Committee Opinion No. 719: Multifetal Pregnancy Reduction

The outcome of reduced and non-reduced triplet pregnancies managed in a tertiary hospital during a 15-year-period - a retrospective cohort study

OBJECTIVES

Triplet pregnancies involve several complications, the most important being prematurity as virtually all triplets are born preterm. We conducted this study to compare the outcomes of reduced vs. non-reduced triplet pregnancies managed in the largest tertiary hospital in Finland.

METHODS

This was a retrospective cohort study in the Helsinki University Hospital during 2006-2020. Data on the pregnancies, parturients and newborns were collected from patient records. The fetal number, chorionicity and amnionicity were defined in first-trimester ultrasound screening. The main outcome measures were perinatal and neonatal mortality of non-reduced triplets, compared to twins and singletons selectively reduced of triplet pregnancies.

RESULTS

There were 57 initially triplet pregnancies and 35 of these continued as non-reduced triplets and resulted in the delivery of 104 liveborn children. The remaining 22 cases were spontaneously or medically reduced to twins (9) or singletons (13). Most (54.4 %) triplet pregnancies were spontaneous. There were no significant differences in gestational age at delivery between triplets (mean 33+0, median 34+0) and those reduced to twins (mean 32+5, median 36+0). The survival at one week of age was higher for triplets compared to twins (p<0.00001).

CONCLUSIONS

Most pregnancies continued as non-reduced triplets, which were born at a similar gestational age but with a significantly higher liveborn rate compared to those reduced to twins. There were no early neonatal deaths among cases reduced to singletons. Prematurity was the greatest concern for multiples in this cohort, whereas the small numbers may explain the lack of difference in gestational age between these groups.

Multifetal Pregnancy After Implementation of a Publicly Funded Fertility Program

Importance

A publicly funded fertility program was introduced in Ontario, Canada, in 2015 to increase access to fertility treatment. For in vitro fertilization (IVF), the program mandated an elective single-embryo transfer (eSET) policy. However, ovulation induction and intrauterine insemination (OI/IUI)-2 other common forms of fertility treatment-were more difficult to regulate in this manner. Furthermore, prior epidemiologic studies only assessed fetuses at birth and did not account for potential fetal reductions that may have been performed earlier in pregnancy.

Objective

To examine the association between fertility treatment and the risk of multifetal pregnancy in a publicly funded fertility program, accounting for both fetal reductions and all live births and stillbirths.

Design, Setting, and Participants

This population-based, retrospective cohort study used linked administrative health databases at ICES to examine all births and fetal reductions in Ontario, Canada, from April 1, 2006, to March 31, 2021.

Exposure

Mode of conception: (1) unassisted conception, (2) OI/IUI, or (3) IVF.

Main Outcomes and Measures

The main outcome was multifetal pregnancy (ie, a twin or higher-order pregnancy). Modified Poisson regression generated adjusted relative risks (ARRs) and derived population attributable fractions (PAFs) for multifetal pregnancies attributable to fertility treatment. Absolute rate differences (ARDs) were used to compare the era before eSET was promoted (2006-2011) with the era after the introduction of the eSET mandate (2016-2021).

Results

Of all 1 724 899 pregnancies, 1 670 825 (96.9%) were by unassisted conception (mean [SD] maternal age, 30.6 [5.2] years), 24 395 (1.4%) by OI/IUI (mean [SD] maternal age, 33.1 [4.4] years), and 29 679 (1.7%) by IVF (mean [SD] maternal age, 35.8 [4.7] years). In contrast to unassisted conception, individuals who received OI/IUI or IVF tended to be older, reside in a high-income quintile neighborhood, or have preexisting health conditions. Multifetal pregnancy rates were 1.4% (95% CI, 1.4%-1.4%) for unassisted conception, 10.5% (95% CI, 10.2%-10.9%) after OI/IUI, and 15.5% (95% CI, 15.1%-15.9%) after IVF. Compared with unassisted conception, the ARR of any multifetal pregnancy was 7.0 (95% CI, 6.7-7.3) after OI/IUI and 9.9 (95% CI, 9.6-10.3) after IVF, with corresponding PAFs of 7.1% (95% CI, 7.1%-7.2%) and 13.4% (95% CI, 13.3%-13.4%). Between the eras of 2006 to 2011 and 2016 to 2021, multifetal pregnancy rates decreased from 12.9% to 9.1% with OI/IUI (ARD, -3.8%; 95% CI, -4.2% to -3.4%) and from 29.4% to 7.1% with IVF (ARD, -22.3%; 95% CI, -23.2% to -21.6%).

Conclusions and Relevance

In this cohort study of more than 1.7 million pregnancies in Ontario, Canada, a publicly funded IVF program mandating an eSET policy was associated with a reduction in multifetal pregnancy rates. Nevertheless, ongoing strategies are needed to decrease multifetal pregnancy, especially in those undergoing OI/IUI.

Multifetal pregnancy reductions and selective fetocide in a tertiary referral center - a retrospective cohort study

OBJECTIVES

Multiple pregnancies involve several complications, most often prematurity, but also higher anomaly rates. Reducing fetuses generally improves pregnancy outcomes. We conducted this study to evaluate the obstetrical and neonatal results after multifetal pregnancy reduction (MFPR) in the largest tertiary hospital in Finland.

METHODS

This retrospective cohort study included all MFPR managed in Helsinki University Hospital during a 13 year period (2007-2019). Data on pregnancies, parturients and newborns were collected from patient files. The number of fetuses, chorionicities and amnionicities were defined in first-trimester ultrasound screening.

RESULTS

There were 54 MFPR cases included in the final analyses. Most often the reduction was from twins to singletons (n=34, 63 %). Majority of these (25/34, 73.5 %) were due to co-twin anomaly. Triplets (n=16, 29.6 %) were reduced to twins (n=7, 13 %) or singletons (n=9, 16.7 %), quadruplets (n=2, 3.7 %) and quintuplets (n=2, 3.7 %) to twins. Most (33/54, 61.1 %) MFPR procedures were done by 15+0 weeks of gestation. There were six miscarriages after MFPR and one early co-twin miscarriage. In the remaining 47 pregnancies that continued as twins (n=7, 14.9 %) or singletons (n=40, 85.1 %) the liveborn rate was 90 % for one fetus and 71.4 % for two fetuses.

CONCLUSIONS

Most MFPR cases were pregnancies with an anomalous co-twin. The whole pregnancy loss risk was 11.1 % after MFPR. The majority (70.6 %) of twins were spontaneous, whereas all quadruplets, quintuplets, and 56.3 % of triplets were assisted reproductive technologies (ART) pregnancies. Careful counselling should be an essential part of obstetrical care in multiple pregnancies, which should be referred to fetomaternal units for MFPR option.

Considering multifetal pregnancy reduction in triplet pregnancies: do we forget the emotional impact on fathers? A qualitative study from The Netherlands

STUDY QUESTION

What factors influence the decision-making process of fathers regarding multifetal pregnancy reduction or maintaining a triplet pregnancy, and how do these decisions impact their psychological well-being?

SUMMARY ANSWER

For fathers, the emotional impact of multifetal pregnancy reduction or caring for triplets is extensive and requires careful consideration.

WHAT IS KNOWN ALREADY

Multifetal pregnancy reduction is a medical procedure with the purpose to reduce the number of fetuses to improve chances of a healthy outcome for both the remaining fetus(es) and the mother, either for medical reasons or social considerations. Aspects of the decision whether to perform multifetal pregnancy reduction have been rarely investigated, and the impact on fathers is unknown.

STUDY DESIGN, SIZE, DURATION

Qualitative study with semi-structured interviews between October 2021 and February 2023.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Fathers either after multifetal pregnancy reduction from triplet to twin or singleton pregnancy or ongoing triplet pregnancies 1-6 years after the decision were included. The interview schedule was designed to explore key aspects related to (i) the decision-making process whether to perform multifetal pregnancy reduction and (ii) the emotional aspects and psychological impact of the decision. Thematic analysis was used to identify patterns and trends in the father's data. The process involved familiarization with the data, defining and naming themes, and producing a final report. This study was a collaboration between a regional secondary hospital (OLVG) and a tertiary care hospital (Amsterdam University Medical Center, Amsterdam UMC), both situated in Amsterdam, The Netherlands.

MAIN RESULTS AND THE ROLE OF CHANCE

Data saturation was achieved after 12 interviews. Five main themes were identified: (i) initial responses and emotional complexity, (ii) experiencing disparities in counselling quality and post-decision care, (iii) personal influences on the decision journey, (iv) navigating parenthood: choices, challenges, and emotional adaptation, and (v) shared wisdom and lessons. For fathers, the decision whether to maintain or reduce a triplet pregnancy is complex, in which medical, psychological but mainly social factors play an important role. In terms of psychological consequences after the decision, this study found that fathers after multifetal pregnancy reduction often struggled with difficult emotions towards the decision; some expressed feelings of doubt or regret and were still processing these emotions. Several fathers after an ongoing triplet had experienced a period of severe stress in the first years after the pregnancy, with major consequences for their mental health. Help in emotional processing was not offered to any of the fathers after the decision or birth.

LIMITATION, REASONS FOR CAUTION

While our study focuses on the multifetal pregnancy reduction process in the Amsterdam region, we recognize the importance of further investigation into how this process may vary across different regions in The Netherlands and internationally. We acknowledge the potential of selection bias, as fathers with more positive experiences might have been more willing to participate. Caution is needed in interpreting the role of the mother in the recruitment process. Additionally, the time span of 1-6 years between the decision and the interviews may have influenced emotional processing and introduced potential reporting bias.

WIDER IMPLICATIONS OF THE FINDINGS

The emotional impact of multifetal pregnancy reduction or caring for triplets is significant, emphasizing the need for awareness among caregivers regarding the emotional challenges faced by fathers. A guided trajectory might optimize the decision-making and primarily facilitate the provision of appropriate care thereafter to optimize outcomes around decisions with potential traumatic implications.

STUDY FUNDING/COMPETING INTEREST(S)

This study received no funding. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Outcomes of fetal reduction versus expectant management in dichorionic triamniotic triplets

OBJECTIVE

To compare the outcomes of dichorionic triamniotic (DCTA) triplets who underwent fetal reduction (FR) to singletons or twins with those managed expectantly.

METHODS

We conducted a retrospective study of DCTA triplets with three living fetuses at 11-14 weeks over a 7-year period. Pregnancy outcomes were compared following different management strategies.

RESULTS

Of 108 included patients, 22 underwent expectant management (EM), 28 were reduced to dichorionic diamniotic twins, and 58 to singletons. The median gestational age at birth for EM, FR to twins, and singletons was 33.1 weeks, 37.0 weeks, and 38.6 weeks, respectively (P < 0.001). Prematurity before 37 and 34 weeks was less common following FR to singletons and twins than in ongoing triplets (18.9%, 46.2% and 90.5%, P < 0.001; 13.2%, 26.9% and 57.1%, P < 0.001). Neonatal birth weight was higher in triplets reduced to singletons and twins compared with EM cases (3140g, 2315g, and 1860g, P < 0.001). However, rates of miscarriage, pregnancies with ≥1 survivor, maternal complications, and adverse neonatal outcomes were comparable among the three groups.

CONCLUSIONS

In our experience, FR in DCTA triplets could reduce prematurity risk compared to EM, but it confers no survival advantage. Fetal reduction to singletons may result in more favorable outcomes than those reduced to dichorionic twins.

Adverse outcomes associated with twin pregnancies conceived via in vitro fertilization

OBJECTIVE

To compare adverse pregnancy and neonatal outcomes in twin pregnancies conceived by in vitro fertilization (IVF) to those conceived spontaneously.

METHODS

Retrospective analysis of the Centers for Disease Control and Prevention, Natality Live Birth database for the years 2016-2019. All twin live births were included and stratified into two groups: those from pregnancies conceived via IVF and those from pregnancies conceived spontaneously. The incidence of several adverse pregnancy and neonatal outcomes were compared between the two groups. Statistical analysis included multivariable logistic regression to adjust for the following potential confounders: maternal age, race/ethnicity, body mass index, education level, type of medical insurance, chronic hypertension, pregestational diabetes, and prior preterm birth. Data were presented as adjusted odds ratios (aOR) with 95% confidence intervals (CI).

RESULTS

Twin live births from pregnancies conceived via IVF comprised 9.5% of the study cohort (39,356 of 415,560). Baseline characteristics varied significantly between IVF and spontaneously conceived twins. After adjusting for these variables, IVF in twins was associated with an increased risk of multiple adverse outcomes including gestational diabetes (aOR = 1.35, 95% CI = 1.30-1.39), hypertensive disorders of pregnancy (aOR = 1.70, 95% CI = 1.65-1.75), preterm birth prior to 28 weeks (aOR = 1.53, 95% CI = 1.43-1.63), maternal intensive care unit admission (aOR = 2.03, 95% CI = 1.79-2.31), maternal blood transfusion (aOR = 2.97, 95% CI = 2.75-3.20), unplanned hysterectomy (aOR = 3.37, 95% CI = 2.73-4.16), and prolonged ventilation in newborns (aOR = 1.76, 95% CI = 1.69-1.82), compared to spontaneously conceived twin pregnancies.

CONCLUSIONS

Based on this large United States population-based cohort, twin pregnancies conceived via IVF represent a subgroup of twins that have an increased risk for several adverse pregnancy and neonatal outcomes, compared to those conceived spontaneously. With increased contemporary utilization of IVF, obstetricians should consider these risks while caring for patients with twin pregnancies conceived via IVF.

Perinatal outcomes of fetoscopic laser surgery for twin-twin transfusion syndrome in triplet pregnancy: cohort study, systematic review and meta-analysis

OBJECTIVES

The aims of this study were to investigate the perinatal outcome of dichorionic triamniotic (DCTA) and monochorionic triamniotic (MCTA) triplet pregnancies complicated by twin-twin transfusion syndrome (TTTS) treated with fetoscopic laser photocoagulation (FLP) in two academic fetal centers, and to conduct a systematic review of previously published data to investigate perinatal survival in this targeted population.

METHODS

The first part of the study was a retrospective cohort study of prospectively collected data of consecutive triplet pregnancies with TTTS that underwent FLP at two fetal treatment centers between 2012 and 2020. Demographic, preoperative and operative variables and postoperative outcome were collected. Perinatal outcomes were investigated. The second part of the study was a systematic review and meta-analysis of studies evaluating the outcome of DCTA and/or MCTA triplet pregnancies, including our cohort study. PubMed, Web of Science and Scopus were searched from inception to September 2020. Primary outcomes were fetal survival (survival to birth), neonatal survival (survival to 28 days of age) and gestational age (GA) at birth.

RESULTS

A total of 31 sets of triplets with TTTS managed with FLP were included in the cohort study. Of these, 24 were DCTA and seven were MCTA. There were no significant differences in preoperative and operative variables between the two groups. There were also no significant differences between groups in GA at delivery or perinatal survival rate, including fetal and neonatal survival of at least one triplet, at least two triplets and all three triplets. Nine studies, including our cohort study, were included in the systematic review (156 DCTA and 37 MCTA triplet pregnancies treated with FLP). The overall fetal and neonatal survival was 79% (95% CI, 75-83%) and 75% (95% CI, 71-79%), respectively, in DCTA cases and 74% (95% CI, 52-92%) and 71% (95% CI, 49-89%), respectively, in MCTA cases. The rate of preterm birth before 28 weeks and before 32 weeks' gestation was 14% (95% CI, 4-29%) and 61% (95% CI, 50-72%), respectively, in DCTA triplets and 21% (95% CI, 3-45%) and 82% (95% CI, 62-96%), respectively, in MCTA triplets.

CONCLUSIONS

Triplet pregnancies with TTTS are at high risk of adverse perinatal outcome and preterm birth, regardless of chorionicity. The rate of survival after FLP in MCTA triplets was higher in our study than that reported in previous studies and is currently comparable with survival in DCTA triplets, which could be due to improved surgical skills. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Outcome of monochorionic triamniotic triplet pregnancies: Expectant management versus fetal reduction

OBJECTIVE

To compare the outcomes of monochorionic triamniotic (MCTA) triplets managed expectantly with those reduced to twins.

METHOD

This was a retrospective cohort study comparing expectant management (EM) with fetal reduction (FR) to twins in 43 consecutive MCTA triplets with 3 live fetuses at 11-14 weeks between 2012 and 2021.

RESULTS

Nineteen patients managed expectantly and 24 triplets reduced to twins were included. The rate of pregnancy with at least one survivor was 84.2% in the EM group and 66.7% in the FR group (P=0.190). Compared to the EM cases, triplets reduced to twins had a higher median gestational age at delivery (36.0 weeks vs 33.3 weeks; P＜0.001), a higher mean birth weight (2244.3±488.6g vs 1751.1±383.2g; P<0.001) and a lower risk of preterm birth before 34 weeks (11.8% vs 64.7%; P=0.001). There were no significant differences in the risk of miscarriage, pregnancy complications and composite adverse neonatal outcomes.

CONCLUSION

In MCTA triplets, FR to twins could reduce the risk of preterm birth, whereas EM seems to be a reasonable choice when the priority is at least one survivor. However, due to the small sample size of this study, these findings must be interpreted with great caution. This article is protected by copyright. All rights reserved.

Society for Maternal-Fetal Medicine Consult Series #60: Management of pregnancies resulting from in vitro fertilization

The use of assisted reproductive technology has increased in the United States in the past several decades. Although most of these pregnancies are uncomplicated, in vitro fertilization is associated with an increased risk for adverse perinatal outcomes primarily caused by the increased risks of prematurity and low birthweight associated with in vitro fertilization pregnancies. This Consult discusses the management of pregnancies achieved with in vitro fertilization and provides recommendations based on the available evidence. The recommendations by the Society for Maternal-Fetal Medicine are as follows: (1) we suggest that genetic counseling be offered to all patients undergoing or who have undergone in vitro fertilization with or without intracytoplasmic sperm injection (GRADE 2C); (2) regardless of whether preimplantation genetic testing has been performed, we recommend that all patients who have achieved pregnancy with in vitro fertilization be offered the options of prenatal genetic screening and diagnostic testing via chorionic villus sampling or amniocentesis (GRADE 1C); (3) we recommend that the accuracy of first-trimester screening tests, including cell-free DNA for aneuploidy, be discussed with patients undergoing or who have undergone in vitro fertilization (GRADE 1A); (4) when multifetal pregnancies do occur, we recommend that counseling be offered regarding the option of multifetal pregnancy reduction (GRADE 1C); (5) we recommend that a detailed obstetrical ultrasound examination (CPT 76811) be performed for pregnancies achieved with in vitro fertilization and intracytoplasmic sperm injection (GRADE 1B); (6) we suggest that fetal echocardiography be offered to patients with pregnancies achieved with in vitro fertilization and intracytoplasmic sperm injection (GRADE 2C); (7) we recommend that a careful examination of the placental location, placental shape, and cord insertion site be performed at the time of the detailed fetal anatomy ultrasound, including evaluation for vasa previa (GRADE 1B); (8) although visualization of the cervix at the 18 0/7 to 22 6/7 weeks of gestation anatomy assessment with either a transabdominal or endovaginal approach is recommended, we do not recommend serial cervical length assessment as a routine practice for pregnancies achieved with in vitro fertilization (GRADE 1C); (9) we suggest that an assessment of fetal growth be performed in the third trimester for pregnancies achieved with in vitro fertilization; however, serial growth ultrasounds are not recommended for the sole indication of in vitro fertilization (GRADE 2B); (10) we do not recommend low-dose aspirin for patients with pregnancies achieved with IVF as the sole indication for preeclampsia prophylaxis; however, if 1 or more additional risk factors are present, low-dose aspirin is recommended (GRADE 1B); (11) given the increased risk for stillbirth, we suggest weekly antenatal fetal surveillance beginning by 36 0/7 weeks of gestation for pregnancies achieved with in vitro fertilization (GRADE 2C); (12) in the absence of studies focused specifically on timing of delivery for pregnancies achieved with IVF, we recommend shared decision-making between patients and healthcare providers when considering induction of labor at 39 weeks of gestation (GRADE 1C).

Three or less? Decision making for or against selective reduction and psychological outcome in forty women with a triplet pregnancy

OBJECTIVES

The aim of the study was to investigate decision making for or against multifetal pregnancy reduction (MFPR) and psychological outcome in women with a triplet pregnancy.

METHODS

We investigated medical and sociodemographic variables and characteristics of the decision process for or against MFPR in forty women with triplet pregnancies who had either undergone MFPR (MFPR-group: N = 10) or had delivered triplets (triplet-group: N = 30). Moreover, emotional experiences of the reduction procedure were assessed. Psychological outcome was measured using the Beck Depression inventory (BDI) and the 36-Item Short Form Health Survey (SF-36).

RESULTS

Women of the MFPR-group had a higher gestational age at delivery (p = 0.001), shorter NICU stay (p = 0.001), higher educational level (p = 0.010), more frequently utilized psychological counseling during the decision process (p = 0.016), rated their gynecologist as more helpful for the decision (p = 0.045), required more time for their decision (p = 0.016), and were more likely to be in paid employment at follow-up (p = 0.041) than women of the triplet-group. MFPR was experienced as stressful (90%) or terrifying (10%). At 3.2 (±2.2) years after delivery, the vast majority of women in both groups were free from clinically relevant depression.

CONCLUSIONS

MFPR, though associated with emotional distress related to the procedure, results in a satisfactory psychological outcome in the majority of women. The decision for or against MFPR may be related to sociodemographic (such as educational) variables, which further supports the concept of framing in medical decision making. Having triplets most probably is associated with multiple (e.g. social or economic) consequences that may remain poorly investigated.

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.

Triplet pregnancy: What do we tell the prospective parents

Experience managing triplet pregnancies has increased over the past few decades as the incidence has changed related to assisted reproductive practices. Physicians caring for women carrying triplets cannot predict an individual outcome or pregnancy course but must educate patients about the challenges related to these high risk pregnancies. Obstetric providers can describe the wide range of risks associated with triplet gestations, and the general plan for management, but ultimately parents must make decisions with potentially lifelong consequences. Here, we present the diagnostic criteria, common complications, and management options for triplet pregnancies, to help obstetricians counsel patients on the medical and psychosocial consequences of triplet pregnancy, potential complications, and multifetal reduction.

Transabdominal fetal reduction: a report of 124 cases

To prevent fetal loss, preterm delivery, and perinatal morbidity of multifetal pregnancies (MPs), fetal reduction (FR) is offered to some patients. We retrospectively analysed the data of 124 MPs that underwent transabdominal FR to twin (n = 63) and singleton (n = 61) pregnancies at a mean gestational age of 12 + 6 weeks between December 2006 and January 2018. FR was performed transabdominally with the injection of potassium chloride into the intracardiac or intrathoracic space of the fetus or fetuses after ultrasound screening for nuchal translucency and anatomical defects. The initial number of embryos were 48 twins, 63 triplets, 11 quadruplets, and 2 quintuplets. The procedure-related pregnancy loss rate was 0.8% (1/124), the overall pregnancy loss rate was 2.4% (3/124), the fetal loss rate was 1.6% (2/124), and the neonatal death rate was 0.8% (1/124). The baby take-home rates were 96% for twin pregnancies and 96.7% for singletons. This study shows that transabdominal FR is an effective and safe procedure with a pregnancy loss rate of 2.4%.Impact statementWhat is already known on this subject? The incidence of multifetal pregnancies has increased over the years. Because multifetal pregnancies increase perinatal morbidity and mortality due to prematurity, fetal reduction is offed to some patients.What the results of this study add? The results of this study add to the growing body of research on fetal reduction. The study showed that transabdominal fetal reduction is a safe procedure with a pregnancy loss rate of 2.4%.What the implications are of these findings for clinical practice and/or further research? The results of this study can be used in counselling couples with multifetal pregnancies who are considering fetal reduction. Further research is needed to confirm the current findings.

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

BACKGROUND

Published findings on perinatal outcomes of multifetal pregnancy reduction (MPR) of dichorionic diamniotic (DCDA) twin pregnancy to singleton are controversial. We performed a meta-analysis to appraise the effects of MPR of DCDA twin pregnancy versus expectant management on perinatal outcomes.

METHODS

Four electronic databases were searched from their inception to June 15, 2019, to identify publications that appraised MPR before 15 weeks of gestation. Studies reporting perinatal outcomes of both MPR of DCDA twin pregnancy to singleton and expectant management were considered. The relative risks (RRs) and mean differences with 95% confidence intervals (CIs) were pooled using a random-effects model.

RESULTS

Six studies involving 7398 participants showed that MPR of DCDA twin pregnancy to singleton was associated with a lower risk of preterm birth (5 studies with 7297 participants; RR: 0.30, 95% CI: 0.22-0.40; P < .001) and higher birth weight (4 studies with 5763 participants; mean differences: 548.10 g, 95% CI: 424.04-672.15; P < .001) than expectant management; there was no difference in the occurrence of miscarriages (5 studies with 7355 participants; RR: 1.57, 95% CI: 0.90-2.75; P = .11). Sensitivity analysis showed that all the results were stable and reliable, with the omission of 2 studies with serious risk of bias.

CONCLUSION

Compared to expectant management, MPR of DCDA twin pregnancy to singleton prevents preterm birth and low birth weight, without increasing the risk of miscarriages. Regarding perinatal morbidity related to preterm birth, MPR can be reserved as a remediation measure to improve the perinatal outcomes of DCDA twin pregnancies.

Comparing pregnancy outcomes and loss rates in elective twin pregnancy reduction with ongoing twin gestations in a large contemporary cohort

BACKGROUND

As compared with singleton gestations, twin pregnancies are associated with a significantly higher risk of preterm birth and maternal complications as well as fetal and neonatal morbidity and mortality. Multifetal pregnancy reduction is a technique developed in the 1980s to reduce the fetal number in higher-order multiple pregnancies to reduce the risk of adverse pregnancy outcomes, most importantly preterm birth.

OBJECTIVE

The objective of the study was to compare pregnancy outcomes and loss rates in elective twin pregnancy reduction to ongoing twin gestations in a large contemporary cohort.

STUDY DESIGN

This was a retrospective review of dichorionic diamniotic twin gestations that underwent first-trimester ultrasound at our institution from January 2008 to September 2016. Planned elective 2-to-1 multifetal pregnancy reductions at less than 15 weeks' gestation were compared with ongoing dichorionic diamniotic twin gestations. Data were collected via chart review. Demographics between 2-to-1 reduced singletons and ongoing twins were assessed using a Student t test or a Wilcoxon rank-sum test, as appropriate, for continuous variables and χ² or Fisher exact tests, as appropriate, for categorical variables. Univariable and multivariable logistic regressions were used to compare pregnancy outcomes between ongoing twins and reduced singletons adjusting for maternal age, body mass index, race, in vitro fertilization, use of chorionic villus sampling, prior term birth, and prior preterm birth.

RESULTS

Of 1070 dichorionic diamniotic twin pregnancies identified, completed follow-up data were available and analyzed for 855 patients (79.9%). Among those, 250 (29.2%) were 2-to-1 singletons and 605 (70.8%) were ongoing twins. Reduced singleton patients were slightly older, more likely white, and had lower body mass index. They were also more likely to have undergone in vitro fertilization (63.6% vs 48.8%), had chorionic villus sampling (92% vs 37.5%), and had prior term births (54% vs 35.7%). Compared with 2-to-1 singletons, the adjusted odds of having preterm delivery at 37 weeks for ongoing twins were 5.62 times (95% confidence interval, 3.67-8.61; P < .001) and 2.22 times (95% confidence interval, 1.20-4.11; P < .001) at 34 weeks. While intrauterine growth restriction, placental abruption, and gestational diabetes were not significant, ongoing twins were more likely to have a cesarean delivery (odds ratio, 5.53, 95% confidence interval, 3.60-8.49; P < .001) and preeclampsia (odds ratio, 3.33, 95% confidence interval, 1.60-6.96; P < .001) after adjusting for maternal characteristics. There were also significant differences between groups for preterm premature rupture of membranes and low birthweight at less than the fifth and 10th percentiles. Total pregnancy loss (at 24 and 20 weeks) was similar between singleton and ongoing twins (4% vs 2.5%, P = .23, and 3.6% vs 1.7%, P = .09 for respective weeks). There were no significant differences in the rate of unintended pregnancy loss (2.4% vs 2.3%; P = .94) and the rate of intrauterine fetal death greater than 24 weeks (1.2% vs 0.7%; P = .43) in reduced singleton versus ongoing twin group, respectively.

CONCLUSION

In our study, patients who elected to reduce to a singleton pregnancy had a higher gestational age of delivery and lower rates of preterm birth and pregnancy complications without an increased risk of pregnancy loss.

Obstetrical outcomes of embryo reduction and fetal reduction compared to non-reduced twin pregnancies

PURPOSE

To prevent perinatal morbidity and mortality of high-order multiple pregnancy (HOMP), multifetal pregnancy reduction (MPR) is offered to some patients. In this study, we investigated whether twin pregnancies derived from MPRs carry a higher adverse obstetrical outcome compared to non-reduced control group of twins.

METHODS

We retrospectively analyzed the data from HOMPs on which transvaginal ER (n = 153) at a mean gestational age of 7.6 weeks or transabdominal FR (n = 59) at a mean gestational age of 12.4 weeks was performed between December 2006 and January 2018. The risk of each procedure was evaluated by comparing obstetrical outcome with that of a control population of 157 non-reduced twins conceived by infertility treatment.

RESULTS

The mean gestational ages at delivery were 35.2 weeks in the ER group, 35.7 weeks in the FR group, and 34.1 weeks in the control group (P = NS). Compared with those in the control group, the ER group had higher miscarriage (1.3% vs. 6.5%; P = 0.047; OR 0.21; 95% CI 0.45-0.898) and higher overall fetal loss (3.8% vs. 14.4%; P = 0.003; OR 0.24; 95% CI 0.09-0.60) rates. Differently compared with those in the control group, the FR group had no statistical difference in miscarriage (2.5% vs. 1.7%; P=NS) and overall fetal loss (3.8% vs. 6.8%; P=NS) rates.

CONCLUSIONS

Compared with the control group, ER in twins had a higher miscarriage and fetal loss rate, whereas FR in twins was similar to the control group. So, the FR procedure is overall a better and safer approach of MPR in reducing morbidity and mortality in HOMPs.