Diamniotic Twin Gestations Research Articles

Survival Outcomes by Fetal Weight Discordance after Laser Surgery for Twin-Twin Transfusion Syndrome Complicated by Donor Fetal Growth Restriction

Introduction: Management options for treatment of twin-twin transfusion syndrome (TTTS) with severe donor intrauterine growth restriction (IUGR) include fetoscopic laser surgery and umbilical cord occlusion (UCO). We studied perinatal survival outcomes in this select group after laser surgery, stratifying patients by preoperative estimated fetal weight (EFW) discordance. Methods: In this retrospective study of monochorionic diamniotic twin gestations with TTTS and selective donor IUGR who underwent laser surgery (2006–2017), preoperative EFW discordance was calculated ([(larger twin – smaller twin)/(larger twin)] × 100) and cases were divided into discordance strata. Severe EFW discordance was defined as >35%. The primary outcome was 30-day donor twin neonatal survival. Results: The 371 cases were distributed by discordance strata: ≤20% (74 [19.9%]), 21–25% (49 [13.2%]), 26–30% (68 [18.3%]), 31–35% (53 [14.3%]), 36–40% (51 [13.7%]), 41–45% (38 [10.2%]), >45% (38 [10.2%]). Donor 30-day survival declined as the discordance strata increased: 86.5, 85.7, 83.8, 75.5, 64.7, 63.2, and 65.8% (p = 0.0046); 30-day survival was inversely associated with severe discordance (>35%) (64.6 vs. 83.2%, p < 0.0001). Discussion: In TTTS cases complicated by donor IUGR with severe growth discordance, laser surgery was associated with donor survivorship greater than 60% suggesting that, in this setting, laser surgery remains a reasonable alternative treatment to UCO.

Renal artery Doppler studies in the assessment of monochorionic, diamniotic twin pregnancies with and without twin-twin transfusion syndrome

In monochorionic, diamniotic twin pregnancies complicated by twin-twin transfusion syndrome, imbalanced fetofetal blood shunting and discordant activation of the renin-angiotensin system result in a hypovolemic, oliguric donor twin and a hypervolemic, polyuric recipient twin. Renal artery Doppler assessments have been reported to predict oligohydramnios in singleton pregnancies; however, their value in assessing monochorionic, diamniotic twin gestations, including pregnancies complicated by twin-twin transfusion syndrome, remains unstudied. This investigation evaluated whether renal artery Doppler parameters are different between sets of monochorionic, diamniotic twins with and without twin-twin transfusion syndrome. We conducted a prospective study of women with monochorionic, diamniotic twin pregnancies complicated by twin-twin transfusion syndrome and women with gestational-age matched monochorionic, diamniotic twin control pregnancies without twin-twin transfusion syndrome. For each twin, renal artery Doppler assessment was performed from a coronal view of the fetus, and pulsatility index, resistive index, and peak systolic velocity were measured. In twin pairs complicated by twin-twin transfusion syndrome, renal artery Doppler pulsatility index, resistive index, and peak systolic velocity intertwin ratios were calculated by comparing paired recipient-to-donor values. Similar ratios were calculated for control twin pairs. We compared each measurement between donors and controls and between recipients and controls. Intertwin ratios were compared between twin-twin transfusion syndrome cases and monochorionic, diamniotic controls. Our primary outcome was a comparison of renal artery Doppler pulsatility index measurement between donor fetuses in twin-twin transfusion syndrome cases and matched control twins. Secondary outcomes included comparisons of other renal artery Doppler parameters between twin-twin transfusion syndrome donor twins and controls and between twin-twin transfusion syndrome recipients and controls and comparisons of the renal artery Doppler parameter ratios between twin-twin transfusion syndrome and non-twin-twin transfusion syndrome twin pair groups. Finally, we performed a subgroup analysis involving pregnancies with twin-twin transfusion syndrome that underwent fetoscopic laser therapy and resulted in twin survivors to evaluate if laser therapy influenced renal artery Doppler findings. We recruited 12 donors and 12 controls. Renal artery Doppler pulsatility index and resistive index did not differ between donors and controls. However, donor renal artery Doppler peak systolic velocity (median, 14.24 [11.51-15.36]) was significantly lower than that of controls (median, 24.79 [22.46-27.03]; P<.0004). When recipient twins were compared with controls, there was no difference in renal artery Doppler pulsatility index, renal artery Doppler resistive index, or renal artery Doppler peak systolic velocity. Renal artery Doppler peak systolic velocity ratios were significantly higher among cases with twin-twin transfusion syndrome (median, 1.70 [1.53-2.02]) than controls (median, 1.06 [1.03-1.15]; P=.002). Applying a renal artery Doppler peak systolic velocity ratio cutoff of >1.35 for the diagnosis of twin-twin transfusion syndrome correctly classified 11 of 12 cases with twin-twin transfusion syndrome and all 12 controls without twin-twin transfusion syndrome (92% sensitivity and 100% specificity). Among donors with twin-twin transfusion syndrome with double survivors after undergoing laser therapy (n=4), prelaser renal artery Doppler peak systolic velocity ratios (mean, 1.46; standard deviation, 0.37) were significantly higher than postlaser renal artery Doppler peak systolic velocity ratios (mean, 0.87; standard deviation=0.37; P=.02). Postlaser intertwin renal artery Doppler peak systolic velocity ratios did not differ from control twin pairs (P=.125). Renal artery Doppler peak systolic velocity ratios differ between monochorionic, diamniotic twins with twin-twin transfusion syndrome and those without twin-twin transfusion syndrome. This effect seems to be driven by altered donor twin renal artery Doppler peak systolic velocity. Laser therapy may normalize renal artery Doppler peak systolic velocity ratios and donor twin renal artery Doppler values to those observed in monochorionic, diamniotic twins without twin-twin transfusion syndrome. Further study is warranted to explore whether renal artery Doppler peak systolic velocity has utility as a tool for twin-twin transfusion syndrome prediction, diagnosis, or staging, and fetal response to laser therapy.

Perinatal outcomes of intrauterine transfusion for the surviving twin in monochorionic twin gestation involving a single fetal demise.

This study aimed to evaluate the feasibility and outcome of intrauterine transfusion (IUT) for the surviving co-twin in monochorionic diamniotic (MCDA) twin gestations involving single intrauterine fetal death (sIUFD). Cases of MCDA twin gestations involving emergent IUT for co-twins experiencing acute feto-fetal hemorrhage (AFFH) subsequent to sIUFD during the second trimester were reviewed. Fetal anemia was confirmed via fetal blood sampling, and perinatal data were retrieved from medical charts to determine the outcomes of surviving co-twins. A poor outcome at 28 days of age was defined as fetal death, neonatal death or neurological impairment such as severe intraventricular hemorrhage or cystic periventricular leukomalacia (PVL). This study included 16 cases of sIUFD diagnosed at a median of 22.5 weeks of gestation (range: 18-25 weeks). The median interval in hours between diagnosis of fetal demise and IUT was approximately 4.2 (0-22) hours. All cases achieved IUT without significant intraoperative complications. Four cases experienced a fetal loss of the co-twin, whereas 12 co-twins were born alive (including 9 preterm births), with only 1 poor outcome in a preterm infant with PVL. IUT may be a feasible prenatal intervention for surviving co-twins with AFFH. However, more extensive or pooled studies are needed to determine the efficacy of this intervention.

Magnetic resonance imaging of the fetal brain in monochorionic diamniotic twin gestation: correlation of cerebral injury with ultrasound staging and survival outcomes.

The current staging system of twin-twin transfusion syndrome (TTTS) is based on the ultrasound criteria and does not consider the cerebral injury. To assess the incidence of cerebral damage on fetal MRI and correlate abnormal cerebral diffusion-weighted imaging (DWI) findings with survival outcome and the ultrasound staging of TTTS. We conducted a retrospective review of MRI/DWI of fetal brains and the electronic medical records in monochorionic diamniotic twin gestations. Axial DWI of each fetal brain was performed on 1.5-tesla (T) clinical magnet with b values of 0s/mm2 and 700s/mm2. We correlated MRI/DWI abnormalities with the Quintero staging system and survival outcomes of the fetuses. Thirty-four pregnancies (68 fetuses) with 42 fetal cerebral abnormalities were identified by MRI/DWI alone. Of these 42 fetal cerebral abnormalities, 33 fetal brain lesions were visible only on DWI (n=25 donor, n=8 recipients; n=30 unilateral, n=3 bilateral; n=26 diffuse, n=7 focal). Quintero staging in these 34 pregnancies was as follows: 9 Stage I, 7 Stage II, 13 Stage III, 4 Stage IV, 1 Stage V. There was no significant correlation between the presence of cerebral infarction or hemorrhage using MRI/DWI and ultrasound staging (P=0.138). The overall survival rate was 63.2% (43/68). There was a significant correlation between the presence of cerebral infarction or hemorrhage on MRI/DWI and delivery status (P=0.009). Abnormal cerebral imaging findings on MRI/DWI from hypoxic-ischemic injury or hemorrhage can be seen at the beginning of the second trimester and do not correlate with the current ultrasound staging system; however, they do correlate with decreased survival. Fetal cerebral abnormalities could be incorporated into the TTTS staging system as an independent risk factor.

Comparing pregnancy outcomes and loss rates in elective twin pregnancy reduction with ongoing twin gestations in a large contemporary cohort

As compared with singleton gestations, twin pregnancies are associated with a significantly higher risk of preterm birth and maternal complications as well as fetal and neonatal morbidity and mortality. Multifetal pregnancy reduction is a technique developed in the 1980s to reduce the fetal number in higher-order multiple pregnancies to reduce the risk of adverse pregnancy outcomes, most importantly preterm birth. The objective of the study was to compare pregnancy outcomes and loss rates in elective twin pregnancy reduction to ongoing twin gestations in a large contemporary cohort. This was a retrospective review of dichorionic diamniotic twin gestations that underwent first-trimester ultrasound at our institution from January 2008 to September 2016. Planned elective 2-to-1 multifetal pregnancy reductions at less than 15 weeks' gestation were compared with ongoing dichorionic diamniotic twin gestations. Data were collected via chart review. Demographics between 2-to-1 reduced singletons and ongoing twins were assessed using a Student t test or a Wilcoxon rank-sum test, as appropriate, for continuous variables and χ2 or Fisher exact tests, as appropriate, for categorical variables. Univariable and multivariable logistic regressions were used to compare pregnancy outcomes between ongoing twins and reduced singletons adjusting for maternal age, body mass index, race, invitro fertilization, use of chorionic villus sampling, prior term birth, and prior preterm birth. Of 1070 dichorionic diamniotic twin pregnancies identified, completed follow-up data were available and analyzed for 855 patients (79.9%). Among those, 250 (29.2%) were 2-to-1 singletons and 605 (70.8%) were ongoing twins. Reduced singleton patients were slightly older, more likely white, and had lower body mass index. They were also more likely to have undergone invitro fertilization (63.6% vs 48.8%), had chorionic villus sampling (92% vs 37.5%), and had prior term births (54% vs 35.7%). Compared with 2-to-1 singletons, the adjusted odds of having preterm delivery at 37 weeks for ongoing twins were 5.62 times (95% confidence interval, 3.67-8.61; P < .001) and 2.22 times (95% confidence interval, 1.20-4.11; P < .001) at 34 weeks. While intrauterine growth restriction, placental abruption, and gestational diabetes were not significant, ongoing twins were more likely to have a cesarean delivery (odds ratio, 5.53, 95% confidence interval, 3.60-8.49; P < .001) and preeclampsia (odds ratio, 3.33, 95% confidence interval, 1.60-6.96; P < .001) after adjusting for maternal characteristics. There were also significant differences between groups for preterm premature rupture of membranes and low birthweight at less than the fifth and 10th percentiles. Total pregnancy loss (at 24 and 20 weeks) was similar between singleton and ongoing twins (4% vs 2.5%, P= .23, and 3.6% vs 1.7%, P= .09 for respective weeks). There were no significant differences in the rate of unintended pregnancy loss (2.4% vs 2.3%; P= .94) and the rate of intrauterine fetal death greater than 24 weeks (1.2% vs 0.7%; P= .43) in reduced singleton versus ongoing twin group, respectively. In our study, patients who elected to reduce to a singleton pregnancy had a higher gestational age of delivery and lower rates of preterm birth and pregnancy complications without an increased risk of pregnancy loss.

Sildenafil use in twin IUGR pregnancy

Introduction: Intrauterine growth restriction (IUGR) is defined as a fetus failing to reach its genetically defined growth potential. IUGR affects approximately 5% of singleton pregnancies and 25% of twin ones. Still, there is not yet an effective medical therapy for this disorder. IUGR is managed by monitoring of the fetal condition, with timely delivery in case of compromise. Unsurprisingly, it is often complicated by early fetal prematurity, accentuating the major risks IUGR poses to perinatal morbidity and mortality. Evidence is increasing for using of sildenafil in IUGR singleton pregnancies. Nevertheless little evidence exists in the literature about its use in di-chorionic di-amniotic twin gestations with IUGR.

Prenatal Diagnosis and Management of Fetal Goiter: A Case Series from Tertiary Perinatal Center in South India

ABSTRACTAims and objectivesThe reported incidence of fetal goiter is 1 in 40,000 live births. The effects of fetal goiter and thyroid dysfunction are significant. The objective of our study is to assess the safety, feasibility, and efficacy of intra-amniotic instillation of levothyroxine (LT4) in fetal goitrous hypothyroidism.Materials and methodsA retrospective observational study of prenatally diagnosed cases of fetal goiter on routine antenatal ultrasound between January 2010 and January 2018 at Fernandez Hospital Foundation, Hyderabad, tertiary perinatal referral center. Data retrieved from electronic database.ResultsDuring this period, 9 cases of fetal goiter were diagnosed on routine ultrasonography with the incidence of 1 in 7,000 live births. The gestation age at diagnosis ranged between 21 weeks and 29 weeks (mean 26 weeks). Of the nine fetuses with goiter, two were excluded as one ended in a miscarriage at 22 weeks and the other was terminated elsewhere at 26 weeks. Data were analyzed in the remaining seven fetuses. Cordocentesis was performed in five fetuses and amniocentesis was performed in one woman with dichorionic diamniotic (DCDA) twin gestation which revealed hypothyroid status. Fetal therapy was offered to all the remaining seven fetuses with intra-amniotic instillation of LT4 100 to 200 μg at 2–3 weeks’ interval. First dose of LT4 was given at mean gestation of 27 weeks (range 23–30 weeks), and the mean time between the identification of fetal goiter and the first dose of LT4 was 6 days (range 2–15 days). Number of injections given ranged between 1 and 7. No adverse events were recorded. Follow-up sonogram showed subjective reduction in the goiter size. All the babies had hypothyroidism at birth.ConclusionOur case series confirms the safety and feasibility of intra-amniotic instillation of LT4 for fetal goitrous hypothyroidism. Although fetal therapy has resulted in reduction in the size of the goiter, the thyroid hormone levels at birth were low. Further research is required to establish the proper management guidelines for this disorder.How to cite this articleBudidapadu M, Vavilala S, Kolar G. Prenatal Diagnosis and Management of Fetal Goiter: A Case Series from Tertiary Perinatal Center in South India. Int J Infertil Fetal Med 2019;10(3):37–41.

Longitudinal reference ranges for serial measurements of myocardial performance index (MPI) by conventional and pulsed-wave tissue Doppler in monochorionic diamniotic twins at 17 to 26weeks of gestation.

To describe the longitudinal changes of fetal myocardial performance index (MPI) measured by conventional Doppler (MPI) and by pulsed-wave tissue Doppler (MPI') based on a prospective cohort of uncomplicated monochorionic diamniotic twin. Single-center observational study. We measured MPI and MPI' in the right and left ventricles 3 times between 17 and 26weeks of gestation. Second-degree fractional polynomials were built to obtain the best fitting curves in relation to gestational age (weeks) for each parameter. Gestational age-specific reference values were estimated by using two-level hierarchical models. Eighty-three uncomplicated monochorionic pregnancies were included in our study with a total of 249 observations. Fetal cardiac function was measured as MPI RV and LV, MPI' RV and LV at a mean gestational age of 18+3 (range 17+1 to 19+2 ), 22+3 (21+1 to 23+5 ), and 24+3 (22+6 to 26+2 ) weeks. The reference ranges for MPI LV, MPI RV, MPI' LV, and MPI' RV at 17 to 26weeks were constructed and conditional percentiles calculated. The present study provides additional data on fetal cardiac function in uncomplicated monochorionic diamniotic twin gestations, describing the evolution of MPI and MPI' in both ventricles in uncomplicated monochorionic diamniotic pregnancies.

Prenatal Diagnosis of Fetus in Fetu pregnancy

Fetus in fetus (FIF) represents an abnormal embryogenesis in monozygotic diamniotic twin gestation. It has been described in less than 200 cases worldwide. Differential diagnosis predominantly includes teratomas. The case presented here meets the accepted criteria of FIF and is one of the few prenatally diagnosed cases with FIF.

The Utility of Transvaginal Cervical Length in Predicting Delivery Interval in Viable Outpatient Twin Pregnancies [27P

INTRODUCTION: Predicting preterm delivery in twin gestations helps identify women who may benefit from interventions such as antenatal corticosteroids within 7 days of delivery. Our aim was to quantify the performance of short cervical length (CL) (&lt;25mm) in outpatient twin gestations to predict delivery within 7 days. METHODS: Outpatient transvaginal ultrasound reports for diamniotic twin gestations of 23w 0d to 28w 6sd were reviewed between January 2010-July 2014. Index CL was defined as the first CL less than 25mm. Primary outcome was the positive predictive value (PPV) of spontaneous delivery within 7 days of index CL. Secondary outcomes included PPV of index CL of 15mm and 10mm. RESULTS: Of the 411 included charts, 52 patients (12.6%) had a short cervix. There were no significant differences in major risk factors for preterm birth. Four women (1% of the total study population) delivered within 7 days of index CL; three of these had a short cervix while one had a normal CL. PPV of 25mm CL was 5.8% (95% CI 1.2-16.0); NPV 99.7% (95% CI 98.5- &gt;99.9). The PPV of 15mm and 10mm CL were 9.1% (95% CI 1.1-29.2) and 20.0% (95% CI 7.5-55.6). CONCLUSION: In this retrospective observational study, CL of less than 25mm had a poor positive predictive value for delivery within 7 days. 25mm CL cutoff may not be useful to time interventions such as betamethasone administration or hospitalization. PPV increases with decreasing CL. Other tools can be considered in addition to CL measurement for intervention.

Survival Rate without Brain Abnormalities on Postnatal Ultrasonography among Monochorionic Twins after Fetoscopic Laser Photocoagulation for Selective Intrauterine Growth Restriction with Concomitant Oligohydramnios

Introduction: We aimed to clarify the survival rate without brain abnormalities (BA) after fetoscopic laser photoco­agulation (FLP) for monochorionic diamniotic twin gestations (MCDA) with selective intrauterine growth restriction (sIUGR) accompanied by abnormal umbilical artery (UA) Doppler waveforms and isolated oligohydramnios in the sIUGR twin. Materials and Methods: This retrospective study included 52 cases that underwent FLP. The main outcome was survival rate without BA of the twins at age 28 days. BA was defined as severe intraventricular hemorrhage and periventricular leukomalacia on postnatal ultrasonography. Results: Median gestational age at FLP was 20 (16–24) weeks. Ten cases were classified as type III based on Doppler for the UA. For all cases, including 20 cases of anterior placenta, FLP was completed without major intraoperative complications. Amnioinfusion was required in 49 cases for better fetoscopic visualization. Fetal loss occurred in 29 sIUGR twins and two larger twins, whereas one larger twin experienced neonatal death. Survival rates without BA were 44% (n = 23) for sIUGR twins and 94% (n = 49) for the larger twins. Discussion: FLP for MCDA with sIUGR presenting with oligohydramnios in the sIUGR twin might be considered a prenatal treatment option.

Third-trimester ultrasound diagnosis of twin-to-twin transfusion syndrome (TTTS) – A review of two cases

Twin‑to‑twin transfusion syndrome (TTTS) is an unbalanced net transfusion of blood between twin fetuses through placental anastomoses. It is a complication of monochorionic diamniotic (MCDA) twin gestation in which one of the twins is the donor while the other twin acts as the recipient. TTTS without treatment is a major cause of increased morbidity and mortality among MCDA twin pregnancies. Ultrasound diagnosis and staging of TTTS are based on Quintero staging which influences the choice of management. We present two cases of ultrasound diagnosed TTTS. A 27‑year‑old G2P1+0 with twin gestation who had an ultrasound scan at 34 weeks gestation, and a diagnosis of Quintero stage 1 TTTS was made. She had an emergency caesarian operation and was delivered of two live babies. A 24‑year‑old G1P0+0 with twin gestation who had an ultrasound scan at 35 weeks gestation, with a diagnosis of Quintero stage 5TTTS. The donor twin was alive while the recipient twin had hydrops fetalis with no cardiac activity. An emergency caesarian section was done and the donor twin survived. TTTS is a common complication among MCDA twins and it is a cause of increased morbidity and mortality among them. Early diagnosis through ultrasonography and prompt management will help reduce the morbidity and mortality associated with the syndrome. Keywords: Third trimester; twin‑to‑twin transfusion syndrome; ultrasound

257: Rates of pregnancy loss in dichorionic diamniotic twin gestations undergoing chorionic villus sampling

257: Rates of pregnancy loss in dichorionic diamniotic twin gestations undergoing chorionic villus sampling

Multifetal Pregnancy Reduction of Trichorionic Triplet Gestations: What is the Benefit?

Objective This study aims to determine the efficacy of multifetal pregnancy reduction (MFPR) in improving obstetrical outcomes for trichorionic triplet gestations. Study Design Retrospective cohort study of patients with multiple gestations delivered by a single maternal-fetal medicine practice from 2005 to 2016. We compared patients with trichorionic triamniotic triplet gestations who underwent MFPR to those with an ongoing triplet pregnancy (TT), as well as primary dichorionic diamniotic twin gestations (DD). Logistic regression analysis was used to control for any differences at baseline. Results There were 42 patients in the MFPR group, 43 women in the TT group, and 693 women in the DD group. Comparing MFPR to TT, the likelihood of preterm birth &lt; 34 weeks was similar (31.0 vs. 39.5%, adjusted odds ratio [aOR]: 0.63, 95% confidence interval [CI]: 0.21, 1.87). There were no differences in gestational age at delivery, pregnancy loss &lt; 24 weeks, or the likelihood of all, none, or at least two babies surviving to discharge. Mean birth weights were significantly higher and cesarean delivery rates lower for MFPR (2,128 vs. 1,836 g, p = 0.028 and 69 vs. 86%, aOR: 0.25, 95% CI: 0.06, 0.94) as compared with the TT group. MFPR had significantly worse outcomes than DD. Conclusion In trichorionic triamniotic triplet pregnancies, our study suggests that obstetrical outcomes may not be as dramatically improved with MFPR as seen in older studies.

Twin Anemia Polycythemia Sequence: A Complication of Monochorionic Diamniotic Twin Gestation [16P

INTRODUCTION: Twin anemia polycythemia sequence (TAPS) is an important prenatal complication of monochorionic twin gestations due to abnormal placental vascular anastomosis. Prenatal ultrasound is the only screening modality. Our objective was to evaluate the prediction potential of current prenatal ultrasound screening in diagnosing TAPS in monochorionic diamniotic twin gestations. METHODS: Maternal and neonatal medical records were reviewed for women with monochorionic diamniotic twins who delivered at Beaumont Hospital System (Royal Oak and Troy) from 2009-2014. Available prenatal ultrasound findings were compared with the neonatal outcomes. Postnatal TAPS diagnosis was confirmed with neonatal peripheral blood hemoglobin values. RESULTS: A total of 132 maternal charts were reviewed and 102 were used in data collection. The median maternal age was 31 years (19-45) with a median parity of 1 (0-3). Among these women 10% (n=10) had assisted reproductive technology. Median gestational age at time of delivery was 35.4 weeks (20.7-39). Median NICU stay for twin A and twin B were 9 (0-264) and 8.5 days, (0-103), respectively. Among 132 prenatal ultrasound screenings, 26% (n=32) were reported as abnormal. Thirty-three percent (n=34) of the neonates were diagnosed with anemia and polycythemia; of these neonates 29% (n=30) had anemia, 4% (n=4) had polycythemia. The sensitivity and specificity of prenatal ultrasound in the prediction of TAPS was 26% (95% CI: 13-44) and 77% (95% CI: 65-87), respectively. CONCLUSION: Current prenatal ultrasound screening guidelines have low sensitivity and specificity in predicting TAPS in monochorionic diamniotic twin gestations. New and updated prenatal screening methods may improve TAPS prediction.

Cervical cerclage for preterm birth prevention in twin gestation with short cervix: a retrospective cohort study.

To determine if cervical cerclage reduces the rate of spontaneous early preterm birth in cases of dichorionic-diamniotic (DCDA) twin gestation with an ultrasound-detected short cervix. This was a retrospective cohort study of 40 consecutive DCDA twin gestations at Saint Peter's University Hospital from November 2006 to November 2014 in which cervical cerclage was performed for an ultrasound-determined cervical length of 1-24 mm at 16-24 weeks' gestation. The cases were matched with 40 controls without cerclage for cervical length and gestational age at cervical assessment. The primary outcome measure was spontaneous birth < 32 weeks. There was no difference between the two groups in maternal age, body mass index (BMI), cigarette smoking, use of in-vitro fertilization (IVF), parity and prior spontaneous preterm birth. There were more Caucasian women among the controls compared with cases. In the cases, compared with controls, spontaneous delivery < 32 weeks was significantly less frequent (20.0% vs 50.0%; relative risk, 0.40 (95% CI, 0.20-0.80)). In the prediction of spontaneous delivery < 32 weeks, logistic regression analysis demonstrated that the risk was reduced with the insertion of cervical cerclage (odds ratio, 0.22 (95% CI, 0.058-0.835); P = 0.026), corrected for maternal age, BMI, racial origin, cigarette smoking, IVF, parity and previous preterm birth. In DCDA twin gestation with a short cervix, treatment with cervical cerclage may reduce the rate of early preterm birth. The findings suggest the need for adequate randomized controlled trials on cerclage in twin gestations with a short cervix. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Twin-twin transfusion and laser therapy.

Twin-to-twin transfusion syndrome (TTTS) is an uncommon, but dangerous, complication of monochorionic diamniotic twin gestations. The purpose of this review is to provide an update on the evolving treatments in TTTS as it pertains primarily to laser photocoagulation, as well as to provide recently published information on outcomes. The Solomon laser technique, in which selective fetoscopic laser photocoagulation is first performed and then followed by laser of the vascular equator from one side of the placenta to the other, reduces TTTS complications of twin anemia-polycythemia syndrome and recurrent TTTS. The addition of fetal echocardiography to the historical staging of TTTS adds important information that may guide future therapies. The postlaser ablation rate of neurodevelopmental delay in TTTS has recently been reported to be 14%. Cotwin demise is a significant complication of untreated TTTS and survival carries a 25% risk of cystic periventricular leukomalacia, middle cerebral artery infarction, and injury to other central nervous system structures as noted by neuroimaging. Laser therapy for TTTS is clearly the only therapy that halts the disease process, allows both fetuses an opportunity to survive and protects a surviving cotwin in the event of the demise of one twin. Laser techniques have evolved greatly over the last 25 years and recent reports with the addition of the Solomon technique appearing to reduce some postlaser complications (twin anemia-polycythemia sequence and recurrent TTTS). Future focus of TTTS therapy should be centered on understanding the pathophysiology of the disease better with improvement in staging of the disease and on comparison of different laser techniques with the overall goal of not only increasing twin survival rates but also reducing long term neurodevelopmental morbidity.

Intrahepatic Cholestasis of Pregnancy with Severe Elevation of Bile Acids in the Setting of Acute Hepatitis C Infection.

Intrahepatic cholestasis of pregnancy (ICP) is a complication of pregnancy resulting in elevation of serum bile acid levels. ICP is often associated with underlying liver disease, including hepatitis C. Bile acids in relationship to the acute infection of hepatitis C virus have not yet been delineated in the literature. A 26-year-old gravida 4 para 2103 with dichorionic, diamniotic twin gestation and history of intravenous drug abuse developed ICP in the setting of acute hepatitis C infection. In addition to clinical symptoms of pruritus and right upper quadrant pain, she developed severe elevation in bile acids, 239 micromol/L, and transaminitis aspartate aminotransferase 1033 U/L, and alanine aminotransferase 448 U/L. She received ursodeoxycholic acid and antenatal testing was performed. Patient delivered vaginally at 33-week gestation following preterm rupture of membranes. Neonates were admitted to NICU and had uncomplicated neonatal courses. In the setting of ICP with significant transaminitis and severe elevation of bile acids, consideration of acute viral hepatitis is important, especially considering the worsening opioid epidemic and concurrent increase in intravenous drug use in the United States. Further study is needed regarding the acute form of HCV infection and its effect on ICP and associated bile acids.

Abnormal Biochemical Analytes Used for Aneuploidy Screening and Adverse Pregnancy Outcomes in Twin Gestations.

The objective of this study was to determine if first- and second-trimester biochemical markers for aneuploidy have an association with adverse pregnancy outcomes in twin gestations. A retrospective cohort study of patients who presented with dichorionic diamniotic twin gestations was performed. Patients with first-trimester low pregnancy-associated plasma protein A (PAPP-A) or low free β human chorionic gonadotropin (β-hCG), or second-trimester elevated α-fetoprotein (AFP), elevated inhibin A, elevated hCG, or low unconjugated estradiol were identified. The rates of adverse pregnancy outcomes were compared between patients with or without abnormal analytes with p < 0.05 used as significance. In this study, 340 pregnancies were included. Patients with a low PAPP-A had an increased risk for delivery < 37 weeks. Patients with an elevated second-trimester hCG had an increased risk for spontaneous delivery < 28 weeks and neonatal intensive care unit (NICU) admission. Patients with an elevated inhibin A had an increased risk of spontaneous delivery at < 37 and NICU admission. Patients with an elevated AFP had an increased risk of a NICU admission. Certain abnormal aneuploidy markers are associated with an increased risk of adverse pregnancy outcomes in twin gestations.

477: Mode of delivery and outcomes in twins less than 32 weeks gestation

Vaginal delivery of twins requires a provider experienced in vaginal breech delivery of the second twin. ACOG/SMFM suggest vaginal delivery is reasonable in diamniotic twin gestations ≥ 32-0/7 weeks with a vertex presenting twin. Evidence is limited regarding delivery mode for twins < 32 weeks. Our practice is to offer vaginal delivery to diamniotic twins with a vertex presenting twin, regardless of gestational age. The objective of this study was to evaluate outcomes of diamniotic twin pregnancies < 32 weeks by mode of delivery.