Outcomes of singleton versus twin pregnancies in the fifth and sixth decades

In Vitro Fertilization/Intracytoplasmic Sperm Injection with Autologous Oocytes in Healthy Women of Advanced Maternal Age: A Comparative Study Investigating Obstetric and Perinatal Outcomes Through Single Versus Double Embryo Transfer

Introduction

The aim of this study was to assess whether the choice between double embryo transfer (DET) and single embryo transfer (SET) in healthy women of advanced maternal age (AMA) was associated with an increased risk of adverse outcomes.

Materials and Methods

Healthy women aged 39-40 years who achieved live birth after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment between 2009 and 2020 at Karolinska University Hospital, Stockholm in Sweden, were included in this prospective, single-center cohort study.

Results

A total of 310 women, who underwent IVF/ICSI treatments and achieved live births, were included in our analysis. Within this cohort, 78% of the women received SET, while 22% received DET. Nulliparity was common in both the SET (62.7%) and DET (85.3%) groups. Fresh embryo transfers were more prevalent in the DET group (91.2%) than in the SET group (31.1%). The rate of pregnancy-induced hypertension was higher in the SET group (8.3%) compared to the DET group (1.5%, p = 0.048). Furthermore, the DET group had a significantly higher rate of twin pregnancies (13.2%) compared to the SET group (0.4%). No statistically significant differences were observed in composite obstetric and perinatal complications between the SET and DET groups across all model estimates following different adjustments.Clinical Trial Registration number: ClinicalTrials.gov NTC04602962.

Conclusions

While DET was more common in nulliparous women and associated with a higher rate of twin pregnancies, our analysis did not reveal significant differences in adverse outcomes between the SET and DET groups after comprehensive adjustments. Our study suggests that in the absence of co-morbidities, meticulous patient selection coupled with comprehensive maternal care can potentially mitigate potential DET-associated risks in women of AMA.

Impact of hypertensive disorders of pregnancy on maternal and neonatal outcomes of twin gestation: a systematic review and meta-analysis

Background

The impact of hypertensive disorders of pregnancy (HDP) on outcomes of twin gestations is not clear. We aimed to collate data via this meta-analysis to examine how HDP alters maternal and neonatal outcomes of twin gestations.

Methods

Studies comparing pregnancy outcomes of twin gestations based on HDP and published on the databases of PubMed, CENTRAL, Scopus, Web of Science, and Embase between 1 January 2000 to 20 March 2023 were eligible for inclusion.

Results

Twelve studies were included. A cumulative of 355,129 twin gestations were analyzed in the current meta-analysis. The pooled analysis found that the presence of HDP increases the risk of preterm birth (OR: 1.86 95% CI: 1.36, 2.55 I2 = 99%) and cesarean section in twin gestations (OR: 1.36 95% CI: 1.20, 1.54 I2 = 89%). Meta-analysis showed a significantly increased risk of low birth weight (OR: 1.30 95% CI: 1.10, 1.55 I2 = 97%), small for gestational age (OR: 1.30 95% CI: 1.09, 1.55 I2 = 96%) and neonatal intensive care unit admissions (OR: 1.77 95% CI: 1.43, 2.20 I2 = 76%) with HDP in twin gestations. There was no difference in the incidence of 5-min Apgar scores <7 (OR: 1.07 95% CI: 0.87, 1.38 I2 = 79%) but a lower risk of neonatal death (OR: 0.39 95% CI: 0.25, 0.61 I2 = 62%) with HDP.

Conclusion

HDP increases the risk of preterm birth, cesarean sections, low birth weight, SGA, and NICU admission in twin gestations. Contrastingly, the risk of neonatal death is reduced with HDP. Further studies are needed to corroborate the current results.

Systematic Review Registration

PROSPERO (CRD42023407725).

Obstetrics and perinatal outcomes between elective single versus double blastocyst transfer in women younger than 35 years: A cross-sectional study

INTRODUCTION

Clinicians have a positive attitude towards multiple embryo transfer in in vitro fertilization (IVF) cycles, considering increased live birth rates compared to single embryo transfer. We aimed to evaluate obstetric and perinatal outcomes among young women who became clinically pregnant after single & double blastocyst transfer.

MATERIAL-METHOD

545 women under 35 years who became clinically pregnant after fresh blastocyst transfer was evaluated retrospectively. The participants were divided¹according to the transferred embryo number - the elective single blastocyst transfer group (eSBT) (n=112) and the double blastocyst transfer group (DBT group) (n=433). Obstetric and perinatal outcomes were recorded.

RESULTS

Live birth and abortion rates per pregnancy and per gestational sac, having a fetus with congenital anomaly per pregnancy and per neonate, and gestational complications were comparable between the groups. Multiple pregnancy, Cesarean section, and admission to neonatal intensive care unit (NICU) and hospitalization day in NICU per neonate were higher in the DBT group than in the eSBT group. Mean gestational week, birth weight, birth height decreased with the embryo transfer number.

CONCLUSION

DBT transfer appears to be associated with increased multiple pregnancies, Cesarean section, prematurity, decreased fetal anthropometric measurements, and admission to NICU without an increase in live birth and abortion rates. Therefore, it will be easier for clinicians to choose eSBT by providing young couples undergoing IVF treatment with detailed information about multiple pregnancies and prematurity.

Association of Optimal Gestational Weight Gain Ranges With Perinatal Outcomes Across Body Mass Index Categories in Twin Pregnancies

IMPORTANCE

The existing gestational weight gain (GWG) recommendations for twin pregnancies are lacking for underweight individuals and are not stratified by obesity class.

OBJECTIVE

To identify optimal GWG ranges associated with reduced adverse perinatal outcomes stratified by prepregnancy body mass index (BMI) categories in twin pregnancies.

DESIGN, SETTING AND PARTICIPANTS

This population-based cohort study of twin pregnancies using data from the National Center for Health Statistics was conducted between January 1, 2014, and December 31, 2018. Statistical analysis was performed from October 24, 2021, to May 7, 2022. The study population comprised 262 604 individuals between 18 and 45 years of age with live-born twins without congenital malformation between 24 and 42 weeks of gestation. Two approaches were used to determine the optimal GWG ranges: a statistics-based approach calculating IQRs of GWG in a low-risk population, and an outcome-based approach identifying GWG thresholds below or above which an adverse perinatal outcome increased.

EXPOSURE

Gestational weight gain.

MAIN OUTCOMES AND MEASURES

Preterm birth less than 36 weeks, gestational hypertensive disorders, small for gestational age status, large for gestational age status, and a composite outcome defined as any occurrence of the individual outcomes.

RESULTS

The main sample comprised 200 810 individuals with twin pregnancies (mean [SD] maternal age, 30.4 [5.5] years; 1624 [0.8%] American Indian or Alaska Native, 13 031 [6.5%] Asian or Pacific Islander, 36 423 [18.1%] Black, and 149 732 [74.6%] White; and 137 409 [68.4%] multiparous). In the low-risk subgroup (n = 61 794), the IQRs of the total GWG after 36 weeks of gestation as assessed using a statistics-based approach and based on BMI group were 15.9 to 22.7 kg for underweight, 15.4 to 22.7 kg for normal weight, 12.7 to 22.2 kg for overweight, 10.0 to 20.0 kg for class 1 obesity, 7.7 to 18.1 kg for class 2 obesity, and 5.9 to 16.3 kg for class 3 obesity. The absolute risk of the composite outcome showed U-shaped associations with GWG across BMI categories. The optimal GWG ranges by 36 weeks identified using an outcome-based approach and BMI group were 17.5 to 24.9 kg for underweight, 15.0 to 24.9 kg for normal weight, 15.0 to 24.9 kg for overweight, 10.0 to 19.9 kg for class 1 obesity, 7.5 to 17.4 kg for class 2 obesity, and 5.0 to 9.9 kg for class 3 obesity. The multivariable logistic models assessed using the validation sample (n = 49 275) showed that GWG defined outside those optimal ranges was associated with preterm birth at less than 36 weeks, gestational hypertensive disorders, and small or large for gestational age.

CONCLUSIONS AND RELEVANCE

This population-based cohort study found that optimal GWG ranges were similar for individuals with underweight and normal weight but decreased with increasing severity of obesity. The current US Institute of Medicine GWG recommendations may be too high for individuals with moderate or severe obesity.

The Maternal-Neonatal Outcomes of Twin Pregnancies with Preeclampsia and Their Association with Assisted Reproductive Technology: A Retrospective Study

Objective: This study aimed to investigate the maternal−neonatal outcomes of twin pregnancies of mothers with preeclampsia and their association with assisted reproductive technology (ART). Methods: A retrospective study on the clinical and maternal−neonatal outcome data of 698 women with twin pregnancies who delivered in our hospital from December 2013 to September 2021 was conducted. Continuous variables were analyzed using a Student’s t-test or Wilcoxon rank-sum test. Categorical variables were analyzed using the Chi-square test. The risk factors of twin pregnancies with preeclampsia were analyzed by logistic regression. Results: The rate of twin pregnancy complicated by preeclampsia was 17.62% (123/698). Logistic regression analysis showed that ART increased the risk of preeclampsia in twin pregnancies (AOR: 1.868, 95% CI: 1.187−2.941). Mothers with preeclampsia carrying twins conceived with ART had a higher rate of delivery at gestational week < 34 (29.9% vs. 12.5%) and asphyxia of the neonate at 5 min after delivery (13.4% vs. 1.8%) than those with preeclampsia conceived without ART (p < 0.05). Conclusions: ART increases the risk of preeclampsia in twin pregnancies and the rate of adverse maternal−neonatal outcomes for twin pregnancies with preeclampsia. The policy of single embryo transfer is a method to reduce the adverse pregnancy outcomes of ART.

Comparison of outcomes of monochorionic twin pregnancies conceived by assisted reproductive technology vs. spontaneous conceptions: A systematic review and meta-analysis

BACKGROUND

This review aimed to assess if monochorionic twin pregnancies conceived by assisted conception have worse maternal and neonatal outcomes as compared to those conceived naturally.

METHODS

Datasets of PubMed, ScienceDirect, CENTRAL, Embase, and Google Scholar were searched for studies comparing maternal and neonatal outcomes of monochorionic twin pregnancies conceived by assisted vs. spontaneous methods.

RESULTS

Eight studies comparing 337 assisted with 2,711 spontaneously conceived monochorionic twin pregnancies were included. Meta-analysis revealed that the mode of conception of monochorionic twin pregnancies had no impact on the risk of hypertensive disorders of pregnancy (HDP) (OR: 1.36 95% CI, 0.73, 2.54 I ² = 9% p = 0.03), twin-twin transfusion syndrome (TTTS) (OR: 0.83 95% CI, 0.52, 1.31 I ² = 0% p = 0.42), and very preterm delivery (OR: 1.18 95% CI, 0.74, 1.88 I ² = 41% p = 0.49). We noted no statistically significant difference in the mean birth weights (MD: -17.66 95% CI, -157.23, 121.91 I ² = 82% p = 0.80), risk of intra-uterine death (OR: 0.90 95% CI, 0.51, 1.60 I ² = 36% p = 0.73) and small for gestational age between the two groups (OR: 0.92 95% CI, 0.67, 1.26 I ² = 0% p = 0.59). There was an increased risk of caesarean sections (OR: 1.34 95% CI, 1.00, 1.80 I ² = 0% p = 0.05) and neonatal death with assisted conceptions as compared to spontaneous conceptions (OR: 2.35 95% CI, 1.11, 5.01 I ² = 37% p = 0.03).

CONCLUSION

Monochorionic twin pregnancies conceived via assisted reproductive technology have a heightened risk of cesarean section and neonatal deaths. However, there is a need for further studies to supplement current evidence.Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=325133, identifier: CRD42022325133.

Association between pre-pregnancy BMI and neonatal weight outcomes in twin pregnancies resulting from assisted reproductive technology: a 10-year cohort study

BACKGROUND/OBJECTIVES

To examine the effect of pre-pregnancy maternal body mass index (BMI) on neonatal weight outcomes of twin infants who were conceived by assisted reproductive technology (ART).

SUBJECTS/METHODS

A 10-year (2006-2015) Chinese sample of 3431 mothers and their twin infants conceived by ART from a retrospective cohort were included. The effects of pre-pregnancy maternal BMI on gestational age and birth weight were assessed by generalized linear model and generalized estimating equation model.

RESULTS

Compared with a normal weight group, pre-pregnancy maternal underweight was associated with lower birth weight and increased risk of small for gestational age (SGA) in twins conceived by ART (birth weight: difference -59.22 g, 95% CI -93.16 to -25.27 g; SGA: RR 1.25, 95% CI 1.09 to 1.43). Pre-pregnancy maternal obesity was associated with higher birth weight and increased risk of preterm birth (birth weight: difference 65.82 g, 95% CI 10.66 to 120.99 g; preterm birth: RR 1.19, 95% CI 1.03-1.37). A nonlinear relationship between pre-pregnancy maternal BMI and SGA was observed. The risk of SGA decreased with the pre-pregnancy maternal BMI up to the turning point (BMI = 21) (RR 0.90, 95% CI 0.86-0.95).

CONCLUSIONS

Among mothers undergoing ART, pre-pregnancy maternal obesity is associated with higher birth weight and higher risk of preterm birth for twin pregnancy, and pre-pregnancy maternal underweight is associated with lower birth weight and higher risk of SGA. Women preparing for ART should maintain a normal BMI to lower the chances of adverse neonatal outcomes.

[Influence of twin pregnancy by assisted reproductive technology on neonatal outcomes]

OBJECTIVE

To study the influence of twin pregnancy by assisted reproductive technology (ART) versus twin pregnancy by spontaneous conception (SC) on neonatal outcomes.

METHODS

A retrospective analysis was performed for the clinical data of 3 356 live twins with a gestational age of ≥24 weeks who were born in Nanjing Maternal and Child Health Hospital from 2017 to 2019, with 2 006 twins (1 003 pairs) in the ART group and 1 350 (675 pairs) in the SC group. The two groups were compared in terms of the mother's general information and pregnancy comorbidities and the general information, diseases, and outcomes of neonates.

RESULTS

Compared with the SC group, the ART group had a significantly higher maternal age (P < 0.05) and significantly higher rates of primiparity, cesarean section, and cervical cerclage (P < 0.05). Compared with the SC group, the ART group had significantly higher incidence rates of maternal pregnancy comorbidities including hypertension, gestational diabetes, and postpartum hemorrhage (P < 0.05). Compared with the SC group, the ART group had a significantly lower mean gestational age of neonates (P < 0.05) and a significantly higher proportion of very-low-birth-weight infants (6.8% vs 5.8%, P < 0.05), while ART did not increase the risks of preterm birth and low Apgar score. There were no significant differences between the two groups in the mortality rate of neonates and the incidence rates of neonatal diseases including respiratory distress syndrome, stage II/III necrotizing enterocolitis, bronchopulmonary dysplasia, and grade III-IV intracranial hemorrhage (P > 0.05).

CONCLUSIONS

Compared with twin pregnancy by SC, twin pregnancy by ART does not increase the neonatal mortality rate and risk of adverse outcomes.

The Feasibility of All-Blastocyst-Culture and Single Blastocyst Transfer Strategy in Elderly Women: A Retrospective Analysis

Objective

To investigate the feasibility and clinical outcome of the all-blastocyst-culture and single blastocyst transfer strategy in women aged ≥35 years.

Methods

A retrospective analysis of patients aged ≥35 years undergoing IVF/ICSI was performed from January 2017 to April 2019 in the reproductive center of the Second Affiliated Hospital of Wenzhou Medical University. A total of 155 cases treated with ovarian hyperstimulation by prolonged protocol and implemented single (84 cases) or double (71 cases) blastocyst transfer were collected. Then, patients were further divided into <38 yr. group and ≥38 yr. group, and the laboratory and clinical outcomes were compared between the groups.

Results

The double-blastocyst-transfer (DBT) group showed higher clinical pregnancy rate and multiple pregnancy rate and lower neonatal birth weight than those in the single-blastocyst-transfer (SBT) group (P < 0.05). However, there were no statistically significant differences between the groups in the embryo implantation rate, biochemical pregnancy rate, miscarriage rate, preterm delivery rate, and term birth rate. For patients < 38 yr., SBT significantly reduced the multiple pregnancy rate and increased the neonate birth weight without significant reduction in the clinical pregnancy rate. While in the ≥38 yr. group, there are no differences in pregnancy outcomes between SBT and DBT. Logistic regression analysis showed that the number of MII oocytes was positively correlated with the live birth rate (OR = 1.18) and negatively correlated with the miscarriage rate (OR = 0.844), suggesting that elderly patients with relatively normal ovarian reserve would obtain better prospect in pregnancy. The number of fetal heart beat in pregnancy was negatively correlated with the live birth rate (OR = 0.322) and positively correlated with the preterm birth rate (OR = 7.16).

Conclusion

The strategy of all-blastocyst-culture and single blastocyst transfer is feasible, safe, and effective for elderly patients with normal ovarian reserve, which would reduce the multiple pregnancy rate.

Impact of the mode of conception on gestational hypertensive disorders at very advanced maternal age

RESEARCH QUESTION

To study gestational hypertensive disorders in oocyte donation pregnancies compared with other modes of conception at very advanced maternal age.

DESIGN

A historical cohort study of all women aged 45-47 years who gave birth to singletons at a tertiary medical centre between March 2011 and May 2018, at 24 weeks' gestation or later. Pregnancy outcomes were compared between donor oocyte (IVF-OD), IVF using autologous oocytes (IVF-A) and naturally conceived pregnancies. A multivariate logistic regression was used to evaluate the association between the mode of conception and gestational hypertensive disorders.

RESULTS

The final analysis included 159, 68 and 73 patients in the IVF-OD, IVF-A and natural conception groups, respectively. The rate of gestational hypertensive disorders was significantly higher among those who conceived by IVF compared with those who conceived naturally but did not differ between the two IVF groups (27.0% for IVF-OD, 19.1% for IVF-A, P = 0.204; 5.5% for natural conception, P < 0.001 and P = 0.013 compared with IVF-OD and IVF-A, respectively). The results remained similar in a multivariate logistic regression analysis. The rate of Caesarean deliveries was significantly higher in the IVF-OD and IVF-A groups compared with the natural conception group (83.6%, 70.6% and 37.0%, respectively, P < 0.001), but other pregnancy outcomes did not differ between the groups.

CONCLUSIONS

IVF pregnancies in the late fifth decade of life were associated with significantly higher rates of gestational hypertensive disorders compared with naturally conceived pregnancies. No difference existed between the two IVF groups. These results may highlight the impact of IVF itself on gestational hypertensive disorders at very advanced maternal age.