Birthweight discordance and neonatal morbidity in twin pregnancies: A systematic review and meta‐analysis

Twin Pregnancy Complicated by Gestational Diabetes Mellitus: Maternal and Neonatal Outcomes

Context

The risk of gestational diabetes mellitus (GDM) in twin pregnancies is more than double that of singleton pregnancies. Although twin pregnancies present unique challenges for fetal growth and prenatal management, the approach to GDM diagnosis and treatment is the same regardless of plurality. Data on pregnancy outcomes for individuals with GDM and a twin pregnancy are limited and conflicting.

Objective

To describe the maternal characteristics associated with GDM in twin pregnancies and to assess the associated pregnancy outcomes compared to twin pregnancies unaffected by GDM.

Methods

A retrospective cohort study was conducted at Mayo Clinic, Rochester, Minnesota, USA, and included predominantly Causasian women aged 18 to 45 years who received prenatal care for a twin pregnancy from 2017-2022. Maternal characteristics and a broad spectrum of pregnancy outcomes were evaluated. Universal GDM screening involved a 50 g oral glucose challenge test +/- a 100 g oral glucose tolerance test.

Results

GDM was diagnosed in 23% pregnancies (n = 104/452). Compared to those without, women with GDM had known risk factors including a higher prepregnancy body mass index (31.1vs 26.3 kg/m2; P < .01) and a prior history of GDM (21.7 vs 5.9%; P < .01). There were no differences in maternal pregnancy complications or neonatal outcomes between groups. Attendance at postpartum glucose testing among women with GDM was poor at 27.9% (29/104).

Conclusion

These data suggest that women with twin pregnancies share a similar GDM risk profile to those with singleton pregnancies and provide reassuring evidence that current management for GDM twin pregnancies produces similar outcomes to twin pregnancies without GDM.

Birth weight discordance and adverse neonatal outcomes in appropriately grown premature twins

Objective

This study aimed to analyze the clinical characteristics of birth weight discordant twins (BWDT) who were premature and appropriate-for-gestational-age or large-for-gestational-age. Additionally, it assessed the impact of birth weight discordance on the prognosis of appropriately grown premature twins, and investigated the effect of maternal factors on neonatal outcomes.

Study design

This retrospective cohort study included twins who were born alive after preterm labor at the Nanjing Drum Tower Hospital from January 2018 to December 2021, along with their mothers. Twins were arranged into discordant and concordant groups according to intertwin birth weight discordance, followed by the analysis of the clinical characteristics of mothers and the prognosis of neonates.

Results

A total of 585 mothers and 1170 neonates were included, with 47 mothers and 94 neonates in the discordant group. The incidence of birth weight discordance was 8.0% (94/1,170) in appropriately grown premature twins. The incidence of complications (43.2% vs. 21.8%) and transfer to the neonatal intensive care unit (NICU) (53.2% vs. 29.2%) was higher in the discordant group than in the concordant group (p < 0.05). Furthermore, the incidence of infectious diseases (36.7% vs. 19.4%), necrotizing enterocolitis (7.6% vs. 1.6%), and oxygen therapy rate (22.8% vs. 12.8%) were statistically significantly higher in the discordant group than in the concordant group (p < 0.05).

Conclusion

Birth weight discordance remains a high-risk factor for complications and transfer to the NICU in appropriately grown premature twins. It is important to pay attention to birth weight discordance when the outcomes of twins are assessed.

Selective fetal growth restriction in dichorionic diamniotic twin pregnancy: systematic review and meta-analysis of pregnancy and perinatal outcomes

OBJECTIVE

Most of the published literature on selective fetal growth restriction (sFGR) has focused on monochorionic twin pregnancies. The aim of this systematic review was to report on the outcome of dichorionic diamniotic (DCDA) twin pregnancies complicated by sFGR.

METHODS

MEDLINE, EMBASE and The Cochrane Library databases were searched. The inclusion criteria were DCDA twin pregnancies complicated by sFGR. The outcomes explored were intrauterine death (IUD), neonatal death and perinatal death (PND), survival of at least one and both twins, preterm birth (PTB) (either spontaneous or iatrogenic) prior to 37, 34, 32 and 28 weeks' gestation, pre-eclampsia (PE) or gestational hypertension, neurological, respiratory and infectious morbidity, Apgar score < 7 at 5 min, necrotizing enterocolitis, retinopathy of prematurity and admission to the neonatal intensive care unit (NICU). A composite outcome of neonatal morbidity, defined as the occurrence of respiratory, neurological or infectious morbidity, was also evaluated. Random-effects meta-analysis was used to analyze the data, and results are reported as pooled proportion or odds ratio (OR) with 95% CI.

RESULTS

Thirteen studies reporting on 1339 pregnancies with sFGR and 6316 pregnancies without sFGR were included. IUD occurred in 2.6% (95% CI, 1.1-4.7%) of fetuses from DCDA pregnancies with sFGR and 0.6% (95% CI, 0.3-9.7%) of those from DCDA pregnancies without sFGR, while the respective values for PND were 5.2% (95% CI, 3.5-7.3%) and 1.7% (95% CI, 0.1-5.7%). Spontaneous or iatrogenic PTB before 37 weeks complicated 84.1% (95% CI, 55.6-99.2%) of pregnancies with sFGR and 69.1% (95% CI, 45.4-88.4%) of those without sFGR. The respective values for PTB before 34, 32 and 28 weeks were 18.4% (95% CI, 4.4-38.9%), 13.0% (95% CI, 9.5-17.1%) and 1.5% (95% CI, 0.6-2.3%) in pregnancies with sFGR and 10.2% (95% CI, 3.1-20.7%), 7.8% (95% CI, 6.8-9.0%) and 1.8% (95% CI, 1.3-2.4%) in those without sFGR. PE or gestational hypertension complicated 19.9% (95% CI, 12.4-28.6%) of pregnancies with sFGR and 12.8% (95% CI, 10.4-15.4%) of those without sFGR. Composite morbidity occurred in 28.2% (95% CI, 7.8-55.1%) of fetuses from pregnancies with sFGR and 13.9% (95% CI, 6.5-23.5%) of those from pregnancies without sFGR. When stratified according to the sFGR status within a twin pair, composite morbidity occurred in 39.0% (95% CI, 11.1-71.5%) of growth-restricted fetuses and 29.9% (95% CI, 3.5-65.0%) of appropriately grown fetuses (OR, 1.9 (95% CI, 1.7-3.1)), while the respective values for PND were 3.0% (95% CI, 1.8-4.5%) and 1.6% (95% CI, 0.9-2.6%) (OR, 2.1 (95% CI, 1.0-4.1)). On risk analysis, DCDA pregnancies complicated by sFGR had a significantly higher risk of IUD (OR, 5.2 (95% CI, 3.2-8.6)) and composite morbidity or admission to the NICU (OR, 3.2 (95% CI, 1.9-5.6)) compared to those without sFGR, while there was no difference in the risk of PTB before 34 weeks (P = 0.220) or PE/gestational hypertension (P = 0.210).

CONCLUSIONS

DCDA twin pregnancies complicated by sFGR are at high risk of perinatal morbidity and mortality. The findings of this systematic review are relevant for counseling and management of complicated DCDA twin pregnancies, in which twin-specific, rather than singleton, outcome data should be used. © 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 Growth and Antenatal Testing in Uncomplicated Multiple Gestations

Multiple gestations experience a slowing of fetal growth in the third trimester and have been described as having a higher risk of growth restriction. Whether this increased diagnosis of fetal growth restriction is physiological or pathologic is controversial. In an attempt to better identify those fetuses most at risk, twin-specific growth charts have been developed and tested. In addition, there are data to suggest that multiple gestations experience an increased risk of unexpected third-trimester stillbirth in apparently uncomplicated pregnancies. This chapter reviews the current data and recommendations for fetal growth assessment, antenatal surveillance, and delivery timing in uncomplicated multiple gestations.

Relationships between birth weight discordance and maternal and perinatal risks among twin pregnancies conceived following frozen embryo transfer

STUDY QUESTION

Is intertwin birth weight discordance associated with adverse maternal and perinatal outcomes following frozen embryo transfer (FET)?

SUMMARY ANSWER

For twins conceived following FET, intertwin birth weight discordance is related to elevated risks of neonatal mortality irrespective of chorionicity, and the risk of hypertensive disorders of pregnancy (HDP) is elevated for the mothers of dichorionic twins affected by such birth weight discordance.

WHAT IS KNOWN ALREADY

While the relationships between intertwin birth weight discordance and adverse maternal or fetal outcomes have been studied for naturally conceived twins, similarly comprehensive analyses for twins conceived using ART remain to be performed.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study of all twin births from 2007 to 2021 at Shanghai Ninth People's Hospital in Shanghai, China that were conceived following FET (N = 6265).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Intertwin birth weight discordance was defined as a 20% difference in neonatal birth weights. The primary study outcome was the incidence of HDP and neonatal death while secondary outcomes included gestational diabetes, placenta previa, placental abruption, intrahepatic cholestasis of pregnancy, preterm premature rupture of the membranes, Cesarean delivery, gestational age, birth weight, stillbirth, birth defect, neonatal jaundice, necrotizing enterocolitis, and pneumonia incidence. Logistic regression models were used to estimate adjusted odds ratios (aORs) and 95% CIs for maternal and neonatal outcomes. Subgroup analyses were conducted, and Kaplan-Meier survival analysis was used to estimate the survival probability. The sensitivity analysis was performed with a propensity score-based patient-matching model, an inverse probability weighting model, a restricted cubic spline analysis, and logistic regression models using other percentage cutoffs for discordance.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 6101 females that gave birth to dichorionic twins during the study interval, birth weight discordance was observed in 797 twin pairs (13.1%). In this cohort, intertwin birth weight discordance was related to an elevated risk of HDP (aOR 1.56; 95% CI 1.21-2.00), and this relationship was confirmed through sensitivity analyses. Hypertensive disease risk rose as the severity of this birth weight discordance increased. Discordant birth weight was also linked to increased odds of neonatal mortality (aOR 2.13; 95% CI 1.03-4.09) and this risk also increased with the severity of discordance. Of the 164 women with monochorionic twins, the discordant group exhibited an elevated risk of neonatal death compared to the concordant group (crude OR 9.00; 95% CI 1.02-79.3).

LIMITATIONS, REASONS FOR CAUTION

The limitations of this study are its retrospective nature and the fact that the available data could not specify which twins were affected by adverse outcomes. There is a lack of an established reference birth weight for Chinese twins born at a gestational age of 24-41 weeks.

WIDER IMPLICATIONS OF THE FINDINGS

These findings suggest that twins exhibiting a birth weight discordance are related to an elevated risk of adverse maternal and perinatal outcomes, emphasizing a potential need for higher levels of antenatal surveillance in these at-risk pregnancies.

STUDY FUNDING/COMPETING INTEREST(S)

Authors declare no conflict of interest. This study was funded by the Clinical Research Program of Shanghai Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine (JYLJ202118) and the National Natural Science Foundation of China (Grant Nos 82271693 and 82273634).

TRIAL REGISTRATION NUMBER

N/A.

Outcome following laser surgery of twin-twin transfusion syndrome complicated by selective fetal growth restriction: systematic review and meta-analysis

OBJECTIVE

The published literature reports mostly on the outcome of twin pregnancies complicated by twin-twin transfusion syndrome (TTTS) without considering whether the pregnancy is also complicated by another pathology, such as selective fetal growth restriction (sFGR). The aim of this systematic review was to report on the outcome of monochorionic diamniotic (MCDA) twin pregnancies undergoing laser surgery for TTTS that were complicated by sFGR and those not complicated by sFGR.

METHODS

MEDLINE, EMBASE and Cochrane databases were searched. The inclusion criteria were studies reporting on MCDA twin pregnancies with TTTS undergoing laser therapy that were complicated by sFGR and those not complicated by sFGR. The primary outcome was the overall fetal loss following laser surgery, defined as miscarriage and intrauterine death. The secondary outcomes included fetal loss within 24 h after laser surgery, survival at birth, preterm birth (PTB) prior to 32 weeks of gestation, PTB prior to 28 weeks, composite neonatal morbidity, neurological and respiratory morbidity, and survival free from neurological impairment. All outcomes were explored in the overall population of twin pregnancies complicated by sFGR vs those not complicated by sFGR in the setting of TTTS and in the donor and recipient twins separately. Random-effects meta-analysis was used to combine data and the results are reported as pooled odds ratios (OR) with 95% CI.

RESULTS

Five studies (1710 MCDA twin pregnancies) were included in the qualitative synthesis and four in the meta-analysis. The overall risk of fetal loss after laser surgery was significantly higher in MCDA twin pregnancies with TTTS complicated by sFGR (20.90% vs 14.42%), with a pooled OR of 1.6 (95% CI, 1.3-1.9) (P < 0.001). The risk of fetal loss was significantly higher in MCDA twin pregnancies with TTTS and sFGR for the donor but not for the recipient twin. The rate of live twins was 79.1% (95% CI, 72.6-84.9%) in TTTS pregnancies with sFGR and 85.6% (95% CI, 81.0-89.6%) in those without sFGR (pooled OR, 0.6 (95% CI, 0.5-0.8)) (P < 0.001). There was no significant difference in the risk of PTB prior to 32 weeks of gestation (P = 0.308) or prior to 28 weeks (P = 0.310). Assessment of short- and long-term morbidity was affected by the small number of cases. There was no significant difference in the risk of composite (P = 0.506) or respiratory (P = 0.531) morbidity between twins complicated by TTTS with vs those without sFGR, while the risk of neurological morbidity was significantly higher in those with TTTS and sFGR (pooled OR, 1.8 (95% CI, 1.1-2.9)) (P = 0.034). The risk of neurological morbidity was significantly higher for the donor twin (pooled OR, 2.4 (95% CI, 1.1-5.2)) (P = 0.029) but not for the recipient twin (P = 0.361). Survival free from neurological impairment was observed in 70.8% (95% CI, 45.0-91.0%) of twin pregnancies with TTTS complicated by sFGR and in 75.8% (95% CI, 51.9-93.3%) of those not complicated by sFGR, with no difference between the two groups.

CONCLUSIONS

sFGR in MCDA pregnancies with TTTS represents an additional risk factor for fetal loss following laser surgery. The findings of this meta-analysis may be useful for individualized risk assessment of twin pregnancy complicated by TTTS and tailored counseling of the parents prior to laser surgery. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The heritability of weight gain in infancy: A population-based twin study

BACKGROUND

Rapid weight gain during infancy is a strong predictor of childhood obesity and is affected by genetic and environmental factors. Identifying ages with low heritability will allow for targeted interventions that might be able to prevent the adverse effects of childhood obesity.

OBJECTIVES

The objective of the study is to estimate the heritability of weight gain from birth to defined ages during infancy, as well as during 6-month periods from birth to 18 months of age. We address this by leveraging large-scale computerised anthropometric data from the state-run network of well-baby clinics in Israel.

METHODS

We performed a population-based twin study. We extracted weight measurements recorded between birth to 24 months from well-baby clinics for 9388 twin pairs born in Israel between 2011 and 2015. The reported sexes of the twins were used as a proxy for their zygosity status. We estimated the heritability of the weight z-score change from birth to specific ages and during particular periods in infancy. To assess the validity of the results, we repeated the analysis in a sub-cohort of twin pairs with complete weight measurements.

RESULTS

During the first 2 years of life, heritability was lowest for birthweight (h 2 = 0.40 ± 0.11 ). Heritability for weight gain since birth was highest at 4 months (h 2 = 0.87 ± 0.13 ), and then gradually decreased until age 18 months (h 2 = 0.62 ± 0.13 ). Estimating the heritability in 6-month intervals from birth to 18 months, heritability was highest during the 6-12-month interval (h 2 = 0.84 ± 0.14 ), and was substantially lower during the subsequent 12-18-month interval (h 2 = 0.43 ± 0.16 ).

CONCLUSIONS

Heritability of weight gain decreases substantially in the second year of life, suggesting that this period could be an appropriate time for interventions for infants who are at an increased risk of childhood obesity.

Pregnancy and perinatal outcomes of early vs late selective termination in dichorionic twin pregnancy: systematic review and meta-analysis

OBJECTIVE

To evaluate outcomes of dichorionic twin pregnancies undergoing early vs late selective termination of pregnancy (ST).

METHODS

MEDLINE, EMBASE, CINAHL and the Web of Science databases were searched electronically up to March 2022. The primary outcome of this study was pregnancy loss prior to 24 weeks' gestation. The secondary outcomes included preterm birth (PTB) before 37, 34, and 32 weeks, preterm prelabor rupture of membranes (PPROM), gestational age (GA) at delivery, Cesarean delivery, mean birth weight, 5-min Apgar score < 7, overall neonatal morbidity and neonatal survival. Only prospective or retrospective studies reporting data on the outcome of early (before 18 weeks) vs late (at or after 18 weeks) ST in dichorionic twin pregnancies were considered suitable for inclusion. Quality assessment of the included studies was performed using the Newcastle-Ottawa scale for cohort studies. Random-effects head-to-head meta-analysis was used to analyze the data.

RESULTS

Seven studies reporting on 649 dichorionic twin pregnancies were included in this systematic review. The risk of pregnancy loss prior to 24 weeks was significantly lower in dichorionic twin pregnancies undergoing early compared with late ST (1% vs 8%; odds ratio (OR), 0.25 (95% CI, 0.10-0.65); P = 0.004). The risk of PTB was significantly lower in dichorionic twin pregnancies undergoing early compared with late ST when considering PTB before 37 weeks (19% vs 45%; OR, 0.36 (95% CI, 0.23-0.57); P < 0.00001), before 34 weeks (4% vs 19%; OR, 0.24 (95% CI, 0.11-0.54); P = 0.0005) and before 32 weeks (4% vs 20%; OR, 0.21 (95% CI, 0.05-0.85); P = 0.03). The mean birth weight was significantly greater in the early-ST group (mean difference (MD), 392.2 g (95% CI, 59.1-726.7 g); P = 0.02), as was the mean GA at delivery (MD, 2.47 weeks (95% CI, 0.04-4.91 weeks); P = 0.049). There was no significant difference between dichorionic twin pregnancies undergoing early compared with late ST in terms of PPROM (P = 0.27), Cesarean delivery (P = 0.38), 5-min Apgar score < 7 (P = 0.35) and neonatal survival of the non-reduced twin (P = 0.54).

CONCLUSIONS

The risk of pregnancy loss prior to 24 weeks and the rate of PTB before 37, 34 and 32 weeks were significantly higher in dichorionic twin pregnancies undergoing late vs early ST, thus highlighting the importance of early diagnosis of fetal anomalies in twin pregnancies. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Prevalence and Factors Associated With Intertwin Birth Weight Discordance Among Same-Sex Twins in Lombardy, Northern Italy

This population-based cohort study investigated the prevalence, potential risk factors, and consequences of birth weight discordance (BWD) among same-sex twins. We retrieved data from the automated system of healthcare utilization databases of Lombardy Region, Northern Italy (2007-2021). BWD was defined as 30% or more disparity in birth weights between the larger and the smaller twin. Multivariate logistic regression was used to analyze the risk factors of BWD in deliveries with same-sex twins. In addition, the distribution of several neonatal outcomes was assessed overall and according to BWD level (i.e., ≤20%, 21-29, and ≥30%). Finally, a stratified analysis by BWD was performed to assess the relationship between assisted reproductive technologies (ART) and neonatal outcomes. We identified 11,096 same-sex twin deliveries; 556 (5.0%) pairs of twins were affected by BWD. Multivariate logistic regression analysis showed that maternal age ≥35 years (OR 1.26, 95% CI [1.05,5.51]), low level of education (OR 1.34, 95% CI [1.05, 1.70]), and ART (OR 1.16, 95% CI [0.94, 1.44], almost significant due to the low power) were independent risk factors for BWD in same-sex twins. Conversely, parity (OR 0.73, 95% CI [0.60, 0.89]) was inversely related. All the adverse outcomes observed were more common among BWD pairs than non-BWD ones. Instead, a protective effect of ART was observed for most neonatal outcomes considered among BWD twins. Our results suggest that conception after ART increases the risk of developing a high disparity between the weights of the two twins. However, the presence of BWD may complicate twin pregnancies, compromising neonatal outcomes, regardless of the modality of conception.

The High-Risk Profile of Selective Growth Restriction in Monochorionic Twin Pregnancies

The present review aims to provide a critical appraisal of the sonographic diagnosis and follow-up and to evaluate the optimal clinical management of monochorionic twin pregnancies where one of the twins is complicated by selective fetal growth restriction (sFGR). The classification is based on the umbilical artery (UA) diastolic flow reflecting the outcome. If the sFGR twin has positive diastolic flow (Type I) then the prognosis is good, and it does not require close surveillance. Biweekly or weekly sonographic and Doppler surveillance and fetal monitoring are recommended strategies to detect unpredictable complications in type II and type III forms, which are defined by persistently absent/reverse end-diastolic flow (AREDF) or cyclically intermittent absent/reverse end-diastolic flow (iAREDF) in the umbilical waveforms, respectively. The latest forms are associated with an increased risk of unexpected fetal demise of the smaller twin and 10-20% risk of neurological injury in the larger twin in addition to the overall risk of prematurity. The clinical course can be affected by elective fetal therapy ('dichorinization' of the placenta with laser or selective fetal reduction) or elective delivery in the presence of severe fetal deterioration. The prediction of the clinical outcome in complicated cases of type II and III sFGR cases remains elusive. Novel routines in fetal and placental scans in order to predict neurological impairments and unexpected fetal death to optimize the delivery time-point are needed.

Chorionicity and neurodevelopmental outcomes in twin pregnancy: a systematic review and meta-analysis

OBJECTIVE

Through a systematic review and meta-analyses, we aimed to analyze the impact of chorionicity on neurodevelopment outcomes.

STUDY DESIGN

We conducted a comprehensive search strategy through Medline, Embase, Web of Science, and reference lists of the retrieved studies until August 2022. Studies that examined the association between chorionicity and children's neurodevelopment outcomes were included.

RESULTS

Twelve studies were included. Monochorionic (MC) twins increased the odds of neurodevelopment impairment, cerebral palsy compared to dichorionic (DC) twins. The differences in neurodevelopmental impairment and cerebral palsy between the two groups disappeared after excluding infants with twin-twin transfusion (TTTS). After fetoscopic laser surgery (FLS) for MC twins, there were no differences too.

CONCLUSIONS

Compared to DC twins, MC twins were associated with an increased risk of neurodevelopment impairment. MC twins complicated by TTTS were at high risk of neurologic disability, and FLS was an acceptable treatment modality for them.

Solomon technique vs selective fetoscopic laser photocoagulation for twin-twin transfusion syndrome: systematic review and meta-analysis of maternal and perinatal outcomes

OBJECTIVE

To ascertain maternal and perinatal outcomes of monochorionic twin pregnancies complicated by twin-twin transfusion syndrome (TTTS) treated with the Solomon technique compared with selective fetoscopic laser photocoagulation (SFLP) of placental anastomoses.

METHODS

MEDLINE, EMBASE and The Cochrane Library were searched to identify relevant studies. The outcomes observed were perinatal loss and survival, preterm prelabor rupture of membranes (PPROM), preterm birth (PTB), gestational age (GA) at delivery, interval between laser treatment and delivery, maternal bleeding, septostomy or chorioamniotic separation, placental abruption, twin anemia-polycythemia sequence (TAPS), recurrence of TTTS, neonatal morbidity and neurological morbidity. Random-effects head-to-head meta-analyses were used to analyze the data. Pooled odds ratios (OR) and mean differences (MD) and their 95% CIs were calculated.

RESULTS

Nine studies were included in the systematic review. There was generally no difference in the main maternal and pregnancy characteristics between pregnancies treated using the Solomon technique and those treated using SFLP of placental anastomoses. The risks of fetal loss (pooled OR, 0.69 (95% CI, 0.50-0.95); P = 0.023), neonatal death (pooled OR, 0.37 (95% CI, 0.16-0.84); P = 0.018) and perinatal loss (pooled OR, 0.56 (95% CI, 0.38-0.83); P = 0.004) were significantly lower in pregnancies treated using the Solomon technique than in those treated with SFLP. Likewise, pregnancies treated using the Solomon technique had a significantly higher chance of survival of at least one twin (pooled OR, 2.31 (95% CI, 1.03-5.19); P = 0.004) and double survival (pooled OR, 2.18 (95% CI, 1.29-3.70); P = 0.001). There was no difference in the risk of PPROM (P = 0.603), PPROM within 10 days from laser surgery (P = 0.982), PTB (P = 0.207), maternal bleeding (P = 0.219), septostomy or chorioamniotic separation (P = 0.224) or chorioamnionitis (P = 0.135) between the two groups, while the risk of placental abruption was higher in pregnancies treated using the Solomon technique (pooled OR, 2.90 (95% CI, 1.55-5.44); P = 0.001). In the Solomon technique group, pregnancies delivered at a significantly earlier GA than did those treated with SFLP (pooled MD, -0.625 weeks (95% CI, -0.90 to -0.35 weeks); P < 0.001), while there was no difference in the interval between laser treatment and delivery (P = 0.589). The rate of recurrence of TTTS was significantly lower in pregnancies undergoing the Solomon technique (pooled OR, 0.43 (95% CI, 0.22-0.81); P < 0.001), while there was no difference in the risk of TAPS between the two groups (P = 0.792). Finally, there was no difference in the overall risk of neonatal morbidity (P = 0.382) or neurological morbidity (P = 0.247) between the two groups.

CONCLUSIONS

Monochorionic twin pregnancies complicated by TTTS undergoing laser treatment using the Solomon technique had a significantly higher survival rate and lower recurrence rate of TTTS but were associated with an increased risk of placental abruption and earlier GA at delivery compared to those treated with SFLP. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Early detection of ischemic brain injuries by diffusion-weighted imaging after radiofrequency ablation for fetal reduction in monochorionic pregnancies

BACKGROUND

This study aimed to investigate the additional advantages of magnetic resonance imaging (MRI), particularly diffusion-weighted imaging (DWI) over fetal ultrasound in the detection of acute ischemic cerebral injuries in complicated monochorionic (MC) pregnancies that underwent selective reduction by radiofrequency ablation (RFA).

METHODS

This prospective cohort study was conducted on 40 women with complicated MC pregnancies who were treated by RFA. Fetal brain imaging by DWI and conventional MRI was performed either in the early (within 10 days after RFA) or late phase (after 3-6 weeks) in the surviving fetuses to detect both acute and chronic ischemic injuries. The presence of anemia after RFA was also evaluated by Doppler ultrasound.

RESULTS

Overall, 13 of the total 43 fetuses (30.23%) demonstrated MRI abnormalities with normal brain ultrasound results including germinal matrix hemorrhage (GMH), extensive cerebral ischemia, and mild ventriculomegaly. Although seven fetuses with GMH eventually survived, fetuses that demonstrated ischemic lesions and ventriculomegaly on MRI died in the uterus.

CONCLUSION

The absence of abnormal cerebral lesions or anemia on ultrasound and Doppler exams does not necessarily rule out fetal brain ischemia. Performing early MRI, particularly DWI seems to be a reasonable option for detection of early intracranial ischemic changes and better management of complicated multiple pregnancies which were treated by RFA.

Prediction of Neonatal Respiratory Morbidity Assessed by Quantitative Ultrasound Lung Texture Analysis in Twin Pregnancies

The objective of this study was to evaluate the performance of quantitative ultrasound of fetal lung texture analysis in predicting neonatal respiratory morbidity (NRM) in twin pregnancies. This was an ambispective study involving consecutive cases. Eligible cases included twin pregnancies between 27.0 and 38.6 weeks of gestation, for which an ultrasound image of the fetal thorax was obtained within 48 h of delivery. Images were analyzed using quantusFLM^® version 3.0. The primary outcome of this study was neonatal respiratory morbidity, defined as the occurrence of either transient tachypnea of the newborn or respiratory distress syndrome. The performance of quantusFLM^® in predicting NRM was analyzed by matching quantitative ultrasound analysis and clinical outcomes. This study included 166 images. Neonatal respiratory morbidity occurred in 12.7% of cases, and it was predicted by quantusFLM^® analysis with an overall sensitivity of 42.9%, specificity of 95.9%, positive predictive value of 60%, and negative predictive value of 92.1%. The accuracy was 89.2%, with a positive likelihood ratio of 10.4, and a negative likelihood ratio of 0.6. The results of this study demonstrate the good prediction capability of NRM in twin pregnancies using a non-invasive lung texture analysis software. The test showed an overall good performance with high specificity, negative predictive value, and accuracy.

Twin Growth Discordance and Risk of Postpartum Hemorrhage: A Retrospective Cohort Study

Background

In recent years, the incidence of postpartum hemorrhage has increased globally. Multiple pregnancies and cesarean sections are well-known risk factors for postpartum hemorrhage. No studies have evaluated the associations between fetal growth anomalies and postpartum hemorrhage in women with twin pregnancies undergoing cesarean section. This study aimed to identify the relationship between fetal growth anomalies and postpartum hemorrhage in women with twin pregnancies undergoing cesarean section.

Methods

This retrospective single-center study included 3,180 women with twin pregnancies at a tertiary hospital between August 2013 and July 2020. Singleton reference charts were used to assess fetal growth restriction at birth. Discordant growth was defined as an intertwin birth weight difference of ≥20%. Logistic regression analyses were used to evaluate the association between fetal growth anomalies and postpartum hemorrhage. Additionally, sensitivity analysis of abnormal placenta and stratification by twin chorionicity were conducted.

Results

The overall incidence of postpartum hemorrhage was 4.3%. Twin growth discordance, especially with fetal growth restriction, was associated with an increased risk of postpartum hemorrhage (adjusted odds ratio [AOR] = 1.62, 95% confidence interval [CI], 1.05-2.51, P = 0.031; AOR = 1.71; 95% CI, 1.08-2.70, P = 0.022; AOR = 1.98, 95% CI, 1.21-3.25, P = 0.006, respectively). After stratification, this relationship persisted in dichorionic twins (OR = 1.71, 95% CI, 1.04-2.82, P = 0.036; OR = 1.90, 95% CI, 1.13-3.21, P = 0.016; OR = 2.48, 95% CI, 1.41-4.38, P = 0.002, respectively). However, no significant association was observed in monochorionic twin pregnancies.

Conclusion

Growth discordance, especially complicated by fetal growth restriction, was associated with an increased risk of postpartum hemorrhage in women with twin pregnancies undergoing cesarean section, and was more evident in patients with dichorionic twins.

Assessment of different thresholds of birthweight discordance for early neonatal outcomes: retrospective analysis of 2348 twin pregnancies

Background

The optimal threshold of birthweight discordance (BWD) remains controversial. This study aimed to evaluate the associations between BWD at different thresholds and early neonatal outcomes and to assess their predictive accuracy.

Methods

This was a retrospective cohort study using a birthweight data with the chorionicity information of 2348 liveborn twin pairs at a gestational age of ≥26 weeks, from 2012 to 2018. The percentage of BWD was calculated by dividing the actual birthweight difference by the weight of the larger twin and multiplying by 100. Outcomes of interest included neonatal intensive care unit (NICU) admission, neonatal respiratory distress syndrome (NRDS), ventilator support and a composite outcome combining major morbidities and neonatal death. Logistic regression models were performed to estimate the association between neonatal outcomes and BWD with different thresholds (≥15.0%, ≥20.0%, ≥25% and ≥ 30%). Generalized estimated equation (GEE) models were used to address intertwin correlation. Restrictive cubic spline (RCS) models were established to draw the dose-response relationship between BWD and the odds ratios of outcomes. Clustered receiver operating characteristic (ROC) curve analyses were performed to assess the predictive accuracy.

Results

Of 2348 twin pairs, including 1946 dichorionic twin pairs and 402 monochorionic twin pairs, BWD was significantly associated with NICU admission, regardless of the thresholds used. The incidence of NRDS, ventilator support and the composite outcome were significantly higher when a threshold of ≥20% or greater was chosen. The dose-response relationship showed nonlinear growth in the risk of adverse neonatal outcomes with increasing BWD. ROC analyses showed a low significant AUROC of 0.569 (95% CI: 0.526–0.612) for predicting NICU admission but no significant AUROCs for predicting other outcomes. A BWD of ≥30% provided a moderate increase in the likelihood of NICU admission [positive likelihood ratio (LR⁺) = 5.77].

Conclusion

Although BWD is independently associated with adverse neonatal outcomes, it is not a single predictor for neonatal outcomes given the weak discriminative ability to predict neonatal outcomes. A cutoff of 30% is more practical for risk stratification among twin gestations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04417-4.

Neonatal Morbidity of Monoamniotic Twin Pregnancies: A Systematic Review and Meta-analysis

OBJECTIVE

This study was aimed to report the incidence of neonatal morbidity in monochorionic monoamniotic (MCMA) twin pregnancies according to gestational age at birth and type of management adopted (inpatient or outpatient).

STUDY DESIGN

Medline and Embase databases were searched. Inclusion criteria were nonanomalous MCMA twins. The primary outcome was a composite score of neonatal morbidity, defined as the occurrence of at least one of the following outcomes: respiratory morbidity, overall neurological morbidity, severe neurological morbidity, and infectious morbidity, necrotizing enterocolitis at different gestational age windows (24-30, 31-32, 33-34, and 35-36 weeks). Secondary outcomes were the individual components of the primary outcome and admission to neonatal intensive care unit (NICU). Subanalysis according to the type of surveillance strategy (inpatient compared with outpatient) was also performed. Random effect meta-analyses were used to analyze the data.

RESULTS

A total of 14 studies including 685 MCMA twin pregnancies without fetal anomalies were included. At 24 to 30, 31 to 32, 33 to 34, and 35 to 36 weeks of gestation, the rate of composite morbidity was 75.4, 65.5, 37.6, and 18.5%, respectively, the rate of respiratory morbidity was 74.2, 59.1, 35.5, and 12.2%, respectively, while overall neurological morbidity occurred in 15.3, 10.2, 4.3, and 0% of the cases, respectively. Infectious morbidity complicated 13, 4.2, 3.1, and 0% of newborns while 92.1, 81.6, 58.7, and 0% of cases required admission to NICU. Morbidity in pregnancies delivered between 35 and 36 weeks of gestation was affected by the very small sample size of cases included. When comparing the occurrence of overall morbidity according to the type of management (inpatient or outpatient), there was no difference between the two surveillance strategies (p = 0.114).

CONCLUSION

MCMA pregnancies are at high risk of composite neonatal morbidity, mainly respiratory morbidity that gradually decreases with increasing gestational age at delivery with a significant reduction for pregnancies delivered between 33 and 34 weeks. We found no difference in the occurrence of neonatal morbidity between pregnancies managed as inpatient or outpatient.

KEY POINTS

· MCMA pregnancies are at high risk of composite neonatal morbidity, mainly respiratory morbidity.. · Neonatal morbidity gradually decreases with increasing GA at delivery, mostly between 33 and 34 weeks.. · There is no difference in the occurrence of neonatal morbidity between in- or outpatient management..

Gestational hypertensive disease and birthweight discordance in twin pregnancies: a systematic review and meta-analysis

INTRODUCTION

The objective of this systematic review was to explore the association between gestational hypertensive disease (GHD) and birthweight discordance in twin pregnancies.

METHODS

PubMed, Embase, Web of Science and Cochrane Library were systematically searched for studies reporting the risk of birthweight discordance in twin pregnancies complicated compared with those not complicated by GHD from establishment until July 2021. Risk of bias was assessed with the Newcastle-Ottawa Scale. According to the classification of GHD, sub-group analyses reporting cases with gestational hypertension (GH), chronic hypertension (CH) and preeclampsia (PE) were performed separately. Stratification by twin chorionicity (dichorionic (DC) and monochorionic (MC)) was also conducted. When there was substantial heterogeneity (I² ≥ 50%), the random effect mode was used to estimate the pooled risk ratio, otherwise the fixed effect model was used.

RESULTS

Nine studies (303,204 twin pregnancies) were included. GHD (OR 1.45, 95% CI 1.41-1.49) was a risk factor for intertwin birthweight discordance [PE (OR 1.69, 95% CI 1.33-2.16); CH (OR 1.59, 95% CI 1.46-1.73); GH (OR1.45, 95%Cl 1.10-1.92]. After stratification, birthweight discordance was related to GHD (OR 2.51, 95% CI 2.01-3.14), GH (OR 2.08, 95% CI 1.33-3.25) and PE (OR 2.74, 95% CI 2.09-3.61) in DC pregnancies, but no longer associated with GHD and PE in MC group.

CONCLUSIONS

Twin gestations complicated with GHD, especially in DC pregnancies, were at significantly higher risk of birthweight discordance.

Patterns of discordant growth and adverse neonatal outcomes in twins

BACKGROUND

Intertwin size discordance is an independent risk factor for adverse neonatal outcomes in twin pregnancies. However, size discordance at a given point in gestation fails to take into consideration information, such as the timing of onset and the rate of progression of discordance, that may be of prognostic value.

OBJECTIVE

In this study, we aimed to identify distinct patterns of discordant fetal growth in twin pregnancies and to determine whether these patterns are predictive of adverse pregnancy outcomes.

STUDY DESIGN

This was a retrospective cohort study of women with twin pregnancies in a single tertiary referral center between January 2011 and April 2020, who had at least 3 ultrasound examinations during pregnancy that included assessment of fetal biometry. Size discordance was calculated at each ultrasound examination, and pregnancies were classified into 1 of 4 predetermined patterns based on the timing of onset and the progression of discordance: pattern 1, no significant discordance group (referent); pattern 2, early (<24 weeks' gestation) progressive discordance group; pattern 3, early discordance with plateau group; or pattern 4, late (≥24 weeks' gestation) discordance group. The associations of discordance pattern (using pattern 1 as referent) with preterm birth, preeclampsia, size discordance at birth, and birthweight<10th percentile were expressed as adjusted relative risk with 95% confidence intervals and were compared with those observed for a single measurement of size discordance at 32 weeks' gestation.

RESULTS

Of 2075 women with a twin gestation who were identified during the study period, 1059 met the study criteria. Of the 1059 women, 599 (57%) were classified as no significant discordance (pattern 1), 23 (2%) as early progressive discordance (pattern 2), 160 (15%) as early discordance with plateau (pattern 3), and 277 (26%) as late discordance (pattern 4). The associations of discordance pattern with preterm birth at <34 weeks' gestation and preeclampsia were strongest for pattern 2 (rates of 43% [adjusted relative risk, 3.43; 95% confidence interval, 2.10-5.62] and 17% [adjusted relative risk, 5.81; 95% confidence interval, 2.31-14.60], respectively), intermediate for pattern 3 (rates of 23% [adjusted relative risk, 1.82; 95% confidence interval, 1.28-2.59] and 6% [adjusted relative risk, 2.08; 95% confidence interval, 1.01-4.43], respectively), and weakest for pattern 4 (rates of 12% [adjusted relative risk, 0.96; 95% confidence interval, 0.65-1.42] and 4% [adjusted relative risk, 1.41; 0.68-2.92], respectively). In contrast, a single measurement of size discordance at 32 weeks' gestation showed no association with preeclampsia and only a weak association with preterm birth at <34 weeks' gestation.

CONCLUSION

We identified 4 distinct discordance growth patterns among twins that demonstrated a dose-response relationship with adverse outcomes and seemed to be more informative than a single measurement of size discordance.

Should singleton birth weight standards be applied to identify small-for-gestational age twins?: analysis of a retrospective cohort study

BACKGROUND

Twin birth weight percentiles are less popular in clinical management among twin pregnancies compared with singleton ones in China. This study aimed to compare the incidence and neonatal outcomes of small for gestational age (SGA) twins between the use of singleton and twin birth weight percentiles.

METHODS

This was a retrospective cohort study of 3,027 pregnancies with liveborn twin pairs at gestational age of > 28 weeks. The newborns were categorized as SGA when a birthweight was less than the 10th percentile based on the singleton and twin references derived from Chinese population. Logistic regression models with generalized estimated equation (GEE) were utilized to evaluate the association between SGA twins and neonatal outcomes including neonatal unit admission, neonatal jaundice, neonatal respiratory distress (NRDS), neonatal asphyxia, ventilator support, hypoxic ischemic encephalopathy (HIE), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), intracranial hemorrhage (ICH), culture-proven sepsis, neonatal death within 28 days after birth as well as the composite outcome.

RESULTS

The incidence of SGA was 33.1 % based on the singleton reference and 7.3 % based on the twin reference. Both of SGA newborns defined by the singleton and twin references were associated with increases in neonatal unit admission, neonatal jaundice and ventilator support. In addition, SGA newborns defined by the twin reference were associated with increased rates of BPD (aOR, 2.61; 95 % CI: 1.18-5.78) as well as the severe composite outcome (aOR, 1.93; 95 % CI: 1.07-3.47).

CONCLUSIONS

The use of singleton birth weight percentiles may result in misdiagnosed SGA newborns in twin gestations and the twin birth weight percentiles would be more useful to identify those who are at risk of adverse outcomes.

The association between maternal and foetal factors with birth weight discordance in twins from Yucatan, Mexico

Birth weight discordance (BWD) is not an uncommon event in twin pregnancies and can be associated with maternal and newborn characteristics. We aimed to analyse the association between maternal sociodemographic and newborn characteristics with BWD in twin infants born in Yucatan, Mexico, during 2008-2017 (n = 2091 pairs). BWD was calculated as the percentage of birth weight of the heavier twin. We defined three categories of BWD: concordant twins: <15%, mild-discordant: 15-24%, and severe discordant: ≥25%. A multinomial logistic regression model was used to analyse the association between maternal sociodemographic and newborn characteristics with BWD. Seventy-four percent (n = 1547) of twin pairs were classified as concordant, 17% (n = 356) met the criteria for mild-discordance and 9% (n = 188) for severe discordance. The odds for mild-discordance were significantly lower for mothers with medium level of education and in the highest quartile of total twin birth weight (TBW). Opposite-sex twin pairs showed increased odds for mild-discordance compared with same-sex pairs. The odds for severe discordance increased as mothers were in older age groups and decreased as TBW increased. Our rates of BWD are similar to those reported in populations from wealthier countries and maternal age and education, infants' sex, and TBW are associated with BWD.

Induction of labor in late FGR

Late-onset FGR is a peculiar condition characterized by the inability for the fetus to reach its growth potential diagnosed from 32 weeks of gestation. Placental insufficiency is among the leading causes of late FGR and is commonly due to a primary maternal cardiovascular non-adaptation potentially leading to fetal decompensation during labor especially once exposed to uterine hyperstimulation. Abnormalities that usually characterize late FGR include reduced fetal growth, decreased Amniotic Fluid Index, and loss of fetal heart rate variability at CTG. Fetal hemodynamics study by Doppler ultrasound significantly improved management of pregnancies affected by fetal growth restriction. A major issue when dealing with pregnancies complicated by late FGR is how to induce these women. Induction of labor (IOL) can be essentially accomplished by pharmacological and non-pharmacological agents. Recent studies suggested that the pregnancies complicated by late FGR should undergo a tailored approach for IOL in view of the higher risk of fetal decompensation following uterine hyperstimulation. The present review aims to provide an up to date on the different types of IOL which can guide clinical management.

Ultrasound in the prediction of birthweight discordance in dichorionic twins

INTRODUCTION

Large birthweight discrepancy has been identified as a risk factor for perinatal morbidity and mortality in twin pregnancies. However, it remains unclear whether such discordance can be predicted by various biological indices with specific cut-off values, and how these depend on the gestational age. We aimed to determine the most effective way to predict large birthweight discordance at various gestational ages.

MATERIAL AND METHODS

A retrospective cohort study of dichorionic twins, live-born between 2008 and 2018, was conducted. Discordances in biparietal diameter, head circumference, humerus and femur length, abdominal circumference, and estimated fetal weight were calculated-([larger twin - smaller twin] / larger twin) × 100%-and compared between those with and without a large birthweight discordance (≥20%). Receiver operating characteristic curves were constructed to analyze the predictive characteristics of each parameter.

RESULTS

Of 598 dichorionic twin pregnancies included, 83 (13.9%) had a birthweight discordance ≥20%. Group differences in biparietal diameter and head circumference discordance were the earliest to emerge (before 20 weeks of gestation), but became insignificant after 36 weeks, followed by humerus and femur length, estimated fetal weight discordance (after 20 weeks), and abdominal circumference discordance (after 28 weeks). The best predictors (with cut-off values) were discordance in biparietal diameter ≥7.8% at <20 weeks, head circumference ≥4.5% at 20-23⁺⁶  weeks, humerus length ≥4.5% at 24-27⁺⁶  weeks, and estimated fetal weight discordance (≥11.6% at 28-31⁺⁶  weeks, ≥10.5% at 32-35⁺⁶  weeks, and ≥15.0% ≥36 weeks), with sensitivity and specificity of 52%-77% and 69%-82%, respectively.

CONCLUSIONS

Different predictors and cut-off values may be useful for predicting large inter-twin birthweight discordance in dichorionic twins at different gestational ages. It is more accurate to use biparietal diameter and head circumference discordance in the early second trimester, humerus length discordance in the late second trimester, and estimated fetal weight discordance in the third trimester.

Role of progesterone, cerclage and pessary in preventing preterm birth in twin pregnancies: A systematic review and network meta-analysis

OBJECTIVE

To determine the role of progesterone, pessary and cervical cerclage in reducing the risk of (preterm birth) PTB in twin pregnancies and compare these interventions using pairwise and network meta-analysis.

STUDY DESIGN

Medline, Embase, CINAHL and Cochrane databases were explored. The inclusion criteria were studies in which twin pregnancies were randomized to an intervention for the prevention of PTB (any type of progesterone, cervical cerclage, cervical pessary, or any combination of these) or to a control group (e.g. placebo or treatment as usual). Interventions of interest were either progesterone [vaginal or oral natural progesterone or intramuscular 17a-hydroxyprogesterone caproate (17-OHPC)], cerclage (McDonald or Shirodkar), or cervical pessary. The primary outcome was PTB < 34 weeks of gestation. Both primary and secondary outcomes were explored in an unselected population of twin pregnancies and in women at higher risk of PTB (defined as those with cervical length <25 mm). Random-effect head-to-head and a multiple-treatment meta-analyses were used to analyze the data and results expressed as risk ratios.

RESULTS

26 studies were included in the meta-analysis. When considering an unselected population of twin pregnancies, vaginal progesterone, intra-muscular17-OHPC or pessary did not reduce the risk of PTB < 34 weeks of gestation (all p > 0.05). When stratifying the analysis for spontaneous PTB, neither pessary, vaginal or intramuscular 17-OHPC were associated with a significant reduction in the risk of PTB compared to controls (all p > 0.05), while there was no study on cerclage which explored this outcome in an unselected population of twin pregnancies. When considering twin pregnancies with short cervical length (≤25 mm), there was no contribution of either pessary, vaginal progesterone, intra-muscular 17-OHPC or cerclage in reducing the risk of overall PTB < 34 weeks of gestation.

CONCLUSIONS

Cervical pessary, progesterone and cerclage do not show a significant effect in reducing the rate of PTB or perinatal morbidity in twins, either when these interventions are applied to an unselected population of twins or in pregnancies with a short cervix.

Fetoscopic laser ablation in twin-to-twin transfusion syndrome: tips for counselling

Twin-to-twin transfusion syndrome (TTTS) is a serious complication that affects approximately 10-15% of monochorionic twin pregnancies. The most important role for the development of this condition is the presence of an unbalanced flow through the inter-twin vascular anastomoses. Depending on the number, type and direction of the connecting vessels, blood can be transfused disproportionately from one twin (the donor) to the other twin (the recipient). The diagnosis is defined prenatally by ultrasound and involves of two main criteria: the presence of a monochorionic diamniotic (MCDA) pregnancy; and the presence of oligohydramnios in the donor's sac- deep vertical pocket (DVP) 2 cm - and polyhydramnios in the recipient's sac- DVP>8 cm. Once diagnosed, TTTS is usually graded by using the Quintero staging system, that is composed by five stages, from oligohydramnios in the donor and polyhydramnios in the recipient twin to fetal demise in one or both twins. Photocoagulation of the anastomotic vessels, usually followed by equatorial dichorionization, it has currently become the most common fetoscopic operation today and is considered as the gold standard for stage II-IV TTTS. pPROM, chorioamniotic separation and iatrogenic preterm birth are among the most common complications of fetoscopic laser ablation, and the mean gestational age at delivery after laser procedure is about 31 weeks.

Outcome of twin-twin transfusion syndrome according to Quintero stage of disease: systematic review and meta-analysis

OBJECTIVES

To report the outcome of pregnancies complicated by twin-twin transfusion syndrome (TTTS) according to Quintero stage.

METHODS

MEDLINE, EMBASE and CINAHL databases were searched for studies reporting the outcome of pregnancies complicated by TTTS stratified according to Quintero stage (I-V). The primary outcome was fetal survival rate according to Quintero stage. Secondary outcomes were gestational age at birth, preterm birth (PTB) before 34, 32 and 28 weeks' gestation and neonatal morbidity. Outcomes are reported according to the different management options (expectant management, laser therapy or amnioreduction) for pregnancies with Stage-I TTTS. Only cases treated with laser therapy were considered for those with Stages-II-IV TTTS and only cases managed expectantly were considered for those with Stage-V TTTS. Random-effects head-to-head meta-analysis was used to analyze the extracted data.

RESULTS

Twenty-six studies (2699 twin pregnancies) were included. Overall, 610 (22.6%) pregnancies were diagnosed with Quintero stage-I TTTS, 692 (25.6%) were Stage II, 1146 (42.5%) were Stage III, 247 (9.2%) were Stage IV and four (0.1%) were Stage V. Survival of at least one twin occurred in 86.9% (95% CI, 84.0-89.7%) (456/552) of pregnancies with Stage-I, in 85% (95% CI, 79.1-90.1%) (514/590) of those with Stage-II, in 81.5% (95% CI, 76.6-86.0%) (875/1040) of those with Stage-III, in 82.8% (95% CI, 73.6-90.4%) (172/205) of those with Stage-IV and in 54.6% (95% CI, 24.8-82.6%) (5/9) of those with Stage-V TTTS. The rate of a pregnancy with no survivor was 11.8% (95% CI, 8.4-15.8%) (69/564) in those with Stage-I, 15.0% (95% CI, 9.9-20.9%) (76/590) in those with Stage-II, 18.6% (95% CI, 14.2-23.4%) (165/1040) in those with Stage-III, 17.2% (95% CI, 9.6-26.4%) (33/205) in those with Stage-IV and in 45.4% (95% CI, 17.4-75.2%) (4/9) in those with Stage-V TTTS. Gestational age at birth was similar in pregnancies with Stages-I-III TTTS, and gradually decreased in those with Stages-IV and -V TTTS. Overall, the incidence of PTB and neonatal morbidity increased as the severity of TTTS increased, but data on these two outcomes were limited by the small sample size of the included studies. When stratifying the analysis of pregnancies with Stage-I TTTS according to the type of intervention, the rate of fetal survival of at least one twin was 84.9% (95% CI, 70.4-95.1%) (94/112) in cases managed expectantly, 86.7% (95% CI, 82.6-90.4%) (249/285) in those undergoing laser therapy and 92.2% (95% CI, 84.2-97.6%) (56/60) in those after amnioreduction, while the rate of double survival was 67.9% (95% CI, 57.0-77.9%) (73/108), 69.7% (95% CI, 61.6-77.1%) (203/285) and 80.8% (95% CI, 62.0-94.2%) (49/60), respectively.

CONCLUSIONS

Overall survival in monochorionic diamniotic pregnancies affected by TTTS is higher for earlier Quintero stages (I and II), but fetal survival rates are moderately high even in those with Stage-III or -IV TTTS when treated with laser therapy. Gestational age at birth was similar in pregnancies with Stages-I-III TTTS, and gradually decreased in those with Stages-IV and -V TTTS treated with laser and expectant management, respectively. In pregnancies affected by Stage-I TTTS, amnioreduction was associated with slightly higher survival compared with laser therapy and expectant management, although these findings may be confirmed only by future head-to-head randomized trials. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Risk of fetal loss following amniocentesis or chorionic villus sampling in twin pregnancy: systematic review and meta-analysis

OBJECTIVE

To assess the rate of fetal loss following amniocentesis or chorionic villus sampling (CVS) in twin pregnancy.

METHODS

MEDLINE, EMBASE and Cochrane databases were searched for studies reporting procedure-related complications following amniocentesis or CVS in twin pregnancy. The primary outcome was the rate of procedure-related fetal loss. The secondary outcomes were fetal loss occurring before 24 weeks of gestation and fetal loss occurring within 4 weeks after the procedure. Head-to-head meta-analyses were used to compare directly each outcome, between women undergoing amniocentesis and those not undergoing amniocentesis and between women undergoing CVS and those not undergoing CVS, and to compute pooled risk differences (RD) between women exposed and those not exposed to each invasive procedure. Additionally, meta-analyses of proportions were used to estimate the pooled rates of each of the three outcomes in women undergoing amniocentesis or CVS and in controls.

RESULTS

Sixteen studies (3419 twin pregnancies undergoing and 2517 not undergoing an invasive procedure) were included. Head-to-head meta-analyses comparing directly twin pregnancies undergoing and those not undergoing amniocentesis showed a higher risk for overall fetal loss in those undergoing amniocentesis (odds ratio (OR), 1.46 (P = 0.04); RD, 0.013 (P = 0.04)), while there was no difference in the risk of either fetal loss before 24 weeks of gestation (OR, 1.59 (P = 0.06); RD, 0.010 (P = 0.11)) or fetal loss within 4 weeks after the procedure (OR, 1.38 (P = 0.3); RD, 0.003 (P = 0.8)). Overall, the pooled rate of fetal loss was 2.4% (95% CI, 1.4-3.6%) in twin pregnancies undergoing amniocentesis compared with 2.4% (95% CI, 0.9-4.6%) in those not undergoing amniocentesis. Head-to-head meta-analyses directly comparing twin pregnancies undergoing and those not undergoing CVS showed no significant difference in either overall fetal loss (OR, 1.61 (P = 0.5); RD, 0.003 (P = 0.8)) or fetal loss before 24 weeks of gestation (OR, 1.61 (P = 0.5); RD, 0.003 (P = 0.8)). Overall, the pooled rate of fetal loss was 2.0% (95% CI, 0.0-6.5%) in twin pregnancies undergoing CVS compared with 1.8% (95% CI, 0.3-4.2%) in those not undergoing CVS.

CONCLUSION

The risk of fetal loss following amniocentesis and CVS in twins is lower than reported previously and the rate of fetal loss before 24 weeks of gestation, or within 4 weeks after the procedure, did not differ from the background risk in twin pregnancy not undergoing invasive prenatal testing. These data can guide prenatal counseling for twin pregnancies undergoing invasive procedures. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Current Resources for Evidence-Based Practice, July 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 whether it is ethical not to offer doula care to all women, and commentaries on reviews focused on folic acid and autism spectrum disorder, and timing of influenza vaccination during pregnancy.