Long-term outcomes in multiple gestations

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comparison of neonatal outcomes between multiples and singletons among very low birth weight infants: the Korean Neonatal Network cohort study

OBJECTIVE

To compare neonatal outcomes between multiples and singletons among very low birth weight infants, this was a prospective cohort study that was conducted by collecting data registered in the Korean Neonatal Network database.

METHODS

From January 2013 to December 2016, there were 8265 infants in the Korean Neonatal Network database, and 2958 of them were from multiples. Among them, 2636 infants were twins, 308 infants were triplets, and 14 infants were quadruplets. Maternal and neonatal variables including and mortality major morbidity were compared. Finally, the predicted rates of major morbidity between singletons and multiples.

RESULTS

Multiples had higher gestational age, birth weight, Apgar score at 5 min, rates of cesarean section and artificial reproductive technology but lower maternal hypertension, oligohydramnios, chorioamnionitis rates and Clinical Risk Index for Babies scores II without base excess than the singletons. In univariate analysis, multiples had a lower incidence of respiratory distress syndrome, bronchopulmonary dysplasia, and sepsis. The mortality rate was not significantly different for overall gestational ages except for those born at ≤26 weeks of gestation. In multivariate logistic analysis, the incidences of intraventricular hemorrhage (grade ≥3), and retinopathy of prematurity requiring treatment were significantly higher than the singletons.

CONCLUSIONS

Mortality was not significantly different between multiples and singletons according to overall gestational age, except for multiples born at ≤26 weeks. A significant higher risk of intraventricular hemorrhage and retinopathy of prematurity requiring treatment was found in multiples. A new strategy to improve the mortality of immature multiples born at ≤26 weeks of gestation should be developed.

Longitudinal neurodevelopmental outcomes in preterm twins

BACKGROUND

Several factors contribute to neurodevelopmental outcomes in preterm infants. The aim of this study was to examine the genetic and environmental influences on long-term outcomes in preterm twins.

METHODS

From a prospective cohort of 225 preterm neonates studied with MRI, 24 monozygotic and 52 dizygotic twins were included. Neurodevelopmental outcomes at 1.5 and 3 years were assessed with the Bayley-III and at 4.5 years with The Movement Assessment Battery for Children and The Wechsler Preschool and Primary Scale of Intelligence-III.

RESULTS

Preterm monozygotic and dizygotic twin pairs (N = 76 neonates) had similar neurodevelopmental outcomes at all time points. Monozygotic twins (N = 24) did not show greater agreement for outcomes relative to dizygotic twins (N = 52). Twin pairs who were discordant in development (N = 12) were born at a lower gestational age and had a higher incidence of bronchopulmonary dysplasia and retinopathy of prematurity. Discordant twins become more similar in cognitive and language outcomes over time.

CONCLUSIONS

Neurodevelopmental outcomes in preterm twins may relate more strongly to environmental factors than genetics. Discordant twins were born earlier and had more perinatal morbidities. Despite the initial discordance, these twin pairs become similar in outcomes over time, which may reflect the positive impact of home environment or early intervention programs.

IMPACT

Neurodevelopmental outcomes in preterm twins relate more strongly to environmental factors than genetics. Monozygotic twins did not show greater agreement in outcomes relative to dizygotic twins suggesting a stronger environmental, rather than genetic, influence on development. Twin pairs who were discordant in development were born at a lower gestational age and had a higher incidence of perinatal morbidities. Despite the initial discordance, these twin pairs become more similar in cognitive and language outcomes over time, which may reflect the positive impact of early intervention programs or home environment. Neurodevelopmental outcomes in preterm twins are influenced by exposure to early-life insults or environmental stressors. The initial variability in outcomes among preterm infants is not fixed, and efforts made post-discharge from the neonatal intensive care unit can have a substantial impact on long-term outcomes.

Temporal trends in the frequency of twins and higher-order multiple births in Canada and the United States

BACKGROUND

The dramatic increase in multiple births is an important public health issue, since such births have elevated risks for adverse perinatal outcomes. Our objective was to explore the most recent temporal trends in rates of multiple births in Canada and the United States.

METHODS

Live birth data from Canada (excluding Ontario) and the United States from 1991-2009 were used to calculate rates of twins, and triplet and higher-order multiples (triplet+). Temporal trends were assessed using tests for linear trend and absolute and relative changes in rates.

RESULTS

Twin live births in the United States increased from 23.1 in 1991 to 32.2 per 1,000 live births in 2004, remained stable between 2004 and 2007, and then increased slightly to an all-time high of 33.2 per 1,000 live births in 2009. In Canada, rates also increased from 20.0 in 1991 to 28.3 per 1,000 live births in 2004, continued to increase modestly between 2004 and 2007, and rose to a high of 31.4 per 1,000 in 2009. Rates of triplet+ live births in the United States increased dramatically from 81.4 in 1991 to 193.5 per 100,000 live births in 1998, remained stable between 1998 and 2003 and then decreased to 148.9 per 100,000 in 2007. The rate declined marginally in 2008, but then rose again in 2009 to 153.5 per 100,000. Rates of triplet+ live births were much lower in Canada, although the temporal pattern of change was similar.

CONCLUSION

The rate of twin live births in the United States and Canada continues to increase, though more modestly than during the 1990s. Recent declines in rates of triplet+ live births in both countries have been followed by unstable trends.

Follow-up issues with multiples

The rate of multiple pregnancy has increased in developed countries, a finding usually attributed to more widespread use of assisted reproductive technologies. Multiple pregnancies are associated with a greater risk of pregnancy complications, including intrauterine growth restriction of one or more of the fetuses, vascular communications within a shared monochorionic placenta and premature delivery. Surviving infants are at significantly greater risk of developing cerebral palsy due to a combination of a higher proportion of them being preterm or of low birth weight, and complications associated with chorionicity. These infants are also at greater risk for abnormal cognitive development and learning disabilities for the same reasons. Parenting styles and family dynamics may also differ with multiples compared with singletons, which may affect long-term behaviour and development.Thus, infants of multiple pregnancies should receive careful neurodevelopmental follow-up. For larger, lower risk infants, this follow-up may be provided by general paediatricians within the community. However, for infants with birth weights of less than 1000 g or with a complicated antenatal or neonatal course, follow-up should be in a high-risk neonatal follow-up clinic with appropriate multidisciplinary support.

One consequence of infertility treatment: multifetal pregnancy

This article discusses the issue of multifetal pregnancy as a result of fertility treatments. Pregnancies with multiple gestations are associated with serious infant and maternal health risks as well as psychological distress and significant financial consequences, and are a far too common consequence of infertility treatments such as assisted reproductive technology (ART) and ovulation induction drugs. Women with multifetal pregnancies are at a higher risk for multiple pregnancy complications and maternal morbidity/mortality as well as stress, depression, and anxiety disorders, especially when there is the threat of a loss of one or more fetuses. The rise in rates of multifetal gestation and the accompanying increased risk to both mother and fetuses have led the American Society for Reproductive Medicine and the Society for Assisted Reproductive Technology to develop guidelines to limit the number of transferred embryos during in vitro fertilization. Nurses who work with infertile women are in a position to educate them about the risks, benefits, and alternatives associated with ARTs and multifetal pregnancies, and should endeavor to learn as much as possible about this topic.

Complicated monochorionic twin pregnancies: updates in fetal diagnosis and treatment

Monochorionic (MC) twin pregnancies may develop significant complications, and twin-to-twin transfusion syndrome (TTTS) has become among the best known to obstetricians and patients alike. A significant percentage of patients referred for suspected TTTS have a different underlying pathologic condition, however, and differentiating the subcategories of MC pathophysiologic conditions may change treatment course and outcome. The key to understanding complicated MC pregnancies lies in the placental angioarchitecture and intertwin vascular communications between the fetuses.

Reproductive ageing in women

The traditional view in respect to female reproduction is that the number of oocytes at birth is fixed and continuously declines towards the point when no more oocytes are available after menopause. In this review we briefly discuss the embryonic development of female germ cells and ovarian follicles. The ontogeny of the hypothalamic-pituitary-gonadal axis is then discussed, with a focus on pubertal transition and normal ovulatory menstrual cycles during female adult life. Biochemical markers of menopausal transition are briefly examined. We also examine the effects of age on female fertility, the contribution of chromosomal abnormalities of the oocyte to the observed decline in female fertility with age and the possible biological basis for the occurrence of such abnormalities. Finally, we consider the effects of maternal age on obstetric complications and perinatal outcome. New data that have the potential to revolutionize our understanding of mammalian oogenesis and follicular formation, and of the female reproductive ageing process, are also briefly considered.

Incidence and complications of multiple gestation in Canada: proceedings of an expert meeting

This paper reports the proceedings of a consensus meeting on the incidence and complications of multiple gestation in Canada. In addition to background presentations about current and possible future practice in Canada, the expert panel also developed a set of consensus points. The need for infertility to be understood, and funded, as a healthcare problem was emphasized, along with recognition of the emotional impact of infertility. It was agreed that the goal of assisted reproduction treatment is the delivery of a single healthy infant and that even though many positive outcomes have resulted from twin or even triplet pregnancies, the potential risks associated with multiple pregnancy require that every effort be made to achieve this goal. The evidence shows that treatments other than IVF (such as superovulation and clomiphene citrate) contribute significantly to the incidence of multiple pregnancy. There is an urgent need for studies to understand better the usage and application of these other fertility technologies within Canada, as well as the non-financial barriers to treatment. The final consensus of the expert panel was that with adequate funding and good access to treatment, it will be possible to achieve the goal of reducing IVF-related multiple pregnancy rates in Canada by 50%.