Evaluation of amniotic membrane in the healing of apicomarginal defects using 2D and 3D imaging modalities: a randomized controlled trial

OBJECTIVE

The study aimed to evaluate healing in apicomarginal defects with amniotic membrane (AM) using 2D periapical radiography and 3D cone beam computed tomography imaging.

METHOD AND MATERIALS

Thirty-four patients with symptomatic apical periodontitis and apicomarginal communication were allocated to either the AM or control group. Clinical and radiographic assessment was performed at baseline and at 12 months using Molven criteria, modified Penn 3D criteria, and RAC and B indices at resected plane, apical area, cortical plate, and combined apicocortical area, respectively.

RESULTS

There was no significant difference in the healing outcome in 2D imaging (93.3% control and 86.7% AM) and 3D imaging (80.0% control and 53.3% AM) between the groups. With RAC scoring, a greater percentage of unhealed cases was observed in cortical plate. Radiographic buccal bone formation in the 3D imaging was evident only in six cases. However, both the groups depicted significantly greater percentage reduction in the size of the lesion in 2D than the 3D analysis (AM group 91.69 ± 15.99 2D, 76.06 ± 47.62 3D, P = .020) and (control group 92.06 ± 14.36 2D, 85.12 ± 18.55 3D, P = .005).

CONCLUSION

No significant difference in healing was observed between the AM and the control groups with the use of both periapical radiography and CBCT imaging. Despite good clinical healing and radiographic apical bone fill, buccal bone formation was not evident in 3D imaging in most of the cases.

Triple pregnancy - etiology and early diagnosis

OBJECTIVE

To provide an overview of the etiology and early dia-gnosis of triple pregnancy, with emphasis on the possibilities of ultrasound and magnetic resonance (MR) imaging.

METHODOLOGY

Processing of data from the available literature on the issue of triple pregnancy.

CONCLUSION

Spontaneous triple pregnancy conception is rare. In most cases, it is a concept associated with assisted reproduction methods. Multiple pregnancy is associated with a higher incidence of complications during pregnancy and childbirth, but it also has its own specific complications. Chorionicity and amnionicity of multiple pregnancies are two important parameters in determining the strategy of dispensary care in pregnancy and management of childbirth. The use of ultrasound and MR imaging is crucial for their accurate determination in early pregnancy.

Prediction of Amnionicity Using the Number of Yolk Sacs in Monochorionic Multifetal Pregnancy

The purpose of this article was to evaluate the accuracy of predicting amnionicity using the number of yolk sacs by diagnostic ultrasound examination in monochorionic (MC) multifetal pregnancies between 7 + 0 and 9 + 6 gestational weeks. A total of 97 patients with MC multifetal pregnancies underwent early ultrasound examination from 2004 to 2014 at Cheil General Hospital and Women's Healthcare Center. All patients for whom the number of yolk sacs was reported were included in this study. We compared the number of yolk sacs with amnionicity confirmed by an intertwine membrane. Overall, there was a 9.3% (9 cases) discrepancy in number of yolk sacs and amnionicity (4.3% for monochorionic diamniotic, 36.4% for monochorionic monoamniotic, and 33% for monochorionic triamniotic). Among the 9 cases with discrepancies, 4 cases with 2 yolk sacs were confirmed as monoamniotic pregnancies and 4 MC twin pregnancies showing a single yolk sac were diagnosed as diamniotic twin pregnancies. One case with 2 yolk sacs was identified as a triamniotic triplet pregnancy. In 9.3% of MC gestations, the number of yolk sacs was not correlated with the number of amnions in our study. To determine amnionicity in MC multifetal pregnancies, we recommend careful evaluation not of the number of yolk sacs but the presence or absence of intertwine dividing membrane after 8 gestational weeks.

Ultrasound and histological measurements of dividing membrane thickness in twin gestations

OBJECTIVE

To determine how prenatal ultrasound measurements of dividing membrane thickness correlate with postnatal histological measurements and chorionicity in twin gestations.

METHODS

This was a prospective, longitudinal cohort study of twin gestations. Dividing membrane thickness was measured by transabdominal ultrasound, with the insonation beam both parallel and perpendicular to the membrane, in the second or third trimester, depending on when care was established. Ultrasound examinations were performed every 4 weeks following initial assessment until delivery. Measurements of membrane thickness from the first ultrasound examination were compared with histological measurements after delivery.

RESULTS

A total of 45 twin pregnancies (32 dichorionic, 13 monochorionic) were included. Mean gestational age at initial ultrasound examination was 24.1 ± 7.3 weeks. Parallel ultrasound measurements of membrane thickness were 1.6 ± 0.8 mm for monochorionic and 2.5 ± 0.9 mm for dichorionic gestations (P = 0.001). Perpendicular ultrasound measurements were 1.6 ± 0.3 mm for monochorionic and 2.2 ± 0.8 mm for dichorionic gestations (P = 0.009). Inter- and intraobserver reliability of ultrasound measurements were 0.847 and 0.950, respectively. Parallel and perpendicular ultrasound measurements correlated better with each other (R = 0.807, P < 0.001) than with histological measurements of membrane thickness (R_parallel  = 0.538, P < 0.001; R_{perpendicular}  = 0.529, P < 0.001). Receiver-operating characteristics curve analyses to predict histological membrane thickness > 50^th percentile resulted in an area under the curve (AUC) of 0.828 for parallel (P < 0.001) and 0.874 for perpendicular (P < 0.001) measurements with a cut-off value of 1.9 mm for both approaches. The AUCs for parallel and perpendicular measurements to predict dichorionicity were 0.892 (P < 0.001) and 0.823 (P < 0.001) with cut-off values of 1.9 and 1.8 mm, respectively.

CONCLUSION

Prenatal ultrasound measurement of twin dividing membrane thickness is positively correlated with postnatal histological measurement. Dichorionicity can be determined by a magnified dividing membrane thickness ≥ 1.9 mm. Measurements with the ultrasound beam parallel to the dividing membrane may be more accurate than perpendicular measurements. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Abnormal ultrasound appearance of the amniotic membranes - diagnostic and significance: a pictorial essay

The obstetrical ultrasound may identify the protrusion of the uterine surface or placental area into the amniotic cavity. The differential diagnosis of this pathology with uterine adhesions, septate uterus, circumvallate placenta, amniotic band or amniotic sheet can be sometimes difficult. The purpose of the pictorial essay is to exemplify the presence of the amniotic sheet and circumvallate placenta in routine obstetrics screening of all trimesters of pregnancy.

[Measurement of gestational sac volume in the first trimester of pregnancy]

OBJECTIVE

The aim of our study was to measure the volume of gestational sac and amniotic sac in physiological pregnancies and missed abortion. We wanted to create nomograms for individual weeks of gestation.

DESIGN

Retrospective cohort study.

SETTING

Institute for the Care of Mother and Child, Prague.

METHODS

The study randomized 413 women after spontaneous conception. The patients were divided into two groups: women with physiological pregnancy and childbirth in the period (374), and women with pregnancy terminated by missed abortion. Both groups were performed measurement volume of gestational and amniotic sac in the first trimester of pregnancy. Analysis was performed using 4D View software applications, and volume calculations were performed using VOCAL (Virtual Organ Computer Aided anaLysis).

RESULTS

We have created the first in the Czech Republic nomograms volumes of gestational and amniotic sac in physiological pregnancies and missed abortion. We performed a correlation between the size of gestational sac and prosperity pregnancy.

CONCLUSION

In our study we found no correlation between the volume of gestational sac and the development of the pregnancy.

Partial monochorionic and monoamniotic twin pregnancies: a report of two cases

Monochorionic (MC) twin pregnancies are at increased risk of adverse outcome because of the vascular anastomoses that connect the two fetal circulations. MC monoamniotic (MA) twins are at an even higher risk because of their almost universal cord entanglement and possible compression, which can cause an acute transfusion imbalance between the twins. Chorionicity and amnionicity should be determined during the first-trimester ultrasound examination to identify high-risk MC and MA twin pregnancies for which a fortnightly follow-up may improve outcome. Although this can be achieved readily by assessing and counting the membranes that separate the twins, some pitfalls may occur. We present our observations of two monozygotic twin pairs with an intermediate type of monodichorionic and monodiamniotic twin pregnancy. The first was recognized during the first-trimester scan and the second during the second-trimester scan.

Chorioamniotic membrane separation over the cervical os ("moon sign") in twin-twin transfusion syndrome

OBJECTIVES

To determine whether chorioamniotic membrane separation from the internal cervical os, the "moon sign," is associated with preterm premature rupture of membranes (PPROM) in twin-twin transfusion syndrome (TTTS).

METHODS

A retrospective study of patients with TTTS treated with laser surgery was performed. Membrane separation before and after surgery was tested against any PPROM, PPROM within 7 days, and PPROM within 21 days. Because intrauterine fetal demise (IUFD) was weakly associated with PPROM, these cases were studied separately.

RESULTS

Among 304 consecutive patients, 247 patients (81.3%) had no IUFD, and preoperative and postoperative membrane separation rates were 13.4% and 13.0%, respectively. In 7 cases (2.8%), preoperative membrane separation disappeared postoperatively, and in 6 cases (2.4%), membrane separation appeared postoperatively; 26 cases (10.5%) had membrane separation at both times. Rates of PPROM did not differ between those who did and did not have preoperative membrane separation (30.3% versus 28.0%; P= .9511). Among those with and without postoperative membrane separation, the rates of any PPROM were 34.4% and 27.4%, respectively (P = .5473), and the rates of PPROM within 21 days were 15.6% and 5.6% (P = .0524). Those with postoperative membrane separation were 3 times more likely to have PPROM within 21 days (odds ratio, 3.13; 95% confidence interval, 1.02-9.58; P= .0453). Preterm premature rupture of membranes was not associated with preoperative or postoperative membrane separation in patients with IUFD.

CONCLUSIONS

The preoperative moon sign does not appear to be associated with PPROM in TTTS. Postoperatively, membrane separation may be weakly associated with PPROM at 21 days, but further research is required to confirm this association.

Gestational age-specific reference ranges for amniotic fluid assessment in monochorionic diamniotic twin pregnancies

OBJECTIVES

To establish gestational age-specific reference ranges for amniotic fluid measurements in monochorionic diamniotic twin pregnancies, to compare them with previously reported singleton and twin reference ranges and to examine the rationale for using a gestational age-dependent cut-off to define polyhydramnios in twin-twin transfusion syndrome, as is the practice in most European centers.

METHODS

We retrospectively evaluated amniotic fluid volume in 32 monochorionic diamniotic twin pregnancies that were followed longitudinally at 2-week intervals from the first trimester until birth. Amniotic fluid volume was assessed by measuring the deepest vertical pocket in both amniotic sacs. We used multilevel modeling to estimate the gestational age-specific reference ranges for deepest vertical pocket measurements.

RESULTS

Based on 429 observations in 64 fetuses, we constructed gestational age-specific reference ranges from 11 weeks until term. The deepest pocket increased from the first trimester to reach a maximum at 26 weeks, followed by a gradual decrease towards term. Measurements between 18 and 28 weeks were comparable to those in singleton pregnancies. However, before 18 weeks values were higher, whereas after 28 weeks they were lower, as compared to singleton references.

CONCLUSION

In monochorionic twin pregnancies, the deepest vertical pocket is a gestational age-dependent measurement. Therefore, a gestational age-dependent definition of polyhydramnios in twin-twin transfusion syndrome, as used by most European centers, seems a logical approach.

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.

Assessment of cardiac function in monochorionic diamniotic twin pregnancies with twin-to-twin transfusion syndrome before and after fetoscopic laser photocoagulation using Speckle tracking

PURPOSE

To assess cardiac function with Speckle tracking in fetuses with twin-to-twin transfusion syndrome (TTTS) before and after laser therapy.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

[Monochorionic biamniotic twins with a common yolk sac in the first trimester ultrasound scan - is there a higher risk of a congenital defect?]

TYPE OF STUDY

Case report.

SETTING

GEST IVF, Centre of Reproductive Medicine, Prague.

METHODS

The case report describes pregnancy after IVF + ET. The first trimester ultrasound scan showed monochorionic biamniotic twins with one common yolk sac (YS) only, which is possible in biamniotic twins, but very rare. Identical congenital defects such as anal, coccygeal atresia, and others, were diagnosed prenatally and postnatally in both twins.

CONCLUSION

Yolk sac number in monochorionic twins can play an important role in embryogenesi. Any possible relation with certain congenital defects has not yet been described. It is necessary to describe more cases.

[Umbilical cord collision in the first trimester in a monoamniotic twin pregnancy--does it really matter?]

A case of an umbilical cord collision diagnosed in the first trimester of a monochorionic monoamniotic twin pregnancy is presented. An intensive surveillance included ultrasound monitoring with color and spectral Doppler and fetal echocardiography. The first signs of fetal distress were observed at 31 weeks of gestation. The brain sparing effect as well as a periodic appearance of the "notch" in the wave forms obtained from the umbilical artery from the collision region were observed. In the first ultrasound scan there were no abnormalities in twin I. In contrast, in twin II a vascular resistance in the umbilical artery was at the upper limit for the gestational age. Five days later, decreased vascular resistance in the middle cerebral artery, which fluctuated at the lower limit, was noticed in twin II. After the next four days, PI in the middle cerebral artery decreased below the lower limit and tricuspid regurgitation appeared. In twin I the vascular resistance in the umbilical artery increased and remained at the upper limit of the reference ranges. Cardiotocographic records did not reveal signs of fetal distress. After a week the signs of brain sparing effect were visible in both fetuses. However, twin II showed features of umbilical cord clamping in the form of abnormal blood flow waveforms in the umbilical artery ("notch"). Therefore, despite the absence of signs of fetal distress in CTG in monochorionic monoamniotic twins with growth discordance of 20% and exponents of periodical clamping of the umbilical cord in twin II at 34 weeks, the decision to perform a caesarean section was made. The patient gave birth to two daughters (twin I: weight 1780g, Ap 10, pH 7.39, 7.40, BE -3.0, -2.6, and twin II: weight 1860g, Ap 10, pH 7.29, 7.35, BE -1.4, -2.4). During the delivery the umbilical cords collision was found at the region close to the body of twins. This case presents the possibility of using ultrasound and Doppler in the early diagnosis, monitoring and surveillance of pregnancies complicated by umbilical cords collision in monochorionic monoamniotic twins from the first trimester. Application of these methods allowed a safe monitoring of the fetuses and the identification of the onset of the cords collision. This in turn allowed the achievement of fetal maturity at 34 weeks, when both the risk of death and neonatal morbidity are significantly minimized. The use of Doppler blood flow velocimetry allowed the diagnosis of umbilical cords tightening before there were any signs of cardiac dysfunction in the CTG. This enabled to determine the most favorable, earlier time for delivery. The paper presents diagnostic management and surveillance in monochorionic monoamniotic pregnancy complicated by umbilical cord collision since the early pregnancy.

Prediction of abortion using three-dimensional ultrasound volumetry of the gestational sac and the amniotic sac in threatened abortion

PURPOSE

To determine whether gestational sac volume (GSV) or amniotic sac volume (ASV) and/or the difference between them can predict abortion in women with first-trimester threatened abortion.

METHODS

Ninety patients between 6 and 12 weeks of gestation presenting with vaginal bleeding were studied. Seventy-six delivered after 24 weeks of gestation (group A) and 14 aborted before 20 weeks of gestation (group B). All patients had a singleton viable pregnancy demonstrated by transvaginal ultrasound. Gestational sac and amniotic sac volumes were measured in all the patients using three-dimensional transvaginal ultrasound with Virtual Organ Computer-aided Analysis software, and the gestational sac volume - amniotic sac volume (GSV - ASV) was calculated.

RESULTS

The groups did not differ in terms of age, parity, number of previous abortions, or term deliveries. The GSV (group A: mean 32.0 ± 27.7 cm(3) ; group B: 26.7 ± 29.1 cm(3) ) and the ASV (group A: 21.1 ± 25.5 cm(3) ; group B: 20.6 ± 26.0 cm(3) ) were not statistically different, while the GSV - ASV was significantly smaller in group B (aborting before week 20) (group A: 10.9 ± 10.9 cm(3) ; group B: 6.1 ± 8.6 cm(3) ; p < 0.05). Using receiver operator curves, the area under the curve for predicting normal pregnancy outcome of the GSV - ASV measurement was 0.654. When the GSV - ASV was 1.8 cm(3) or less, abortion was predicted with 84% sensitivity and 43% specificity.

CONCLUSIONS

The measurement of the GSV and the ASV are not good predictors of abortion in patients with first-trimester vaginal bleeding, whereas the use of the GSV - ASV may be helpful in predicting the outcome of pregnancy.

Three-dimensional sonograph of a monochorionic diamniotic triplet pregnancy

A monochorionic diamniotic triplet pregnancy was diagnosed by sonographic scan at 9 weeks of gestation. The three embryos appeared to share the same trophoblast, with two of them sharing the same amniotic sac. The two amniotic sacs were divided by a thin membrane, with no chorionic projection within it, and each amniotic sac presented a single yolk sac. Only few cases of nontrichorionic-triamniotic triplets have been reported in the literature. Although the diagnosis was reached using the two-dimensional ultrasound, the complementary use of three-dimensional ultrasound helped in confirming the diagnosis, and in offering the couple an adequate counseling.

Prenatal sonographic assessment and perinatal course of ichthyosis prematurity syndrome

All cases of ichthyosis prematurity syndrome (IPS), registered at the National Center for Fetal Medicine in Trondheim, Norway between 1987 and 2010 were identified and the findings analyzed. Five fetuses with IPS were identified between 1988 and 2000. All five developed polyhydramnios between 28 and 31 weeks. The fetal stomach appeared to be empty in four cases, and was not described in one case. The fetal skin was described as 'uneven' at ultrasound examination in two cases. Separation of chorionic and amniotic membranes with a peculiar appearance of echo-free fluid in the chorionic cavity and echogenic sediment in the amniotic cavity were observed between 28 + 5 and 32 + 3 weeks in all cases. All fetuses were delivered prematurely between 30 and 34 weeks. All neonates had difficulties in breathing, two developed aspiration pneumonia, and one had bilateral pneumothorax after intubation and died at 6 months because of pulmonary and cardiac sequelae. Prenatal sonographic signs of IPS are separation of the membranes, echogenic amniotic fluid and echo-free chorionic fluid occurring between 28 and 32 weeks' gestation. Delivery occurs at 30-34 weeks and, as there is a high risk of asphyxia, an experienced neonatal intensive care unit team should be present at delivery.

Ultrasound to Identify Cord Knotting in Monoamniotic Monochorionic Twins

This case report demonstrates the use of ultrasound and doppler flow in the management of mono-amniotic monochorionic (M/M) twins. M/M twinning is a rare but significant event. It is associated with high rates of fetal mortality, most commonly cited at anywhere from between 30% and 70%. A common cause of death is cord entanglement. The case presented is that of a 19-year-old gravida 1 at 30 weeks with M/M twins in which multiple cord knots were found by ultrasound color doppler flow after variable fetal heart rate decelerations occurred. This prompted a decision for immediate cesarean delivery with normal fetal outcomes. Improvements in perinatal imaging systems are therefore beneficial in the management of M/M twins.

Monoamniotic twin pregnancy: continuous inpatient electronic fetal monitoring-an impossible goal?

OBJECTIVE

We sought to determine the effectiveness of continuous fetal monitoring in monoamniotic twins and assess the percentage of successful monitoring across gestation.

STUDY DESIGN

This was a single-center retrospective cohort analysis of monoamniotic twins. Each subject's entire electronic fetal heart tracing was reviewed. The primary outcome measure was the percentage of time that 0, 1, and 2 fetuses were successfully monitored. To compare the effectiveness of monitoring across gestation, these data were stratified by gestational age (<27, 27-30, and >30 weeks).

RESULTS

A total of 10,402 hours of fetal monitoring were reviewed for 17 monoamniotic twin pairs. Successful monitoring of 0, 1, and 2 fetuses occurred 21.2%, 27.1%, and 51.6% of the time, respectively. Successful monitoring of both fetuses was positively correlated with gestational age (<27 weeks 37%; 27-30 weeks 51%; >30 weeks 57%; P < .007).

CONCLUSION

Successful monitoring of both fetuses occurred 51.6% of the time. Continuous monitoring efficiency improved with advancing gestational age.

Cervical funneling: effect on gestational length and ultrasound-indicated cerclage in high-risk women

OBJECTIVE

The purpose of this study was to assess funnel type and pregnancy duration in women with previous spontaneous preterm birth and cervical length <25 mm.

STUDY DESIGN

We performed a secondary analysis of a multicenter randomized trial of cerclage. At the randomization scan that documented short cervix, the presence and type of funnel (U or V) were recorded.

RESULTS

One hundred forty-seven of 301 women (49%) had funneling: V-shaped funnel, 99 women; U-shaped funnel, 48 women. U-shaped funnel was associated significantly with preterm birth at <24, <28, <35, and <37 weeks of gestation. In multivariable models that controlled for randomization cervical length and cerclage, women with U-shaped funnel delivered earlier than women with either V-shaped funnel or no funnel. Interaction between cerclage and U-shaped funnel was observed, and analyses that were stratified by cerclage showed that women with a U-shaped funnel and cerclage delivered at a mean of 33.8 +/- 6.6 weeks of gestation, compared with women who did not receive cerclage (28.9 +/- 6.9 weeks of gestation).

CONCLUSION

U-shaped funnels in high-risk women with a short cervix are associated with earlier birth.

Monochorionic monoamniotic twin pregnancies with two yolk sacs may not be a rare finding: a report of two cases

The exact determination of amnionicity is a major issue for the clinical management of monochorionic twin pregnancies, due to the high risk of perinatal mortality and morbidity in monochorionic monoamniotic (MCMA) twins. Counting the number of yolk sacs is believed to be a good indicator of amnionicity in the early first trimester, and it has previously been suggested that the number of yolk sacs is equal to amnionicity in both MCMA and monochorionic diamniotic twin pregnancies. However, the accuracy of the relationship between number of yolk sacs and amnionicity has recently been called into question. To the best of our knowledge, no previous reports have shown two yolk sacs in MCMA twin pregnancies. We report two cases of MCMA twins with two yolk sacs on first-trimester ultrasonography, and confirmed monoamnionicity in the second trimester showing umbilical cord entanglement. Postnatal examination showed an MCMA placenta in both cases, and entangled umbilical cords confirmed monoamnionicity. The possibility of monoamnionicity must still be suspected when two yolk sacs are detected early in the first trimester on ultrasound examination in monochorionic twin pregnancies.

Further observations on the empty "amnion sign"

OBJECTIVE

To assess the positive predictive value of the empty "amnion sign" (visualization of an amnion without concomitant visualization of an embryo) for the diagnosis of early pregnancy failure.

METHODS

Retrospective study of 882 1st trimester sonographic examinations with abnormal findings among women who were threatening to abort. Eight hundred six met the inclusion criteria.

RESULTS

In the study cohort 286 (35.5%) had no identifiable embryo and 71 of those without an identifiable embryo had a visible amnion (24.8%). The breakdown of the mean sac diameter of the study cohort was as follows: those measuring less than 16 mm (n = 16); those measuring 16-20 mm (n = 20); those measuring 21 mm or more (n = 35). Sixty-eight of the 71 patients had adequate follow-up. Pregnancy failure was confirmed in all 68 patients (positive predictive value = 100%).

CONCLUSIONS

The data from this study indicate that visualization of an amnion without concomitant visualization of an embryo (the empty "amnion sign") confirms pregnancy failure regardless of the mean sac diameter and with a sufficiently high positive predictive value to make a definitive diagnosis.

The expanded amnion sign: evidence of early embryonic death

OBJECTIVE

The purpose of this study was to assess the positive predictive value for confirming early embryonic death in the clinical scenario wherein an embryo is identified without a visible heartbeat, but the embryonic crown-rump length (CRL) is 5 mm or less.

METHODS

We conducted a retrospective study of 882 first-trimester sonograms with abnormal findings among women who were threatening to abort. Eight hundred six met the inclusion criteria.

RESULTS

Among the cohort of 806 cases, 520 (64.5%) had an identifiable embryo, and 255 of those with an identifiable embryo had a visible amnion (49.0%). One hundred sixteen of the 255 with a visible amnion and an identifiable embryo without a heartbeat had a CRL that measured 5 mm or less (45.5%). The CRL of these embryos ranged from 1.7 to 5.4 mm (ie, when rounded to the nearest millimeter, these embryos would be 5 mm) with the breakdown as follows: those measuring less than or equal to 3.4 mm (n = 28), those measuring 3.5 to 4.4 mm (n = 45), and those measuring 4.5 to 5.4 mm (n = 43). Eight of these 116 patients did not have any documented follow-up. In the remaining 108 patients, pregnancy failure was confirmed.

CONCLUSIONS

We conclude that any embryo that is surrounded by an amnion and that also lacks a heartbeat has unfortunately but definitively died. This is equally true for embryos measuring less than 5 mm in CRL.

Antepartum amnioinfusion: a review

OBJECTIVE

Antepartum amnioinfusion is a relatively recent procedure introduced with fetal medicine techniques. It is usually indicated for severe oligohydramnios in order to avoid the related complications such as pulmonary hypoplasia, the deforming effects of oligohydramnios, variable fetal heart rate decelerations and intraventricular hemorrhage. Antepartum amnioinfusion is also employed to improve ultrasound visualization in cases with oligohydramnios. Our objective was to evaluate the benefits and complications related to this procedure which is still less commonly used compared to intrapartum amnioinfusion, and whose risks are therefore not well established.

STUDY DESIGN

Reports of study designs identified from searches of MEDLINE, PUBMED, the Cochrane Collaboration, specialized databases and bibliographies of review articles were identified. Studies in women who underwent amnioinfusion between 1987 and 2002 were included.

RESULTS AND CONCLUSIONS

Amnioinfusion seems to offer several benefits, in terms of both prenatal diagnosis and favorable perinatal outcome. Most clinical experiences report that amnioinfusion is safe, both for the mother and for the fetus. However, randomized control-group studies subdivided on the basis of the cause of oligohydramnios (e.g. premature rupture of membranes, fetal growth restriction, obstructive uropathy and renal agenesis) could help to determine the advantages and risks linked to this procedure. Prospective randomized studies should therefore be encouraged, to clarify any possible doubts regarding the procedure, before it can be introduced into routine practice in the management of oligohydramnios.

Hydrothorax treated in utero and monitored by fetal echocardiography

Primary fetal hydrothorax is a relatively rare disorder, occurring in 1 out of 15,000 pregnancies, but connected with high perinatal mortality. In the event of little or no progress of the effusion or stable clinical course, conservative management seems to be the most appropriate course of action. In nearly half of the cases, a placement of only one pleuroamniotic shunt enables a total regression of the primary fetal hydrothorax and, consequently, a favourable outcome. The remaining cases require the placement of yet another shunt. In the case of repeated shunt failure, the prognosis is very poor. In the following paper we have presented a fetus with a giant re-accumulating hydrothorax after thoracocentesis, treated by pleuroamniotic shunts and monitored by fetal echocardiography and cardiovascular profile score. Despite dramatic fetal presentation and rapid re-accumulation of the hydrothorax, monitoring by fetal echocardiography and cardiovascular profile score proved the repeated fetal needling and double shunting to be safe. If there are no complications such as premature rupture of the membranes and preterm delivery, fetal echocardiography is a sufficient way of monitoring fetal well-being and the results of intrauterine procedures.

Reliability of transvaginal ultrasonography at 7-9 weeks' gestation in the determination of chorionicity and amnionicity in twin pregnancies

OBJECTIVES

To assess the agreement in the diagnosis of chorionicity and amnionicity between transvaginal ultrasound examination at 7-9 weeks' gestation and at the 11-14-week transabdominal scan.

METHODS

This was a retrospective analysis of prospectively collected data of twin pregnancies over a 3-year period. Chorionicity and amnionicity were assessed in women with viable twin pregnancies who underwent a transvaginal ultrasound scan at between 7 and 9 weeks' gestation. These findings were compared with the diagnoses of chorionicity and amnionicity at the subsequent 11-14-week scan in these women.

RESULTS

Chorionicity and amnionicity were documented in 67 viable twin pregnancies at both 7-9 and 11-14 weeks' gestation. There was agreement in the chorionicity and amnionicity reported at each of the two scans in 65 out of 67 (97%) cases. Of the dichorionic-diamniotic (DCDA) pregnancies reported at 7-9 weeks, 53 out of 54 (98%) were confirmed at the 11-14-week scan and one (2%) was found to be monochorionic-diamniotic (MCDA). However, at birth these twins were of different sex, confirming DCDA twins as initially diagnosed at 7-9 weeks. Of the 12 pregnancies diagnosed as MCDA at 7-9 weeks, all were found to be MCDA at the 11-14-week scan. There was one monochorionic-monoamniotic (MCMA) pregnancy diagnosed at 7-9 weeks that was subsequently found to be MCDA at the 11-14-week scan.

CONCLUSION

Transvaginal ultrasound examination at 7-9 weeks' gestation shows very high agreement with the 11-14-week scan in the diagnosis of chorionicity and amnionicity in twin pregnancies, suggesting that it provides a similar level of accuracy. Accuracy may be higher for DC twins than MC twins, which may relate to the gestational age at which the sonographic appearance of the amniotic sac develops.

Application of Carnegie stages of development to unify human and baboon ultrasound findings early in pregnancy

The objective of this study was to determine if very early ultrasonographic measurements obtained from human and baboon are comparable. For this purpose, the gestational, amniotic and yolk sacs, embryonic crown rump length (CRL) and heart rate were measured ultrasonographically between 35 and 47 days from the mean day of a three-day mating period in baboons (n=18) and between 42 to 58 days from fertilization as calculated from the CRL measurements in human pregnancies (n=82). Ultrasonographic measurements from both species were then plotted in the same graph using Carnegie stages of embryonic development as the independent variable to allow for visual comparisons. Mean gestational age at ultrasonographic studies was significantly different for humans and baboons (50.4 vs. 41 days, respectively; p>0.01). Significant correlations (p>0.01) were noted between ultrasonographic measurements and Carnegie stages of development in both humans and baboons. Only the gestational and the yolk sacs were significantly smaller in baboons than in humans (p>0.05). The findings that embryonic CRL, extra-embryonic space and heart rate are very similar between the 17th and 23rd Carnegie developmental stages make the baboon a promising surrogate of human pregnancy for investigations using celocentesis.

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.

Transient Chorioamniotic Membrane Separation after Fetoscope Guide Laser Therapy for Twin–Twin Transfusion Syndrome: A Case Report

Chorioamniotic membrane separation (CMS) means that the close attachment of amniotic and chorionic membranes is disrupted, usually following the traumatic entry into the amniotic cavity including fetal therapy. We report a case of twin-twin transfusion syndrome receiving fetoscopic guide laser therapy at gestational age of 19 weeks with partial CMS detected at the fifth week (gestational age of 24 weeks) after surgery and resealed 1 week later. There was no more CMS noted till delivery at gestational age of 34 weeks 6 days. CMS after fetoscope surgery may reseal spontaneously.

[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.

Determining chorionicity in twin gestations: three-dimensional (3D) multiplanar sonographic measurement of intra-amniotic membrane thickness

OBJECTIVES

Measuring the thickness of the membranes to determine chorionicity in twins using two-dimensional (2D) ultrasound may provide uncertain results, given the possibility of measuring in an oblique view. We aimed to determine whether chorionicity can be assessed during the second and third trimesters by measuring the thickness of the membranes with three-dimensional (3D) multiplanar ultrasound, which ensures the measurement is perpendicular to the membranes, and to evaluate the reproducibility of the technique.

METHODS

This was a prospective study of 84 twin pregnancies (30 monochorionic and 54 dichorionic) between 20 and 35 weeks of gestation. The dividing membranes between the fetuses were visualized with 2D and 3D transabdominal sonography and the thickness of the membranes was measured by the multiplanar technique. Intraobserver variability was assessed by comparing the measurements obtained in sagittal and axial views by the same observer. We examined the frequency distributions to determine the optimal cut-off point of the thickness of the membranes to predict chorionicity. Kappa index, intraclass correlation coefficients and 95% limits of agreement were calculated to evaluate the inter- and intraoperator variability. We also compared membrane-thickness measurement, during the second and third trimesters, using 2D and 3D ultrasound.

RESULTS

In monochorionic and dichorionic pregnancies, respectively, the mean thickness was 1.42 (SD, 0.31) mm and 2.48 (SD, 0.47) mm. With 3D ultrasound, the intraclass correlation coefficient was 0.99 in all cases. The 95% limits of agreement were all within +/-0.2 mm. The best cut-off for membrane thickness for discriminating monochorionic from dichorionic twinning was 1.8 mm. Using this cut-off, there were one false-negative (sensitivity, 97%; 95% CI, 83-99%) and three false-positive (specificity, 94%; 95% CI, 85-99%) diagnoses of monochorionic twins. Kappa indices for intra- and interoperator variability were all above 90%, suggesting almost perfect agreement. Measurements with 2D sonography were less accurate (sensitivity and specificity, 83%).

CONCLUSION

Prenatal assessment of dividing membranes using 3D multiplanar ultrasound is reproducible and may be a useful alternative method for determining chorionicity in twin pregnancies during the second and third trimesters.

[Umbilical cord entanglement in monoamniotic twin preganacy--case presentation and literature review]

Monoamniotic twins are at most increased risk of perinatal complications with perinatal mortality of 28-60 % reported in literature. The most specific complication to monoamniotic twins is entanglement and (or) knotting of the cords leading to intrauterine death of both (more often) or one twin. In first presented case 1, 23-year-old primigravida in 33wks of twin monoamniotic gestation was reffered to our Institute due to intrauterine death of one co-twin caused by umbilical cord entanglement. In second case, 26-year-old multigravida in monoamniotic twin gestation was admitted to our institution. A serious umbilical cord entanglement was observed and a presence of true knot of umbilical cord was suspected. Presented cases indicate that establishing a chorionicity and amniocity in twin pregnancy is an essential part of ultrasound examination. The diagnosis of cord entanglement in monoamniotic twin pregnancy enables a forecasting of possible complications. According to the established diagnosis future protocols of perinatal management could be proposed. Due to possible complications counseling and management of monoamniotic twins should be performed in tertiary medical centers.

Amnion degeneration over fetal placental surface vessels possibly resulting from focal hypoxia: a case report

The monoamnionic placenta of this twin gestation had focal amnion necrosis, but this was present only over the fetal surface vessels of one twin; this twin also developed cerebral atrophy. We hypothesize that this degeneration is due to a more severely reduced oxygen tension in its vessels. The placental amnion epithelium may undergo several degenerative processes, including amnion nodosum and changes due to meconium staining. Sonography had disclosed what appeared to be a dividing membrane, but this was not found at birth when monoamnionic twins with entangled cords presented. The amnion degeneration was present only over the large surface fetal vessels of the placenta of that twin who also developed central nervous system degeneration, and macrophage infiltration was confined to the same lesions. Focal hypoxia from entangling cords may have caused this defect.