Perinatal outcomes of elderly primiparous dichorionic twin pregnancies conceived by in vitro fertilization compared with those conceived spontaneously

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.

Maternal and perinatal outcomes in twin pregnancies following assisted reproduction: a systematic review and meta-analysis involving 802 462 pregnancies

BACKGROUND

ART is associated with higher rates of twin pregnancies than singleton pregnancies. Whether twin pregnancies conceived following ART have additional maternal and neonatal complications compared with non-ART twin pregnancies is not known.

OBJECTIVE AND RATIONALE

The objective was to quantify the risk of adverse maternal and perinatal outcomes among twin pregnancies conceived following ART compared with non-ART and natural conception. Existing reviews vary in the reported outcomes, with many studies including triplet pregnancies in the study population. Therefore, we aimed to perform an up-to-date review with an in-depth analysis of maternal and perinatal outcomes limited to twin pregnancies.

SEARCH METHODS

We searched electronic databases MEDLINE and EMBASE from January 1990 to May 2023 without language restrictions. All cohort studies reporting maternal and perinatal outcomes following ART compared with non-ART twin pregnancies and natural conception were included. Case-control studies, case reports, case series, animal studies, and in vitro studies were excluded. The Newcastle-Ottawa Scale was used to assess the methodological quality of the studies. Using random-effects meta-analysis, the estimates were pooled and the findings were reported as odds ratios (OR) with 95% CI.

OUTCOMES

We included 111 studies (802 462 pregnancies). Twin pregnancies conceived following ART were at higher risk of preterm birth at <34 weeks (OR 1.33, 95% CI 1.14-1.56, 29 studies, I2 = 73%), <37 weeks (OR 1.26, 95% CI 1.19-1.33, 70 studies, I2 = 76%), hypertensive disorders in pregnancy (OR 1.29, 95% CI 1.14-1.46, 59 studies, I2 = 87%), gestational diabetes mellitus (OR 1.61, 95% CI 1.48-1.75, 51 studies, I2 = 65%), and caesarean delivery (OR 1.80, 95% CI 1.65-1.97, 70 studies, I2 = 89%) compared with non-ART twins. The risks for the above maternal outcomes were also increased in the ART group compared with natural conception. Of the perinatal outcomes, ART twins were at significantly increased risk of congenital malformations (OR 1.17, 95% CI 1.05-1.30, 39 studies, I2 = 59%), birthweight discordance (>25% (OR 1.31, 95% CI 1.05-1.63, 7 studies, I2 = 0%)), respiratory distress syndrome (OR 1.32, 95% CI 1.09-1.60, 16 studies, I2 = 61%), and neonatal intensive care unit admission (OR 1.24, 95% CI 1.14-1.35, 32 studies, I2 = 87%) compared with non-ART twins. When comparing ART with natural conception, the risk of respiratory distress syndrome, intensive care admissions, and birthweight discordance >25% was higher among the ART group. Perinatal complications, such as stillbirth (OR 0.83, 95% CI 0.70-0.99, 33 studies, I2 = 49%), small for gestational age <10th centile (OR 0.90, 95% CI 0.85-0.95, 26 studies, I2 = 36%), and twin-twin transfusion syndrome (OR 0.45, 95% CI 0.25-0.82, 9 studies, I2 = 25%), were reduced in twin pregnancies conceived with ART versus those without ART. The above perinatal complications were also fewer amongst the ART group than natural conception.

WIDER IMPLICATIONS

ART twin pregnancies are associated with higher maternal complications than non-ART pregnancies and natural conception, with varied perinatal outcomes. Women seeking ART should be counselled about the increased risks of ART twin pregnancies and should be closely monitored in pregnancy for complications. We recommend exercising caution when interpreting the study findings owing to the study's limitations.

Short-term neonatal and long-term infant outcome of late-preterm twins: nationwide population-based study

OBJECTIVES

To evaluate the short- and long-term outcome of late-preterm compared with term birth in twin pregnancy.

METHODS

This retrospective observational cohort study included all women who had a twin delivery between 1 January 2007 and 31 December 2010 recorded in the claims database of the Korea National Health Insurance, with at least one follow-up recorded in the database of the National Health Screening Program for Infants and Children. Outcomes were analyzed at the pregnancy level, with adverse outcome being defined as an adverse outcome in one or both twins, identified by a diagnosis according to the International Classification of Diseases 10^th Revision. The primary short-term outcome was composite morbidity, which included any of the following: transient tachypnea, respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage and bronchopulmonary dysplasia. Long-term adverse outcome included any neurological or neurodevelopmental outcome, defined by prespecified neurological and developmental diagnoses; these were assessed by following up all neonates until the end of 2018, by which time they were 8-11 years of age. Outcomes were compared between twins delivered late preterm (34 + 0 to 36 + 6 weeks) and those delivered at term (≥ 37 weeks).

RESULTS

Among 17 189 women who delivered twins at ≥ 34 weeks of gestation during the study period, 5032 (29.27%) women delivered in the late-preterm period. On multivariate analysis, compared with the twins delivered at term, the late-preterm twins had an increased risk for the primary short-term outcome of composite morbidity (adjusted odds ratio (aOR), 2.09; 95% CI, 1.90-2.30), including transient tachypnea (aOR, 1.85; 95% CI, 1.64-2.09), respiratory distress syndrome (aOR, 2.31; 95% CI, 2.04-2.62), necrotizing enterocolitis (aOR, 2.10; 95% CI, 1.20-3.69) and intraventricular hemorrhage (aOR, 2.13; 95% CI, 1.46-3.11). For the long-term outcome, the late-preterm twins also had an increased risk for any neurological or neurodevelopmental outcome (adjusted hazard ratio, 1.14; 95% CI, 1.07-1.21).

CONCLUSIONS

Twins delivered in the late-preterm period have an increased risk for short- and long-term morbidity compared with twins delivered at term. These results should be considered when determining the timing of delivery in uncomplicated twin pregnancy. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Obstetric Outcomes and Successful Reduction of Twin Pregnancies Achieved by In Vitro Fertilization

The use of in vitro fertilization methods around the world is constantly increasing. In some developed countries, up to 5% of newborns are as a result of pregnancies after IVF procedures. In vitro fertilization as one of the main and widespread methods for treatment of infertility is the main reason for the high frequency of multiple pregnancies, which, in many countries, is still too high. Most of the multiple pregnancies are in fact twin pregnancies. Twin pregnancies, regardless of how they are achieved, are associated with large number of complications compared with singleton ones. More often these pregnancies can lead to maternal complications and adverse pregnancy outcomes. Maternal complications include development of preeclampsia, gestational diabetes, placenta previa, placental abruption, premature rupture of membranes, antepartum and postpartum hemorrhage, and delivery by cesarean sections. Adverse pregnancy outcomes mostly include preterm birth (PTB), low birth weight (LBW), small for gestational age newborn (SGA), intrauterine growth restriction (IUGR), neonatal respiratory distress syndrome (RDS), and admission to neonatal intensive care unit (NICU). A number of studies have found differences in the course of twin pregnancies according to their mode of occurrence – spontaneous or after IVF. Some of them have found that twin pregnancies after IVF are associated with poorer obstetric and perinatal outcomes, others do not find such a difference, and there are even studies that find a better outcome in IVF twin pregnancies. Twin pregnancy is a common occurrence after IVF procedure, because multiple-embryo transfer is commonly regarded as an effective strategy to improve the likelihood of a successful pregnancy. Understanding the risks of these pregnancies should be a strong motive for the transfer of fewer embryos during IVF procedures. The most effective way to do this is to transfer a single-embryo into the uterus in cases, where this is justified and the chances of getting pregnant are high. An important element in achieving this goal is the use of methods for vitrification of embryos, which leads to a sufficiently high rate of clinical pregnancies after freezing of embryos obtained by IVF and their subsequent transfer after thawing in case of failure of fresh ET.

Maternal and perinatal outcomes of dichorionic diamniotic twins in women after spontaneous and assisted conception

OBJECTIVE

Twin pregnancies have been shown to be associated with numerous maternal and perinatal complications. Published data shows conflicting reports on whether assisted conception influences these risks. The purpose of this study was to assess the impact of mode of conception on maternal and perinatal outcomes of dichorionic diamniotic twin pregnancies.

STUDY DESIGN

This was a large retrospective study of 497 women with dichorionic diamniotic twins that were conceived spontaneously or with assisted conception in a single centre over a 10-year period.

RESULTS

This study showed no significant difference in mode of delivery (OR 1.40 95% CI 0.88 - 2.24), need for admission to neonatal unit (OR 1.56 95% CI 0.88-2.77), or preterm births between dichorionic twin pregnancies conceived following assisted conception when compared to spontaneously conceived dichorionic twin pregnancies. Women who conceived twins by assisted conception that did not have an elective caesarean section were more likely to go into spontaneous labour than have an induction of labour (OR 0.54 95% CI 0.3 - 0.99). They also had a higher chance of having an estimated blood loss of more than 1L than women who conceived naturally (OR 1.70 95% CI 1.06 - 2.73).

CONCLUSIONS

In the case of dichorionic twins, this study showed that assisted conception does not seem to be associated with adverse obstetric and perinatal outcomes when compared with spontaneous conception. These results should be considered reassuring to women undergoing assisted conception, and may assist clinicians when counselling patients for assisted conception treatment. Further research is needed to assess the impact of assisted conception on postpartum blood loss.

Assisted reproductive technology and hypertensive disorders of pregnancy: systematic review and meta-analyses

Background

Hypertensive disorders of pregnancy (HDP) is one of the most common pregnancy complications and causes of maternal morbidity and mortality. Assisted reproductive technology (ART) has been associated with adverse pregnancy outcomes, including HDP. However, the impact of multiple pregnancies, oocyte donation, as well as fresh and frozen embryo transfer needs to be further studied. We conducted a systematic review and meta-analyses to evaluate the association between ART and HDP or preeclampsia relative to spontaneous conception (SC).

Methods

We identified studies from EMBASE, MEDLINE, and Cochrane Library (up to April 8, 2020) and manually using structured search strategies. Cohort studies that included pregnancies after in vitro fertilization (IVF) with or without intracytoplasmic sperm fertilization (ICSI) relative to SC with HDP or preeclampsia as the outcome of interest were included. The control group was women who conceived spontaneously without ART or fertility medications. The pooled results were reported in odds ratios (OR) with 95% confidence intervals based on random effects models. Numbers needed to harm (NNH) were calculated based on absolute risk differences between exposure and control groups.

Results

Eighty-five studies were included after a screening of 1879 abstracts and 283 full text articles. Compared to SC, IVF/ICSI singleton pregnancies (OR 1.70; 95% CI 1.60–1.80; I² = 80%) and multiple pregnancies (OR 1.34; 95% CI 1.20–1.50; I² = 76%) were both associated with higher odds of HDP. Singleton pregnancies with oocyte donation had the highest odds of HDP out of all groups analyzed (OR 4.42; 95% CI 3.00–6.51; I² = 83%). Frozen embryo transfer resulted in higher odds of HDP (OR 1.74; 95% CI 1.58–1.92; I² = 55%) than fresh embryo transfer (OR 1.43; 95% CI 1.33–1.53; I² = 72%). The associations between IVF/ICSI pregnancies and SC were similar for preeclampsia. Most interventions had an NNH of 40 to 100, while singleton and multiple oocyte donation pregnancies had particularly low NNH for HDP (16 and 10, respectively).

Conclusions

Our meta-analysis confirmed that IVF/ICSI pregnancies are at higher odds of HDP and preeclampsia than SC, irrespective of the plurality. The odds were especially high in frozen embryo transfer and oocyte donation pregnancies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03938-8.

Association of Gestational Age at Birth With Risk of Perinatal Mortality and Special Educational Need Among Twins

IMPORTANCE

Twin pregnancies account for 3% of live births but experience substantially more perinatal morbidity and mortality than singleton pregnancies. Optimizing the timing of birth is a key strategy in improving twin pregnancy outcomes. Current UK and US policies are based on observational studies of perinatal mortality and not on longer-term effects. The association of timing of birth with long-term childhood outcomes among twins is uncertain.

OBJECTIVE

To identify the optimal gestation week for birth of twin infants by calculating the week of birth associated with the lowest risk of short-term and long-term adverse outcomes (perinatal mortality and special educational need [SEN] at school).

DESIGN, SETTING, AND PARTICIPANTS

This population-based, data-linkage cohort study included 43 133 twin infants born at a gestational age of 34 weeks onward between January 1, 1980, and December 31, 2015, in Scotland. The data were analyzed from June 1, 2017, to March 1, 2019.

EXPOSURES

Gestational age (in weeks) at the time of birth.

MAIN OUTCOMES AND MEASURES

The primary outcomes were extended perinatal mortality and a record of SEN (≥1 of intellectual disabilities, dyslexia, physical or motor impairment, language or speech disorder, autistic spectrum disorder, and social, emotional, or behavioral difficulties) at school (children aged 4-18 years). To infer the consequence of the gestational age at birth, clinical outcomes of twin infants born at each week of gestation from 34 weeks onward were compared with those of twin infants remaining in utero thereafter.

RESULTS

Of the total 43 133 twin infants included in the study, 21 696 (50.3%) were females. Although maternity records were available for all infants, 9519 sex-discordant twin children were linked to their educational data, of whom 1069 (13.8%) had a record of SEN. Compared with twins remaining in utero (n = 26 172), birth at any gestational age from 34 to 37 weeks was associated with increased odds of perinatal death (ie, adjusted odds ratio [AOR], 1.99; 95% CI, 1.53-2.69 at 36 weeks [n = 8056]) and increased risk of SEN at school (AOR, 1.39; 95% CI, 1.11-1.74, for birth at 36 weeks compared with 37 weeks). In a competing risk analysis, the risks of stillbirth and neonatal death were balanced at 37 weeks (risk difference, 2.05; 95% CI, 0.8-3.3).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that, in the absence of a medical complication, twins should not be routinely delivered before 37 completed weeks of gestation. These findings may help optimize shared decision-making around the timing of twin birth.

Assisted reproductive technology and the risk of gestational diabetes mellitus: a systematic review and meta-analysis

Background

The use of assisted reproductive technology (ART) is increasing worldwide, and observational studies have indicated that women who conceived by ART have an increased risk of pregnancy complications including gestational diabetes mellitus (GDM). We aimed to determine the risk of GDM among women who conceived with ART by systematic review and meta-analysis.

Main text

A systematic literature search was conducted in ISI Web of Knowledge, MEDLINE, Scopus, and Embase through May 2017 for English-language articles using a list of keywords. All studies comparing GDM in women conceived by ART and those who conceived spontaneously were included. Data extraction was performed by two authors independently and discrepancies were resolved by discussion. In total, 48 studies with 91,487 pregnancies conceived through ART and 2,525,234 spontaneously conceived met the inclusion criteria. There was evidence of substantial heterogeneity among these studies (P < 0.001, I2 = 98.6%). Random effects meta-analysis showed a significant increase in GDM among those who conceived by ART compared with those who conceived spontaneously (pooled relative risk = 1.51, 95% confidence interval = 1.18–1.93). Visual inspection of the funnel plot did not reveal any publication bias, which was supported by Egger’s test and Begg’s test.

Conclusion

The findings of this systematic review indicate that the use of ART treatment is associated with a 1.51-fold increase in GDM. Women need to be counselled carefully before undergoing ART treatment about the possibility and risk of GDM.

Risk of gestational diabetes mellitus following assisted reproductive technology: systematic review and meta-analysis of 59 cohort studies

OBJECTIVE

The use of assisted reproductive technology (ART) has been associated with an increased risk of gestational diabetes mellitus (GDM) in previous studies, but its risk has not been consistent. Therefore, we aimed to estimate the risk of GDM in women who conceived with ART via a systematic review and meta-analysis of cohort studies.

METHODS

ISI Web of Knowledge, Medline/PubMed, Scopus, and Embase databases were searched to identify studies that evaluated the risk of GDM through May 2017 using the relevant keywords. Two reviewers independently performed the screening, data extraction, and quality assessment. Meta-analysis was performed with a random effects model.

RESULTS

The search yielded 957 records relating to GDM and use of ART, from which 59 eligible cohorts were selected for meta-analysis (n = 96,785). There was evidence of substantial heterogeneity among these studies (χ₍₅₈₎² = 3072.34, p < .001; I²=98.1%). The pooled estimate of GDM risk using the random effects model was 9.00% (95% CI: 7.90-10.20). Visual inspection of the funnel plot indicated the presence of low publication bias, but Egger's test did not reveal publication bias.

CONCLUSIONS

The findings revealed that the risk of GDM was very high among women who conceived with ART treatment. GDM screening, management, and improved care are vital in ART pregnancy.

Gestational age at delivery of twins and perinatal outcomes: a cohort study in Aberdeen, Scotland

Background: Twin pregnancy is associated with a threefold increase in perinatal death compared to singletons.  The objective of this study was to determine the risk of perinatal death in twins by week of gestation and to quantify the effect of known risk factors. Methods: A cohort analysis was performed using data from the Aberdeen Maternity and Neonatal Databank (AMND).  The exposure was gestational age at delivery and the primary outcome was perinatal death.  Adjusted hazard ratios (aHRs) for perinatal death according to gestational age at delivery were determined by multivariate Cox proportional hazards regression modelling with robust standard errors to account for clustering in the twin infants.  Confounders and risk factors quantified and adjusted for in the model included maternal age, smoking, parity, marital status and year of birth.  Kaplan-Meier time to event analysis was used to determine the differences in survival according to chorionicity and assisted reproduction technologies (ART) conception status. Results: The population comprised of 7,420 twin babies born between 1950 and 2013 in the Grampian area of Northern Scotland.  There were 272 stillbirths in the cohort (3.67%) and 273 neonatal deaths (3.68%). Compared to delivery at 37-38 weeks, delivery before 37 weeks was associated with a 2-fold increase in perinatal death. Monochorionic twins had a 2-fold increase in perinatal death compared to dichorionic twins (aHR 2.15, 95% CI 1.60-2.90). Twins conceived by ART did not have a greater risk of perinatal death compared to those naturally conceived (aHR 1.21, 95% CI 0.87-1.68) Conclusion:  This study suggests that delivery of twins at 37-38 weeks is associated with the lowest risk of perinatal death.

Assisted reproductive technology and the risk of preeclampsia: an updated systematic review and meta-analysis

Background

The objective of this systematic review and meta-analyses was to assess the risk of preeclampsia among women who conceived with assisted reproductive technology (ART).

Methods

We searched the ISI Web of Knowledge, Medline/PubMed, Scopus, and Embase (from inception to May 2017) for English language articles using a list of key words. In addition, reference lists from identified studies and relevant review articles were also searched. Data extraction was performed by two authors, and the study quality was assessed using the Newcastle–Ottawa Scale. Random-effects model meta-analysis was applied to pool the relative risks (RR) across studies.

Results

A total of 48 studies (5 case-control studies and 43 cohort studies) were included in this meta-analysis. The Cochran Q test and I² statistics revealed substantial heterogeneity (Q = 26,313.92, d.f. = 47, p < 0.001 and I² = 99.8%). Meta-analysis showed a significant increase in preeclampsia in women who conceived by ART compared with those who conceived spontaneously (RR = 1.71, 95% CI = 1.11–2.62, p = 0.015).

Conclusions

The findings of this systematic review indicate that the use of ART treatment is associated with a 1.71-fold increase in preeclampsia.

Gestational age at delivery of twins and perinatal outcomes: a cohort study in Aberdeen, Scotland

Background: Twin pregnancy is associated with a threefold increase in perinatal death compared to singletons.  The objective of this study was to determine the risk of perinatal death in twins by week of gestation and to quantify the effect of known risk factors. Methods: A cohort analysis was performed using data from the Aberdeen Maternity and Neonatal Databank (AMND).  The exposure was gestational age at delivery and the primary outcome was perinatal death.  Adjusted hazard ratios (aHRs) for perinatal death according to gestational age at delivery were determined by multivariate Cox proportional hazards regression modelling with robust standard errors to account for clustering in the twin infants.  Confounders and risk factors quantified and adjusted for in the model included maternal age, smoking, parity, marital status and year of birth.  Kaplan-Meier time to event analysis was used to determine the differences in survival according to chorionicity and assisted reproduction technologies (ART) conception status. Results: The population comprised of 7,420 twin babies born between 1950 and 2013 in the Grampian area of Northern Scotland.  There were 272 stillbirths in the cohort (3.67%) and 273 neonatal deaths (3.68%). Compared to delivery at 37-38 weeks, delivery at or beyond 39 weeks was associated with a significant increase in perinatal death (aHR 2.00 [95% CI 1.45-2.78]).  Monochorionic twins had a 2-fold increase in perinatal death compared to dichorionic twins (aHR 2.15, 95% CI 1.60-2.90). Twins conceived by ART did not have a greater risk of perinatal death compared to those naturally conceived (aHR 1.21, 95% CI 0.87-1.68) Conclusion:  This study suggests that delivery of twins at 37-38 weeks is associated with the lowest risk of perinatal death.

Delivery and feto-neonatal outcomes of diamniotic twin pregnancies in women with no chronic disease or gestational complications: impact of mode of conception

Introduction: Autologous and heterologous assisted reproductive technology (ART) conceptions have been on the rise for the last few decades and alongside with that have the rate of multiple pregnancies. Multiple gestations are associated with high odds of gestational complications and, in turn, adverse delivery and feto-neonatal outcomes. Whether ART-conception further increases such elevated risk is still debated. ART is more commonly accessed by older women with chronic diseases, which relate to heightened likelihood of complications. We decided to investigate the influence of autologous and heterologous ART conception compared to spontaneous conception on delivery and feto-neonatal outcomes of diamniotic twin pregnancies in a cohort of healthy women with no chronic conditions or gestational complications.Materials and methods: Retrospective cohort study among diamniotic twin pregnancies in mothers without pregestational or gestational disease. Delivery and feto-neonatal outcomes were compared among three groups according to mode of conception: (1) spontaneous conception (SC, referent group, n = 251 pregnancies), (2) autologous ART-conception (A-ART, n = 87), and (3) heterologous ART-conception (H-ART, n = 22).Results: At adjusted analyses, twin pregnancies conceived by A-ART showed a twofold heightened risk of delivery by urgent/emergent cesarean section, as well as four and sevenfold increase in odds of blood loss >1000 and >1500 mL, respectively. H-ART pregnancies were at fivefold higher risk of undergoing prelabor cesarean section compared to SC, whereas no differences were identified for odds of severe post-partum hemorrhage. Also, A-ART and H-ART gestations displayed fetal and neonatal outcomes similar to SC pregnancies when analysis was adjusted for relevant confounding factors.Conclusion: Our results suggest that both A-ART and H-ART conception associate with increased odds of operative delivery among diamniotic twin pregnancies in healthy mothers with no chronic diseases or gestational complications. Also, a higher risk of severe postpartum hemorrhage appears to relate to A-ART independent of mode of delivery and maternal age. Further studies with larger series of uncomplicated twin pregnancies are warranted to improve our understanding of the relationship of ART to adverse delivery outcomes.

Risk of preeclampsia following assisted reproductive technology: systematic review and meta-analysis of 72 cohort studies

Objective: Previous studies have indicated that women with assisted reproductive technology (ART) pregnancy have an increased risk of preeclampsia. The aim of this current study was to estimate, through a systematic review and meta-analysis of cohort studies, the risk of preeclampsia in women who conceived with ART.Materials and methods: We searched ISI Web of Knowledge, Medline/PubMed, Scopus and Embase up to August 2017 for English-language articles pertaining to risk of preeclampsia in ART pregnancy using standard keywords. Data extraction was conducted by two authors and quality of the studies was assessed using the Newcastle-Ottawa Scale. A random-effects model was used for the meta-analysis.Results: In total, 72 cohort studies (n = 164 870) were included. The results of Cochran test and I² statistic indicated considerable heterogeneity among studies (Q = 15 415.61, df = 71, p < .001, I²=99.5%). The pooled estimate of preeclampsia risk using the random effects model was 10.8% (95% CI: 9.10-12.5). Furthermore, the funnel plot and Begg's test showed evidence of publication bias.Conclusions: We found that the risk of preeclampsia was very high among women who conceived with ART. Women should be counseled carefully before undergoing ART treatment.

Obstetric Outcomes of Twin Pregnancies in Japanese Women Aged 40 and Older

Background

The aim of this study was to compare the obstetric outcomes of twin pregnancies between Japanese women aged ≥ 40 years and their younger counterparts aged 25 - 29.

Methods

This was a retrospective study of twin pregnancies managed at Japanese Red Cross Katsushika Maternity Hospital between 2002 and 2016. Women aged 40 and older at delivery (n = 117) were compared with women aged 25 - 29 at delivery (n = 536).

Results

Although the women ≥ 40 years old were more likely to have increased risks of HELLP (hemolytic, elevated liver enzymes and low platelet) syndrome and very low birth weight neonates, there were no measurable differences in obstetric outcomes such as hypertensive disorders, premature delivery and neonatal asphyxia between the two groups.

Conclusion

Advanced maternal age did not seem to affect obstetric outcomes in twin pregnancies seriously.

Birth weight discordance and adverse perinatal outcomes

OBJECTIVE

Our purpose was to examine the association between discordant growth and perinatal mortality and morbidity among twins with careful adjustment for maternal confounding factors.

STUDY DESIGN

Two cohorts with and without chorionicity data were compared using generalized estimating modeling.

RESULTS

Our population-based dataset consisted of 12,656 individual twins from whom 4% (452/12,656) had≥30% growth discordance. A subgroup of this population with chorionicity information had an incidence of 7.3%≥30% growth discordance. In growth-discordant twins, perinatal mortality and morbidity were higher than concordant pairs (P<0.01). Low Apgar score and perinatal mortality were more frequent in growth-discordant twins compared with growth-concordant ones (all P<0.01).

CONCLUSION

Birth weight discordance (BWD) places twins at increased risk of perinatal mortality. Growth discordance was also an independent risk factor for lower Apgar score of 5 min less than 5.

Multiple pregnancies following assisted reproductive technologies--a happy consequence or double trouble?

The association between assisted reproduction technologies (ART) and multiple pregnancy is well-established, with a multiple birth rate of 24% in ART pregnancies. Multiple pregnancy is associated with significantly increased maternal and perinatal morbidity and mortality, as well as increased costs to the National Health Service. Evidence relating to the obstetric outcomes of ART twins versus naturally conceived twins is discussed in this review. Methods to reduce the risk of multiple births including elective single embryo transfer and multifetal pregnancy reduction are also discussed.

Degree and rate of growth discordance in dichorionic twins conceived by in vitro fertilization

Objective. Our objective was to estimate degree and rate of discordant growth and its impact on perinatal outcome in dichorionic twin pregnancies conceived by in vitro fertilization (IVF) compared to those conceived spontaneously. Study Design. Growth discordance was defined as 90th percentiles for the study population. Adverse perinatal outcome was defined as 5-minute Apgar score <7 and/or admission to neonatal intensive care unit. Results. In the total study population of dichorionic twins (176 conceived by IVF and 215 spontaneously), 30% discordant growth represented the 90th percentile. After adjusting for gestational age, discordant twins conceived by IVF or spontaneously were at higher risk for adverse perinatal outcome (hazard ratio 4.4; 95% CI 2.4-8.3, P < 0.0001; hazard ratio 2.5; 95% CI 1.5-4.4, P = 0.001, resp.). Similar rates of 5-minute Apgar score <7, admission to neonatal intensive care unit, and delivery <34 weeks were found between discordant twins conceived by IVF and those conceived spontaneously. Conclusion. Dichorionic twins conceived by IVF are at similar risk for the rate and degree of discordant growth and adverse perinatal outcome compared to dichorionic twins conceived spontaneously.

Effect of advanced maternal age on perinatal outcomes in twins: the impact of chorionicity

PURPOSE

In contrast to singletons, twins born to older mothers have lower rates of perinatal mortality than twins born to younger mothers. We examined whether differences in chorionicity could explain this unexpected maternal age effect.

METHODS

We used population-based data on twins born to mothers aged 20-29 (n = 3702) and ≥35 years (n = 1880) in the North of England, UK, 1998-2007. We calculated rate ratios (RR) and 95% confidence intervals (CIs) to estimate the effect of maternal age; adjusted RRs (ARRs) were estimated by the use of generalized estimating equations for Poisson regression controlling for chorionicity and other confounders.

RESULTS

Older mothers had a lower proportion of monochorionic twins (17.6% vs. 24.3%, P < .01); lower neonatal (RR, 0.57; 95% CI, 0.34-0.95) and perinatal mortality (RR, 0.74; 95% CI, 0.53-1.04). Adjustment for chorionicity attenuated these associations (ARR, 0.59; 95% CI, 0.35-0.98 and ARR, 0.80; 95% CI, 0.57-1.12, respectively) and after further adjustment for additional factors, both associations became nonsignificant. Older mothers had greater rates of small-for-gestational-age infants (ARR, 1.59; 95% CI, 1.24-2.05), and cesarean delivery (ARR, 1.31; 95% CI, 1.16-1.48).

CONCLUSIONS

Perinatal death rates were lower but not statistically different for twins born to older versus younger mothers. This association was attenuated by adjustment for chorionicity.

Long-term complications of assisted reproductive technologies

Since the birth of the first baby through in vitro fertilisation over 30 years ago, there has been a rapid increase in the number of women using assisted reproductive technologies. New techniques are constantly being introduced and are evolving rapidly. Understanding the long-term impact of these treatments, which have been linked with several potential complications affecting the mother and the child, poses a constant challenge for the scientific community. The main complications discussed in this review include the rare but serious risk of thromboembolic disease particularly in the upper half of the body and a higher risk of pregnancy complications including abnormal placentation, miscarriage, gestational diabetes and hypertensive disorders. A link between assisted conception and a number of genital cancers particularly of the breast, ovary and endometrium has also been suggested, but the evidence is currently inconclusive. A number of foetal and neonatal complications including imprinting disorders, low birth weight, congenital malformations and growth disorders are also discussed.