Fetoscopic Laser Ablation for Twin-to-Twin Transfusion Syndrome: A 15-year Review of Perinatal Survival.

Objective Twin to twin transfusion syndrome (TTTS) complicates 5-15% of monochorionic twin pregnancies and untreated is associated with a 90% mortality rate. The aim was to present the perinatal survival of patients with TTTS treated with laser ablation, by a national fetal medicine team. Methods This was a review of all cases of TTTS treated with fetoscopic laser ablation performed from March 2006 through to December 2020. All patients treated with fetoscopic laser were identified from the hospital database. The perinatal outcomes for the overall cohort and the individual Quintero stages were determined. Results A total of 155 cases of TTTS underwent fetoscopic laser ablation during the study period. The median gestational age at diagnosis was 19+1 weeks, with a mean growth discordance of 23.6%. The Quintero stage at diagnosis was: Stage 1 6.5% (10/155), Stage 2 49% (76/155), Stage 3 38.7% (60/155), Stage 4 5.8% (9/155). There was at least one survivor in 83.2% (129/155) of pregnancies, with dual survival in 52.9% (82/155). An increase in the rate of any survivor was observed from 75% (2006-2014) to 94% (2014-2020) (p<0.05). Dual survival decreased with increasing Quintero Stage (p<0.05). 80.6% (125/155) of pregnancies delivered prior to 34+6 weeks gestation. Conclusion Fetoscopic laser ablation is the recommended first line treatment for severe TTTS. We observed a survival rate of at least one twin in 83.2% pregnancies which is comparable to internationally published data on single-centre outcomes.

Sonographic markers of fetal adiposity and risk of Cesarean delivery.

OBJECTIVE: Increased fetal size is associated with shoulder dystocia during labor and subsequent need for assisted delivery. We sought to investigate if increased fetal adiposity diagnosed sonographically in late pregnancy is associated with increased risk of operative delivery. METHODS: This secondary analysis of the Genesis Study recruited 2392 nulliparous women with singleton pregnancy in cephalic presentation, in a prospective, multicenter study, to examine prenatal and intrapartum predictors of Cesarean delivery. Participants underwent ultrasound and clinical evaluation between 39 + 0 and 40 + 6 weeks' gestation. Data on fetal biometry were not revealed to patients or to their managing clinicians. A fetal adiposity composite of fetal thigh adiposity and fetal abdominal wall thickness was compiled for each infant in order to determine whether fetal adiposity > 90th centile was associated with an increased risk of Cesarean or operative vaginal delivery. RESULTS: After exclusions, data were available for 2330 patients. Patients with a fetal adiposity composite > 90th centile had a higher maternal body mass index (BMI) (25 ± 5 kg/m2 vs 24 ± 4 kg/m2 ; P = 0.005), birth weight (3872 ± 417 g vs 3585 ± 401 g; P < 0.0001) and rate of induction of labor (47% (108/232) vs 40% (834/2098); P = 0.048) than did those with an adiposity composite ≤ 90th centile. Fetuses with adiposity composite > 90th centile were more likely to require Cesarean delivery than were those with adiposity composite ≤ 90th centile (P < 0.0001). After adjusting for birth weight, maternal BMI and need for induction of labor, fetal adiposity > 90th centile remained a risk factor for Cesarean delivery (P < 0.0001). A fetal adiposity composite > 90th centile was more predictive of the need for unplanned Cesarean delivery than was an estimated fetal weight > 90th centile (odds ratio, 2.20 (95% CI, 1.65-2.94; P < 0.001) vs 1.74 (95% CI, 1.29-2.35; P < 0.001). Having an adiposity composite > 90th centile was not associated with an increased likelihood of operative vaginal delivery when compared with having an adiposity composite ≤ 90th centile (P = 0.37). CONCLUSIONS: Fetuses with increased adipose deposition are more likely to require Cesarean delivery than are those without increased adiposity. Consideration should, therefore, be given to adding fetal thigh adiposity and abdominal wall thickness to fetal sonographic assessment in late pregnancy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

MRI in adult patients with aortic coarctation: diagnosis and follow-up.

Aortic coarctation is a disease that usually presents in infancy; however, a proportion of patients present for the first time in adulthood. These lesions generally require repair with either surgery or interventional techniques. The success of these techniques means that increasing numbers of patients are presenting for follow-up imaging in adulthood, whether their coarctation was initially repaired in infancy or as adults. Thus, the adult presenting to the radiologist for assessment of possible coarctation or follow-up of coarctation repair is not an uncommon scenario. In this review, we present details of the MRI protocols and MRI findings in these patients so that a confident and accurate assessment can be made.

Red cell alloimmunisation following intrauterine transfusion and the feasibility of providing extended phenotype-matched red cell units.

OBJECTIVES: To analyse the incidence of additional alloantibody formation following intrauterine red cell transfusion and to evaluate the feasibility of providing extended phenotype-matched red cells in future intrauterine transfusion (IUT). BACKGROUND: IUT is performed in severe, life-threatening fetal anaemia, usually in alloimmunised pregnancies. Its complications include the formation of additional alloantibodies to other red cell antigens. MATERIALS AND METHODS: This was an 11-year retrospective, observational study of additional alloantibody formation in patients receiving IUT in the National Maternity Hospital, Dublin. The study included evaluation of the donor population in the Republic of Ireland (RoI) with regards to the feasibility of providing extended phenotype-matched units in future IUT. RESULTS: Following IUT, 22% of mothers formed additional red cell alloantibodies. In 67% of cases, the transfused donor red cells expressed the cognate antigen. Suitable donors are available for most combinations of Fy, Jk and Ss antigens. CONCLUSIONS: In our population, it is feasible to provide more extensively phenotype-matched red cells for future IUT. These can be supplied from the current donor pool with no significant extra phenotyping required. We consider their provision to be a reasonable proactive step in a known at-risk group.

A correlation between severe haemolytic disease of the fetus and newborn and maternal ABO blood group.

OBJECTIVE: To analyse anti-D quantification levels and frequency of intrauterine transfusion (IUT), per maternal ABO blood group. BACKGROUND: Maternally derived red cell allo-antibodies can target fetal red cell antigens in utero leading to haemolytic disease and fetal anaemia. When a clinically significant allo-antibody is formed the priority is ascertaining the risk to the fetus and maternal ABO blood groups are not considered relevant. MATERIALS AND METHODS: This was a 10-year retrospective, observational study carried out on women referred for anti-D quantification (n = 1106), and women whose fetuses required an IUT to treat fetal anaemia (n = 62) due to anti-D, in the Republic of Ireland. RESULTS: Relative to the overall incidence of RhD allo-immunisation by blood group, women of blood group A were more likely to require IUT compared with those who were blood group O (P = 0.002). CONCLUSION: It is known that ABO feto-maternal compatibility can influence the incidence and level of red cell allo-antibodies in pregnancy; however, it does not account for the significantly high rate of severe haemolytic disease requiring IUT seen in blood group A women.

Mode of delivery in pregnancies complicated by major fetal congenital heart disease: a retrospective cohort study.

OBJECTIVE: To determine the mode of delivery in pregnancies complicated by complex fetal congenital heart disease (CHD). STUDY DESIGN: Five-year retrospective cohort study at a tertiary fetal medicine center (2007 to 2011). Cases of complex fetal CHD (n=126) were compared with 45 069 non-anomalous singleton infants ⩾500 g to determine rates of emergency intrapartum cesarean section (CS), preterm delivery and induction of labor. RESULT: Intrapartum CS is significantly higher in fetal CHD than non-anomalous controls (21% vs 13.5%, odds ratio (OR) 1.7, 95% confidence interval (CI): 1.0 to 2.7; P=0.035), predominantly related to CS for non-reassuring fetal status (OR 2.2, 95% CI: 1.1 to 4.1; P=0.022). Although fetal CHD did not increase emergency CS rates in nulliparous women, CS was significantly increased in multiparous pregnancies (OR 2.4, 95% CI: 1.8 to 4.6; P=0.014). Rates of preterm delivery (OR 3.4, 95% CI: 2.0 to 5.4; P<0.0001) and induction of labor (OR 1.9, 95% CI: 1.3 to 2.9; P=0.001) were higher in the CHD cases. CONCLUSION: Emergency CS is increased in fetal CHD, attributed to a higher rate of CS for non-reassuring fetal status and seen mostly in multiparous women.

Reassessing critical maternal antibody threshold in RhD alloimmunization: a 16-year retrospective cohort study.

OBJECTIVE: To determine the critical maternal antibody threshold for specialist referral in cases of RhD alloimmunization. METHODS: This was a retrospective cohort study, covering a 16-year period at the national tertiary fetal medicine center for management of alloimmunization. Data concerning RhD alloimmunized pregnant women were extracted from an institutional database and maternal anti-D antibody levels were cross-checked with the national reference laboratory. Fetal hemoglobin (Hb) levels were determined only at the first intrauterine transfusion (IUT) and were compared with the pretransfusion maternal anti-D antibody level (IU/mL). Sensitivity, specificity and positive and negative predictive values of maternal antibody thresholds for detecting moderate to severe (Hb ≤ 0.64MoM) fetal anemia were calculated. RESULTS: Between 1996 and 2011, 66 women underwent a first IUT for RhD alloimmunization at our institution. The highest serum anti-D antibody level was extracted for 208 RhD alloimmunized women who did not require IUT during the last 10 years of the study period. The traditional maternal antibody threshold of > 15 IU/mL failed to detect 20% of cases of moderate to severe fetal anemia. The ≥ 4 IU/mL threshold had 100% sensitivity but a 45% false-positive rate. The optimal anti-D antibody threshold for specialist referral in our population was ≥ 6 IU/mL; at this level, no case of moderate to severe anemia was missed and specificity was 61%. Use of this threshold would have eliminated 10% of referrals to our fetal medicine unit without compromising fetal outcomes. CONCLUSIONS: Setting the critical maternal RhD antibody level at >15 IU/mL does not provide sufficient sensitivity. The lower threshold of ≥ 4 IU/mL, though sensitive, is associated with a 45% false-positive rate. In our population, a threshold of ≥ 6 IU/mL minimizes false-positive referrals while maintaining 100% sensitivity for moderate to severe fetal anemia.

Routine obstetric ultrasound services.

Antenatal ultrasonography is widely used in pregnancy to assess fetal growth, wellbeing and anatomy. Although ultrasound screening is now an integral part of routine antenatal care, recommendations for the delivery of obstetric ultrasound vary from country to country. A recent survey of English maternity units reported that 100% of women are offered routine mid-trimester fetal anomaly scanning, in line with expert recommendations. Currently in Ireland, no national guidance exists to inform practitioners on the minimum standards for obstetric ultrasound practice. In 2012, we conducted a structured telephone survey of all 20 maternity units in Ireland (n = 74,377 births). Routine mid-trimester anomaly scanning was offered universally to all women in 7/20 (35%) units, offered selectively to some women in 9/20 (45%) units and not offered to any women in 4/20 (20%) of units. The time allotted for a complete fetal anatomical survey was 10-15 minutes in 4/16 (25%) units, 20 minutes in 7/16 (44%) units and 25-30 minutes in 5/16 (31%) units. Written guidelines on the appropriate management of "soft markers" for fetal aneuploidy were routinely used in 11/16 (69%) of units. In no Irish unit currently, are images from fetal anomaly scanning routinely reviewed by an Obstetrician with an interest in fetal medicine. 19/20 (95%) of respondents believed that a minimum of 2 scans should be offered in routine uncomplicated pregnancies. Improvements in the availability of obstetric ultrasound to pregnant women in Ireland will require increased staffing numbers at both the ultrasonographer and fetal specialist levels. There is a clear need for national guidelines on the provision of routine obstetric ultrasound in Ireland.

Obstetric management of moderate and late preterm labour.

Moderate and late preterm births account for the majority of preterm babies. The common perception that birth at 32-36 weeks' gestation carries few risks is now being challenged, as these babies have increased risk of neonatal mortality and morbidity. However, spontaneous labour at this gestation frequently has no specific, easily identifiable precursor, although preterm birth per se has a number of epidemiological and clinical associations. Prediction and prevention of preterm birth is currently largely aimed at identifying women at high risk such as those with previous preterm birth, and targeting intervention at this group. Both cervical length assessment and fibronectin testing permit some modification of the likelihood of preterm birth in this group. Progesterone treatment for the prevention of preterm birth is currently being researched widely, and appears a potentially promising strategy. Babies born at 32-36 weeks' gestation need careful monitoring in labour, with modification of intervention in labour due to their prematurity.

Successful fetoscopic laser coagulation for twin-to-twin transfusion syndrome under local anaesthesia.

A review of the efficacy and outcome of fifteen fetoscopic laser ablations under local anaesthesia for twin to twin transfusion syndrome (TTTS) in the National Maternity Hospital Dublin was undertaken. The mean gestation at laser was 19.7 weeks (range 16-25 weeks) with a mean gestation at delivery of 29.1 weeks (range 20-35 weeks). The overall liveborn birth rate was 79% (22 infants) and one pregnancy was still ongoing. There were four neonatal deaths secondary to complications of prematurity. The surviving eighteen infants (64%) undergo regular paediatric review. The procedure was performed successfully in all cases with local anaesthesia. In no case was there maternal discomfort that warranted the procedure to be abandoned and good visual access of the vascular anastamoses was obtained in all cases. Local anaesthesia therefore offers a safe effective anaesthetic option for fetoscopic laser coagulation in monochorionic pregnancies complicated by TTTS.

Thoraco-amniotic shunting for fetal pleural effusion--a case series.

Fetal pleural effusion is a rare occurrence, with an incidence of 1 per 10-15,000 pregnancies. The prognosis is related to the underlying cause and is often poor. There is increasing evidence that in utero therapy with thoraco-amniotic shunting improves prognosis by allowing lung expansion thereby preventing hydrops and pulmonary hypoplasia. This is a review of all cases of fetal pleural effusion managed over an eight year period the National Maternity Hospital Dublin. Over the nine year period there were 21 cases of fetal pleural effusion giving an overall incidence of 1 per 9281 deliveries. Of these, 15 underwent thoraco-amniotic shunting. There were associated anomalies diagnosed in 5 (33%) of cases. The overall survival in our cohort was 53%. The presence of hydrops was a poor prognostic factor, with survival in cases with hydrops of 33% (3/9) compared to 83% (5/6) in those cases without associated hydrops.

Cardiac drugs used in cross-sectional cardiac imaging: what the radiologist needs to know.

The demand for cross-sectional imaging of the heart is increasing dramatically and in many centres these imaging techniques are being performed by radiologists. Although radiologists are familiar with the computed tomography (CT) and magnetic resonance imaging (MRI) techniques to generate high-quality images and with using contrast agents, many are less familiar with administering the drugs necessary to perform CT coronary angiography and cardiac MR reliably. The aim of this article is to give an overview of the indications for and the contraindications to administering cardiac drugs in cross-sectional imaging departments. We also outline the complications that may be encountered and provide advice on how to treat these complications when they occur.

How effective is amniotomy as a means of induction of labour?

BACKGROUND: Amniotomy or artificial rupture of membranes is routinely used for induction of labour. AIMS: To assess the efficacy of amniotomy alone for induction. METHODS: A retrospective descriptive study of 3,586 cases of amniotomy for induction of labour between July 1996 and December 1999. RESULTS: In total, 26,670 women delivered in the National Maternity Hospital during the study period. Of these 4,928 women required induction of labour and 72.8% of these (n = 3,586) underwent amniotomy only for induction of labour. Spontaneous labour occurred in 90.1% of the women who underwent amniotomy within 24 h. Oxytocin as an induction agent was employed in 9.8% of cases. Overall, 80.5% of the women had a spontaneous delivery, 7.3% had a ventouse delivery, 4.3% had a forceps delivery, and 7.9% underwent a caesarean section. In total, 90.5% of multips and 63.4% of primips had a spontaneous vaginal delivery. CONCLUSIONS: Amniotomy is a simple, safe and effective method of induction of labour.

Natural history of apparently isolated severe fetal ventriculomegaly: perinatal survival and neurodevelopmental outcome.

OBJECTIVE: To review the prenatal diagnosis of apparently isolated severe ventriculomegaly (SVM) in a tertiary referral fetal medicine unit and report on perinatal and neurodevelopmental outcomes. METHODS: All cases of isolated SVM referred to Fetal Medicine at the NMH between 2000 and 2008 were identified. Outcome information was obtained from detailed telephone interviews with parents and paediatric records and histopathology in cases of stillborn fetuses. RESULTS: Thirty-six cases of SVM were referred, out of which 19 were diagnosed with 'apparently' isolated SVM. Macrocrania was present in 88% at 36 weeks (mean HC 439 mm). Cephalocentesis was performed in six cases with poor prognosis. All resulted in perinatal loss. The neurodevelopmental outcome of survivors with isolated SVM (ten live-born survivors) showed major neurological morbidity in 50% (5/10) of the cases, mild morbidity in 40% (4/10) and a normal outcome in only one case. CONCLUSION: Isolated SVM had a very poor perinatal outcome with neurological and physical disability in the overwhelming majority. Only one case of the 17 (6%) diagnosed initially with 'apparently' isolated SVM was born alive without handicap. Information from our series may aid couples in decision making about pregnancy interruption and the difficult decision of prenatal or intrapartum cephalocentesis.

Ultrasound screening for fetal abnormality in Ireland: a national survey.

BACKGROUND: Since 1997, the RCOG have recommended that ultrasound screening for fetal abnormality in pregnancy should be offered to all women. AIM: This study describes the practices and service provision of ultrasound screening for fetal abnormality in Ireland. METHODS: A national survey of all maternity units providing an obstetric ultrasound service (n = 21) was undertaken. RESULTS: All units responded to the survey. First trimester ultrasound for dating was performed routinely in 57% of units. Second trimester ultrasound screening for fetal anomaly was available either routinely or selectively in all units. Wide variations in the management of a pregnancy after an adverse diagnosis were observed. CONCLUSION: This survey indicates a wide variation in the use of ultrasound to screen for fetal abnormality. Recommendations are made to improve the service through the use of a standard protocol to examine fetal structures. A national debate on screening for fetal abnormality is required urgently.