Pregnancy outcome after multifetal pregnancy reduction

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.

Quadruplet pregnancy outcome with and without fetal reduction: Danish national cohort study (2008-2018) and comparison with dichorionic twins

OBJECTIVES

To perform a nationwide study of quadrichorionic quadriamniotic (QCQA) quadruplet pregnancies and to compare the pregnancy outcome in those undergoing fetal reduction with non-reduced quadruplets and dichorionic diamniotic (DCDA) twin pregnancies from the same time period.

METHODS

This was a retrospective Danish national register-based study performed using data from the national Danish Fetal Medicine Database, which included all QCQA quadruplets and all non-reduced DCDA twin pregnancies with an estimated due date between 2008 and 2018. The primary outcome measure was a composite of adverse pregnancy outcomes, including pregnancy loss or intrauterine death of one or more fetuses. Secondary outcomes included gestational age at delivery, the number of liveborn children, preterm delivery before 28, 32 and 37 gestational weeks and birth weight. Data on pregnancy complications and baseline characteristics were also recorded. Outcomes were compared between reduced and non-reduced quadruplet pregnancies, and between DCDA pregnancies and quadruplet pregnancies reduced to twins. A systematic literature search was performed to describe and compare previous results with our findings.

RESULTS

Included in the study were 33 QCQA quadruplet pregnancies, including three (9.1%) non-reduced pregnancies, 28 (84.8%) that were reduced to twin pregnancy and fewer than three (6.1%) that were reduced to singleton pregnancy, as well as 9563 DCDA twin pregnancies. Overall, the rate of adverse pregnancy outcome was highest in non-reduced quadruplets (66.7%); it was 50% in quadruplets reduced to singletons and 10.7% in quadruplets reduced to twins. The proportion of liveborn infants overall was 91.1% of the total number expected to be liveborn in quadruplet pregnancies reduced to twins. This was statistically significantly different from 97.6% in non-reduced dichorionic twins (P = 0.004), and considerably higher than 58.3% in non-reduced quadruplets. The rates of preterm delivery < 28, < 32 and < 37 weeks were decreased in quadruplets reduced to twins compared with those in non-reduced quadruplet pregnancies. Quadruplets reduced to twins did not achieve equivalent pregnancy outcomes to those of DCDA twins.

CONCLUSION

This national study of QCQA quadruplets has shown that multifetal pregnancy reduction improves pregnancy outcome, including a decreased rate of preterm delivery and higher proportion of liveborn children. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Fetal Reduction Could Improve but Not Completely Reverse the Pregnancy Outcomes of Multiple Pregnancies: Experience From a Single Center

OBJECTIVE

To investigate the effectiveness and limitations of multifetal pregnancy reduction (MFPR) on the improvement of pregnancy outcomes of triplet or twin pregnancies conceived by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).

METHODS

We performed a cohort study of women undergoing IVF or ICSI from 2002-2016 in reproductive center, women's hospital, Zhejiang University School of Medicine. The cohort included 502 women who underwent MFPR and 9641 non-reduced women. Pregnancy outcomes were gestational age (GA) at delivery, pregnancy loss, preterm delivery, low birth weight (LBW), very low birth weight (VLBW), and small for gestational age (SGA). Multiple linear regression and logistic regression models were used to compare pregnancy outcomes between groups.

RESULTS

Triplets reduced to singletons had a longer median GA (39.07 vs 37.00, P<0.001), and lower rates of LBW (8.9% vs 53.2%, P<0.001) and SGA (17.8% vs 44.7%, P=0.001) than triplets reduced to twins, with a similar pregnancy loss rate (6.7% vs 6.6%, P=0.701). Twins reduced to singletons had a comparable pregnancy loss rate (4.8% vs. 6.5%, P=0.40), a longer median GA (38.79 vs. 37.00, P<0.001), and lower rates of LBW (13.5% vs. 47.0%, P<0.001) and SGA (13.5% vs. 39.6%, P<0.001) than primary twins. Triplets reduced to twins had higher rates of LBW (53.2% vs. 47.0%, P=0.028) and SGA (44.7% vs. 39.6%, P=0.040) than primary twins, with a similar pregnancy loss rate (6.6% vs. 6.5%, P=0.877). Singletons reduced from triplets/twins had higher rates of preterm delivery (15.8% vs. 7.3%, P<0.001), LBW (12.3% vs. 4.32%, P<0.001), VLBW (2.3% vs. 0.4%, P=0.002), and SGA (14.6% vs.6.6%, P<0.001) than primary singletons, with a comparable pregnancy loss rate (5.3% vs. 5.4%, P=0.671).

CONCLUSIONS

This study suggests that the pregnancy loss rate is similar between reduction and non-reduction groups. MFPR improves pregnancy outcomes, including the risk of preterm delivery, LBW, and SGA, but still could not completely reverse the adverse pregnancy outcomes of multiple pregnancies.

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.

Elective Fetal Reduction in Dichorionic Diamniotic Twin Pregnancies on Parental Request: A Single-Centre Experience

OBJECTIVES

Our study aimed to examine a subset of electively reduced twins and compare their outcomes with those of expectantly managed twins, along with a cohort of singleton pregnancies. The secondary aim was to ascertain the procedure-related miscarriage risks.

METHODS

A retrospective cohort analysis was performed at Apollo Centre for Fetal Medicine, New Delhi, comparing pregnancy outcomes in dichorionic diamniotic twin pregnancies which were reduced to singletons (group 1) with that of women with dichorionic twins managed expectantly (group 0) and women with a singleton pregnancy (group 2). Comparison of continuous and categorical variables was conducted using standard statistical tests.

RESULTS

We analysed 35 twins which were reduced to singletons, 421 expectantly managed dichorionic twins and 1915 women with a singleton pregnancy. In the reduction group, the rate of procedure related pregnancy loss<24 weeks was lower, compared to the expectantly managed twins, although the difference was not statistically significant (5.71% [2/35] vs. 7.13% [30/421]; p = 1.000). The median gestational age at delivery was significantly higher in reduced twins compared to expectantly managed twin pregnancies (38.0 vs. 35.4 weeks respectively, p < 0.001) with a higher mean birth weight at delivery, both of which were comparable to that among the singleton pregnancies (38.3 weeks). The rates of preterm birth <32 weeks and <34 weeks in the expectantly managed twins were significantly higher at 19.8% (66/334) and 25.7% (86/334) compared to the reduced twins, all of whom delivered beyond 34 weeks. The rates of preterm births <32 weeks, <34 weeks, and the late preterm births in the reduced twins were comparable to those in the singleton cohort.

CONCLUSIONS

The obstetric and perinatal outcomes after reduction of a dichorionic twin are better than an expectantly managed twin without an associated increase in pregnancy loss rates. Fetal reduction of dichorionic twin to a singleton appears to be a safe procedure in expert hands.

Foetal therapies and their influence on preterm birth

Foetal therapy aims to improve perinatal survival or to prevent severe long-term handicap. Foetal medicine opens a new territory by treating the foetus as a patient. The mother has nothing to gain in terms of health benefits, yet she is inherently also undergoing treatment. In utero foetal interventions can be divided into ultrasound-guided minimally invasive procedures, fetoscopic procedures and open hysterotomy procedures, which carry an inherent risk of ruptured membranes and preterm birth. In this review, we summarise the conditions that may benefit from foetal therapy and review the current therapies on offer, each with their associated risk of ruptured membrane and preterm birth. We also look into some risk limiting and preventative strategies to mitigate these complications.

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.

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.

Multifetal pregnancy reduction of triplets to twins compared with non-reduced triplets: a meta-analysis

The current systematic review and meta-analysis evaluate the perinatal outcomes in twin pregnancies following multifetal pregnancy reduction (MPR) compared with non-reduced triplet pregnancies. All studies comparing perinatal outcome of twin pregnancies following MPR to non-reduced triplet pregnancies were considered. MEDLINE, non-indexed MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and Web of Science were searched for relevant published articles up to August 2016. The search yielded 653 publications of which 92 were assessed for eligibility. A total of 24 studies met the inclusion criteria. Overall, the outcomes of pregnancies following MPR were better compared with expectantly managed triplets. The MPR group delivered at a later gestational age and was less likely to be delivered before 32 or 28 weeks' gestation. Newborns in the MPR group had significantly higher birthweight at delivery (mean difference 500 g [95% CI 439.95, 560.04]). Rates of pregnancy loss before 24 weeks' gestation and overall infant survival were comparable between the groups. This meta-analysis suggests that MPR of triplet pregnancies to twins is associated with improved perinatal outcome compared with non-reduced triplets. Should primary prevention of high order multiple pregnancy fail, MPR is an appropriate alternative to minimize the perinatal morbidity and mortality of triplet pregnancies.

Reducing the number of fetuses in a pregnancy: providers' and patients' views of challenges

STUDY QUESTION

How do patients and providers perceive and make decisions about possible reductions of multi-fetal pregnancies?

SUMMARY ANSWER

Physicians may be transferring additional embryos, assuming that patients will later undergo reduction if need be; but decisions to reduce pregnancies are difficult for patients, who may agree to undergo the procedure in advance and later renege.

WHAT IS ALREADY KNOWN

Implanting more than one embryo increases the likelihood that at least one embryo will successfully lead to a child but also that the patient may end up with twins or higher-order multiple births.

STUDY DESIGN, SIZE, DURATION

In-depth interviews of ~1 h each were conducted with 37 ART providers and patients (17 physicians, 10 other health providers and 10 patients) and systematically analyzed.

PARTICIPANTS/MATERIALS, SETTING, METHOD

The telephone interviews explored the participants' views and decisions regarding pregnancy reduction. The answers were analyzed systematically.

MAIN RESULTS AND THE ROLE OF CHANCE

Providers may be transferring additional embryos, thinking that doing so will increase the likelihood of a 'take home baby' and that the patients could undergo reductions, if need be, to avoid the risks and complications of twins or multiple births. Yet patients often appear to have difficulty confronting the prospect of fetal reduction and/or renege on prior agreements to undergo the procedure. Providers should thus be wary and exceedingly careful about these situations.

LIMITATIONS, REASONS FOR CAUTION

The sample size was sufficient for qualitative research designed to elucidate the issues and themes that emerge, but not for statistically analyzing how various groups may differ (e.g. physicians versus patients). Future studies should investigate these issues with larger samples.

WIDER IMPLICATIONS OF THE FINDINGS

These data, the first to examine how IVF providers and patients view and approach decisions regarding the reduction of fetuses, suggest several complications and dilemmas. This information has critical implications for future practice, guidelines, research and education of providers, patients, insurers, policymakers and others.

STUDY FUNDING/COMPETING INTERESTS

Funding was provided by grant #UL1 RR024156 from the National Center for Research Resources, the Greenwall Foundation and the John Simon Guggenheim Memorial Foundation. There are no conflicts of interest to declare.

Outcomes in twin pregnancies reduced to singleton pregnancies compared with ongoing twin pregnancies

OBJECTIVE

Multifetal pregnancy reduction has been shown to improve outcomes in triplet and higher-order multiple pregnancies. The data for fetal reduction of twin pregnancies are limited. The purpose of this study was to compare adverse pregnancy outcomes in ongoing twin pregnancies compared with twin pregnancies reduced to singletons.

STUDY DESIGN

This was a retrospective cohort study comparing dichorionic diamniotic twin pregnancies with dichorionic diamniotic twin pregnancies reduced to singleton gestations between 11 and 24 weeks' gestation in a single maternal-fetal medicine practice over a 9 year period. Adverse pregnancy outcomes after 24 weeks were compared, with a value of P < .05 used for significance.

RESULTS

Five hundred one ongoing twin pregnancies and 63 twin pregnancies reduced to singletons were included. Patients with reductions to singletons had a significantly lower risk of preterm delivery before 37 weeks' gestation (10% vs 43%; P < .001) but no difference in the risk of preterm delivery before 34 weeks' or 28 weeks' gestation. Patients with reductions to singletons also had a lower risk of infant birthweight less than the 10% (23% vs 49%; P < .001) but no difference in the risk of infant birthweight less than the 5%. There was no difference in the risk of fetal demise after 24 weeks' gestation.

CONCLUSION

Fetal reduction of twin pregnancies decreases the risk of late preterm birth and birthweight less than the 10% but not the risks of more severe complications such as early preterm birth or birthweight less than the 5%.

Pregnancy outcome after fetal reduction in women with a dichorionic twin pregnancy

STUDY QUESTION

What are the pregnancy outcomes for women with a twin pregnancy that is reduced to a singleton pregnancy?

SUMMARY ANSWER

Fetal reduction of a twin pregnancy significantly improves gestational age at birth and neonatal birthweight, however at an increased risk of pregnancy loss and preterm delivery.

WHAT IS KNOWN ALREADY

Women with a multiple pregnancy are at increased risk for preterm delivery. Fetal reduction can be considered in these women.

STUDY DESIGN, SIZE, AND DURATION

Retrospective cohort study of 118 women with a twin pregnancy reduced to a singleton pregnancy between 2000 and 2010.

PARTICIPANTS/MATERIALS, SETTING, AND METHODS

We compared the outcome of pregnancy in consecutive women with a dichorionic twin pregnancy that was reduced to a singleton pregnancy to that of women with a dichorionic twin pregnancy that was managed expectantly and women with a primary singleton pregnancy. Reductions were performed between 10-23(6/7) weeks' gestation by intracardiac or intrathoracic injection of potassium chloride, mostly for congenital anomalies. We compared median gestational age, pregnancy loss <24 weeks, preterm delivery <32 weeks, neonatal birthweight and perinatal deaths.

MAIN RESULTS AND THE ROLE OF CHANCE

We studied 118 women with a twin pregnancy that was reduced to a singleton, 818 women with an ongoing dichorionic twin pregnancy and 611 women with a primary singleton pregnancy. Loss of the entire pregnancy <24 weeks and preterm delivery occurred significantly more in the reduction group compared with the ongoing twin group (11.9 versus 3.1% <24 weeks, P< 0.001 and 18.6 versus 11.5% <32 weeks, respectively, P < 0.001). In the reduction group, the percentage of women without any surviving child was significantly higher compared with the ongoing twin and primary singleton group (14.4, 3.4 and 0.7%, respectively, P < 0.001). Median gestational age was 38.9 weeks (interquartile range (IQR) 34.7-40.3) for reduced pregnancies, 37.1 weeks (IQR 35.3-38.1) for ongoing twin pregnancies and 40.1 (IQR 39.1-40.9) for primary singletons (P < 0.001 for all comparisons).

LIMITATIONS, REASONS FOR CAUTION

The main limitations of the study were its retrospective character, and the fact that indications for reduction were heterogeneous.

WIDER IMPLICATIONS OF THE FINDINGS

In women with a dichorionic twin pregnancy fetal reduction increases median gestational age only at considerable risk of complete early pregnancy loss.

STUDY FUNDING/COMPETING INTERESTS

The study was not funded. None of the authors has conflicts of interest.

Selective reduction in twins and multiple pregnancies

The number of multiple pregnancies has increased, mainly due to the uncontrolled use of the assisted conception techniques. Multifetal pregnancy reduction (MFPR) has been used to reduce the risks associated with these high-risk pregnancies. It is performed in the first trimester of pregnancy by transabdominal injection of potassium chloride into the fetal heart. The risk of miscarriage seems to be associated with the final number of fetuses. A review of the literature suggests that MFPR results in better pregnancy outcome, regardless of the initial number of fetuses. The reduction to a lower number of fetuses reduces fetal losses, prematurity, infant mortality and morbidity.

Non-selective fetal reduction is malpractice

Non-selective multifetal pregnancy reduction is carried out to reduce healthy higher order multiple fetuses to one or two fetuses. No studies exist to show any benefit of this practice and a Cochrane review, as well as investigators in the field, have not found any justification for such practice. From a medical point of view, this non evidence-based practice is not following good clinical practice. Any practice that transfers more than one or two embryos, for instance due to commercial interests, should be abandoned by the international medical community because multifetal pregnancies can, to a large extent, be avoided by transferring only one or a maximum of two fertilized eggs by in vitro fertilization. Further, ovarian stimulating programs should strictly adhere to protocols aiming at mono-ovulation.