validated phenotyping/genotyping methods, where available. A 2.5% subtractive allele frequency threshold was set after comparing MPS predictions for K, RhC/c, RhE/e and Fya /Fyb against expected outcomes. This threshold was used for subsequent predictions, including HPA-15a, Jka /Jkb , Kpa /Kpb and Lua . MPS outcomes were 97.2% concordant with validated methods; one RhC case was discordantly negative and lacked IISNPs. IISNPs were informative for 30/33 cases as controls. NIPT MPS is feasible for fetal blood group genotyping and covers multiple blood groups and control targets in a single test. Noting caution for the Rh system, this has the potential to provide a personalised service for alloimmunised women.

Safety and Immunogenicity of an Investigational Respiratory Syncytial Virus Vaccine (RSVPreF3) in Mothers and Their Infants: A Phase 2 Randomized Trial.

BACKGROUND: In a phase 1/2 study, a maternal respiratory syncytial virus vaccine candidate (RSVPreF3) demonstrated an acceptable safety profile and efficiently increased RSV-specific humoral immune responses in non-pregnant women. METHODS: In this phase 2 observer-blind, placebo-controlled, randomized clinical trial (NCT04126213), the safety of RSVPreF3 (60 or 120 µg), administered during late second or third trimester, was evaluated in 213 18- to 40-year-old healthy pregnant women through 6 months postdelivery and their offspring through infancy; immunogenicity was evaluated through day 43 postdelivery and day 181 postbirth, respectively. RESULTS: RSVPreF3 was well tolerated. No pregnancy-related or neonatal adverse events of special interest were considered vaccine/placebo related. In the 60 and 120 µg RSVPreF3 groups: (1) neutralizing antibody (nAb) titers in mothers increased 12.7- and 14.9-fold against RSV-A and 10.6- and 13.2-fold against RSV-B, respectively, 1 month postvaccination and remained 8.9-10.0-fold over prevaccination at day 43 postdelivery; (2) nAb titers were consistently higher compared to placebo recipients; (3) placental transfer ratios for anti-RSVPreF3 antibodies at birth were 1.62 and 1.90, respectively, and (4) nAb levels in infants were highest at birth and declined through day 181 postbirth. CONCLUSIONS: RSVPreF3 maternal vaccination had an acceptable safety risk profile and induced robust RSV-specific immune responses with successful antibody transfer to their newborns. CLINICAL TRIALS REGISTRATION: NCT04126213.

WHAT IS THE CONTEXT?: Infants, especially those less than 6 months of age, are at increased risk of lung infection caused by respiratory syncytial virus (RSV). However, this risk could be reduced with maternal vaccination against RSV during pregnancy. A previous clinical trial found that a vaccine candidate (named RSVPreF3) was well tolerated when given to non-pregnant women. WHAT IS NEW?: In pregnant women, RSVPreF3 was also well tolerated. Occurrence of unsolicited adverse events was similar between vaccine and placebo recipients. None of the serious adverse events or events of interest for pregnant women or newborns were considered related to the study intervention. One month after vaccination, mothers who received RSVPreF3 had 11­15 times higher levels of antibodies against RSV than before vaccination. These antibody levels remained similar until 43 days after delivery. In the infants born to mothers vaccinated during pregnancy with RSVPreF3, antibody levels were highest at birth, when levels were higher than in their mothers, and declined through day 181 postbirth. WHAT IS THE IMPACT?: RSVPreF3 had an acceptable safety risk profile in pregnant women and their babies. This vaccine induced potent immune responses against RSV, with maternal antibodies transferred to infants of the vaccinated mothers.

The randomized Tracheal Occlusion To Accelerate Lung growth (TOTAL)-trials on fetal surgery for congenital diaphragmatic hernia: reanalysis using pooled data.

BACKGROUND: Two randomized controlled trials compared the neonatal and infant outcomes after fetoscopic endoluminal tracheal occlusion with expectant prenatal management in fetuses with severe and moderate isolated congenital diaphragmatic hernia, respectively. Fetoscopic endoluminal tracheal occlusion was carried out at 27+0 to 29+6 weeks' gestation (referred to as "early") for severe and at 30+0 to 31+6 weeks ("late") for moderate hypoplasia. The reported absolute increase in the survival to discharge was 13% (95% confidence interval, -1 to 28; P=.059) and 25% (95% confidence interval, 6-46; P=.0091) for moderate and severe hypoplasia. OBJECTIVE: Data from the 2 trials were pooled to study the heterogeneity of the treatment effect by observed over expected lung-to-head ratio and explore the effect of gestational age at balloon insertion. STUDY DESIGN: Individual participant data from the 2 trials were reanalyzed. Women were assessed between 2008 and 2020 at 14 experienced fetoscopic endoluminal tracheal occlusion centers and were randomized in a 1:1 ratio to either expectant management or fetoscopic endoluminal tracheal occlusion. All received standardized postnatal management. The combined data involved 287 patients (196 with moderate hypoplasia and 91 with severe hypoplasia). The primary endpoint was survival to discharge from the neonatal intensive care unit. The secondary endpoints were survival to 6 months of age, survival to 6 months without oxygen supplementation, and gestational age at live birth. Penalized regression was used with the following covariates: intervention (fetoscopic endoluminal tracheal occlusion vs expectant), early balloon insertion (yes vs no), observed over expected lung-to-head ratio, liver herniation (yes vs no), and trial (severe vs moderate). The interaction between intervention and the observed over expected lung-to-head ratio was evaluated to study treatment effect heterogeneity. RESULTS: For survival to discharge, the adjusted odds ratio of fetoscopic endoluminal tracheal occlusion was 1.78 (95% confidence interval, 1.05-3.01; P=.031). The additional effect of early balloon insertion was highly uncertain (adjusted odds ratio, 1.53; 95% confidence interval, 0.60-3.91; P=.370). When combining these 2 effects, the adjusted odds ratio of fetoscopic endoluminal tracheal occlusion with early balloon insertion was 2.73 (95% confidence interval, 1.15-6.49). The results for survival to 6 months and survival to 6 months without oxygen dependence were comparable. The gestational age at delivery was on average 1.7 weeks earlier (95% confidence interval, 1.1-2.3) following fetoscopic endoluminal tracheal occlusion with late insertion and 3.2 weeks earlier (95% confidence interval, 2.3-4.1) following fetoscopic endoluminal tracheal occlusion with early insertion compared with expectant management. There was no evidence that the effect of fetoscopic endoluminal tracheal occlusion depended on the observed over expected lung-to-head ratio for any of the endpoints. CONCLUSION: This analysis suggests that fetoscopic endoluminal tracheal occlusion increases survival for both moderate and severe lung hypoplasia. The difference between the results for the Tracheal Occlusion To Accelerate Lung growth trials, when considered apart, may be because of the difference in the time point of balloon insertion. However, the effect of the time point of balloon insertion could not be robustly assessed because of a small sample size and the confounding effect of disease severity. Fetoscopic endoluminal tracheal occlusion with early balloon insertion in particular strongly increases the risk for preterm delivery.

Randomized Trial of Fetal Surgery for Moderate Left Diaphragmatic Hernia.

BACKGROUND: Fetoscopic endoluminal tracheal occlusion (FETO) has been associated with increased postnatal survival among infants with severe pulmonary hypoplasia due to isolated congenital diaphragmatic hernia on the left side, but data are lacking to inform its effects in infants with moderate disease. METHODS: In this open-label trial conducted at many centers with experience in FETO and other types of prenatal surgery, we randomly assigned, in a 1:1 ratio, women carrying singleton fetuses with a moderate isolated congenital diaphragmatic hernia on the left side to FETO at 30 to 32 weeks of gestation or expectant care. Both treatments were followed by standardized postnatal care. The primary outcomes were infant survival to discharge from a neonatal intensive care unit (NICU) and survival without oxygen supplementation at 6 months of age. RESULTS: In an intention-to-treat analysis involving 196 women, 62 of 98 infants in the FETO group (63%) and 49 of 98 infants in the expectant care group (50%) survived to discharge (relative risk , 1.27; 95% confidence interval [CI], 0.99 to 1.63; two-sided P = 0.06). At 6 months of age, 53 of 98 infants (54%) in the FETO group and 43 of 98 infants (44%) in the expectant care group were alive without oxygen supplementation (relative risk, 1.23; 95% CI, 0.93 to 1.65). The incidence of preterm, prelabor rupture of membranes was higher among women in the FETO group than among those in the expectant care group (44% vs. 12%; relative risk, 3.79; 95% CI, 2.13 to 6.91), as was the incidence of preterm birth (64% vs. 22%, respectively; relative risk, 2.86; 95% CI, 1.94 to 4.34), but FETO was not associated with any other serious maternal complications. There were two spontaneous fetal deaths (one in each group) without obvious cause and one neonatal death that was associated with balloon removal. CONCLUSIONS: This trial involving fetuses with moderate congenital diaphragmatic hernia on the left side did not show a significant benefit of FETO performed at 30 to 32 weeks of gestation over expectant care with respect to survival to discharge or the need for oxygen supplementation at 6 months. FETO increased the risks of preterm, prelabor rupture of membranes and preterm birth. (Funded by the European Commission and others; TOTAL ClinicalTrials.gov number, NCT00763737.).

Spontaneous twin anemia polycythemia sequence: diagnosis, management, and outcome in an international cohort of 249 cases.

BACKGROUND: Twin anemia polycythemia sequence is a chronic form of unbalanced fetofetal transfusion through minuscule placental anastomoses in monochorionic twins, leading to anemia in the donor and polycythemia in the recipient. Owing to the low incidence of twin anemia polycythemia sequence, data on diagnosis, management, and outcome are limited. OBJECTIVE: This study aimed to investigate the diagnosis, management, and outcome in a large international cohort of spontaneous twin anemia polycythemia sequence. STUDY DESIGN: Data from the international twin anemia polycythemia sequence registry, retrospectively collected between 2014 and 2019, were used for this study. A total of 17 fetal therapy centers contributed to the data collection. The primary outcomes were perinatal mortality and severe neonatal morbidity. Secondary outcomes included a risk factor analysis for perinatal mortality and severe neonatal morbidity. RESULTS: A total of 249 cases of spontaneous twin anemia polycythemia sequence were included in this study, 219 (88%) of which were diagnosed antenatally and 30 (12%) postnatally. Twin anemia polycythemia sequence was diagnosed antenatally at a median gestational age of 23.7 weeks (interquartile range, 9.7-28.8; range, 15.1-35.3). Antenatal management included laser surgery in 39% (86 of 219), expectant management in 23% (51 of 219), delivery in 16% (34 of 219), intrauterine transfusion (with partial exchange transfusion) in 12% (26 of 219), selective feticide in 8% (18 of 219), and termination of pregnancy in 1% (3 of 219) of cases. Perinatal mortality rate was 15% (72 of 493) for the total group, 22% (54 of 243) for donors, and 7% (18 of 242) for recipients (P<.001). Severe neonatal morbidity occurred in 33% (141 of 432) of twins with twin anemia polycythemia sequence and was similar for donors (32%; 63 of 196) and recipients (33%; 75 of 228) (P=.628). Independent risk factors for spontaneous perinatal mortality were donor status (odds ratio, 3.8; 95% confidence interval, 1.9-7.5; P<.001), antenatal twin anemia polycythemia sequence stage (odds ratio, 6.3; 95% confidence interval, 1.4-27.8; P=.016 [stage 2]; odds ratio, 9.6; 95% confidence interval, 2.1-45.5; P=.005 [stage 3]; odds ratio, 20.9; 95% confidence interval, 3.0-146.4; P=.002 [stage 4]), and gestational age at birth (odds ratio, 0.8; 95% confidence interval, 0.7-0.9; P=.001). Independent risk factors for severe neonatal morbidity were antenatal twin anemia polycythemia sequence stage 4 (odds ratio, 7.9; 95% confidence interval, 1.4-43.3; P=.018) and gestational age at birth (odds ratio, 1.7; 95% confidence interval, 1.5-2.1, P<.001). CONCLUSION: Spontaneous twin anemia polycythemia sequence can develop at any time in pregnancy from the beginning of the second trimester to the end of the third trimester. Management for twin anemia polycythemia sequence varies considerably, with laser surgery being the most frequent intervention. Perinatal mortality and severe neonatal morbidity were high, the former especially so in the donor twins.

Non-invasive prenatal testing for management of haemolytic disease of the fetus and newborn induced by maternal alloimmunisation.

Anti-D immunoglobulin prophylaxis reduces the risk of RhD negative women becoming alloimmunised to the RhD antigen and is a major preventative strategy in reducing the burden of haemolytic disease of the fetus and newborn (HDFN). HDFN also arises from other maternal red cell antibodies, with the most clinically significant, after anti-D, being anti-K, anti-c and anti-E. Among the 39 human blood group systems advanced genomic technologies are still revealing novel or rare antigens involved in maternal alloimmunisation. Where clinically significant maternal antibodies are detected in pregnancy, non-invasive prenatal testing (NIPT) of cell-free fetal DNA provides a safe way to assess the fetal blood group antigen status. This provides information as to the risk for HDFN and thus guides management strategies. In many countries, NIPT fetal RHD genotyping as a diagnostic test using real-time PCR has already been integrated into routine clinical care for the management of women with allo-anti-D to assess the risk for HDFN. In addition, screening programs have been established to provide antenatal assessment of the fetal RHD genotype in non-alloimmunised RhD negative pregnant women to target anti-D prophylaxis to those predicted to be carrying an RhD positive baby. Both diagnostic and screening assays exhibit high accuracy (over 99 %). NIPT fetal genotyping for atypical (other than RhD) blood group antigens presents more challenges as most arise from a single nucleotide variant. Recent studies show potential for genomic and digital technologies to provide a personalised medicine approach with NIPT to assess fetal blood group status for women with other (non-D) red cell antibodies to manage the risk for HDFN.

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.

Noninvasive fetal RHD genotyping of RhD negative pregnant women for targeted anti-D therapy in Australia: A cost-effectiveness analysis.

OBJECTIVE: To undertake a cost-effectiveness analysis of noninvasive fetal RHD genotyping to target pregnant women for antenatal anti-D prophylaxis therapy. METHOD: A decision-analytic model was constructed to compare RHD testing and targeted anti-D prophylaxis, with current universal anti-D prophylaxis among pregnant women with RhD negative blood type. Model estimates were derived from national perinatal statistics, published literature, donor program records, and national cost sources. One-way sensitivity analyses addressed the uncertainty of variables on the main findings. RESULTS: The unit cost for RHD genotyping was estimated at AU$45.48 (US$31.84). The "mean cost per healthy baby" was AU$7495 (US$5247) for universal prophylaxis and AU$7471 (US$5230) for targeted prophylaxis. The findings were sensitive to the unit costs of anti-D 625 IU (AU$59-AU$88) (US$41-US$62), the genetic test (AU$36-AU$55) (US$25-US$39), and packaging/transport costs of the samples for testing (AU$15-AU$40, US$11-US$28 per sample). With RHD genotyping, 13 938 women would avoid antenatal anti-D prophylaxis at a total cost savings to the National Blood Authority of AU$2.1 million (US$1.5 million) per year. To the health system, net cost savings of AU$159 701 (US$111 791) per year (0.05%) were predicted for total health care costs. CONCLUSIONS: Given the vulnerable supply of donor plasma and other health concerns, RHD genotyping is an economically sound option for Australia.

Non-invasive fetal RHD genotyping for RhD negative women stratified into RHD gene deletion or variant groups: comparative accuracy using two blood collection tube types.

Non-invasive fetal RHD genotyping in Australia to reduce anti-D usage will need to accommodate both prolonged sample transport times and a diverse population demographic harbouring a range of RHD blood group gene variants. We compared RHD genotyping accuracy using two blood sample collection tube types for RhD negative women stratified into deleted RHD gene haplotype and RHD gene variant cohorts. Maternal blood samples were collected into EDTA and cell-free (cf)DNA stabilising (BCT) tubes from two sites, one interstate. Automated DNA extraction and polymerase chain reaction (PCR) were used to amplify RHD exons 5 and 10 and CCR5. Automated analysis flagged maternal RHD variants, which were classified by genotyping. Time between sample collection and processing ranged from 2.9 to 187.5 hours. cfDNA levels increased with time for EDTA (range 0.03-138 ng/µL) but not BCT samples (0.01-3.24 ng/µL). For the 'deleted' cohort (n=647) all fetal RHD genotyping outcomes were concordant, excepting for one unexplained false negative EDTA sample. Matched against cord RhD serology, negative predictive values using BCT and EDTA tubes were 100% and 99.6%, respectively. Positive predictive values were 99.7% for both types. Overall 37.2% of subjects carried an RhD negative baby. The 'variant' cohort (n=15) included one novel RHD and eight hybrid or African pseudogene variants. Review for fetal RHD specific signals, based on one exon, showed three EDTA samples discordant to BCT, attributed to high maternal cfDNA levels arising from prolonged transport times. For the deleted haplotype cohort, fetal RHD genotyping accuracy was comparable for samples collected in EDTA and BCT tubes despite higher cfDNA levels in the EDTA tubes. Capacity to predict fetal RHD genotype for maternal carriers of hybrid or pseudogene RHD variants requires stringent control of cfDNA levels. We conclude that fetal RHD genotyping is feasible in the Australian environment to avoid unnecessary anti-D immunoglobulin prophylaxis.

Evaluation of an international educational programme for health care professionals on best practice in the management of a perinatal death: IMproving Perinatal mortality Review and Outcomes Via Education (IMPROVE).

BACKGROUND: Stillbirths and neonatal deaths are devastating events for both parents and clinicians and are global public health concerns. Careful clinical management after these deaths is required, including appropriate investigation and assessment to determine cause (s) to prevent future losses, and to improve bereavement care for families. An educational programme for health care professionals working in maternal and child health has been designed to address these needs according to the Perinatal Society of Australia and New Zealand Guideline for Perinatal Mortality: IMproving Perinatal mortality Review and Outcomes Via Education (IMPROVE). The programme has a major focus on stillbirth and is delivered as six interactive skills-based stations. We aimed to determine participants' pre- and post-programme knowledge of and confidence in the management of perinatal deaths, along with satisfaction with the programme. We also aimed to determine suitability for international use. METHODS: The IMPROVE programme was delivered to health professionals in maternity hospitals in all seven Australian states and territories and modified for use internationally with piloting in Vietnam, Fiji, and the Netherlands (with the assistance of the International Stillbirth Alliance, ISA). Modifications were made to programme materials in consultation with local teams and included translation for the Vietnam programme. Participants completed pre- and post-programme evaluation questionnaires on knowledge and confidence on six key components of perinatal death management as well as a satisfaction questionnaire. RESULTS: Over the period May 2012 to May 2015, 30 IMPROVE workshops were conducted, including 26 with 758 participants in Australia and four with 136 participants internationally. Evaluations showed a significant improvement between pre- and post-programme knowledge and confidence in all six stations and overall, and a high degree of satisfaction in all settings. CONCLUSIONS: The IMPROVE programme has been well received in Australia and in three different international settings and is now being made available through ISA. Future research is required to determine whether the immediate improvements in knowledge are sustained with less causes of death being classified as unknown, changes in clinical practice and improvement in parents' experiences with care. The suitability for this programme in low-income countries also needs to be established.

Neonatal outcomes after prelabour rupture of membranes before 24 weeks' gestation.

AIM: The aim of this study was to determine neonatal outcomes in pregnancies complicated by prelabour rupture of membranes (PROM) before 24 weeks' gestation. METHODS: We performed a retrospective review of medical records over a 5-year period (2007-2011) at Mater Health Services, South Brisbane, Australia. Data relating to the antenatal and perinatal course of pregnancies complicated by PROM before 24 weeks' gestation were collected. Data were also collected on neonatal diagnoses, management and outcomes for all liveborn infants resulting from these pregnancies. RESULTS: One hundred and six pregnancies were complicated by PROM before 24 weeks' gestation. Thirty-three (31%) of these pregnancies resulted in delivery at pre-viable gestations (<23 weeks). There were 36 (37%) infants who survived to hospital discharge. At discharge, 47% of infants had chronic lung disease, with 81% of this group requiring supplemental oxygen at home. CONCLUSIONS: Almost one-third of pregnancies complicated by PROM before 24 weeks resulted in pre-viable preterm delivery. In pregnancies continuing to a viable gestation, there remained a significant risk of neonatal mortality and morbidity, primarily due to respiratory disease.

Is the third trimester repeat ultrasound scan for placental localisation needed if the placenta is low lying but clear of the os at the mid-trimester morphology scan?

INTRODUCTION: It is unclear whether women with a low-lying placenta (not overlapping the internal cervical os) at the mid-trimester scan need follow-up. The aim of the study was to determine the rate of placenta praevia, vasa praevia and cord prolapse in the third trimester in this cohort of women. METHODS: A retrospective cohort study of women with a documented low-lying placenta (<30 mm from the internal cervical os) at the mid-trimester morphology ultrasound scan was done. A composite outcome of rate of placenta praevia, vasa praevia or cord prolapse at term was evaluated. Multivariate analysis was performed to investigate the variables influencing the composite outcome. In addition, a meta-analysis of methodologically similar studies was performed to investigate the effect of the placenta to os distance at the mid-trimester scan on the rate of placenta praevia at term. RESULTS: One hundred and eighty-one women with a low-lying placenta not overlapping the os at mid-trimester scan were identified. The composite outcome was documented in 20 (11.0%) women, including placenta praevia in 15 (8.3%). Based on multivariate analysis, multiparity, distance from os < 10 mm and antenatal bleeding were independently associated with the composite outcome. Meta-analysis demonstrated significant reduction in rate of placenta praevia for every 10-mm increase in placenta-os distance at mid-trimester. CONCLUSION: Our study supports the recommendation to follow up all women with a placenta lying <20 mm from the cervical os at mid-trimester.

Fetoscopic endoluminal tracheal occlusion (FETO) for congenital diaphragmatic hernia in Australia and New Zealand: are we willing, able, both or neither?

AIM: An estimated 140 pregnancies are diagnosed with congenital diaphragmatic hernia (CDH) in Australia and New Zealand each year, with these fetuses having a less than even chance of 1-year survival. Fetoscopic endoluminal tracheal occlusion (FETO) is a relatively new technique that offers a prenatal interventional strategy for selective cases of CDH. This is not routinely offered in Australia or New Zealand. The aim of this systematic review is to critically appraise controlled clinical trials investigating the role of FETO in moderate and severe isolated CDH and explore whether this treatment is justified within our region. METHODS: A systematic literature search of multiple electronic databases was undertaken, with restrictions to human subjects and controlled clinical trials. RESULTS: Nine relevant studies were identified. No current evidence was found in favour of FETO for moderate severity CDH. For severe CDH, the most recent evidence demonstrates significantly improved survival following FETO performed using contemporary percutaneous minimally invasive techniques. Optimum timing for balloon insertion, removal and occlusion duration remains conjectural. Substantial variation in survival rates observed among control groups highlights the impact of post-natal care in prenatally diagnosed CDH. CONCLUSION: Until recently, evidence to support a role for FETO in prenatal CDH management was weak. Recently reported and ongoing controlled trials give cause for optimism, with improved FETO safety and increased survival reported for severe CDH cases. Should Australasia embrace FETO for selected CDH cases, a co-ordinated, evidence-informed service should be established under the guidance of experienced international partnerships.

Strategy for managing maternal variant RHD alleles in Rhesus D negative obstetric populations during fetal RHD genotyping.

OBJECTIVES: Fetal RHD screening programs that aim to reduce unnecessary antenatal anti-D prophylaxis are being introduced into clinical practice. Strategies to manage women serologically typed as Rhesus D negative who have maternal RHD variants are needed. This study describes maternal RHD allelic variants detected in nonselected and alloimmunised Rhesus D negative obstetric populations and explores a mathematical approach to identify these variants. METHODS: Fetal RHD status was defined by testing cell-free fetal DNA in maternal plasma. Women at risk of an RHD variant were identified by selection for C and E haplotypes or by recognition of low polymerase chain reaction cycle threshold on fetal RHD typing. Maternal RHD alleles were defined by SNP profiling or sequencing. RESULTS: The prevalence of RHD variants in nonselected and alloimmunised groups was 1% (6/603) and 5.5% (6/110), respectively (p < 0.001). An inverse association between RHD cycle threshold values and gestational age was described by a linear model (p < 0.001). Standard residual values with a Z score threshold of -3.00 would have detected all maternal variants with one (1/713) false positive. CONCLUSIONS: The prevalence of maternal RHD variants was significantly higher in alloimmunised cases. The causative mechanism for this needs further investigation. Mathematical modeling simplifies the detection of maternal RHD variants.

A test of agreement of customised birthweight models.

BACKGROUND: The objective of this study was to determine whether the physiological effects on birthweight as described by customised birthweight models (CBMs) from various populations and locations are consistent when applied to a single sample. METHODS: The predicted birthweight was calculated for 52 826 White-European singleton term births between 1997 and 2008 from a large Australian hospital using the same set of variables from 12 published CBMs. The accuracy of prediction was tested against both the actual birthweight and a reference model. Intraclass correlation coefficients (ICCs) along with 95% confidence intervals of the measurements, paired differences (predicted-actual birthweight) and absolute values of the paired differences are reported. RESULTS: The average difference in predicted and actual birthweight was <200 g for all CBMs, with ICCs for all but one model indicating fair agreement (between 0.3 and 0.5). When compared with the reference model, eight of the 11 models had a difference in predicted birthweight of <220 g, and the ICCs indicated that the majority of models had strong agreement. CONCLUSION: All published CBMs demonstrated ability to predict birthweight with reasonable accuracy. The effects of maternal and fetal characteristics on birthweight appear to be consistent across birthweight models. This finding is a further step in validating the CBM, and provides greater evidence for the creation of a global model.

Anti-D in pregnant women with the RHD(IVS3+1G>A)-associated DEL phenotype.

BACKGROUND: Pregnant women with the DEL phenotype appear to be D- by routine serology. Women with DEL phenotypes that show a partial D-like epitope loss may develop anti-D. It has been proposed that this alloantibody could have a deleterious effect with respect to hemolytic disease in the fetus and newborn. CASE REPORTS: Two pregnant women, one in Australia and one in Germany, were serotyped as D- and were sensitized to the D antigen. Noninvasive fetal RHD genotyping was performed to plan pregnancy management. RESULTS: In both cases the fetal RHD status could not be assigned due to the presence of a maternal DEL allele. This was suspected through detection of high RHD amplicon levels during quantitative polymerase chain reaction. For both cases extended molecular typing of the maternal genomic DNA revealed a RHD(IVS3+1G>A) allele. For case one, the D+ infant developed a mild hemolytic disease requiring phototherapy. In the second case a D- (or DEL) newborn was unaffected. CONCLUSION: Fetal genotyping from maternal plasma reveals RHD variants in pregnant women with anti-D. Fetuses and newborns of sensitized pregnant women carrying the RHD(IVS3+1G>A) allele are at risk of hemolytic disease.

Evaluation of non-invasive prenatal RHD genotyping of the fetus.

OBJECTIVE: To evaluate a non-invasive molecular test using free circulating fetal DNA in maternal plasma to predict the fetal RHD type. DESIGN: A prospective cohort study. PARTICIPANTS AND SETTING: Venous blood samples were collected from 140 Rhesus (Rh) D-negative women booked for antenatal care in two tertiary maternity hospitals in Sydney and Brisbane between November 2006 and April 2008. Cell-free DNA, including free maternal and fetal DNA, was extracted from maternal plasma in the tertiary Australian Red Cross Blood Service laboratory, and three exon regions of the RHD gene were amplified. MAIN OUTCOME MEASURES: Comparison of the predicted fetal RHD status and the infant's RhD serotype. Secondary analysis involved using SRY and RASSF1A assays as internal controls to confirm the presence of fetal DNA in RHD-negative samples. RESULTS: Of 140 samples tested, results for RHD status were assigned for 135, and all 135 predictions were correct. A result was not assigned in five cases: three did not meet strict threshold criteria for classification, and two were due to RHD variants. Fetal SRY status was correctly predicted in 137 of 140 cases. In 16 samples typed both RHD- and SRY-negative, a positive RASSF1A result verified the presence of fetal DNA. CONCLUSIONS: Non-invasive testing of multiple exons provides a robust method of assessing fetal RHD status, and provides a safer alternative to amniocentesis for the management of RhD-negative pregnant women who are isoimmunised.