Twins born following assisted reproductive technology: perinatal outcome and admission to hospital

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.

Perinatal and pediatric outcomes associated with the use of fertility treatment: a population-based retrospective cohort study in Ontario, Canada

BACKGROUND

Around 2% of births in Ontario, Canada involve the use of assisted reproductive technology (ART), and it is rising due to the implementation of a publicly funded ART program in 2016. To better understand the impact of fertility treatments, we assessed perinatal and pediatric health outcomes associated with ART, hormonal treatments, and artificial insemination compared with spontaneously conceived births.

METHODS

This population-based retrospective cohort study was conducted using provincial birth registry data linked with fertility registry and health administrative databases in Ontario, Canada. Live births and stillbirths from January 2013 to July 2016 were included and followed to age one. The risks of adverse pregnancy, birth and infant health outcomes were assessed by conception method (spontaneous conception, ART - in vitro fertilization and non-ART - ovulation induction, intra-uterine or vaginal insemination) using risk ratios and incidence rate ratios with 95% confidence intervals (CI). Propensity score weighting using a generalized boosted model was applied to adjust for confounding.

RESULT(S)

Of 177,901 births with a median gestation age of 39 weeks (IQR 38.0-40.0), 3,457 (1.9%) were conceived via ART, and 3,511 (2.0%) via non-ART treatments. There were increased risks (adjusted risk ratio [95% CI]) of cesarean delivery (ART: 1.44 [1.42-1.47]; non-ART: 1.09 [1.07-1.11]), preterm birth (ART: 2.06 [1.98-2.14]; non-ART: 1.85 [1.79-1.91]), very preterm birth (ART: 2.99 [2.75-3.25]; non-ART: 1.89 [1.67-2.13]), 5-min Apgar < 7 (ART: 1.28 [1.16-1.42]; non-ART: 1.62 [1.45-1.81]), and composite neonatal adverse outcome indicator (ART: 1.61 [1.55-1.68]; non-ART: 1.29 [1.25-1.34]). Infants born after fertility treatments had increased risk of admission to neonatal intensive care unit (ART: 1.98 [1.84-2.13]; non-ART: 1.59 [1.51-1.67]) and prolonged birth admission (≥ 3 days) (ART: 1.60 [1.54-1.65]; non-ART: 1.42 [1.39-1.45]). The rate of emergency and in-hospital health services use within the first year was significantly increased for both exposure groups and remained elevated when limiting analyses to term singletons.

CONCLUSION(S)

Fertility treatments were associated with increased risks of adverse outcomes; however, the overall magnitude of risks was lower for infants conceived via non-ART treatments.

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.

Cerebral palsy in twins and higher multiple births: a Europe-Australia population-based study

AIM

To describe the birth prevalence, temporal trends, and clinical outcomes of twins, triplets, or quadruplets with cerebral palsy (CP).

METHOD

This was a cross-sectional study using data for twins, triplets, and quadruplets with prenatally or perinatally acquired CP and pooled from the Surveillance of Cerebral Palsy in Europe network (born 1992-2009) and Australian Cerebral Palsy Register (born 1993-2009). Children were at least 4 years old at time of registration. Children born in regions with population ascertainment and available denominator data were included in prevalence calculations (n=1033 twins, 81 triplets, and 11 quadruplets). Clinical data from children registered in all participating registers were described, including 2163 twins (56% male), 187 triplets (59% male), and 20 quadruplets (45% male).

RESULTS

The birth prevalence of CP was higher with increasing plurality (twins 6.5 per 1000 live births [95% confidence interval {CI} 6.1-6.9], triplets 17.1 [95% CI 13.6-21.2], quadruplets 50.7 [95% CI 25.6-88.9]); however, prevalence by gestational age was similar across all pluralities. Between 1992-1994 and 2007-2009, prevalence of CP among twins declined (p=0.001) but prevalence of CP among triplets did not change significantly over time (p=0.55). The distributions of Gross Motor Function Classification System, epilepsy, and impairments of intellect, vision, and hearing were similar regardless of plurality.

INTERPRETATION

The data combined from two CP register networks indicated that triplets and quadruplets had increased risk of CP compared to twins. The higher prevalence of CP in triplets and quadruplets is due to their higher risk of preterm birth. Prevalence of CP among twins significantly declined in Europe and Australia. Clinical outcomes were similar for all multiple births.

Neonatal and maternal outcomes among twin pregnancies stratified by mode of conception in the United States

OBJECTIVE

To compare neonatal and maternal outcomes among twin pregnancies conceived as a result of different types of fertility treatments with those of spontaneously conceived twin pregnancies.

DESIGN

Retrospective Cohort.

SETTING

Population-based analysis.

PATIENT(S)

Population-based analysis of twin pregnancies in the United States based on their mode of conception using the natality data from the National Center for Health Statistics from the Centers for Disease Control and Prevention (from January 2015 through December 2017).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Adverse neonatal and maternal outcomes.

RESULT(S)

The overall prevalence of early adverse maternal outcomes and medical complications and obstetric complications including the risk of unplanned hysterectomy, intensive care unit admission, maternal blood transfusion, and perineal laceration were significantly higher in the fertility treatment group (including both ovulation induction/intrauterine insemination and assisted reproductive technology groups) compared with those of the spontaneous conception group, even after adjusting for several potential confounders. The risk of adverse composite neonatal outcomes was slightly lower in the spontaneous conception live twin birth group even after adjustment for several potential confounders.

CONCLUSION(S)

The rate of maternal and neonatal morbidity in twins conceived via different fertility treatments was slightly increased compared with those of twins conceived spontaneously. Because the absolute risks of maternal and neonatal morbidity were low, overall reassurance regarding these outcomes can be provided to the patients undergoing all types of fertility treatments.

Effect of adenomyosis on adverse obstetrical outcomes in twin pregnancies achieved with assisted reproductive technology

The incidence of twin pregnancy with adenomyosis (AD) is increasing due to advanced maternal age and infertility treatment. We retrospectively analysed the data of 45 dichorionic twin pregnancies complicated with AD in contrast to a control group of dichorionic twin pregnancies without AD (n = 130). Compared with those in the control group, the AD group had a higher overall foetal loss rate (8.9% vs. 0.8%; adjusted p = .031; odds ratio (OR), 13.6; 95% confidence interval (CI), 1.27-146.3), higher early preterm delivery rate (20% vs. 6.9%; adjusted p = .007; OR, 4.22; 95% CI, 1.47-12.13) and higher rate of hypertensive disorders of pregnancy (26.7% vs. 7.7%; adjusted p = .005; OR, 3.94; 95% CI, 1.5-10.2). Patients in the AD group were significantly more likely to require transfusion during or after delivery (17.8% vs. 5.4%; p = .026) and have smaller babies (2168 g vs. 2399 g; p = .004) compared with those in the control group. This is the first study to report that twin pregnancies with AD may be treated as high-risk for placental dysfunction and may need closer monitoring during pregnancy.Impact StatementWhat is already known on this subject? The incidence of twin pregnancy with adenomyosis (AD) is increasing due to advanced maternal age and infertility treatment. However, there are very few studies on the effect of AD on pregnancy outcomes.What the results of this study add? This is the first study to report that twin pregnancies with AD have higher rates of early preterm delivery, hypertensive disorders of pregnancy, and transfusion compared to controls.What the implications are of these findings for clinical practice and/or further research? The results of this study can be used in counselling twin pregnancies with AD. Further research is needed to confirm the current findings.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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 factors for failure in the newborn hearing screen test in very preterm twins

BACKGROUND

We aimed to identify prenatal and postnatal risk factors associated with abnormal newborn hearing screen (NHS) results and subsequently confirmed sensorineural hearing loss (SNHL) in preterm twin neonates.

METHODS

Electronic medical records of 159 twin neonates who were born alive after ≤32 weeks were retrospectively reviewed for hearing loss in both ears. Histopathologic examination of the placenta was performed and clinical data, including method of conception and factors specific to twins, were retrieved from a computerized perinatal database. The main outcome measure was failure to pass the NHS test. The generalized estimation equations model was used for twins.

RESULTS

Thirty-two neonates (20.1%) had a "refer" result, and, on the confirmation test, permanent SNHL was identified in 4.4% (7/159) of all neonates. Neonates who had a "refer" result on the NHS test were more likely to be of lower birth weight, more likely to have been conceived with the use of in vitro fertilization (IVF), and more likely to have higher rates of intraventricular hemorrhage (IVH) and bronchopulmonary dysplasia. However, monochorionic placentation, death of the co-twin, or being born first was not associated with a "refer" result on the NHS test. Multivariable logistic regression revealed that conception after IVF and the presence of IVH were the only variables to be statistically significantly associated with "refer" on the NHS test. No parameters studied were found to be significantly different between the SNHL and no SNHL groups, probably because of the relatively small number of cases of SNHL.

CONCLUSION

In preterm twin newborns, IVF and the presence of IVH were independently associated with an increased risk of abnormal NHS results, whereas the factors specific to twins were not associated with abnormal NHS results.

Do paternal semen parameters influence the birth weight or BMI of the offspring? A study from the Utah Population Database

PURPOSE

To study the role of individual semen parameters on the offspring birth weight and body mass index (BMI) from a population of men evaluated in an assisted reproduction technology (ART) clinic compared to fertile controls.

METHODS

We performed a retrospective study using a cohort with fertile, age-matched controls of men evaluated with semen analysis at the University of Utah Andrology Clinic from 1996 to 2011 and Intermountain Healthcare from 2002 to 2011. We use the offspring from both our sub-fertile cohort and controls using the Utah Population Database. The two main outcomes of interest were offspring birth weight and adolescent BMI.

RESULTS

The offspring of men with impaired sperm parameters had significantly lower birth weight compared to fertile control offspring. Low-concentration offspring weighed 158 g less (95% CI - 278~- 38; p = 0.01), low total count weighed 172 g less (95% CI - 294~- 51; p = 0.005), and low total motility weighed 155 g less (95% CI - 241~- 69; p < 0.001) compared to those of the controls. When we controlled for the use of ART within the sub-fertile group, we found that there was a significant trend of increasing birth weight across levels of total motile count and total sperm count compared to the azoospermic group. We did not find any consistent significant differences between the subject and control adolescence BMI based on semen parameters.

CONCLUSIONS

Despite limitations within our population-based dataset, we found that poor quality semen analysis parameters pointed towards an association with low birth weight in the offspring of sub-fertile men compared to the offspring of normal fertile controls. However, in contrast to studies of ART effects on offspring, we did not find evidence of long-term associations between semen quality and offspring BMI.

Perinatal outcome of monochorionic and dichorionic twins after spontaneous and assisted conception: a retrospective cohort study

Introduction

The aim of this study was to compare pregnancy outcomes in twin pregnancies after assisted conception and spontaneous conception, according to chorionicity.

Material and methods

Retrospective cohort study of 1305 twin pregnancies between 1995 and 2015. All spontaneous (n = 731) and assisted conception conceived (n = 574) twin pregnancies with antenatal care and delivery in University Medical Center Utrecht, the Netherlands, a tertiary obstetric care center were studied according to chorionicity.

Results

Maternal age and incidence of nulliparity were higher among the assisted conception twins. Hypertensive disorders also appeared to be more frequent in assisted conception pregnancies, which could largely be explained by the higher proportion of elderly nulliparous women in this group. Spontaneously conceived twins were born earlier than twins after assisted conception, with subsequent lower birthweights and more admissions to a neonatal intensive care unit with increased neonatal morbidity. Monochorionic twins had worse pregnancy outcomes compared with dichorionic twins, irrespective of mode of conception; monochorionic twins conceived by assisted reproduction had more neonatal morbidity (mainly respiratory distress syndrome and necrotizing enterocolitis) and late neonatal deaths compared with spontaneously conceived monochorionic twins.

Conclusions

Spontaneously conceived twins have worse pregnancy outcome compared with twins after assisted conception, probably due to a lower incidence of monochorionicity in the assisted conception group. The already increased perinatal risks in monochorionic twins are even higher in monochorionic twins conceived after infertility treatments compared with spontaneously conceived monochorionic twins, which warrants extra attention to these high‐risk pregnancies.

Adverse pregnancy, birth, and infant outcomes in twins: effects of maternal fertility status and infant gender combinations; the Massachusetts Outcomes Study of Assisted Reproductive Technology

BACKGROUND

It is unknown whether the risk of adverse outcomes in twin pregnancies among subfertile women, conceived with and without in vitro fertilization, differs from those conceived spontaneously.

OBJECTIVE

We sought to evaluate the effects of fertility status on adverse perinatal outcomes in twin pregnancies on a population basis.

STUDY DESIGN

All twin live births of ≥22 weeks' gestation and ≥350 g birthweight to Massachusetts resident women in 2004 through 2010 were linked to hospital discharge records, vital records, and in vitro fertilization cycles. Women were categorized by their fertility status as in vitro fertilization, subfertile, or fertile, and by twin pair genders (all, like, unlike). Women whose births linked to in vitro fertilization cycles were classified as in vitro fertilization; those with indicators of subfertility but without in vitro fertilization treatment were classified as subfertile; all others were classified as fertile. Risks of 6 adverse pregnancy outcomes (gestational diabetes, pregnancy hypertension, uterine bleeding, placental complications [placenta abruptio, placenta previa, and vasa previa], prenatal hospitalizations, and primary cesarean) and 9 adverse infant outcomes (very low birthweight, low birthweight, small-for-gestation birthweight, large-for-gestation birthweight, very preterm [<32 weeks], preterm, birth defects, neonatal death, and infant death) were modeled by fertility status with the fertile group as reference, using multivariate log binomial regression and reported as adjusted relative risk ratios and 95% confidence intervals.

RESULTS

The study population included 10,352 women with twin pregnancies (6090 fertile, 724 subfertile, and 3538 in vitro fertilization). Among all twins, the risks for all 6 adverse pregnancy outcomes were significantly increased for the subfertile and in vitro fertilization groups, with highest risks for uterine bleeding (adjusted relative risk ratios, 1.92 and 2.58, respectively) and placental complications (adjusted relative risk ratios, 2.07 and 1.83, respectively). Among all twins, the risks for those born to subfertile women were significantly increased for very preterm birth and neonatal and infant death (adjusted relative risk ratios, 1.36, 1.89, and 1.87, respectively). Risks were significantly increased among in vitro fertilization twins for very preterm birth, preterm birth, and birth defects (adjusted relative risk ratios, 1.28, 1.07, and 1.26, respectively).

CONCLUSION

Risks of all maternal and most infant adverse outcomes were increased for subfertile and in vitro fertilization twins. Among all twins, the highest risks were for uterine bleeding and placental complications for the subfertile and in vitro fertilization groups, and neonatal and infant death in the subfertile group. These findings provide further evidence supporting single embryo transfer and more cautious use of ovulation induction.

Risk factors vary early preterm birth and perinatal complications after assisted reproductive technology

We conducted a study of markers of endothelial dysfunction and angiogenesis regulation, as well as the identification of the main lymphocyte populations, activated CD3 ⁺ CD95⁺-cells and cytokine-producing CD4 ⁺ IFN-γ⁺-, CD4 ⁺ IL-4⁺-lymphocytes in the 1st trimester of gestation in women with ART-induced pregnancy and spontaneous pregnancy. We used the same indicators to assess the immune status of ELBW infants at birth and at the post-conceptual age of 38-40 weeks. It was determined that the risk factors of very early preterm delivery are: threatened miscarriage, chronic placental insufficiency, endothelial dysfunction, increased spontaneous production of intracellular cytokines. Adverse perinatal outcomes in ELBW infants from ART-induced pregnancy are associated with lower anthropometric measures, low Apgar scores high level of inflammatory infections (pneumonia), grade II intraventricular hemorrhage, movement disorders in the form of lower paraparesis. Immune status of those infants is characterized by the increase in the number of CD8⁺- and CD3^-CD16 ⁺ CD56⁺-lymphocytes, the expression level of Fas-receptor by T-cells, and the increased production of intracellular and serum IFNγ against the decrease in the number of CD4⁺-cells, which indicates enhancing of cytotoxic effector potential and proinflammatory orientation of cell responses.

Dizygotic twin pregnancies after medically assisted reproduction and after natural conception: maternal and perinatal outcomes

OBJECTIVE

To compare maternal and perinatal outcomes in dizygotic twin pregnancies conceived after medically assisted reproduction (MAR) with outcomes after natural conception (NC).

DESIGN

Nationwide registry based study.

SETTING

Academic medical center.

PATIENT(S)

Primiparous women who delivered opposite sex twins between January 2000 and December 2012 in the Netherlands, comprising dizygotic twin pregnancies: 6,694 women, 470 after ovulation induction (OI), 511 after intrauterine insemination with controlled ovarian hyperstimulation (IUI-COH), 2,437 after in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI), and 3,276 after NC.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Multivariable logistic regression and generalized linear mixed models to evaluate differences in outcomes: maternal outcomes of hypertension, preeclampsia, preterm delivery, hemorrhage, and delivery mode, perinatal outcomes including small for gestational age (SGA) with birth weight <10th percentile, birth weight <1,500 g, 5-minute Apgar score <7, admission to neonatal intensive care unit, congenital anomalies, and perinatal mortality.

RESULT(S)

We found no statistically significant differences in maternal or perinatal outcomes after OI compared with NC. Women pregnant after IVF-ICSI had a lower risk for hypertension (adjusted odds ratio [aOR] 0.74; 95% confidence interval [CI], 0.66-0.83) compared with women pregnant after NC. After IUI-COH more children had Apgar scores <7 (adjusted odds ratio (aOR) 1.38; 95% confidence interval (CI) 1.05-1.81) and perinatal mortality rates were higher (aOR 1.56; 95% CI, 1.04-2.33) compared with NC. We found no differences in perinatal outcomes after IVF-ICSI compared with NC.

CONCLUSION(S)

Overall, maternal and perinatal risks other than those due to multiplicity are similar for twin pregnancies conceived after MAR and after NC.

Nutritional advice for improving outcomes in multiple pregnancies

BACKGROUND

Multiple pregnancies are associated with higher rates of perinatal mortality and morbidity than singleton pregnancies, mainly due to an increased risk of preterm birth. Because fetal outcome is best at a particular range of maternal weight gain, it has been suggested that women with multiple pregnancies should take special diets (particularly high-calorie diets) designed to boost weight gain. However, 'optimal weight gain' in the mother in retrospective studies may merely reflect good growth of her babies and delivery at or near term (both associated with a good outcome) and artificially boosting weight gain by nutritional input may confer no advantage. Indeed, a high-calorie diet may be unpleasant to consume, and could lead to long-term problems of being overweight. It is therefore important to establish if specialised diets are actually of benefit to women with multiple pregnancies and their babies.

OBJECTIVES

To assess the effects of specialised diets or nutritional advice for women with multiple pregnancies (two or more fetuses).

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (15 June 2015).

SELECTION CRITERIA

Randomised controlled trials, 'quasi-random' studies, and cluster-randomised trials of women with multiple pregnancies (two or more fetuses) either nulliparous or multiparous and their babies. Cross-over trials and studies reported only as abstracts were not eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We identified no trials for inclusion in this review.

MAIN RESULTS

A comprehensive search of the Cochrane Pregnancy and Childbirth Group's Trials Register found no potentially eligible trial reports.

AUTHORS' CONCLUSIONS

There is no robust evidence from randomised trials to indicate whether specialised diets or nutritional advice for women with multiple pregnancies do more good than harm. There is a clear need to undertake a randomised controlled trial.

Health and disease in children born after assistive reproductive therapies (ART

In vitro fertilisation (IVF) and other assisted reproductive therapies (ART) offer hope to subfertile couples worldwide. At least 5 million ART children have been born to date. Their health is an issue that is increasingly relevant: first, to those children and young adults themselves; second, to couples considering fertility treatment; and third, to the general population as ART has progressed from experimental treatment to routine practice. Many concerns about the potential risks to these children have been voiced with varying degrees of supportive evidence. This article summarises some key long-term data. Current evidence suggests that ART does increase risk of: higher order pregnancy (with its inherent pre- and perinatal risks); prematurity and low birth weight; congenital malformations in particular of the male urogenital system; imprinting disorders. Reassuringly, evidence points away from an increased overall cancer risk or differences in neurodevelopmental outcomes. Many unknowns remain, including future fertility and cardiovascular risks and risk of cerebral palsy.

Triplet Pregnancy: Is the Mode of Conception Related to Perinatal Outcomes?

Many triplets are conceived as a consequence of assisted reproductive technology (ART). Concerns have been raised that triplet pregnancies conceived by ART are more complicated than those conceived spontaneously. The purpose of this study was to evaluate all triplet pregnancies managed over a 12-year period to determine if there were any differences in outcome based on the mode of conception. All triplet pregnancies between 1999 and 2011 that reached at least 20 weeks’ gestation and that were managed at the Royal Women's Hospital (RWH), Melbourne, Victoria were identified. Maternal and neonatal outcomes were compared between ART conceived and spontaneously conceived triplets. In the study period, 53 sets of triplets managed in our institution met the eligibility criteria. Twenty-five triplet sets were conceived by ART and 28 were conceived spontaneously. More ART conceptions resulted in trichorionic triamniotic (TCTA) triplets than did spontaneous conceptions (p= .015). There were no differences between ART and spontaneously conceived triplets for any of the maternal or neonatal complications studied. Trichorionic (TC) triplets delivered at a later gestation than other triplets: 32.1 (SD2.9) versus 30.4 (SD3.9) weeks (p= .08). TC triplets were significantly less likely to die than monochorionic (MC) or dichorionic (DC) triplets: 3/93 (3%) versus 13/66 (20%) (p= .025). In conclusion, triplets conceived by ART are more likely to have TCTA placentation and TCTA triplet sets had lower mortality rates than other triplet combinations. Outcomes for triplets conceived by ART were similar to those of triplets conceived spontaneously.

Pregnancy Complications and Neonatal Outcomes in Multiple Pregnancies: A Comparison between Assisted Reproductive Techniques and Spontaneous Conception

Background

This study compared neonatal outcome and maternal complications in multiple pregnancies after assisted reproductive technologies (ART) to spontaneous pregnancies.

Materials and Methods

In this cross-sectional study, we reviewed medical records of 190 multiple pregnancies and births conceived by ART or spontaneous conceptions between 2004 and 2009 in Women Hospital. Obstetric history and outcomes were recorded and compared between these two groups. SPSS version 13 was used for data analysis. The results were analyzed using student’s t test, chi square and logistic regression (p<0.05).

Results

There were 106 deliveries from spontaneous conceptions and 84 that resulted from ART. Parity history and mode of delivery significantly differed between the two groups (p<0.001). The ART group had significantly higher preterm labor and premature rupture of membranes (PROM) whereas pregnanc-induced hypertension (PIH) was higher in the spontaneous group (p=0.01). Newborn intensive care unit (NICU) admission, duration of hospitalization, still birth and low gestational age were significantly higher in the ART group while neonatal jaundice was higher in the spontaneous group. Logistic regression analysis by considering neonatal complications as the dependent variable showed that respiratory distress syndrome (RDS), NICU admission and Apgar score were independent predictors for neonatal complications.

Conclusion

Obstetric and neonatal outcomes must be considered in multiple pregnancies conceived by ART.

Assisted reproductive technology and somatic morbidity in childhood: a systematic review

OBJECTIVE

To assess whether children conceived by assisted reproductive technology are at increased risk of somatic morbidity in childhood compared with spontaneously conceived children.

DESIGN

Systematic review.

SETTING

None.

PATIENT(S)

Children conceived by assisted reproductive technology and reference groups of spontaneously conceived children or children from the background population.

INTERVENTION(S)

Medline/Pubmed, Embase, and the Cochrane Library were searched as well as reference lists of the retrieved relevant studies. Only cohort studies and case-control studies were included. All studies were scored using the Newcastle-Ottawa scale to assess study quality and the risk of bias in the individual studies.

MAIN OUTCOME MEASURE(S)

Postneonatal somatic diseases, health care use, chronic illnesses (unspecified), surgery, use of medication, and mortality.

RESULT(S)

Thirty-eight studies were included. Results indicated that children conceived by assisted reproductive technology may be at increased risk of unspecified infectious and parasitic diseases, asthma, genitourinary diseases, epilepsy or convulsions, and longer hospitalizations. However, several results in individual studies were not statistically significant and some inconsistency existed between study results. No differences between groups were found regarding hospital admission, outpatient visits, or use of medication. Results regarding mortality, unspecified cancer, pneumonia, allergy, respiratory, and gastrointestinal diseases were contradictory. When considering only the 13 studies allocated the highest score on the Newcastle-Ottawa scale, similar results were found.

CONCLUSION(S)

Children conceived by assisted reproductive technology may be at increased risk of somatic morbidity in childhood compared with spontaneously conceived children, although some inconsistency exists between study results.

Is the flexible GnRH antagonist protocol better suited for fresh eSET cycles?

OBJECTIVE

This study was performed to evaluate the efficacy of the flexible GnRH antagonist protocol in comparison with the long GnRH agonist protocol in elective single embryo transfer (eSET) practice. It was conducted in a publicly funded in vitro fertilization program.

METHODS

We performed a prospective cohort analysis of data from a private infertility clinic from August 2010 to August 2011. Three hundred fourteen women with normal ovarian reserve and undergoing fresh eSET cycles were included. Sixty-four women underwent follicular stimulation using a flexible GnRH antagonist protocol, and 250 underwent stimulation with a standard long mid-luteal GnRH agonist protocol.

RESULTS

Implantation rates (35.9% in the GnRH antagonist group and 29.6% in the GnRH agonist group, P = 0.5) and ongoing pregnancy rates (32.8% in the GnRH antagonist group and 28.8% in the GnRH agonist group, P = 0.5) were equivalent in both groups. The duration of stimulation (9.8 ± 2 days vs. 10.7 ± 1.8 days, P < 0.001) and total FSH dose required (2044 vs. 2775 IU, P < 0.001) were lower in the GnRH antagonist group than in the GnRH agonist group. The number of mature oocytes (6.0 vs. 10.0, P < 0. 001) and number of embryos (5.0 vs. 7.0, P < 0.001) were also lower in GnRH antagonist group. However, the number of embryos cryopreserved was similar in both groups (median 2.0, P = 0.3).

CONCLUSION

In women undergoing in vitro fertilization, the flexible GnRH antagonist protocol yields implantation and ongoing pregnancy rates that are similar to the long GnRH agonist protocol, and requires lower doses of gonadotropins and a shorter duration of treatment. The flexible GnRH antagonist protocol appears to be the protocol of choice for an eSET IVF program.

The risk of neurodisability and other long-term outcomes for infants born following ART

Children born after assisted reproductive technologies (ART) have an increased morbidity. The risk of developing cerebral palsy is nearly doubled and the risk of developing epilepsy is also higher. Behavioural problems including attention deficit/hyperactivity disorder may be more common in children born following ART than among naturally conceived children but the finding is uncertain. Data on autism are difficult to interpret. There may exist a small increase in the incidence of childhood cancer and there is greater evidence of an elevated risk of asthma. To some extent, these risks are mediated by neonatal complications including prematurity and low birth weight but some effects such as cerebral palsy are likely to be linked to the increased rate of multiple births after ART. Many of the neonatal complications after ART are most likely linked to parental subfertility and are less an effect of the ART technology. The possibility exists that imprinting errors, associated with subfertility and/or ART, may result in long-term morbidity.

The economic implications of multiple pregnancy following ART

The clinical risks to mothers and babies associated with assisted reproductive technology (ART) multiple birth pregnancies are well described and widely recognized. In contrast, the long-term economic consequences that follow are less appreciated. The few economic analyses that do exist consistently demonstrate the greater patient, healthcare and societal costs associated with twins and higher-order multiples when compared with singleton infants, and convincingly add to the argument that single embryo transfer should be standard practice in most patient groups. Several recent studies have shown that the relative price paid by patients for ART treatment not only has implications for who can afford to access treatment, but also plays an important role in incentivizing embryo transfer practices and thus ART multiple birth rates. This review summarizes the current literature on the costs and consequences of ART multiple births, the contribution of ART multiple births to the economic burden associated with preterm birth, the evidence for the cost-effectiveness of single embryo transfer, and the association between the cost of treatment and the downstream costs associated with multiple births.

Obstetric and perinatal outcome of babies born from vitrified oocytes

OBJECTIVE

To assess outcomes after oocyte vitrification on obstetric and perinatal outcomes compared with those achieved with fresh oocytes.

DESIGN

Retrospective cohort study.

SETTING

Private university-affiliated IVF center.

PATIENT(S)

Children born after use of vitrified oocytes (1,027 from 804 pregnancies) and fresh oocytes (1,224 from 996 pregnancies). Singleton and multiples pregnancies from own and donated ova were included.

INTERVENTION(S)

Oocyte vitrification by the Cryotop method.

MAIN OUTCOME MEASURE(S)

Pregnancy, delivery, and neonatal outcomes.

RESULT(S)

Vitrification had no clinically relevant adverse effects on obstetric and perinatal outcomes after adjusting for potential confounders. No differences were found between the vitrified and fresh oocyte groups in the rate of obstetric problems (including diabetes, pregnancy-induced hypertension, preterm birth, anemia, and cholestasis), gestational age at delivery, birth weight, Apgar scores, birth defects, admission to neonatal intensive care unit (ICU), perinatal mortality, and puerperal problems. Only a greater number of invasive procedures (adjusted odds ratio 2.12; 95% confidence interval 1.41-3.20), and a reduced occurrence of urinary tract infection (adjusted odds ratio 0.51; 95% confidence interval 0.28-0.91), were observed in the vitrified oocytes group.

CONCLUSION(S)

Although our data, the largest series to date, suggest that oocyte vitrification does not increase adverse obstetric and perinatal outcomes in children conceived with vitrified oocytes, further studies with larger samples are required to reinforce our conclusions.

Birthweight percentiles by gestational age for births following assisted reproductive technology in Australia and New Zealand, 2002-2010

STUDY QUESTION

What is the standard of birthweight for gestational age for babies following assisted reproductive technology (ART) treatment?

SUMMARY ANSWER

Birthweight for gestational age percentile charts were developed for singleton births following ART treatment using population-based data.

WHAT IS KNOWN ALREADY

Small for gestational age (SGA) and large for gestational age (LGA) births are at increased risks of perinatal morbidity and mortality. A birthweight percentile chart allows the detection of neonates at high risk, and can help inform the need for special care if required.

STUDY DESIGN, SIZE, DURATION

This population study used data from the Australian and New Zealand Assisted Reproduction Database (ANZARD) for 72 694 live born singletons following ART treatment between January 2002 and December 2010 in Australia and New Zealand.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 69 315 births (35 580 males and 33 735 females) following ART treatment were analysed for the birthweight percentile. Exact percentiles of birthweight in grams were calculated for each gestational week between Week 25 and 42 for fresh and thaw cycles by infant sex. Univariate analysis was used to determine the exact birthweight percentile values. Student t-test was used to examine the mean birthweight difference between male and female infants, between single embryo transfer (SET) and double embryo transfer (DET) and between fresh and thaw cycles.

MAIN RESULTS AND THE ROLE OF CHANCE

Preterm births (birth before 37 completed weeks of gestation) and low birthweight (<2500 g) were reported for 9.7 and 7.0% of live born singletons following ART treatment. The mean birthweight was 3280 g for live born singletons following fresh cycles (3338 g for male infants and 3217 for female infants) and 3413 g for live born singletons following thaw cycles (3475 g for male infants and 3349 for female infants). The proportion of SGA for male ART births following thaw cycles at 35-41 weeks gestation was significantly lower than for the Australian general population, ranging from 3.8% (95% confidence interval (CI): 1.3%, 6.2%) at 35 weeks gestation to 7.9% (95% CI: 6.3%, 9.5%) at 41 weeks gestation. The proportion of LGA for male ART births following thaw cycles was significantly higher than for the Australian general population between 33 weeks (17.1%, 95% CI: 8.9%, 25.2%) and 41 weeks (14.4%, 95% CI: 12.3%, 16.5%). A similar trend was shown for female infants following thaw cycles. The live born singletons following SET were, on average, 45 g heavier than live born singletons following DET (P< 0.001). Overall, SGA was reported for 8.9% (95% CI: 8.6%, 9.1%) of live born singletons following SET and for 9.9% (95% CI: 9.5%, 10.3%) of live born singletons following DET.

LIMITATIONS, REASONS FOR CAUTION

Birthweight percentile charts do not represent fetal growth standards but only the weight of live born infants at birth.

WIDER IMPLICATIONS OF THE FINDINGS

The comparison of birthweight percentile charts for ART births and general population births provide evidence that the proportion of SGA births following ART treatment was comparable to the general population for SET fresh cycles and significantly lower for thaw cycles. Both fresh and thaw cycles showed better outcomes for singleton births following SET compared with DET. Policies to promote single embryo transfer should be considered in order to minimize the adverse perinatal outcomes associated with ART treatment.

STUDY FUNDING/COMPETING INTERESTS

No specific funding was obtained. The authors have no conflicts of interest to declare.

Methodology for establishing a population-based birth cohort focusing on couple fertility and children's development, the Upstate KIDS Study

BACKGROUND

Critical data gaps remain regarding infertility treatment and child development. We assessed the utility of a birth certificate registry for developing a population cohort aimed at answering such questions.

METHODS

We utilised the Upstate New York livebirth registry (n = 201,063) to select births conceived with (n = 4024) infertility treatment or exposed infants, who were then frequency-matched by residence to a random sample of infants conceived without (n = 14,455) treatment or unexposed infants, 2008-10. Mothers were recruited at 2-4 months postpartum and queried about their reproductive histories, including infertility treatment for comparison with birth certificate data. Overall, 1297 (32%) mothers of exposed and 3692 of unexposed (26%) infants enrolled.

RESULTS

Twins represented 22% of each infant group. The percentage of infants conceived with/without infertility treatment was similar whether derived from the birth registry or maternal report: 71% none, 16% drugs or intrauterine insemination, and 14% assisted reproductive technologies (ART). Concordant reporting between the two data sources was 93% for no treatment, 88% for ART, and 83% for fertility drugs, but differed by plurality. Exposed infants had slightly (P < 0.01) earlier gestations than unexposed infants (38.3 ± 2.8 and 38.7 ± 2.7 weeks, respectively) based upon birth certificates but not maternal report (38.7 ± 2.7 and 38.7 ± 2.9, respectively). Conversely, mean birthweight was comparable using birth certificates (3157 ± 704 and 3194 ± 679 g, respectively), but differed using maternal report (3167 ± 692 and 3224 ± 661, respectively P < 0.05).

CONCLUSIONS

The birth certificate registry is a suitable sampling framework as measured by concordance with maternally reported infertility treatment. Future efforts should address the impact of factors associated with discordant reporting on research findings.

Perinatal and somatic growth properties of preterm babies born from spontaneous and in vitro fertilization multiple pregnancies

AIM

The objective of this study was to examine perinatal and neonatal properties of preterm infants with a corrected age of 24-36 months who were born as a result of spontaneous and in vitro fertilization multiple pregnancies, to interrogate somatic growth properties of these infants and evaluate the factors which had an impact by comparing groups.

MATERIAL AND METHODS

A total of 125 children with a birth weight below 2 500 g and a gestational age below the 37(th) gestational week 60 of whom were born as a result of in vitro fertilization multiple pregnancies and 65 of whom were born as a result of spontaneous multiple pregnancies were included in the study. Maternal age and morbidity, early rupture of membranes, birth weigth, gestational week, gender, APGAR score, hospitalization reasons in the neonatal period, requirement for intensive care, frequency of congenital anomaly, outpatient follow-up status, rehospitalization and socioeconomic levels were interrogated in the patients. Detailed physical examination and current height, weight and head circumference measurements were performed and the findings were placed in the growth curves of Neyzi et al. Ethics committee approval was received for this study from the ethics committee of Bakırköy Gynecology Obstetrics and Pediatrics Education and Research Hospital (12.10.2010; no:305).

RESULTS

The rate of cesarean section, mean maternal age, the rate of chronic disease in the mother and the rate of maternal disease which occured during pregnancy were significantly higher in the in vitro fertilization group (p<0.05). While no difference was found in mean gestational age, birth weight, rate of hospitalization, time of hospitalization, frequency of follow-up in the intensive care unit, rates of congenital anomaly and rehospitalization, APGAR score in the 5(th) minute was significantly higher in the in vitro fertilization group. The socioeconomical score was not different between the groups, but the in vitro fertilization group presented more regularly for outpatient follow-up visits. Height, head circumference measurements and mean current weight were found to be significantly higher in the in vitro fertilization group (p<0.05).

CONCLUSION

The fact that there was no difference in the rate of hospitalization, time of hospitalization, frequency of follow-up in the intensive care unit, rates of congenital anomaly and rehospitalization was attributed to the fact that the study and control groups were composed of only multiple pregnancies and preterms.

Maternal and perinatal outcomes in spontaneous versus assisted conception twin pregnancies

OBJECTIVE

To compare maternal and perinatal outcomes in twin pregnancies conceived via assisted reproductive techniques (ART) compared with spontaneous twin pregnancies.

STUDY DESIGN

This retrospective study examined 345 dichorionic, di-amniotic twin pregnancies (207 conceived spontaneously and 138 conceived via ART), delivered between January 2007 and June 2011 at the San Pietro Fatebenefratelli Hospital, Rome, a tertiary medical centre. Maternal and perinatal outcomes were compared. A multiple logistic regression analysis was performed to calculate risk estimates as odds ratios (OR) adjusted for maternal age, parity and systemic diseases. Patient data were obtained from a computerized database and analyzed using Statistical Package for the Social Sciences Version 17.

RESULTS

Gestational age and birth weight were lower in the ART group, and preterm delivery, gestational diabetes and placental abruption were higher in the ART group compared with the spontaneous conception group. The incidence rates of respiratory complications, patent ductus arteriosus and admission to the neonatal intensive care unit were higher among ART newborns. Length of hospital stay for mothers and newborns was longer in the ART group. No differences in mode of delivery, Apgar score at 5min, congenital anomalies, perinatal mortality, and other considered pregnancy and neonatal complications were found between the two groups. Multivariate analysis adjusted for maternal age, parity and systemic diseases revealed that only the rates of placental abruption [OR 7.45, 95% confidence interval (CI) 2.05-26.98] and patent ductus arteriosus (OR 3.39, 95% CI 1.01-11.46) were significantly higher for the ART group.

CONCLUSIONS

Twin pregnancies conceived via ART are at greater risk of poorer outcomes than spontaneous twin pregnancies. This may be related to the type of conception and specific negative features of subfertile patients undergoing infertility treatment.

Relationship of mode of conception and sex concordance with mortality/morbidity in preterm twins

OBJECTIVE

To assess the association of mode of conception and sex concordance with neonatal outcomes in very preterm twins.

STUDY DESIGN

Twin pairs born at gestational age ≤ 32 weeks and admitted to a Level 3 neonatal intensive care unit (NICU) in 2010-2011 were retrospectively identified from the Canadian Neonatal Network™ database. A composite outcome representing neonatal mortality or any severe morbidity (intraventricular hemorrhage grades ≥ 3 or periventricular leukomalacia, retinopathy of prematurity stages ≥ 3, bronchopulmonary dysplasia, or necrotizing enterocolitis stages ≥ 2) was compared between twins conceived using assisted reproduction technologies (ARTs) or spontaneously (SP), and tested for association with sex concordance in individual-level and pair-wise multivariable logistic regression analyses.

RESULTS

Study subjects included 1,508 twins from 216 ART (53 [25%] male-male, 104 [48%] male-female, and 59 [27%] female-female) and 538 SP (192 [36%] male-male, 123 [23%] male-female, and 223 [41%] female-female) pairs. No statistically significant association was detected between mode of conception and the composite outcome of mortality/morbidities. The composite outcome was significantly higher in same-sex than in opposite-sex twins (OR = 1.68; 95% CI = [1.09, 2.59]). This relationship was most pronounced in ART pairs (OR = 2.25; 95% CI = [1.02, 4.98]), with increased rates in one or both twins from male-male versus opposite-sex ART pairs (OR = 3.0; 95% CI = [1.07, 8.36]).

CONCLUSION

Same-sex pairing was associated with higher mortality/morbidities in very preterm twins admitted to the NICU, and can be used in clinical practice to identify twins at higher risk of adverse neonatal outcomes.

Long-term follow-up of children conceived through assisted reproductive technology

Children conceived via assisted reproductive technologies (ART) are nowadays a substantial proportion of the population. It is important to follow up these children and evaluate whether they have elevated health risks compared to naturally conceived (NC) children. In recent years there has been a lot of work in this field. This review will summarize what is known about the health of ART-conceived children, encompassing neonatal outcomes, birth defects, growth and gonadal developments, physical health, neurological and neurodevelopmental outcomes, psychosocial developments, risk for cancer, and epigenetic abnormalities. Most of the children conceived after ART are normal. However, there is increasing evidence that ART-conceived children are at higher risk of poor perinatal outcome, birth defects, and epigenetic disorders, and the mechanism(s) leading to these changes have not been elucidated. Continuous follow-up of children after ART is of great importance as they progress through adolescence into adulthood, and new ART techniques are constantly being introduced.

Assisted reproductive technologies and children's neurodevelopmental outcomes

Initial reports suggested that children conceived with assisted reproductive technologies (ART) may be at increased risk for a spectrum of developmental disabilities. Evolving evidence suggests that some of the early risks may have been overstated when not taking plurality of birth or gestational age at delivery into consideration, as both are independent risk factors for neurodevelopmental disabilities arising from alterations in structure and function or limitations in activities. Continued research is needed to overcome lingering data gaps in light of the equivocal literature for many neurodevelopmental disabilities relative to ART, increasing utilization of services, and changes in the clinical management of infecund couples such as the adoption of natural cycles or in vitro maturation treatment options. Population-based cohorts with longitudinal assessment of the multifaceted nature of neurodevelopment across critical and sensitive windows is paramount for the development of empirically based guidance for clinical and population health.

The longer-term health outcomes for children born as a result of IVF treatment: Part I--General health outcomes

BACKGROUND Several million children have been born from in vitro fertilization (IVF) treatment, but limited data exist regarding their health and development beyond the first year of life. It has been alleged that IVF may lead to long-term adverse consequences, in addition to the documented worse perinatal outcome and increased risk of congenital abnormalities in children born resulting from IVF treatment. METHODS A search strategy restricted to studies relating to the medical condition of children of at least 1 year of age born as a result of IVF treatment was performed to include case series, data linkage and prospective studies published 1 January 2000-1 April 2012. RESULTS Limited long-term follow-up data suggest that there is potentially an increase in the incidence of raised blood pressure, elevated fasting glucose, increase in total body fat composition, advancement of bone age and potentially subclinical thyroid disorder in the IVF offspring. Whether these potential associations are related to the IVF treatment per se, the adverse obstetric outcomes associated with IVF treatment or are related to the genetic origin of the children is yet to be determined. CONCLUSIONS This review provides evidence to suggest that the short-term health outcome for children born from IVF treatment is positive. However, it is expected that the cardiovascular and metabolic risk factors found in childhood and tracking into adulthood could be worse in later life, and may be responsible for chronic cardiometabolic disease. These observations need to be addressed by further studies.

Reproductive outcomes after assisted conception

The last three decades have witnessed a dramatic increase in the use of assisted reproductive technology (ART) so that now, in developed countries, 1.7% to 4.0% of all children are born after ART. Although absolute risks appear small, data from prospective and retrospective studies indicate increased risks of adverse maternal and perinatal outcomes after ART as compared with spontaneous conception. Recent studies suggest that underlying maternal factors and subfertility play an important role in some of these outcomes rather than the ART procedure itself. A significant risk of assisted conception is multiple pregnancies, but even singleton pregnancies achieved by ART are at a higher risk of hypertensive disease, diabetes, prematurity, low birth weight, and perinatal mortality even after adjusting for confounders. Couples undergoing ART procedures should be counseled in advance regarding increased risks of pregnancy complications and higher rates of obstetric interventions. Although conflicting data exist, studies of children born from ART suggest increased rates of congenital malformations, imprinting disorders (Beckwith-Wiedemann syndrome and Angelman syndrome), and marginally increased risk of cancer. However, the current evidence is inadequate, and prospective long-term studies are needed to eliminate the effect of confounders and draw definite conclusions about the long-term outcomes after ART. The absolute risk of imprinting disorders remains small, and routine screening is not recommended at present. The long-term outcomes after ART are difficult to evaluate because of the variability in ART methods and data reporting, and there is a need for standardized methodology for follow-up after ART.

Elective single-embryo transfer in women aged 40-44 years

STUDY QUESTION

Is an elective single-embryo transfer (eSET) policy feasible for women aged 40 or older?

SUMMARY ANSWER

For older women (aged 40-44 years) with a good prognosis, an eSET policy can be applied with acceptable cumulative clinical pregnancy rates and live birth rates.

WHAT IS KNOWN ALREADY

Various studies have shown the effectiveness of eSET in women aged <35 years with high cumulative pregnancy rates and low rates of multiple births.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study included 628 women treated between 2000 and 2009.

PARTICIPANTS, SETTING, METHODS

Women aged 40-44 years underwent a fresh cycle of IVF or ICSI treatment with eSET (n = 264) or double-embryo transfer (DET) (n = 364). In the subsequent frozen-thawed embryo transfer cycles, SET/DET was performed in both groups according to the number of embryos available and the opinion of the couple. The study was performed at the Family Federation of Finland Helsinki Fertility Clinic.

MAIN RESULTS AND THE ROLE OF CHANCE

In the fresh cycles, the clinical pregnancy rates were 23.5 and 19.5% in the eSET and DET groups, respectively, and live birth rates were 13.6 and 11.0%, respectively. In the fresh cycles with eSET, there were no twin pregnancies, but in the DET group, there were three sets of twins (7.5%). The cumulative clinical pregnancy rates per oocyte retrieval were 37.1 and 24.2% in the eSET and DET groups, respectively (P < 0.001), and the cumulative live birth rates were 22.7 and 13.2%, respectively (P = 0.002). Cumulative twin rates were 6.7% (n = 4) in the eSET group and 8.3% (n = 4) in the DET group (P = 0.726). All of the twin pregnancies in the eSET group resulted from frozen and thawed DET embryo transfer cycles.

LIMITATIONS

The characteristics of the two patients groups are not comparable because the suitability of eSET was individually assessed by a clinician based on both clinical prognostic factors and the outcome of IVF or ICSI, i.e. the number and quality of embryos.

WIDER IMPLICATIONS OF THE FINDINGS

This study may be generalized to IVF units having experience in eSET and cryopreservation.

Multiple births associated with assisted human reproduction in Canada

OBJECTIVE

Assisted human reproduction has been associated with increased rates of multiple births. Data suggest that twins and higher order multiple pregnancies are at risk for pre- and postnatal health complications that contribute to stress on both the family and the Canadian health care system. No published Canadian data estimate the contribution of assisted human reproduction to multiple birth rates. This study was designed to determine the contributions of age and assisted human reproduction to multiple birth rates in Canada.

METHODS

We performed analyses of existing Canadian databases, using a mathematical model from the Centers for Disease Control and Prevention. More specifically, data from the Canadian Vital Statistics: Births and Stillbirths database were combined with data from the Canadian Assisted Reproductive Technologies Register collected by the Canadian Fertility and Andrology Society. Datasets were standardized to age distributions of mothers in 1978.

RESULTS

RESULTS suggest that in vitro fertilization, ovulation induction, and age each contribute more to the rates of triplets than to twins. As expected, the contribution of natural factors was higher to twins than to triplets.

CONCLUSION

These are the first Canadian data analyzed to separate and measure the contributions of age and assisted reproductive technologies to multiple birth rates. Our findings are important for guiding physician and patient education and informing the development of treatment protocols that will result in lower-risk pregnancies and improved long-term health for women and their offspring.

Atopic diseases in twins born after assisted reproduction

We examined the risk of atopic diseases in twins born after assisted reproduction. Data on atopic diseases and assisted reproduction in 9694 twin pairs, 3-20 years of age, from the Danish Twin Registry were collected via multidisciplinary questionnaires. The risk of atopic diseases in twins born after assisted reproduction was compared with the risk in twins born after spontaneous conception using logistic regression and variance components analysis. Children born after assisted reproduction did not have a different risk of atopic outcomes (adjusted odds ratios [95% confidence intervals] for asthma: 0.95 [0.85, 1.07], P = 0.403; hay fever: 1.01 [0.86, 1.18], P = 0.918; and atopic dermatitis: 1.02 [0.81, 1.11], P = 0.773 respectively) compared with children born after spontaneous conception. Assisted reproduction did not modify the heritability of atopic diseases. This study does not support an association between assisted reproduction and development of atopic diseases. This result must be confirmed in subsequent studies, preferably of singleton populations.

Obstetric and Perinatal Outcomes of Dichorionic Twin Pregnancies According to Methods of Conception: Spontaneous Versus In-Vitro Fertilization

We have observed the inconsistent findings from various studies on twin pregnancy outcomes obtained by assisted reproductive technology and spontaneous conception. In most studies, however, the concrete chorionicity, regarded as a confounding factor for predicting the perinatal outcomes of twin pregnancies, has not been determined. The purpose of this study was to compare obstetric and perinatal outcomes of only the dichorionic twin pregnancies according to the methods of conception: spontaneous and in-vitro fertilization (IVF). The twin pairs with dichorionicity reported from 1995 to 2008 were investigated and we divided them into two groups which consisted of 286 and 134 twins by spontaneous conception and IVF, respectively. Odds ratios for associations between IVF and pregnancy outcomes were analyzed after adjustment for maternal age and parity. There were no risk differences between the two groups regarding the obstetric complications, which include preterm delivery, preterm labor, preterm premature rupture of membranes, preeclampsia, placenta previa, and abruption. Any differences were not shown in the two groups for the risk estimates of perinatal outcomes, such as low birthweight, very low birthweight, small for gestational age, Apgar scores of < 7 at 5 minutes, discordance in birthweights, congenital anomalies and mortality. However, twins conceived after IVF were less likely to be admitted to the neonatal intensive care unit than those conceived spontaneously (adjusted OR 0.488; 95% confidence interval 0.261–0.910). In the cases of dichorionic twins, IVF may not be associated with adverse perinatal and obstetric outcomes compared with spontaneous conception.