Monochorionic Diamniotic Twin Pairs Research Articles

Aberrant Fetal Brain Sulcus Formation: A Clue to the Diagnosis of Sotos Syndrome.

This study aims to elucidate two distinct fetal ultrasound features associated with aberrant brain sulcus formation as potential prenatal markers for Sotos syndrome caused by mutations in the NSD1 gene. This retrospective study investigated three fetuses across two pregnancies, including a pair of monochorionic diamniotic twins, all diagnosed with Sotos syndrome via whole exome sequencing (WES). Comprehensive clinical and laboratory data were collected and analyzed. Each fetus underwent a series of specialized neurosonographic assessments to evaluate the development of the cerebral cortex. All three fetuses exhibited aberrant brain sulcus formation characterized by Sylvian fissure (SF) abnormalities and shallow parietooccipital sulcus (POS). WES revealed the presence of two de novo NSD1 variants in these fetuses. Fetal aberrant brain sulcus formation may represent a distinctive ultrasound feature indicative of Sotos syndrome, thereby offering additional diagnostic insights for the identification of this condition.

Calcium, Potassium, Sodium, and Magnesium Concentrations in the Placenta, Umbilical Cord, and Fetal Membrane from Women with Multiple Pregnancies.

Calcium (Ca), potassium (K), sodium (Na), and magnesium (Mg) are the elements responsible for the fundamental metabolic and biochemical processes in the cells of the body. The demand for these elements increases significantly during pregnancy, where an adequate supply protects women from the hypertension common in pre-eclampsia and preterm labor. This study aimed to evaluate the association between macro-elements (Ca, Mg, Na, and K) in the placenta, fetal membrane, and umbilical cord and the morphometric parameters of newborns from multiple pregnancies. The study involved 57 pregnant European women with healthy uncomplicated twin pregnancies (n = 52) and triple pregnancies (n = 5); 40 pairs of dichorionic diamniotic twins, 11 pairs of monochorionic diamniotic twins, 1 pair of monochorionic monoamniotic twins, 3 trichorionic triamniotic triplets, and 2 dichorionic triamniotic triplets. Placentas (n = 107), umbilical cords (n = 114), and fetal membranes (n = 112) were collected immediately following delivery, and then weighed and measured. The levels of Ca, K, Na, and Mg were determined using inductively coupled plasma atomic emission spectroscopy (ICP-OES) in a Thermo Scientific ICAP 7400 Duo (Waltham, MA, USA). The respective mean concentrations of Ca, K, Na, and Mg (mg/kg-1 dry mass) were: 2466, 8873, 9323, and 436 in the placenta; 957, 6173, 26,757, and 326 in the umbilical cord, and 1252, 7460, 13,562, and 370 in the fetal membrane. In the studied materials from northwestern Poland, we found strong positive correlations between Ca and Mg concentrations in both the umbilical cord (r = 0.81, p = 0.00) and the fetal membrane (r = 0.73, p = 0.00); between K and Mg concentrations in the umbilical cord (r = 0.73, p = 0.00); between Ca and K concentrations in the fetal membrane (r = 0.73, p = 0.00), and we found moderately positive correlations between placental Ca concentration and placental weight (ρ = 0.42, p = 0.00) and between umbilical cord Mg concentrations and the length of the pregnancy (ρ = 0.42, p = 0.00). Negative correlations were found between Na and Ca concentrations in the fetal membrane (r = -0.40, p = 0.00) and Na concentrations in the fetal membrane and Mg concentrations in the placenta (r = -0.16, p = 0.02). Negative correlations were confirmed between the length of pregnancy and head circumference (ρ = -0.42; p = 0.00), infant weight (ρ = -0.42; p = 0.00), infant length (ρ = -0.49; p = 0.00), shoulder width (ρ = -0.49; p = 0.00); and between the infant weight and head circumference (ρ = -0.62; p = 0.00), weight before delivery (ρ = -0.36; p = 0.00), infant length (ρ = -0.45; p = 0.00), shoulder width (ρ = -0.63; p = 0.00), and weight gain during pregnancy (ρ = -0.31; p = 0.01). We found statistically significant correlations between cigarette smoking before pregnancy and the women's weight before delivery (ρ = 0.32, p = 0.00), and a negative correlation between the women's ages and infant head circumference (ρ = -0.20, p = 0.02). This is probably the first study to evaluate Ca, Na, K, and Mg concentrations in the afterbirth tissues of multiple pregnancies. It adds to the knowledge of elemental concentrations in multiple pregnancies and their possible effects on fetal morphometric parameters.

Left myocardial performance index in monochorionic diamniotic twin pairs complicated by selective fetal growth restriction with abnormal umbilical artery Doppler

To evaluate left myocardial performance index (MPI) and its time intervals in monochorionic diamniotic (MCDA) twin pairs complicated by selective fetal growth restriction (sFGR) with abnormal (persistent -type II- or intermittent -type III- absent or reversed end-diastolic flow) umbilical artery Doppler. Retrospective study including 16 MCDA twin pairs with sFGR type II, 26 MCDA twin pairs with sFGR type III and 42 gestational age-matched uncomplicated MCDA twin pairs in a single tertiary center. Left isovolumetric contraction time (ICT), ejection time (ET), and isovolumetric relaxation time (IRT) were measured and MPI calculated by conventional Doppler at diagnosis of sFGR. In sFGR type II, the smaller twin had shorter ET and prolonged IRT and MPI, while the larger twin showed prolonged ICT and MPI as compared to uncomplicated MCDA twins. In sFGR type III, the smaller twin had shorter ICT and ET, while the larger twin showed prolonged ICT, IRT, and MPI in comparison to controls. A differential pattern of MPI time intervals could be observed in MCDA twins with sFGR type II and III. All twins had echocardiographic signs of pressure/volume overload, except the smaller twin type III with shorter systolic times probably reflecting reduced volume load.

Intrafetal Laser Coagulation for Trap Sequence in a Complicated Dichorionic Triamniotic Triplet Pregnancy Case Report and Review of the Literature

Summary A rare case is reported of twin-reversed arterial perfusion (TRAP) sequence in a triplet pregnancy, fetal intervention in the first trimester and pregnancy outcome. We report a case of TRAP sequence complication in dichorionic triamniotic triplet pregnancy, with a normally developing fetus and an acardiac fetus connected via arterio-arterial anastomoses in a monochorionic diamniotic twin pair and a separate fetus. TRAP sequence was diagnosed at 13 weeks in triplet pregnancy after in vitro fertilization (IVF) and embryo transfer of two blastocysts. Color Doppler assessment showed persistent arterial flow in the acardiac twin. Intrafetal laser coagulation was carried out at the time of the diagnosis, and the pregnancy outcome was two survivals at 36.4 weeks of gestation.

Different patterns of left ventricular "rigid body rotation" in 8-year-old twins with anamnestic twin-to-twin transfusion syndrome (from the MAGYAR-Twin Study).

Cardiac dysfunction could be present in twins with anamnestic twin-to-twin transfusion syndrome (TTTS) (1). An 8-year-old monochorionic diamniotic twin pair with anamnestic TTTS was referred for echocardiographic examination. Twins presented prematurity at birth (donor twin: weight, 1,570 g; Apgar: 3-7-9; recipient twin: weight: 2,490 g; Apgar: 8-9-10).

Prenatal diagnosis of five cases of monochorionic-diamniotic twins discordant for karyotype analysis

OBJECTIVE To explore the mechanism and diagnostic method for monochorionic-diamniotic twins discordant for karyotype analysis. METHODS Dual amniocentesis was performed on five pairs of monochorionic-diamniotic twins, which all consisted of a normal twin and one with multiple malformations revealed by ultrasound. Karyotype analysis was performed on amniocytes derived from each of the twins. Zygosity was also determined with DNA extracted from amniocytes with 16 polymorphic microsatellite markers. RESULTS Three cases of 45,X, one case of 47,XX,+9 and one case of 47,XY,+18 were detected among the abnormal twins, while the normal fetuses all had a normal karyotype. DNA analysis suggested that, in all cases, the twins have shared the 16 polymorphic microsatellite markers, which confirmed their monozygosity. CONCLUSION Monochorionic-diamniotic twins may be discordant for karyotyping, for which anaphase lagging, chromosomal non-disjunction and trisomy rescue may be the underlying reasons. As a simple method, dual amniocentesis can be used to obtain amniotic fluid samples for karyotype analysis and determination of zygosity for such twins.

Testicular hypoplasia in monochorionic dizygous twin with confined blood chimerism

Monochorionic diamniotic (MCDA) twins identified by ultrasound in early pregnancy are rarely dizygotic. Since Shouter et al. first reported that MCDA twin pregnancies can occur in dizygous (DZ) twin pregnancies, there have been about ten reports of such cases [1]. MCDZ twins can be easily overlooked except in cases of discordant sex discovered during prenatal care or delivery of MCDA twins. In our case, chimerism of a set of MCDZ twins was confirmed by STR analysis for both parents and the live male twin after the discovery of discordant sex in a pair of MCDA twins at delivery. Testicular atrophy was suspected in a follow-up sonogram of the testes of the live male twin; Testicular hypoplasia was revealed by a subsequent testicular biopsy. We report herein a rare case of testicular hypoplasia in a male infant with chimerism that was observed on follow-up examination after birth.

Perinatal outcome of monochorionic diamniotic twins with selective intrauterine growth restriction

To evaluate the perinatal outcome of three types of monochorionic diamniotic (MCDA) twins with selective intrauterine growth restriction (sIUGR). From January 2005 to June 2012, clinical data of 42 pairs of MCDA twins (84 fetuses) with sIUGR and 71 pairs of normal MCDA twins (142 fetuses) in the same period were analyzed retrospectively in the First Affiliated Hospital of Sun Yat-Sen University. Fetuses with sIUGR were classified into three groups based on umbilical artery Doppler flow.There were 25 cases of type I, 11 cases of type II and 6 cases of type III. The perinatal outcome was compared between sIUGR and normal MCDA twins, and among the three types of sIUGR as well. Perinatal outcomes included gestational age at delivery, rate of intrauterine fetal death (IUFD), birth weight, intertwin discordance of birth weight, neonatal death and survival rate at 6 months. (1) The gestational age of sIUGR at delivery was significantly earlier than the control group [(34±3), (36±2) weeks, respectively], and the rate of IUFD of both fetuses of sIUGR was significantly higher (4.8%, 0, respectively). In the sIUGR group, the average birth weight of large or small twins [(2130±350), (1520±400) g, respectively] was smaller than those in the control group [(2470±500), (2340±460) g, respectively]. The difference was statistically significant (P<0.05, P<0.01, respectively). The intertwin discordance of birth weight in sIUGR group was significantly larger (27.6%) than the control group (4.0%, P<0.01). (2) The gestational age at delivery in type II and type III [(34±5), (34±2) weeks, respectively] was significantly earlier than the control group (P<0.05). The rate of IUFD of both fetuses in type II (18%) was significantly higher than in type I (0) and the control group (0, P<0.05). In sIUGR group, the average birth weight of small twins in type I, type II and type III was (1640±430), (1330±310) and (1500±380) g respectively, all of which were significantly smaller than that in the control group (P<0.05). The average birth weight of small twins in type II was smaller than in type I and the difference was statistically significant (P<0.05). In sIUGR group, the intertwin discordance of birth weight in type I, type II and type III was 24.1%, 34.6%, 31.3% respectively, all of which were significantly larger than that in the control group (4.0%, P<0.05). There were no statistically significant differences of the intertwin discordance of birth weight among the three types of sIUGR (P>0.05). Survival rate at 6 months in type II (64%) was significantly lower than in type I (92%) and the control group (91.5%, P<0.01). The perinatal outcome of MCDA twins with sIUGR is poor. The outcome is different among the three types of sIUGR, and typeIIis the worst. Type II is associated with a high risk of intrauterine fetal demise. It is important to monitor the intrauterine situation closely.

Severe retinopathy of prematurity with retinal detachment in monozygotic twins

We report a monochorionic diamniotic twin pair born at 29 weeks of gestation in which both twins developed severe retinopathy of prematurity (ROP) with retinal detachment. The pregnancy was terminated due to reversal of donor-recipient phenotypes in possible TTTS. Both twins had unstable cardiopulmonary status during the first week, and developed chronic lung disease. The larger twin, born at 1372 g, developed stage 4a ROP in both eyes, and the smaller twin, born at 1168 g, developed stage 4a ROP in the left eye. Genetic analysis of NDP, FZD4, LRP5, TSPAN12 genes revealed no mutations; however, VEGF gene polymorphism analysis showed heterozygous carrier state of the VEGF 936T allele in both twins, which is a risk factor for threshold ROP in Japanese newborn infants. We speculate the synergistic effects of unstable perinatal cardiopulmonary status and genetic predisposition due to VEGF 936C>T polymorphism caused the development of severe ROP with retinal detachment.

Assessment of Cardiac Function in Monochorionic Diamniotic Twin Pregnancies with Twin-to-Twin Transfusion Syndrome Before and After Fetoscopic Laser Photocoagulation Using Speckle Tracking

To assess cardiac function with Speckle tracking in fetuses with twin-to-twin transfusion syndrome (TTTS) before and after laser therapy. A prospective case control study was conducted on 11 monochorionic diamniotic twin pairs with TTTS. Based on normal curves derived from healthy controls, global systolic longitudinal myocardial velocity, strain and strain rate values were transformed to z-scores. Right and left ventricular systolic global strain (-27.45 % and -22.41 %) and strain rate (-4.13/sec and -3.27/sec) were reduced in recipients compared with normal values and all parameters tended to decrease even more after treatment (RV and LV: strain -23.79 % and -20.21 %; strain rate: -3.67/sec and -2.87/sec). The corresponding measurements in donor fetuses revealed no statistical difference compared to reference values. The global systolic myocardial function of donor twins before and after laser therapy was in the normal ranges. In contrast, recipient twins exhibited global cardiac dysfunction with decreased pre- and postoperative strain and strain rate. Speckle tracking can identify compromised ventricular myocardial function in fetuses with TTTS.

Vascular programming in twins: the effects of chorionicity and fetal therapy for twin-to-twin transfusion syndrome.

We assessed vascular programming in genetically identical monochorionic twin pairs with twin-to-twin transfusion syndrome (TTTS) treated differently in utero by serial amnioreduction or fetal laser arterial photocoagulation. This case-control study re-assessed four twin groups at median 11 years comprising 20 pairs of monochorionic diamniotic twins: nine treated by amnioreduction (TTTS-amnio) and eleven by laser (TTTS-laser) with seven monochorionic and six dichorionic control pairs. Outcome measures were current blood pressure (BP), brachio-radial arterial stiffness derived from pulse wave velocity (PWV), resting microcirculation (Flux) and response to heating and post-occlusive reactive hyperaemia measured using laser Doppler. Potential confounders [PWV and BP at first study, current height, weight, heart rate and twin type (ex-recipient, ex-donor or heavier/lighter of pair)] were accounted for by Mixed Linear Models statistical methodology. PWV dichorionic > monochorionic (P = 0.024); systolic and diastolic BP dichorionic > TTTS-amnio and TTTS-laser (P = 0.004, P = 0.02 and P = 0.005, P = 0.02, respectively). Within-twin pair pattern of PWV discordance was similar in laser treated and dichorionic controls (heavier-born > lighter), opposite to TTTS-amnio and monochorionic controls. Flux monochorionic > dichorionic (P = 0.044) and heavier > lighter-born (P = 0.024). TTTS-laser and dichorionic diamniotic showed greatest hyperaemic responses (dichorionic > TTTS-amnio or monochorionic controls (P = 0.007, P = 0.025). Hyperaemic responses were slower in heavier-born twins (P = 0.005). In summary, monochorionic twins had lower BP, arterial stiffness and increased resting vasodilatation than dichorionic twins implying shared fetal circulation affects vascular development. Vascular responses in laser-TTTS were similar to dichorionic and opposite to TTTS-amnio suggesting a lasting effect of fetal therapy on vascular health.

P02.11: Conservative management of a complicated heterotopic triplet pregnancy with a cornual monochorionic twin pair

A 29 year old G5 P0040 presented for evaluation of a multifetal gestation at 8 postmenstrual weeks. The patient had an extensive obstetrical history significant for prior right tubal pregnancy and right salpingectomy, two 1st trimester miscarriages, and a subsequent IVF pregnancy resulting in a simultaneous bilateral, ovarian heterotopic pregnancy, which was managed by laparoscopic resections and left salpingectomy. The index pregnancy was assisted by IVF/ET. Two frozen embryos were transferred. Ultrasound detected a heterotopic triplet gestation. 2D ultrasound and 3D reconstruction were instrumental in depicting the location of the three embryos. This was significant for an intrauterine singleton, and a right cornual monochorionic diamniotic twin pair. Extensive counseling was performed regarding the different management options. Given that this was a highly desired pregnancy and that a normally implanted intrauterine singleton was seen, selective reduction of the cornual twin pair was performed by transcervical ultrasound guided KCl injection. Following the procedure, serial clinical and sonographic evaluation were performed. This surveillance revealed increased amount of fluid accumulating in the cul-de-sac, suggesting bleeding from the cornual pregnancy. The patient therefore, underwent laparotomy in which evacuation of the hemiperitoneum and cornual pregnancy were followed by closure of the cornual gestations’ bed. During the surgery, caution was exercised using gentle handling of the uterus to maintain the intrauterine singleton embryo intact. Ultrasound demonstrated a reasonably large distance from it to the affected cornua which was interpreted as a positive prognostic factor. After recovery, outpatient surveillance confirmed an otherwise uncomplicated prenatal course. Scheduled cesarean delivery was performed at 37 weeks. This unusual case highlights the efforts to conservatively manage this extremely rare and complicated heterotopic pregnancy.

Clinical outcome and placental characteristics of monochorionic diamniotic twin pairs with early- and late-onset discordant growth

The purpose of this study was to examine the clinical and placental characteristics of monochorionic diamniotic twin pregnancies with early-onset discordant growth diagnosed at 20 weeks, late-onset discordant growth diagnosed at 26 weeks or later, and concordant growth. We studied a prospective cohort that underwent an ultrasound scan in the first trimester, at 16, 20, and 26 weeks. We excluded pregnancies complicated by twin-to-twin transfusion syndrome, miscarriage, fetal death less than 16 weeks, or severe congenital anomalies. Placental sharing and angioarchitecture were assessed by injection of each cord vessel with dyed barium sulphate. The 2 territories were delineated on an X-ray angiogram. The diameter of each intertwin anastomosis was measured on a digital photograph. We included 178 twin pairs. Early onset discordant growth, late-onset discordant growth, and concordant growth occurred in 15, 13, and 150 pregnancies, respectively. Twin pairs with early-onset discordant growth had lower survival rates and were delivered at an earlier gestational age than pairs with late-onset discordant and concordant growth. The degree of birthweight discordance was similar in early- and late-onset discordant growth. Severe intertwin hemoglobin differences at the time of birth occurred in 0%, 38%, and 3% of pairs with early-onset discordant growth, late-onset discordant growth, and concordant growth, respectively. The placentas of pairs with early-onset discordant growth were more unequally shared and had larger arterioarterial anastomoses and a larger total anastomotic diameter as compared with placentas of pairs with late onset-discordant or concordant growth. Unequal placental sharing appears to be involved in the etiology of early-onset discordant growth, whereas a late intertwin transfusion imbalance may be involved in some cases with late-onset discordant growth.

Nonlinear Analyses of Heart Rate Variability in Monochorionic and Dichorionic Twin Fetuses

Aims: To examine whether the heart rate dynamics of a monochorionic diamniotic (MD) twin fetus is different from a dichorionic diamniotic (DD) twin fetus by nonlinear methods of time series analysis. Methods: 32 fetal heart rate (FHR) recordings from healthy MD twin fetuses and 58 recordings from healthy DD twin fetuses were used. Nonlinear analyses included attractor reconstruction, calculation of the largest Lyapunov exponents, and estimation of correlation dimension. Results: FHR of healthy twin fetuses was shown to have unique nonlinear characteristics. The largest Lyapunov exponent significantly increased during the pregnancy period. In 30–36 weeks, correlation dimension in MD twins was significantly lower than that in DD twins. In DD twins, we observed a significant increase of correlation dimension from 22–29 to 30–36 weeks. In 22–29 weeks, the difference of the values of correlation dimension in each MD twin pair was significantly lower than that in each DD twin pair. Conclusions: The heart rate dynamics of healthy MD and DD twin fetuses becomes more chaotic according to gestational age. From the viewpoint of the FHR-regulating system, a pair of MD twins seems to have a more strict binding than a pair of DD twins before 30 weeks’ gestation.