Perinatal outcomes in dichorionic diamniotic twins with multifetal pregnancy reduction versus expectant management: A systematic review and meta-analysis

Pregnancy outcomes of foetal reduction from twin to singleton gestation compared to ongoing twin gestations: a systematic review and meta-analysis

BACKGROUND

Foetal reduction, which involves selectively terminating one or more foetuses in a multiple gestation pregnancy, has become more common. This systematic review and meta-analysis aims to assess and compare pregnancy outcomes of foetal reduction from twin to singleton gestation to ongoing twin gestations.

METHODS

A comprehensive search of electronic databases (MEDLINE, EMbase, Cochrane Library, CINAHL and PsycINFO) was done for studies published until 15 April 2023. The outcomes analysed included gestational diabetes mellitus (DM), hypertension, caesarean delivery, foetal loss, perinatal death, preterm birth (PTB), intrauterine growth restriction (IUGR), preterm prelabour rupture of membranes (PPROM) and birth weight.

RESULTS

A total of 13 studies comprising 1241 cases of twin to singleton foetal reduction gestation were compared to 20,693 ongoing twin gestations. Our findings indicate that foetal reduction was associated with a significantly lower risk of developing maternal gestational DM (odds ratio [OR] = 0.40, 95% confidence interval [CI] 0.27-0.59) and hypertension (OR = 0.36, 95% CI 0.23-0.57) compared to the control group. Incidence rate of caesarean delivery (OR = 0.65, 95% CI 0.53-0.81) after foetal reduction was significantly lower compared to ongoing twin gestations. There was a 63% lower chance of PTB before 37 weeks of pregnancy. However, there was no significant association between foetal reduction and outcomes such as foetal loss, perinatal death, IUGR and PPROM.

CONCLUSIONS

Our findings suggest that foetal twin to singleton reduction entails potential benefits as compared to ongoing twin gestations. Further well planned studies are needed to explore underlying mechanisms to understanding of the outcomes associated with foetal reduction procedures and inform clinical decision-making for pregnant individuals and healthcare providers alike.

Trans-abdominal fetal reduction in higher order multiple pregnancies: a pioneer cohort retrospective study in Nepal

Objective

To share the initial experience of trans-abdominal multifetal pregnancy reduction (MFPR) in Nepal.

Method

The procedure was performed in 108 patients in a private hospital over a period of 3 years. Under ultrasound guidance, intracardiac injection of 0.2-3.0 ml of 15% w/v (2 mEq/ml) potassium chloride (KCl) was administered via trans-abdominal route.

Results

A total of 108 fetal reduction procedures were carried out at the seventh to fifteenth weeks of gestation, a maximum of 44 (40.7%) of which were done at the ninth to tenth weeks of gestation. A total of 123 fetuses were reduced. Out of total 108 multifetal pregnancies, 96 (88.8%) were due to in-vitro fertilization (IVF). Eighty-five pregnancies (78.7%) underwent reduction from triplet to twin. The second-time reduction was needed in five cases. Two attempts (in the same sitting) were required in three cases. The inadvertent demise of the second fetus was noted in three cases of dichorionic tri-amniotic triplet pregnancy.

Conclusion

Ultrasound-guided trans-abdominal fetal reduction performed between the seventh and twelfth weeks of gestation is safe and effective.

ESHRE guideline: number of embryos to transfer during IVF/ICSI†

STUDY QUESTION

Which clinical and embryological factors should be considered to apply double embryo transfer (DET) instead of elective single embryo transfer (eSET)?

SUMMARY ANSWER

No clinical or embryological factor per se justifies a recommendation of DET instead of eSET in IVF/ICSI.

WHAT IS KNOWN ALREADY

DET is correlated with a higher rate of multiple pregnancy, leading to a subsequent increase in complications for both mother and babies. These complications include preterm birth, low birthweight, and other perinatal adverse outcomes. To mitigate the risks associated with multiple pregnancy, eSET is recommended by international and national professional organizations as the preferred approach in ART.

STUDY DESIGN, SIZE, DURATION

The guideline was developed according to the structured methodology for development and update of ESHRE guidelines. Literature searches were performed in PUBMED/MEDLINE and Cochrane databases, and relevant papers published up to May 2023, written in English, were included. Live birth rate, cumulative live birth rate, and multiple pregnancy rate were considered as critical outcomes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on the collected evidence, recommendations were discussed until a consensus was reached within the Guideline Development Group (GDG). A stakeholder review was organized after the guideline draft was finalized. The final version was approved by the GDG and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

The guideline provides 35 recommendations on the medical and non-medical risks associated with multiple pregnancies and on the clinical and embryological factors to be considered when deciding on the number of embryos to transfer. These recommendations include 25 evidence-based recommendations, of which 24 were formulated as strong recommendations and one as conditional, and 10 good practice points. Of the evidence-based recommendations, seven (28%) were supported by moderate-quality evidence. The remaining recommendations were supported by low (three recommendations; 12%), or very low-quality evidence (15 recommendations; 60%). Owing to the lack of evidence-based research, the guideline also clearly mentions recommendations for future studies.

LIMITATIONS, REASONS FOR CAUTION

The guideline assessed different factors one by one based on existing evidence. However, in real life, clinicians' decisions are based on several prognostic factors related to each patient's case. Furthermore, the evidence from randomized controlled trials is too scarce to formulate high-quality evidence-based recommendations.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides health professionals with clear advice on best practice in the decision-making process during IVF/ICSI, based on the best evidence currently available, and recommendations on relevant information that should be communicated to patients. In addition, a list of research recommendations is provided to stimulate further studies in the field.

STUDY FUNDING/COMPETING INTEREST(S)

The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, the literature searches, and the dissemination of the guideline. The guideline group members did not receive payment. DPB declared receiving honoraria for lectures from Merck, Ferring, and Gedeon Richter. She is a member of ESHRE EXCO, and the Mediterranean Society for reproductive medicine and the president of the Croatian Society for Gynaecological Endocrinology and Reproductive Medicine. CDG is the past Chair of the ESHRE EIM Consortium and a paid deputy member of the Editorial board of Human Reproduction. IR declared receiving reimbursement from ESHRE and EDCD for attending meetings. She holds an unpaid leadership role in OBBCSSR, ECDC Sohonet, and AER. KAR-W declared receiving grants for clinical researchers and funding provision to the institution from the Swedish Cancer Society (200170F), the Senior Clinical Investigator Award, Radiumhemmets Forskningsfonder (Dnr: 201313), Stockholm County Council FoU (FoUI-953912) and Karolinska Institutet (Dnr 2020-01963), NovoNordisk, Merck and Ferring Pharmaceuticals. She received consulting fees from the Swedish Ministry of Health and Welfare. She received honoraria from Roche, Pfizer, and Organon for chairmanship and lectures. She received support from Organon for attending meetings. She participated in advisory boards for Merck, Nordic countries, and Ferring. She declared receiving time-lapse equipment and grants with payment to institution for pre-clinical research from Merck pharmaceuticals and from Ferring. SS-R received research funding from Roche Diagnostics, Organon/MSD, Theramex, and Gedeo-Richter. He received consulting fees from Organon/MSD, Ferring Pharmaceuticals, and Merck Serono. He declared receiving honoraria for lectures from Ferring Pharmaceuticals, Besins, Organon/MSD, Theramex, and Gedeon Richter. He received support for attending Gedeon Richter meetings and participated in the Data Safety Monitoring Board of the T-TRANSPORT trial. He is the Deputy of ESHRE SQART special interest group. He holds stock options in IVI Lisboa and received equipment and other services from Roche Diagnostics and Ferring Pharmaceuticals. KT declared receiving payment for honoraria for giving lectures from Merck Serono and Organon. She is member of the safety advisory board of EDQM. She holds a leadership role in the ICCBBA board of directors. ZV received reimbursement from ESHRE for attending meetings. She also received research grants from ESHRE and Juhani Aaltonen Foundation. She is the coordinator of EHSRE SQART special interest group. The other authors have no conflicts of interest to declare.

DISCLAIMER

This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained. Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgement to each individual presentation, nor variations based on locality and facility type. ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose (full disclaimer available at https://www.eshre.eu/Guidelines-and-Legal).

Adverse outcome following selective termination of presenting twin vs non-presenting twin

OBJECTIVE

Data are lacking on the impact on pregnancy outcome of the position of the abnormal fetus in a discordant twin pregnancy undergoing selective termination (ST). Tissue maceration post ST of the presenting twin may lead to early rupture of membranes, amnionitis and preterm labor. The aim of this study was to evaluate pregnancy complications and outcome following ST of the presenting vs non-presenting twin.

METHODS

This was a multicenter retrospective cohort study of dichorionic diamniotic twin pregnancies that underwent ST due to a discordant fetal anomaly (structural or genetic) between 2007 and 2021. The study population was divided into two groups according to the position of the reduced twin (presenting or non-presenting) and outcomes were studied accordingly. The primary outcome was a composite of early complications following ST, including infection, preterm prelabor rupture of membranes and pregnancy loss.

RESULTS

A total of 190 dichorionic twin pregnancies were included, of which 73 underwent ST of the presenting twin and 117 of the non-presenting twin. The groups did not differ in either baseline demographic characteristics or mean gestational age at the time of the procedure. ST of the presenting twin resulted in a significantly higher rate of early complications compared with the non-presenting twin (19.2% vs 7.7%; P = 0.018). Moreover, the rates of preterm delivery (75.3% vs 37.6%; P < 0.001) and neonatal intensive care unit admission (45.3% vs 17.1%; P < 0.001) were higher, and birth weight was lower (P < 0.001), in those pregnancies in which the presenting twin was reduced.

CONCLUSIONS

ST of the presenting twin resulted in a higher rate of adverse pregnancy outcome compared with that of the non-presenting twin. These findings should be acknowledged during patient counseling and, if legislation permits, taken into consideration when planning ST. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Twin pregnancy reduction is not an 'all or nothing' problem: a response to Räsänen

In his paper, 'Twin pregnancy, fetal reduction and the 'all or nothing problem', Räsänen sets out to apply Horton's 'all or nothing' problem to the ethics of multifetal pregnancy reduction from a twin to a singleton pregnancy (2-to-1 MFPR). Horton's problem involves the following scenario: imagine that two children are about to be crushed by a collapsing building. An observer would have three options: do nothing, save one child by allowing their arms to be crushed, or save both by allowing their arms to be crushed. Horton offers two intuitively plausible claims: (1) it is morally permissible not to save either child and (2) it is morally impermissible to save only one of the children, which taken together lead to the problematic conclusion that (3) if an observer does not save both children, then it is better to save neither than save only one. Räsänen applies this problem to the case of 2-to-1 MFPR, arguing ultimately that, in cases where there is no medical reason to reduce, the woman ought to bring both fetuses to term. We will argue that Räsänen does not provide adequate support for the claim, crucial to his argument, that aborting only one of the fetuses in a twin pregnancy is wrong, so the 'all or nothing' problem does not arise in this context. Furthermore, we argue that the scenario Räsänen presents is highly unrealistic because of the clinical realities of 2-to-1 MFPR, making his argument of limited use for real-life decision making in this area.

Fetal reduction from twin to singleton gestation: A meta-analysis

OBJECTIVE

To evaluate outcomes of fetal reduction in twin pregnancy.

SEARCH STRATEGY

PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Google Scholar were searched from 1980 through December 2020.

SELECTION CRITERIA

Prospective or retrospective studies of pregnant women with twin gestations who had a transabdominal reduction of twin to singleton pregnancy with a comparison group of ongoing twin gestations.

DATA COLLECTION AND ANALYSIS

Outcomes were meta-analyzed only if reported in at least three studies.

MAIN RESULTS

Six studies with a pooled sample of 2867 women with a twin pregnancy of whom 624 underwent 2-to-1 reduction and 2243 did not. In the fetal reduction group, the odds of preterm birth before 34 and 37 weeks of pregnancy were lower by 36% (odds ratio [OR] 0.64, 95% confidence interval [CI] 0.48-0.86, P < 0.003) and 77% (OR 0.23, 95% CI 0.12-0.44, P < 0.001), respectively, than in the control group, and the odds of hypertensive disorders and cesarean delivery were lower by 75% (OR 0.25, 95% CI 0.15-0.43, P < 0.001) and 65% (OR 0.35, 95% CI 0.20-0.62, P < 0.001), respectively.

CONCLUSION

Twin reduction to singleton pregnancy decreased the possibility of preterm birth, hypertensive disorders in pregnancy and cesarean delivery. Sufficiently powered prospective studies are needed to support these findings.

Multifetal Gestations: Twin, Triplet, and Higher-Order Multifetal Pregnancies: ACOG Practice Bulletin, Number 231

The incidence of multifetal gestations in the United States has increased dramatically over the past several decades. For example, the rate of twin births increased 76% between 1980 and 2009, from 18.9 to 33.3 per 1,000 births (1). However, after more than three decades of increases, the twin birth rate declined 4% during 2014-2018 to 32.6 twins per 1,000 total births in 2018 (2). The rate of triplet and higher-order multifetal gestations increased more than 400% during the 1980s and 1990s, peaking at 193.5 per 100,000 births in 1998, followed by a modest decrease to 153.4 per 100,000 births by 2009 (3). The triplet and higher-order multiple birth rate was 93.0 per 100,000 births for 2018, an 8% decline from 2017 (101.6) and a 52% decline from the 1998 peak (193.5) (4). The long-term changes in the incidence of multifetal gestations has been attributed to two main factors: 1) a shift toward an older maternal age at conception, when multifetal gestations are more likely to occur naturally, and 2) an increased use of assisted reproductive technology (ART), which is more likely to result in a multifetal gestation (5). A number of perinatal complications are increased with multiple gestations, including fetal anomalies, preeclampsia, and gestational diabetes. One of the most consequential complications encountered with multifetal gestations is preterm birth and the resultant infant morbidity and mortality. Although multiple interventions have been evaluated in the hope of prolonging these gestations and improving outcomes, none has had a substantial effect. The purpose of this document is to review the issues and complications associated with twin, triplet, and higher-order multifetal gestations and present an evidence-based approach to management.

Bibliometric analysis of research hotspots and development trends in selective fetal reduction

AIM

To evaluate the theme trends and knowledge structure of multifetal pregnancy reduction (MPR)-related literature by using bibliometric analysis.

METHODS

Published scientific papers regarding MPR were retrieved from the PubMed database. Data extraction and statistics were conducted using Bibliographic Item Co-Occurrence Matrix Builder (BICOMB). Furthermore, gCLUTO software was used in the study for bi-clustering analysis and strategic diagram analysis.

RESULTS

According to the search strategy, 906 total papers were included. Among all the extracted MeSH terms, 41 high frequency ones were identified and hotspots were clustered into four categories. In the strategic diagram, research on intrauterine treatment of MPR was most well developed. In contrast, statistical data on the sequelae of fetal reduction surgery and applications of MPR in assisted reproductive technologies were relatively immature.

CONCLUSION

The analysis of common terms among the high-frequency network terms in multiparous pregnancy reduction can help researchers and clinicians understand the hotspots, key topics, and issues to be discovered on MPR. Research on intrauterine treatment of MPR was most well developed.

Current Resources for Evidence-Based Practice, November 2020

An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of diversity in the maternity care workforce and commentaries on reviews focused on burnout in midwifery and a cross-national comparison of guidelines for uncomplicated childbirth.