Selective termination for structural, chromosomal, and mendelian anomalies: international experience

Thanatophoric dysplasia in a dichorionic twin confirmed by genetic analysis at the early second trimester: A case report and literature review

Thanatophoric dysplasia (TD) is caused by mutation of the gene that encodes fibroblast growth factor 3 (FGFR3). Owing to the poor prognosis for TD, prenatal diagnosis is critical to optimal perinatal management. We report here a case of TD in twin pregnancy, which was prenatally diagnosed by DNA analysis following amniocentesis at 15 weeks, and was managed by selective fetal termination. Prenatal ultrasonography and molecular analysis to detect TD-specific mutations enable accurate diagnosis of FGFR3-related TD in utero and appropriate obstetrical management at early gestation during twin pregnancy.

Fetal diagnostic indications for second and third trimester outpatient pregnancy termination

OBJECTIVE

To determine the frequency of diagnostic indications among women seeking to terminate pregnancies for reasons of fetal abnormality, spontaneous fetal demise, or a genetic disorder in a private outpatient clinic specializing in late outpatient abortion procedures.

METHOD

A total of 1005 women requested termination of pregnancy for reasons of genetic disorder, fetal anomaly, or fetal demise over 20 years (1992-2012). Gestational ages ranged from 12 to 39 weeks. In all cases, a documented diagnosis of fetal abnormality or fetal demise was made prior to referral. Records were reviewed to verify fetal diagnosis for all patients seeking termination of pregnancy for reasons of fetal disorder. Major complications included major unintended surgery, hemorrhage requiring transfusion, or pelvic infection.

RESULTS

Preoperative diagnoses included the following: chromosomal abnormalities (n = 378), genetic syndromes and single gene disorders (n = 30), structural anomalies (n = 494), and other conditions (n = 103). These include 26 cases of spontaneous fetal demise and nine selective terminations of one abnormal twin. The major complication rate was 0.5%.

CONCLUSIONS

The majority of diagnoses were in the categories of genetic disorder and neurologic abnormality.

Outcome following selective fetal reduction in monochorionic and dichorionic twin pregnancies discordant for structural, chromosomal and genetic disorders

BACKGROUND

To investigate the indications for offering selective fetal reduction in monochorionic (MC) and dichorionic (DC) twins and to correlate obstetric outcome with the antenatal procedure.

METHODS

All cases of MC and DC twins discordant for structural anomalies and for chromosomal/genetic abnormalities were included. Selective reductions performed for twin-to-twin transfusion syndrome or growth restriction were excluded. For DC twins, feticide was achieved using intracardiac injection of potassium chloride (KCl). For MC twins, bipolar cord occlusion (BCO), interstitial laser or radiofrequency ablation (RFA) was used.

RESULTS

There were 121 twin pregnancies discordant for structural and chromosomal abnormalities. Only 88 (56 were MC twins and 32 were DC twins) had selective reduction. For both MC and DC twins, the leading indication for selective reduction was structural anomalies with CNS malformations the most common. For all MC fetal reduction techniques, the overall pregnancy loss rate (<24 weeks) was 8.9% with RFA having the lowest procedure loss rate (7.7%). The preterm delivery rate was lowest with reduction in DC pregnancies. The live birth rates for MC twins were >87% and 100% for DC twins.

CONCLUSIONS

Selective reduction in MC pregnancies carries an increased procedure-related and preterm delivery rate compared with DC pregnancies. The main indication for selective reduction was structural malformations, with a predominance of CNS anomalies.

Differences between selective termination of pregnancy and fetal reduction in multiple pregnancy: a narrative review

Although selective termination of pregnancy and fetal reduction in multiple pregnancy both involve the termination in utero of the development of live fetuses, these two procedures are different in several aspects. Nevertheless, several authors tend to amalgamate and confuse their psychosocial consequences and the ethical issues they raise. Therefore, this narrative review, derived from a comparative analysis of 91 articles, shines a light on these amalgamations and confusions, as well as on the medical, contextual, experiential and ethical differences specific to selective termination and fetal reduction.

Expectant management in twin pregnancies with discordant structural fetal anomalies

OBJECTIVE

Routine obstetric ultrasound increasingly leads to the detection of structural fetal anomalies. In twin pregnancies with one anomalous twin, counseling on management strategies is complicated.

PATIENTS AND METHODS

Twin pregnancies (n = 212) were referred to a tertiary center between January 2007 and July 2009. In a retrospective analysis, twins discordant for a structural fetal anomaly were compared to twins without anomalies in the prenatal ultrasound. Outcome parameters were survival and gestational age at birth.

RESULTS

Anomalies were seen in at least one fetus of 30 twin pairs. The two pregnancies in which the anomalies were concordant were terminated. Selective feticide was performed in three cases of major but non-lethal anomalies in dichorionic twins. The remaining 25 cases were managed expectantly. In three of these cases, spontaneous fetal demise of the affected fetus was observed. In five cases with major (lethal) anomalies, the pregnant women and their partners opted for non-intervention comfort care after birth for the affected fetus. Median gestational age at delivery was 257 days for twins without structural anomalies and was 254 days (n = 22) for twins with one anomalous fetus. This was not significantly different (Mann Whitney U, p = .69). Again, no difference was found for median gestational age at delivery in normal vs. discordant anomalous dichorionic twins if subdivided for chorionicity (Mann Whitney U, p = .68).

CONCLUSION

In this cohort we describe the request for expectant management by pregnant women and their partners of those twins discordant for major (lethal) anomalies. Expectant management was not associated with increased risk of premature delivery. Fetocide was only opted for in a small number of cases with severe but non-lethal anomalies in dichorionic twins.

The use of in utero MR imaging to delineate developmental brain abnormalities in multifetal pregnancies

BACKGROUND AND PURPOSE

iuMR has been shown to increase the detection rate of developmental abnormalities of the CNS, though most reports are limited to singleton pregnancies. The hypothesis tested in this study was that iuMR performed in multifetal pregnancies will show additional information about fetal CNS abnormalities in a similar proportion of cases when compared with singleton pregnancies.

MATERIALS AND METHODS

Fifty women with multifetal pregnancies were recruited consecutively carrying at least 1 fetus with a suspected developmental fetal CNS abnormality on sonography. All had iuMR at the same center by using the same MR imaging protocol. When the sonography and MR imaging reports were discrepant, 1 fetomaternal expert assessed the reports independently to predict in what percentage a change in prognosis/counseling would have occurred if iuMR was included in the diagnostic pathway.

RESULTS

There was agreement between the sonography and iuMR reports in 66% and disagreement in 34% of cases. The major cause for discrepancy was the presence or absence of the corpus callosum, which accounted for 10/17 of the disagreements. In 12/17 of the discrepant cases, the effect on management was judged to be significant.

CONCLUSIONS

We conclude that iuMR has a similar rate of discrepancy to sonography in multifetal pregnancies compared with the published data concerning singleton pregnancies. Our analysis of the effect on management shows that changes in the decision to consider termination of pregnancy would have occurred in 12/17 of the discrepant cases (ie, in 24% of our cases overall).

Health policy, patient-centred care and clinical ethics

RATIONALE, AIMS AND OBJECTIVES

Patient-centred care has been a central part of US and UK health policy for over a decade, but, despite its importance, the policy literature often fails to provide an adequate theoretical justification for why and how we should value it. This omission is problematic because it renders the status, content and appropriate evaluation of patient-centredness unclear. In this paper we aim to examine two different accounts of patient-centred care.

METHOD

We draw upon methods of conceptual and ethical analysis.

RESULTS

We argue that neither of the two accounts of patient-centred care identified appropriately grounds patient-centredness because neither of them takes into account the inherently moral nature of terms such as 'respect' and 'dignity', terms that are central to discussions of patient-centred care.

CONCLUSIONS

We suggest that clinical ethics can help to provide a theoretical justification for patient-centred care, and that clinical ethical practices can further patient-centred initiatives through ethics consultation, education and policy development and review.

Selective reduction and termination of multiple pregnancies

The substantial increase in high order multiple pregnancies in the last two decades as a result of assisted reproductive techniques has necessitated the development of multifetal pregnancy reduction as a management tool to decrease fetal number and improve perinatal survival. The evidence in favour of reduction in pregnancies with more than four fetuses to twins is undisputed. Despite the recent improvements in expectant management of triplets with reasonable perinatal outcomes, the evidence suggests that reduction to twins significantly reduces the risk of preterm delivery without an increase in miscarriage rates. Recent advances in vascular-occlusive techniques have allowed the possibility of selective termination in monochorionic pregnancies in the presence of discordant anomalies or indeed multifetal reduction in non-trichorionic triplets, with radiofrequency ablation and cord occlusion appearing to be the most successful. However, the techniques vary in complexity and complication rates, which increase with gestation. Hence the need to refer these pregnancies early to specialist centres.

Twins: prevalence, problems, and preterm births

The rate of twin pregnancies in the United States has stabilized at 32 per 1000 births in 2006. Aside from determining chorionicity, first-trimester screening and second-trimester ultrasound scanning should ascertain whether there are structural or chromosomal abnormalities. Compared with singleton births, genetic amniocentesis-related loss at <24 weeks of gestation for twin births is higher (0.9% vs 2.9%, respectively). Selective termination for an anomalous fetus is an option, although the pregnancy loss rate is 7% at experienced centers. For singleton and twin births for African American and white women, approximately 50% of preterm births are indicated; approximately one-third of these births are spontaneous, and 10% of the births occur after preterm premature rupture of membranes. From 1989-2000, the rate of preterm twin births increased, for African American and white women alike, although the perinatal mortality rate has actually decreased. As with singleton births, tocolytics should be used judiciously and only for a limited time (<48 hours) in twin births. Administration of antenatal corticosteroids is an evidence-based recommendation.

Pregnancy outcome after multifetal pregnancy reduction

OBJECTIVE

To study the effects of multifetal pregnancy reduction (MFPR) as a means to reduce the adverse outcome of multiple gestations.

METHODS

This was a retrospective study evaluating the outcome of 334 multiple pregnancies after embryo reduction.

RESULTS

In 313 multiple pregnancies in which MFPR was performed before 15 weeks, the rates of miscarriage, preterm delivery <33 weeks, preterm delivery <36 weeks and total fetal loss were 9.12%, 13.33%, 38.60% and 16.25%, respectively, and median gestational age at delivery was 35 weeks. There was a significant correlation between miscarriage and the finishing number of fetuses. In 185 triplets reduced to twins, miscarriage, preterm delivery <33 weeks, preterm delivery <36 weeks and total fetal loss occurred in 8.25%, 11.18%, 40.59% and 15.41% of cases, respectively, and median gestational age at delivery was 36 weeks. In the subgroup of 32 reduced triplet pregnancies that also had second-trimester amniocentesis, the risk of miscarriage (3.13%) was not significantly different from that in the rest of the group. Among 21 twin pregnancies that had selective termination at or after 15 weeks, the risk of preterm delivery <33 weeks was three times higher than in the group of 22 twin pregnancies with first-trimester procedures.

CONCLUSION

MFPR resulted in at least one live neonate in 83.75% of cases and was effective in reducing the risks of pregnancy loss and severe prematurity in quadruplets and higher-order pregnancies. The risk of miscarriage increased with increasing finishing number of fetuses. In reduced triplets gestation was prolonged in comparison with average figures reported in the literature. In twin pregnancies selective termination in the first trimester carries a lower risk of severe preterm delivery and this emphasizes the need for first-trimester diagnosis.

Late termination of pregnancy and foetal reduction for foetal anomaly

Late termination of pregnancy is a relatively rare procedure accounting for approximately 1% of all registered terminations in England and Wales; however, with improving detection rates for foetal anomalies, this number is increasing. Surgical dilation and evacuation (D&E) appears to be a safe and cost-effective procedure as long as the clinical expertise exists to provide this service. Medical termination appears equally safe and is best undertaken with the combined use of mifepristone and misoprostol. Foeticide, when required, should be performed from 22 weeks' gestation using strong KCl administered either by cardiocentesis or by cordocentesis. All women should be offered a post-mortem and any other appropriate investigation to allow accurate counselling regarding future pregnancies. The issue of late selective foetal reduction for foetal abnormality is complicated by the need to balance the risks to the healthy co-twin of expectant management versus selective termination.

[Discordant anomaly in twin pregnancy]

The risk of fetal loss is multiplied by 4 in monochorionic pregnancies by comparison with dichorionic one. The incidence of selective growth retardation (sIUGR) is between 12.5 to 25%. This variation is explained by the mixture between pure twin-to-twin transfusion syndrome (TTTS) and pregnancies without TTTS but with a pure sIUGR. The ability to diagnose prenatally sIUGR is low; the positive predictive value is only 37% (EL4). The umbilical flow velocity waveforms with absent diastolic flow (Type II) or with diastolic intermittent flow (Type III) is clearly a strong risk factor of mortality of the IUGR and also a risk factor of leucomalacia of the bigger fetus (EL3). The observed incidence of malformations in twins is 4.05% versus 2.38% for singletons (OR=1.7 [IC 95% 1.47-1.97]). Furthermore, the rate of fetal malformations is higher in monochorionic pregnancies by comparison with dichorionic one, 6.33% versus 3.43% (OR=1.8 [IC 95% 1.3-2.5]) (EL3). In the majority of the cases, the malformation is concerning only one fetus. The most frequent malformations are those of the central nervous system by comparison with singletons, those of the urinary tract and the cardiovascular malformations. Monozygotic pregnancies are not necessarily phenotypically and genetically identical. In situation of asymmetrical malformation, it is necessary to propose fetal karyotype of the malformed fetus. In case aneuploidy of the malformed fetus, secondarily it will be necessary to explore the other apparently normal one. Uniparental disomy should be suspected in such situation (EL3). In TRAP sequence, an intensive follow up should be organised with serial measurement of the respective size of the acardiac fetus and the normal one, Doppler exploration should be done to look for early sign of cardiac decompensation (expert viewpoint). In dichorionic pregnancies, when the malformation is threatening the whole pregnancy like anencephaly, a selective feticide allow a prolongation of the pregnancy, but with a risk of fetal loss of 8% and a risk of iatrogenic prematurity of 12%. In such situation, it could be wise to evaluate the evolution or to wait until the third trimester to undergo the procedure (EL3). In monochorionic pregnancies, in the same situation of anencephalic fetus the best option is bipolar cord coagulation. The result seems to be better after 18 weeks of gestation (EL4). There is a 20% risk of premature rupture of membrane. In the up to date analysis of the literature, there is no formal indication of selective feticide expect case of TRAP sequence with cardiac decompensation of the normal fetus. The very special situation of sIUGR is the object of a randomized trial. In all cases the active participation of the patients to the therapeutic option is mandatory (expert viewpoint).

Difficult diagnosis and management of an heterokaryotypic monochorionic twin pregnancy with discordant fetal sex and 45,X/47,XYY karyotypes

We report twins for whom ultrasound examinations revealed a Turner syndrome in the female fetus and a normal male fetus. A selective pregnancy termination was decided on the female fetus with hydrops. The death of both twins called in question the chorionic diagnosis. Amniotic fluid cytogenetic analysis revealed a 45,X karyotype in the female twin and a 47,XYY karyotype in the male twin. Molecular cytogenetic analysis on genital and renal cells showed different levels of 45,X/47,XYY mosaicism in both twins; molecular analysis on the amniocytes showed monozygosity. Monozygotic twins with discordant sex are very rare. This study showed the difficult diagnosis and management of a monochorionic twin pregnancy with discordant fetal sex.

Information and decision-making process for selective termination of dichorionic pregnancies: some French obstetricians' points of view

BACKGROUND

In France, neither Bioethics Law nor law related to abortion make reference to selective terminations (ST). Because they apply in the context of multiple pregnancies, ST raises problems which differ from those we usually see in prenatal medicine.We wanted to know: 1) which approaches were used by obstetricians to inform couples about processes and risks of ST, 2) their role in the decision-making process of couples, and 3) their representations about the level of autonomy that couples are able to assume.

METHODS

Qualitative research, eight semi-structured interviews performed with eight obstetricians from seven public hospitals in Parisian region.

RESULTS

Similarities: *Necessity to devote a lot of time to information. *Importance to give the couples the maximum of time for reflection. *Belief that the final decision belongs to couples. Discordances: *Heterogeneity of revealed information. *Discrepancy in the will to assure a complete and non directive information transfer. *Divergence in representations of what is an ethical support. *Differences in the limits of the autonomy of couples.

CONCLUSIONS

All physicians believe that they respect the autonomy of couples, arguing that final decision belongs to them. Paradoxically, some results are indicative of a sizeable level of directiveness from the physicians.

Growth abnormalities and multiple gestations

Growth abnormalities which include intrauterine growth restriction and weight discordance between twins are common in pregnancies complicated by multiple gestations and may be associated with poor perinatal outcomes. Knowledge of chorionicity is paramount when managing a multiple pregnancy. Monochorionic twins are at greater risk than dichorionic twins for growth issues, which may result in long-term complications including adverse neurological sequelae for the offspring. The purpose of the following article is to define normal and abnormal growth in multiples. In addition, the management of growth abnormalities in relationship to chorionicity will be discussed.

Fetal cardiocentesis: a review of indications, risks, applications and technique

OBJECTIVES

To review the indications, applications and technique of fetal cardiocentesis.

METHODS

Review of published case reports and case series of fetal cardiocentesis utilizing the PubMed search engine of the National Library of Medicine.

RESULTS

Case reports and case series demonstrate that fetal cardiocentesis may be an alternative method by which to facilitate prenatal diagnosis, intravascular therapy, multifetal and selective fetal reduction and in utero therapy of congenital heart disease. However, procedure-associated risk is higher than with cordocentesis and may limit use of this procedure.

CONCLUSIONS

Fetal cardiocentesis may be a reasonable option to obtain fetal intravascular access and facilitate therapeutic interventions when cordocentesis fails or is not feasible. However, expected benefit must clearly outweigh the procedure-associated risk.

Radiofrequency ablation for selective reduction in the complicated monochorionic gestation

OBJECTIVE

This study was undertaken to describe the efficacy and safety of radiofrequency ablation for selective reduction in the treatment of complicated monochorionic gestations.

STUDY DESIGN

Case series of all consecutive patients treated at 1 institution. A 17-gauge radiofrequency needle was inserted under continuous ultrasound guidance into the fetal abdomen at the site of the umbilical cord insertion of the affected twin and radiofrequency energy delivered until cessation of vascular flow was documented with pulsed and color flow Doppler.

RESULTS

Nine patients with monochorionic twin gestations (1 set was part of a triplet gestation) underwent the radiofrequency ablation procedure. Gestational age at the procedure ranged between 18.6-22 weeks. Liveborn infants resulted in two-thirds of cases. Preterm premature rupture of the membranes occurred in 2 of the 9 cases. All liveborn neonates were alive and well.

CONCLUSION

Radiofrequency ablation can be effectively used for selective reduction in complicated monochorionic gestations.

First-trimester risk assessment for trisomies 21 and 18 in twin pregnancy

OBJECTIVE

Our objective was to describe performance of first-trimester combined risk assessment in twin pregnancies.

STUDY DESIGN

Twin pregnancies that underwent risk assessment in our ultrasound unit from 2003-2006 were included. Adjusted risks for trisomies 21 and 18 that were based on age, nuchal translucency (NT), and biochemistry were provided for each twin. Detection rates for Down syndrome and trisomy 18 were calculated for age/NT, and age/NT/biochemistry at a screen-positive rate of 5% of pregnancies.

RESULTS

Five hundred thirty-five pregnancies were included. Median maternal age was 34 years, with 47% of women > or = 35 years old. There were 7 fetuses in 6 dichorionic pregnancies with Down syndrome and 3 fetuses in 3 pregnancies with trisomy 18. For a 5% false-positive rate, age/NT identified 83.3% of Down syndrome and 66.7% of Trisomy 18 pregnancies. Adding biochemistry resulted in 100% detection rates for both conditions.

CONCLUSION

The addition of biochemistry may enhance first-trimester risk assessment in twin pregnancies. Further studies with larger numbers of affected pregnancies are needed.

Dilemmas in the management of twins discordant for anencephaly diagnosed at 11 + 0 to 13 + 6 weeks of gestation

OBJECTIVE

To help develop an evidence-based approach to the best management of twin pregnancies discordant for anencephaly.

METHODS

We retrospectively examined the management and outcome of 18 pregnancies discordant for anencephaly diagnosed at 11 + 0 to 13 + 6 weeks of gestation in our center. We combined these data with those from other publications. In total, there were 44 dichorionic pregnancies that were managed expectantly (n = 35) or by selective feticide (n = 9) and 19 monochorionic pregnancies that were managed expectantly. We also reviewed the literature to ascertain the outcome of monochorionic twin pregnancies undergoing cord occlusion.

RESULTS

In the 35 dichorionic pregnancies that were managed expectantly, 20 (57.1%) developed polyhydramnios at 25-31 weeks; 13 were managed expectantly, five had amniodrainage and two had selective feticide. In 34 of the 35 cases the non-anencephalic twin was liveborn at a median gestation of 36 (range, 28-39) weeks and in six (17.6%) of these it was born before 33 weeks. In the dichorionic pregnancies that had selective feticide, there was one miscarriage and eight (88.9%) live births at a median gestation of 37 (range, 30-40) weeks and in one (12.5%) of these it was born before 33 weeks. In the monochorionic pregnancies, four (21.1%) anencephalic fetuses died at 20-32 weeks and in three of these the normal co-twin also died. In the 16 (84.2%) cases resulting in the live birth of the normal twin, delivery occurred at a median gestation of 33 (range, 27-39) weeks and in six (37.5%) of these it was before 33 weeks. Ultrasound-guided bipolar cord coagulation in 92 pregnancies, mostly complicated by twin reversed arterial perfusion sequence or severe twin-to-twin transfusion syndrome, was associated with a survival rate of 77.2% and early preterm delivery rate of 31.0%.

CONCLUSION

Dichorionic twins discordant for anencephaly are best managed with serial ultrasound examinations for early diagnosis of polyhydramnios, which can then be treated either by amniodrainage or selective feticide. In monochorionic twins it is uncertain whether the best management is expectant or by cord occlusion.

Disseminated intravascular coagulation following selective termination in a twin pregnancy. A case report

OBJECTIVE

Coagulation abnormalities after single fetal demise are well described, but similar cases had not been previously reported following therapeutic selective termination.

CASE

A 23-year-old G(3) P(2001) with a monochorionic-diamnionic twin pregnancy underwent selective termination at 20 4/7 weeks for severe twin-twin transfusion syndrome. Her fibrinogen thereafter decreased and she developed disseminated intravascular coagulopathy with pathological bleeding during a cesarean section. The maternal coagulopathy resolved postpartum.

CONCLUSION

Coagulation disorders can follow selective termination. Recommendations to serially follow coagulation parameters after these procedures, however, cannot be based upon a single case.

Pregnancy and infant outcome of 80 consecutive cord coagulations in complicated monochorionic multiple pregnancies

OBJECTIVE

This study was undertaken to document pregnancy and infant outcome after cord coagulation with laser and/or bipolar as a technique for selective feticide in complicated monochorionic multiple pregnancies.

STUDY DESIGN

Prospective follow-up study in 2 tertiary fetal medicine centers.

RESULTS

Eighty cases were included in the study (73 twins, 7 triplets). The survival rate was 83% (72/87). There were 9 intrauterine fetal deaths (10%), 5 within 24 hours and 4 between 4 and 10 weeks after the procedure. There was 1 termination of pregnancy because of chorioamnionitis. Median gestational age at delivery was 35.4 weeks, with 79% of patients delivering after 32 weeks. Preterm prelabor rupture of the membranes before 25 weeks accounted for all perinatal deaths (n = 5). Of the children older than 1 year of age (n = 67), 62 (92%) have a normal development.

CONCLUSION

Cord coagulation is an effective method for selective feticide in monochorionic multiple pregnancies.

First trimester screening for Down syndrome in multiple pregnancy

The incidence of twins, triplets, and high-order multiples has increased substantially in the last two decades secondary to fertility treatments and to delayed childbearing. Prenatal diagnosis in these patients is challenging. Options for screening tests are limited. First trimester screening for Down syndrome in patients with multiples appears promising. This paper will review the advantages of first trimester screening in this high-risk patient population.

Diagnosis and management of obstetrical complications unique to multiple gestations

Obstetrical complications unique to multiple gestations pose a number of unique challenges. The presence of more than one fetus complicates the diagnosis and management of a pregnancy when one fetus has a structural or chromosomal abnormality, intrauterine demise, preterm premature rupture of the membranes, or delivers prematurely. Similarly, the diagnosis and management of monoamniotic twins and conjoined twins is challenging. These obstetrical complications that are unique to multiple gestations require thorough counseling of the expectant parents, as well as care by physicians with expertise in the management of multiple gestations.

Discordant Lower Urinary Tract Obstruction in Early Twin Gestations

OBJECTIVE

To report our experience with the management of twin pregnancies discordant for lower urinary tract obstruction.

METHODS

Cases of twin pregnancies discordant for lower urinary tract obstruction were identified from our fetal medicine database. Information on ultrasonographic findings, antenatal course, pregnancy complications, and perinatal outcome was obtained by reviewing medical records or contacting the referring obstetricians.

RESULTS

Five twin pregnancies discordant for lower urinary tract obstruction were diagnosed between 11 and 15 weeks of gestation. There were 3 dichorionic and 2 monochorionic pregnancies (1 diamniotic and 1 monoamniotic). The dichorionic pregnancies were managed conservatively, resulting in a pregnancy loss of both twins in 1 case, a single fetal death at 29 weeks in 1 case, and an early neonatal death due to lung hypoplasia of the affected twin in 1 case. On the other hand, both monochorionic twin pregnancies were managed with serial vesicocenteses. In both cases, the prenatal course was complicated, 1 by premature rupture of the membranes and the other by cord entanglement, requiring delivery at 29 and 31 weeks, respectively. Among the 4 continuing pregnancies with complete perinatal outcome, none of the affected twins survived, and the structurally normal twins were delivered between 29 and 36 weeks and discharged from the hospital in good condition.

CONCLUSION

Twin pregnancies discordant for lower urinary tract obstruction are at high risk of perinatal death and premature delivery. Prenatal intervention seems not to be associated with an improved perinatal outcome of the affected twin, but it may be beneficial in selected cases to attain viability of the unaffected twin.

IVF/ICSI twin pregnancies: risks and prevention

Since the 1970s, the national twin birth rates have been increasing worldwide. Apart from the increasing childbearing age, the main cause is the use of assisted reproductive technologies (ART). To explore the overall consequences of dual embryo transfer (DET), the literature has been reviewed systematically regarding short- and long-term outcomes of IVF/ICSI twin pregnancies i.e. pregnancy complications, maternal risks, obstetric outcome and long-term morbidity including neurological sequelae, cognitive development and family implications. Another consequence of DET is vanishing twins, which seems to be a possible cause of adverse outcome in IVF singletons. The sparse literature on vanishing twins in IVF pregnancies and the influence on the surviving co-twin were also addressed. Finally, to determine the effects of implementing elective single embryo transfer (eSET), trials concerning eSET versus DET were analysed. In the light of the steadily increasing twin birth rates and the findings in this overview, where IVF/ICSI twins carry adverse outcome, it should be emphasized that the major obstacle in IVF remains the high twin birth rate. Furthermore vanishing twins account for another hazard of DET. These problems can be resolved by implementing eSET, diminishing the twin birth rate without affecting the overall goal of achieving a healthy infant.

Management of Multiple Pregnancy

Over the past 20 years, the number and rate of multiple births have dramatically increased in the United States. The rise in multiple births is mainly attributable to the increased use of ovulation-inducing drugs and the newly developed assisted reproductive technologies such as in vitro fertilization. Multifetal gestation is associated with an increased risk of perinatal morbidity and mortality. Multiple births account for an increasing percentage of low-birth-weight infants, preterm births, and infant mortality. In this article, the unique complications of multiple gestation and their management are reviewed. Also, selective termination and multifetal reduction in multiple gestation are discussed.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians

LEARNING OBJECTIVES

After completion of this article, the reader should be able to describe the effects of the rising rate of multiple pregnancies on perinatal morbidity and mortality, to recall the complications of diagnosing and treating abnormalities of multiple pregnancies, to list the multiple severe complications associated with multiple gestations, and to describe the difficulty in managing these complications.

Invasive procedures in multifetal pregnancies

This review discusses the various invasive techniques currently performed in multiple pregnancies.

Invasive Antenatal Interventions in Complicated Multiple Pregnancies

Multiple pregnancies still pose challenging problems for modern medicine. Complications in monochorionic multiple pregnancies have sparked a revival of fetoscopy as a means surgery on the placenta and umbilical cord. As such, fetoscopic laser coagulation is currently the best first-line treatment for severe twin-to-twin transfusion syndrome. Also, fetoscopic or ultrasound-guided cord coagulation seems to be an effective technique for selective feticide in monochorionic twins, albeit with still considerably higher fetal loss rates compared with selective feticide by potassium chloride injection in dichorionic twins.

Managing twins discordant for fetal anomaly

An excess of structural anomalies is observed in twins compared to singletons. Approximately 1-2% of twin pregnancies may face the dilemma of expectant management versus selective termination following diagnosis of an anomaly affecting only one fetus. If the option of selective fetocide is considered, the main variable determining the technique to achieve this aim is chorionicity. In a dichorionic pregnancy, passage of substances from one twin into the circulation of the co-twin is unlikely due to the lack of placental anastomoses, hence KCl can be injected safely into the circulation of the affected twin to produce fetal asystole. In monochorionic twin pregnancies, selective termination needs to be performed by ensuring complete and permanent occlusion of both the arterial and venous flows in the umbilical cord of the affected twin, in order to avoid acute haemorrhage from the co-twin into the dying fetus, which may lead to death or organ damage. Bipolar cord coagulation under ultrasound guidance is associated with approximately 70-80% survival rates.

Prenatal screening for Down syndrome and neural tube defects in twin pregnancies

Prenatal screening and diagnosis in a twin pregnancy is not straightforward. Once a twin pregnancy has been identified, women and their partners need time to consider the implications and decide whether they wish the pregnancy to be screened for Down syndrome or neural tube defects. We discuss here how multiple marker screening for Down syndrome and alpha-fetoprotein screening for neural tube defects can be carried out, given that this is the parents' chosen option and that the health professionals involved are capable of performing a diagnosis and selective feticide, should this arise.

Invasive diagnostic procedures in twin pregnancies

The rising rate of multiple pregnancies and its association with advanced maternal age has expanded the need for prenatal diagnosis in twins and higher order gestations. The complexity of the invasive diagnostic procedures and the risk of loss of an unaffected twin raise significant clinical, technical and ethical issues. In this review we discuss the specific issues of early scanning, counseling and determination of chorionicity prior to invasive procedures in twins. We present the available data describing the risk associated with these procedures in twins and compare data of fetal loss rate from different studies. We also discuss the issues of fetal blood sampling and late karyotyping in twin pregnancies.

Psychological aspects of prenatal diagnosis and its implications in multiple pregnancies

Couples expecting twins are often unrealistically optimistic and are therefore unprepared for the complications as well as the practical and emotional impact the birth of twins can have on the family. All such couples will need information and support throughout the pregnancy and beyond. In this review, the various aspects that should be addressed are discussed, in particular, health care workers and counsellors need to be aware of the stress experienced by parents who have been through prolonged treatment for infertility or who face the special problems associated with the loss of one twin (implies the loss could be other than death).

Two hundred ninety consecutive cases of multifetal pregnancy reduction: comparison of the transabdominal versus the transvaginal approach

OBJECTIVE

The purpose of this study was to compare the performance of the transabdominal versus the transvaginal route for the multifetal pregnancy reductions.

STUDY DESIGN

Two hundred ninety consecutive cases of multifetal pregnancy reduction were reviewed. Two hundred three reductions (70.0%) were done transabdominally; 75 cases (25.9%) were done transvaginally, and 12 cases (4.1%) used both routes. The indications for the transvaginal route were extreme obesity, abdominal scars, or if the lower fetus could not be reached transabdominally. Two hundred seventy-one women were delivered of live born babies after 24 weeks (group 1). Nineteen cases had pregnancy losses </=24 weeks (group 2).

RESULTS

The complete pregnancy loss rate was 6.5% (19/290 cases). Total pregnancy loss rates of multifetal pregnancy reduction were 3.5% (7/203 reductions) for the transabdominal route and 13.3% (10/75 reductions) for the transvaginal route ( P = .004). Overall pregnancy losses were 4.8% for starting with twins, 6.6% for starting with triplets, 1.8% for starting with quadruplets, 14.3% for starting with quintuplets, and 14.3% with starting numbers of >/=6 fetuses. For finishing numbers, total pregnancy losses were 5.1% for ending with a singleton infant, 6.6% for ending with twins, and 0% for ending with triplets. Significant differences in complete pregnancy loss were observed between transabdominal and transvaginal routes for starting with triplets (2.7% for transabdominal versus 16.7% for transvaginal; P = .006) and for finishing with a single fetus (0% for transabdominal versus 20% for transvaginal; P < .004).

CONCLUSION

The multifetal pregnancy reduction success rate was higher with the transabdominal route compared with the transvaginal route. Significant differences in favor of the transabdominal route were observed for starting with triplets or finishing with a single fetus. The transvaginal route should be reserved only for cases in which the transabdominal approach is hard or impossible to perform. The performance of the procedure at 12 to 13 weeks of gestation enables structural evaluation of the fetuses before reduction.

Obstetric complications of twin pregnancies

Advances in assisted reproductive technology and increases in the proportion of maternities in older women have both contributed to the steep increase in the incidence of twin pregnancies since the 1980s. Maternal and perinatal complications are higher in twins than in singleton pregnancies. A significant proportion of perinatal mortality and morbidity among twins is due to the high incidence of preterm delivery and the added complication of twin-to-twin transfusion syndrome (TTTS) in monochorionic twins. Monochorionic twins also have a much higher rate of perinatal mortality than dichorionic twins, the greatest risk being before fetal viability (<24 weeks gestation). Early diagnosis of twins and their chorionicity, close fetal surveillance, particularly of monochorionic twins, and prompt therapeutic intervention in TTS are necessary to reduce perinatal mortality. Intrapartum management in the hospital setting with anaesthetic and neonatal facilities, as well as critical assessment of mode of delivery, have led to better outcomes. Ultrasonography is a valuable tool in the management of twin pregnancy. This chapter briefly summarises these topics, with a particular focus on recent literature.

Methods for Induced Abortion

We describe present methods for induced abortion used in the United States. The most common procedure is first-trimester vacuum curettage. Analgesia is usually provided with a paracervical block and is not completely effective. Pretreatment with nonsteroidal analgesics and conscious sedation augment analgesia but only to a modest extent. Cervical dilation is accomplished with conventional tapered dilators, hygroscopic dilators, or misoprostol. Manual vacuum curettage is as safe and effective as the electric uterine aspirator for procedures through 10 weeks of gestation. Common complications and their management are presented. Early abortion with mifepristone/misoprostol combinations is replacing some surgical abortions. Two mifepristone/misoprostol regimens are used. The rare serious complications of medical abortion are described. Twelve percent of abortions are performed in the second trimester, the majority of these by dilation and evacuation (D&E) after laminaria dilation of the cervix. Uterine evacuation is accomplished with heavy ovum forceps augmented by 14-16 mm vacuum cannula systems. Cervical injection of dilute vasopressin reduces blood loss. Operative ultrasonography is reported to reduce perforation risk of D&E. Dilation and evacuation procedures have evolved to include intact D&E and combination methods for more advanced gestations. Vaginal misoprostol is as effective as dinoprostone for second-trimester labor-induction abortion and appears to be replacing older methods. Mifepristone/misoprostol combinations appear more effective than misoprostol alone. Uterine rupture has been reported in women with uterine scars with misoprostol abortion in the second trimester. Fetal intracardiac injection to reduce multiple pregnancies or selectively abort an anomalous twin is accepted therapy. Outcomes for the remaining pregnancy have improved with experience.