Management of monoamniotic twin pregnancies: Where, when, how?

Management difficulties for monochorionic monoamniotic (MCMA) twin pregnancy reflect the absence of high-quality research into optimal types of monitoring, essential as MCMA twins have a high risk of intrauterine and neonatal death with perinatal mortality. D'Antonio et al's meta-analysis and the MonoMono study published in 2019, investigated the impact of monitoring location, out- or in-patient, of MCMA pregnancies and concluded that no specific management location is associated with improvement in prognosis. To evaluate the optimal timing for delivery of MCMA pregnancies, Van Mieghem and Chitrit carried out retrospective studies comparing gestational age of intrauterine death and risk of neonatal complication. The crossover point between the propective risk of intrauterine fetal death and neonatal complication was found at 32,33 weeks of gestation (WG), in accordance with American College of Obstetricians and Gynecologists and Royal College of Obstetricians and Gynaecologists recommendations but inclusion of complicated pregnancies and analysis of fetuses individually may be regarded as a bias. The majority of studies of MCMA pregnancies focused on elective scheduled cesareans, with only rare retrospective studies reporting on vaginal delivery. Of these, two recent studies carried out by French teams suggest that vaginal deliveries may be as safe as cesarean births for MCMA twin pregnancies when specific criteria are met. In summary, concerning MCMA pregnancies, prognosis is not found to improve with inpatient management, optimal timing for delivery is at approximately 33 GW and vaginal delivery should not be excluded.

Chorioamniotic Membrane Separation Found on Routine Testing in an Otherwise Asymptomatic Woman With Late Preterm Twin Gestation.

BACKGROUND: Chorioamniotic membrane separation (CMS) is a rare finding that is commonly preceded by invasive fetal procedures. The presence of CMS can also be associated with uncommon maternal or fetal conditions as well as preterm delivery, amniotic band syndrome, umbilical cord complications, and fetal and neonatal death. It is classified as a high-risk antepartum condition due to the significant fetal morbidity and mortality that may ensue. CASE REPORT: A 40-year-old gravida 5 para 1212 at 35 weeks presented for antepartum fetal testing. Her antepartum course was complicated by di-di twin gestation, chronic hypertension, and advanced maternal age. A routine ultrasound (as part of the antepartum fetal testing) identified an incidental finding of CMS. The patient's only reported symptom was that of preterm contractions, without evidence of active labor, and other fetal testing was reassuring. She had a repeat cesarean section that day and the suspected etiology was preterm, premature rupture of membranes of Twin B that was seen on entry into the uterine cavity. DISCUSSION: Chorioamniotic separation is a rare occurrence associated with significant adverse fetal outcomes. This is the first reported case of incidental diagnosis in a twin pregnancy during antepartum fetal surveillance testing. Our detection resulted in the delivery of late preterm, but otherwise healthy, twin neonates.

Pseudomonoamniotic Pregnancy: Case Report and Review of Etiologic Considerations.

Pseudomonoamniotic gestations are increasingly recognized through sonographic surveillance of monochorionic twins, though etiologic factors remain undefined. We present a case of spontaneous pseudomonoamniotic twins and propose umbilical cord insertion proximity as a sonographic marker. Systematic review of the literature was performed and additional cases with similar findings were noted. Approximately 75% of reported cases (28/37) were deemed spontaneous and several included short inter-cord distances. Shunting of blood away from the membranes in the region between the cord insertions may be responsible for membrane rupture. Further investigation is needed into short inter-cord distance as a marker for monochorionic twins at risk to become a pseudomonoamniotic gestation.

Selective intrauterine growth restriction in monochorionic twin pregnancies: markers of endothelial damage and metabolomic profile.

The aim of this study was to assess the aorta-intima thickness (aIT) and serum metabolomic profile in selective intrauterine growth-restricted (sIUGR) monochorionic diamniotic (MCDA) twin fetuses presenting Doppler velocimetry alterations. Fetal abdominal aIT was measured by ultrasound at 32 weeks of gestation, enrolling 24 MCDA twin fetuses (8 sIUGR and 16 controls). sIUGR twin fetuses were classified into two groups: Group 1 consisted of sIUGR with abnormal umbilical artery (UA) Doppler waveforms and Group 2 included sIUGR with normal UA Doppler. Group 3 were control fetuses appropriate for gestational age (AGA). Fetal blood samples were obtained from the umbilical vein immediately after fetal extraction. A non-targeted metabolomic profiling investigated fetal metabolism alterations by using liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Median fetal aIT was significantly larger in Group 1 (median value = 0.9 mm; range = 0.8-1.0 mm; p < .002) and Group 2 (median value = 0.8 mm; range = 0.7-0.8 mm; p < .002) than in AGA Group 3 (median value = 0.5 mm; range = 0.4-0.6 mm; p < .002). Metabolomic analyses, performed on four sIUGR cases (Group 1) compared with four AGA co-twins, showed an upregulation of phenylalanine, sphingosine, glycerophosphocholine, and choline, and a downregulation of valine, tryptophan, isoleucine, and proline sIUGR Group 1 compared with AGA. Although for metabolomics data only a statistical tendency (and not a statistical significance) was reached due to the small sample size, we believe that our results represent a valid starting point for further in-depth metabolomic and proteomic investigations of sIUGR in MCDA fetuses.

Effect of an amniotic sheet on pregnancy outcomes.

OBJECTIVES: Our aim was to evaluate whether the presence of an amniotic sheet affects obstetric and neonatal outcomes. METHODS: All singleton pregnant women with and without a sonographic diagnosis of an amniotic sheet between the 16th and 24th weeks of pregnancy were retrospectively identified. Two women without an amniotic sheet were randomly selected from the similar stratified periods as a control group for each case. The demographic characteristics and obstetric and perinatal outcomes were compared between the groups. Multivariable logistic regression was also performed for potential confounding factors. In addition, the subsequent pregnancies of 12 women with an amniotic sheet were followed during the antenatal and postnatal periods. RESULTS: The prevalence of an amniotic sheet was 1.13%. The risk factors for an amniotic sheet were primiparity, previous normal vaginal delivery, previous dilation and curettage, and previous abortions. When the groups were compared in terms of maternal and neonatal outcomes, the rates of a nuchal cord at birth, breech birth, birth weight of less than 2500 g, preterm delivery (<37 weeks), and neonatal intensive care unit admission were higher in the amniotic sheet group than the control group. There were 2 intrauterine deaths in the amniotic sheet group. In addition, an amniotic sheet was not observed again in any of the subsequent pregnancies of the 12 cases from the amniotic sheet group, and these pregnancies eventuated uneventfully. CONCLUSIONS: An amniotic sheet is associated with an increase in poor obstetric outcomes. Therefore, close monitoring of pregnancies after diagnosis is required.

Placental endoglin levels in diamniotic-monochorionic twin gestations: correlation with clinical and placental characteristics.

OBJECTIVE: While endoglin has been implicated in the pathogenesis of various complications in singleton pregnancies, its potential contribution to complications of monochorionic twinning remains largely undetermined. The aim of this study was to determine the correlation between relevant clinical and pathological variables and placental endoglin levels in diamniotic-monochorionic twin pregnancies. METHODS: Endoglin expression was studied by immunohistochemistry and Western blot in a prospective cohort of 68 non-TTTS and 7 TTTS monochorionic twin placentas. Placental endoglin levels were correlated with clinical and placental characteristics associated with twin-to-twin transfusion syndrome (TTTS) and selective growth restriction, including birth weight discordance, uneven placental sharing, peripheral cord insertion and choriovascular anatomy. RESULTS: In non-TTTS gestations discordant for these criteria, placental endoglin levels were significantly higher for the twin with smaller birth weight, intrauterine growth restriction, and/or abnormal ultrasound Doppler studies than for the more normal co-twin. Similarly, placental endoglin levels were significantly higher in the placental territory with smaller share and/or peripheral cord insertion in cases discordant for these placental characteristics. In TTTS gestations, placental endoglin levels tended to be higher for donor twins than for recipients. There was no correlation between endoglin levels and superficial choriovascular anastomoses. CONCLUSIONS: While the exact functional implications remain to be determined, our findings suggest a strong correlation between unbalanced placental endoglin levels and intertwin growth discordance in monochorionic twins.

Caso interesante de lámina amniótica / Interesting case of amniotic sheet

Antecedentes: Las anormalidades de las membranas intrauterinas amnióticas del embarazo incluye 1) bridas amnióticas, 2) adherencias intrauterinas que condicionan las sinequias y las láminas amnióticas y 3) tabiques uterinos. Son un diagnóstico frecuente en el examen ultrasonográfico rutinario en embarazadas. La lámina amniótica es una lámina de tejido aberrante visualizado dentro de la cavidad uterina, resultado de una sinequia que es rodeada por el amnios y el corion que se expande, es de naturaleza benigna, no produce restricción a la movilidad fetal ni deformidad del mismo. Caso Clínico: Paciente de 23 años de edad, con historia gineco-obstétrica de 2 gestas, el primer embarazo término en aborto, por lo que se le realizo legrado uterino instrumentado, a las 29 7/4 semanas gestacionales se detecta con ultrasonido convencional, una lámina amniótica completa a nivel del segmento inferior del útero. A las 38 semanas presenta ruptura prematura de membranas, por lo que se realiza cesárea sin complicaciones, obteniéndose recién nacido femenino con APGAR 8 y 9 a los 15 minutos respectivamente, con peso de 2945 g, sin anormalidades estructurales, además la placenta y el cordón umbilical no evidenciarón ninguna anormalidad. Conclusión: Las anormalidades de las membranas amnióticas son de reciente descripción y se desconoce su frecuencia, la lámina amniótica es más común que las bandas, la etiología no está bien establecida, pero una de las teorías más aceptada es que son consecuencia de sinequias, debido a infecciones, procedimientos quirúrgicos, instrumentación uterina, entre ellos el legrado como se presentó en este caso...

Gray-scale and color Doppler US findings of amniotic sheets.

PURPOSE: To identify the gray-scale and color Doppler ultrasonography (US) findings of amniotic sheets. MATERIALS AND METHODS: Among 1201 pregnant patients who underwent detailed second trimester US, nine had amniotic sheets. An amniotic sheet was defined as a shelf-like structure in the uterine cavity with a free edge not attached to the fetus or umbilical cord. There was no major fetal anomaly observed in any patient. Eight patients had solitary amniotic sheets, and one patient had double sheets. All gray-scale and Doppler US features of amniotic sheets were noted. RESULTS: The incidence of an amniotic sheet was determined to be 0.75% (ten amniotic sheets were observed in nine patients). On gray-scale US images, amniotic sheets were observed as bands of tissue that originated from the uterine wall with a triangular-shaped base that tapered toward the free edge. A three-layered appearance was identified in seven amniotic sheets. Using Doppler US images, four of ten sheets showed a low-resistance arterial flow, and five of ten sheets showed non-pulsatile venous flows. No vascularization was observed in one patient with a thin, membranous sheet. CONCLUSION: Gray-scale US is sufficient for the diagnosis of amniotic sheets because of the typical US characteristics; however, Doppler US findings of amniotic sheets are highly variable. Thus, Doppler US may not be beneficial in the diagnosis of amniotic sheets.

Monochorionic diamniotic twins concordant for anencephaly: a case report.

BACKGROUND: Anencephaly occurs in 1.4-4.7 per 10,000 deliveries and is thought to result from failed closure of the anterior neuropore at 24-26 days post fertilization. Among twins, risk for congenital malformations is greatest among monozygotic twins. Several occurrences of twin pairs being discordant for neural tube defects have been reported: 1 twin affected with anencephaly and co-twin affected with holoprosencephaly, spina bifida or encephalocele, is consistent with a multifactorial pattern of inheritance. We present an instance of monochorionic diamniotic twins concordant for anencephaly. CASE: An 18-year-old, gravida 1, para 0, Caucasian woman presented with monochorionic diamniotic twin gestation at 22 weeks. Prenatal ultrasound identified polyhydramnios, anencephaly, ventricular septal defect and suspected rocker-bottom feet in twin A. Twin B was identified as anencephalic, with left renal agenesis and spinal distortion visualized on ultrasound. Postnatal cytogenetic evaluations of placenta, umbilical cord blood and fetal skin samples from both twins revealed 46,XX karyotypes. CONCLUSION: A rare case of a monochorionic diamniotic gestation concordant for anencephaly is presented. Previously published reports of concordant twin anencephaly have postulated a possible autosomal recessive or multifactorial mode of inheritance. Subsequent pregnancies with anencephaly or other open neural tube defects would indicate a mendelian process.

Neovaginoplastia com membrana amniótica na síndrome de Mayer-Rokitansky-Küster-Hauser / Neovaginoplasty using amniotic membrane in Mayer-Rokitansky-Küster-Hauser syndrome

OBJETIVO: avaliar resultados da neovaginoplastia com utilização de enxerto amniótico humano em pacientes portadoras da síndrome de Mayer-Rokitansky-Küster-Hauser (MRKH). MÉTODOS: o estudo foi uma análise retrospectiva de uma série de 28 casos de pacientes com síndrome de MRKH, tratadas entre 1990 e 2003. As pacientes foram atendidas no Ambulatório de Ginecologia Infanto-Puberal (AGIP) do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), sendo submetidas a neovaginoplastia pela técnica de McIndoe e Bannister modificada pela utilização de enxerto de membrana amniótica humana. Foram avaliadas epitelização, amplitude e profundidade das neovaginas com sete e 40 dias do procedimento e, no pós-operatório tardio, a satisfação das pacientes, a presença de desconforto e dispareunia às relações sexuais. RESULTADOS: no pós-operatório, sete pacientes (25 por cento) apresentaram estenose vaginal. Destas, seis foram submetidas a nova intervenção cirúrgica, uma teve encurtamento da neovagina, corrigido com o uso de exercícios com molde vaginal, três (10,7 por cento) tiveram fístula retovaginal, uma (3,6 por cento) fístula uterovesical e uma (3,6 por cento) teve excesso de pele no intróito vaginal - todas corrigidas com êxito com nova cirurgia. Quatro pacientes (14,3 por cento) apresentaram infecção do trato urinário. Dois meses após a cirurgia, 11 de 19 pacientes (57,8 por cento) apresentaram atividade sexual satisfatória e 42 por cento relataram dispareunia e, no período máximo de quatro anos, 20/21 pacientes (95,2 por cento) tiveram atividade sexual satisfatória e 4,8 por cento dispareunia. CONCLUSÕES: o enxerto de membrana amniótica é uma boa opção no tratamento da agenesia vaginal. O acompanhamento perioperatório envolve questões educacionais, de orientação quanto ao uso do molde e em relação à sexualidade da paciente, com vistas à redução das queixas de coito disfuncional na presença de evolução...

PURPOSE: to evaluate the results of neovaginoplasty with the use of a human amniotic graft in patients with the Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome. METHODS: the study was a retrospective analysis of a series of 28 patients with the MRKH syndrome conducted from 1990 to 2003. The patients were attended and treated at the Ambulatório de Ginecologia Infanto-Puberal (AGIP) of the Hospital Universitário of the Faculdade de Medicina de Ribeirão Preto of the Universidade de São Paulo (FMRP-USP), being submitted to neovaginoplasty by the technique of McIndoe and Bannister, modified by the use of a human amniotic membrane graft. Epithelization, amplitude and depth of the neovaginas were evaluated 7 and 40 days after the procedure. Patient satisfaction was determined during the late postoperative period in terms of the presence of discomfort and dyspareunia during sexual relations. RESULTS: postoperatively, seven patients (25 percent) presented vaginal stenosis and six of them were submitted to a new surgical intervention, one had shortening of the neovagina, corrected with the use of exercises with a vaginal mold, three (10.7 percent) developed a rectovaginal fistula, one (3.6 percent) a uterovesical fistula, and one (3.6 percent) excess skin in the vaginal introitus - all successfully corrected with surgery. Four patients (14.3 percent) presented urinary tract infection. Two months after surgery, 11/19 patients (57.8 percent) presented satisfactory sexual activity and 42 percent dyspareunia, and within a maximum period of four years, 20/21 patients (95.2 percent) had satisfactory sexual activity and 4.8 percent dyspareunia. CONCLUSIONS: an amniotic membrane graft is a good option for the treatment of vaginal agenesis. Perioperative follow-up involves educational guidance regarding the use of the mold and regarding patient sexuality in order to reduce the complaints of dysfunctional coitus in the presence of a favorable surgical evolution...

[Case report of ADAM syndrome at 16 weeks of gestation].

We present a case of ADAM complex diagnosed at 16 weeks gestation due to severe fetal abnormalities and discuss the protocol of an adequate obstetrical management.

The umbilical mass: a rare neonatal anomaly.

Umbilical anomalies are a rare presentation in the pediatric patient. The differential diagnosis includes anomalies resulting from urachal and vitelline duct derivatives such as urachal sinus, urachal cyst, urachal diverticulum, patent urachus, herniated Meckel's diverticulum, umbilico-enteric fistula, or umbilical polyp. In this article, a case presentation of an umbilical anomaly along with the differential diagnosis and management options are discussed. Based upon this review of the literature, the authors propose a management algorithm for treating children with umbilical anomalies.

Complete chorioamniotic membrane separation with fetal restrictive dermopathy in two consecutive pregnancies.

OBJECTIVE: To describe an instance of complete chorion-amnion membrane separation with fetal restrictive dermopathy in two consecutive pregnancies. METHODS: We performed prenatal ultrasounds in two consecutive pregnancies and evaluated gross and microscopic postnatal findings. RESULTS: The first pregnancy ended at 32 weeks of gestation with spontaneous chorioamniotic membrane separation and preterm premature rupture of membranes. The mother delivered an abnormal male infant with generalized fixed joint contractures, rigid and shiny skin, skin laceration around the neck, a rounded and opened mouth, and palpebral conjunctival eversion. The subsequent pregnancy was also complicated by spontaneous complete chorioamniotic membrane separation, oligohydramnios, and fetal growth restriction at 26 + 3 weeks of gestation. A immaturely born second baby also carried multiple anomalies similar to those of the first. Both infants died shortly after birth. After microscopic examination of the skin, we diagnosed the infant as restrictive dermopathy. CONCLUSIONS: Complete separation of the chorion-amnion membrane may be regarded as a serious prenatal condition. Restrictive dermopathy or skin disorders caused by defects in collagen or elastic tissue metabolism may be one of the many causes of chorion-amnion separation.

Predictors of perinatal survival in a cohort of pregnancies with severe oligohydramnios due to premature rupture of membranes at <26 weeks managed with serial amnioinfusions.

OBJECTIVE: To evaluate whether successful amnioinfusion is an independent predictor of perinatal survival in a cohort of cases with extreme and persistent oligohydramnios due to preterm premature rupture of membranes (pPROM) who reached viability and were managed with serial amnioinfusions. STUDY DESIGN: We included all consecutive singleton pregnancies with pPROM at <26 weeks and oligohydramnios lasting >4 days between 1/1991 and 12/2001 and who consented to undergo amnioinfusion (n=77). Women received serial transabdominal amnioinfusions in an attempt to maintain a pocket of fluid >2 cm. The procedure was deemed successful if the median deepest pocket of fluid during the latency period was >2 cm. Excluded were miscarriages (n=10), fetal deaths before viability (24 weeks) (n=15), and cases that did not develop oligohydramnios (n=17). Prenatal predictors of outcome were compared between cases who survived the perinatal period and those who did not using Wilcoxon rank-sum test, Fisher's exact test and stepwise logistic regression analysis, with a two-tailed P<0.05 considered significant. RESULTS: Of the 35 patients fulfilling the study criteria, 20 (57%) survived the perinatal period. Perinatal survivors had similar gestational age at pPROM (P=0.68) and at first amnioinfusion (P=0.53) as those who died in the perinatal period, but longer latency (P=0.013). Consequently, median gestational age at delivery [29.2 (25.4-35.3) weeks versus 26.1 (24.0-34.0) weeks, P<0.001] and median birth weight [1220 (650-2240) g versus 863 (520-2200) g, P=0.001] were significantly greater among survivors than among those who died. Significant predictors of survival at univariate analysis were entered into a stepwise logistic regression analysis in the chronological order in which they normally occur. The analysis demonstrated that successful amnioinfusion (OR=6.9, 95% CI 1.2-40.4) and administration of steroids (OR=14.6, 95% CI 1.5-144.1) were independent and significant predictors of perinatal survival. CONCLUSION: In a cohort of women with pPROM at <26 weeks and severe oligohydramnios managed with serial amnioinfusions, successful procedures and prenatal administration of corticosteroids are the only independent predictors of perinatal survival.

The Young's modulus of fetal preterm and term amniotic membranes.

OBJECTIVE: To examine the Young's modulus of the human amniotic membranes, as well as its relationship to gestational age. To determine whether cellular and material-related parameters affect this modulus. STUDY DESIGN: In a prospective study at the Obstetric outpatient clinic of the University Hospital Zurich Young's modulus, thickness and mesenchymal:epithelial cell ratio of amniotic membranes of preterm (N=23) and term (N=40) placentae were examined. Significance (P<0.05) was calculated with the Mann-Whitney two-sample rank sum test and Wilcoxon signed rank test, while correlations were made using the Spearman's correlation. RESULTS: The Young's modulus of preterm amniotic membranes was significantly higher than that of term membranes. It varied within the same amniotic membrane. The thickness of the amnion in both preterm and term membranes did not differ significantly. The thinner the preterm and term amniotic membranes, the higher the Young's modulus was. There was no relation to the mesenchymal:epithelial cell ratio in the amnion. CONCLUSIONS: Preterm amniotic membranes are stiffer than term amniotic membranes. Tentatively, we hypothesise that there may be a correlation between the extracellular matrix components and the elastic properties of the membrane.