Perinatal characteristics and outcome of preterm singleton, twin and triplet infants in NSW and the ACT, Australia (1994-2005)

Retrospective Comparative Analysis of Neonatal Mortality and Morbidity in Preterm Singleton and Multiple Births -Single Center Experience

Objective. To compare mortality and major neonatal morbidities between singleton preterm infants and preterm infants of multiple gestations born <33 weeks' gestation. Method. Case-control study of preterm multiples and singletons <33 weeks' born at King Abdul-Aziz Medical City Riyadh (KAMC-R) between January 2017 and December 2020. Out-born infants and infants with lethal congenital abnormalities were excluded from the study. Mortality and major neonatal morbidities including bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), sepsis and surgical necrotizing enterocolitis (NEC) were compared between preterm singletons and multiples. Results. A total of 803 preterm infants were included: 567 (70.6%) were singletons, 158 (19.6%) were twins and 36 (4.5%) infants were higher multiples. Adjusted mortality before hospital discharge was significantly higher among preterm infants of multiple gestations compared to preterm singletons (12.3% vs 7.9%; P = .003; AOR, 2.2; 95% CI, 1.3-3.7). Retinopathy of prematurity (ROP) needing treatment was significantly higher among preterm infants of multiple pregnancies compared to preterm singletons (11% vs 6.5%, P = .033, AOR 1.1, 95% CI, 1.04-2.99). In addition, the incidence of bronchopulmonary dysplasia (BPD) at 36 weeks post menstrual age (PMA) (29.7% vs 20.5%; P = .003; AOR, 1.7; 95% CI, 1.2-2.5) and culture positive sepsis (24.2% vs 17.5%; P = .044; AOR, 1.5; 95% CI, 1.01-2.2) were significantly higher among preterm infants of multiple pregnancy. There were no differences in mortality and adverse neonatal outcomes between twins and higher multiples. Conclusion. Preterm infants of multiple gestations suffered higher mortality and neonatal morbidities compared to preterm singleton infants despite a higher utilization of maternal antenatal steroids and better antenatal care.

Neonatal and Early Childhood Outcomes of Twin and Singleton Infants Born Preterm

OBJECTIVE

To compare neonatal and early-childhood outcomes of twins and singletons born preterm and explore the association of chorionicity with outcomes.

STUDY DESIGN

This was a national retrospective cohort study of singleton and twin infants admitted at 230/7-286/7 weeks to level III neonatal intensive care units in Canada (2010-2020). The primary neonatal outcome was a composite of neonatal death or severe neonatal morbidities. The primary early-childhood outcome was a composite of death or significant neurodevelopmental impairment.

RESULTS

The study cohort included 3554 twin and 12 815 singleton infants. Twin infants born at 230/7-256/7 weeks had a greater risk of the composite neonatal outcome (adjusted risk ratio 1.04, 95% CI 1.01-1.07). However, these differences were limited to the subgroups of same-sex and monochorionic twin pregnancies. Twin infants of 230/7-256/7 weeks were also at an increased risk of the composite early-childhood outcome (adjusted risk ratio 1.22, 95% CI 1.09-1.37). Twin infants of 260/7-286/7 weeks were not at an increased risk of adverse neonatal outcomes or the composite early-childhood outcome compared with singleton infants.

CONCLUSIONS

Among infants born at 230/7-256/7 weeks, twins have a greater risk of adverse neonatal outcomes and the composite early-childhood outcome than singleton infants. However, the increased risk of adverse neonatal outcomes is mostly limited to monochorionic twins and may thus be driven by complications related to monochorionic placentation.

Primary and pharmaceutical care usage concurrent associations with a severe smoke episode and low ambient air pollution in early life

BACKGROUND

Due to climate change, landscape fires account for an increasing proportion of air pollution emissions, and their impacts on primary and pharmaceutical care are little understood.

OBJECTIVES

To evaluate associations between exposure in two early life periods to severe levels of PM_2.5 from a mine fire, background PM_2.5, and primary and pharmaceutical care.

METHODS

We linked records of births, general practitioner (GP) presentations and prescription dispensing for children born in the Latrobe Valley, Australia, 2012-2014, where a severe mine fire occurred in February-March 2014 in an area with otherwise low levels of ambient PM_2.5. We assigned modelled exposure estimates for fire-related (cumulative over the fire and peak 24-hour average) and annual ambient PM_2.5 to residential address. Associations with GP presentations and dispensing of prescribed medications in the first two years of life (exposure in utero) and in the two years post-fire (exposure in infancy) were estimated using two-pollutant quasi-Poisson regression models.

RESULTS

Exposure in utero to fire-related PM_2.5 was associated with an increase in systemic steroid dispensing (Cumulative: IRR = 1.11, 95%CI = 1.00-1.24 per 240 μg/m³; Peak: IRR = 1.15, 95%CI = 1.00-1.32 per 45 μg/m³), while exposure in infancy was associated with antibiotic dispensing (Cumulative: IRR = 1.05, 95%CI = 1.00-1.09; Peak: IRR = 1.06, 95%CI = 1.00-1.12). Exposure in infancy to ambient PM_2.5, despite relatively low levels from a global perspective (Median = 6.1 μg/m³), was associated with an increase in antibiotics (IRR = 1.10, 95%CI = 1.01-1.19 per 1.4 μg/m³) and in GP presentations (IRR = 1.05, 95%CI = 1.00-1.11), independently from exposure to the fire. We also observed differences in associations between sexes with GP presentations (stronger in girls) and steroid skin cream dispensing (stronger in boys).

DISCUSSION

Severe medium-term concentrations of PM_2.5 were linked with increased pharmaceutical treatment for infections, while chronic low levels were associated with increased prescriptions dispensed for infections and primary care usage. Our findings also indicated differences between sexes.

Perinatal characteristics and neonatal outcomes of singletons and twins in Chinese very preterm infants: a cohort study

BACKGROUND

The prevalence of preterm birth has been rising, and there is a paucity of nationwide data on the perinatal characteristics and neonatal outcomes of twin deliveries of very preterm infants (VPIs) in China. This study compared the perinatal characteristics and outcomes of singletons and twins admitted to neonatal intensive care units (NICUs) in China.

METHODS

The study population comprised all infants born before 32 weeks in the Chinese Neonatal Network (CHNN) between January 2019 and December 2019. Three-level and population-average generalized estimating equation (GEE)/alternating logistic regression (ALR) models were used to determine the association of twins with neonatal morbidities and the use of NICU resources.

RESULTS

During the study period, there were 6634 (71.2%) singletons and 2680 (28.8%) twins, with mean birth weights of 1333.70 g and 1294.63 g, respectively. Twins were significantly more likely to be delivered by caesarean section (p < 0.01), have antenatal steroid usage (p = 0.048), have been conceived by assisted reproductive technology (ART) (p < 0.01), have a higher prevalence of maternal diabetes (p < 0.01) and be inborn (p < 0.01) than singletons. In addition, twins had a lower prevalence of small for gestational age, maternal hypertension, and primigravida mothers than singletons (all p < 0.01). After adjusting for potential confounders, twins had higher mortality rates (adjusted odds ratio [AOR] 1.28, 95% confidence interval [CI] 1.10-1.49), higher incidences of short-term composite outcomes (AOR 1.28, 95% CI 1.09-1.50), respiratory distress syndrome (RDS) (AOR 1.30, 95% CI 1.12-1.50), and bronchopulmonary dysplasia (BPD) (AOR 1.10, 95% CI 1.01-1.21), more surfactant usage (AOR 1.22, 95% CI 1.05-1.41) and prolonged hospital stays (adjusted mean ratio 1.03, 95% CI 1.00-1.06), compared to singletons.

CONCLUSION

Our work suggests that twins have a greater risk of mortality, a higher incidence of RDS and BPD, more surfactant usage, and longer NICU stays than singletons among VPIs in China.

Outcomes of multiple gestation births compared to singleton: analysis of multicenter KID database

Background

The available data regarding morbidity and mortality associated with multiple gestation births is conflicting and contradicting.

Objective

To compare morbidity, mortality, and length of stay (LOS) outcomes between multiple gestation (twin, triplet and higher-order) and singleton births.

Methods

Data from the national multicenter Kids’ Inpatient Database of the Healthcare Cost and Utilization Project from the years 2000, 2003, 2006, 2009, 2012, and 2016 were analyzed using a complex survey design using Statistical Analysis System (SAS) 9.4 (SAS Institute, Cary NC). Neonates with ICD9 and ICD10 codes indicating singletons, twins or triplets, and higher-order multiples were included. Mortality was compared between these groups after excluding transfer outs to avoid duplicate inclusion. To analyze LOS, we included inborn neonates and excluded transfers; who died inpatient and any neonates who appear to have been discharged less than 33 weeks PMA. The LOS was compared by gestational age groups.

Results

A total of 22,853,125 neonates were analyzed for mortality after applying inclusion-exclusion criteria; 2.96% were twins, and 0.13% were triplets or more. A total of 22,690,082 neonates were analyzed for LOS. Mean GA, expressed as mean (SD), for singleton, twins and triplets, were 38.30 (2.21), 36.39 (4.21), and 32.72 (4.14), respectively. The adjusted odds for mortality were similar for twin births compared to singleton (aOR: 1.004, 95% CI:0.960–1.051, p = 0.8521). The adjusted odds of mortality for triplet or higher-order gestation births were higher (aOR: 1.33, 95% CI: 1.128–1.575, p = 0.0008) when compared to the singleton births. Median LOS (days) was significantly longer in multiple gestation compared to singleton births overall (singletons: 1.59 [1.13, 2.19] vs. twins 3.29 [2.17, 9.59] vs. triplets or higher-order multiples 19.15 [8.80, 36.38], p < .0001), and this difference remained significant within each GA category.

Conclusion

Multiple gestation births have higher mortality and longer LOS when compared to singleton births. This population data from multiple centers across the country could be useful in counseling parents when caring for multiple gestation pregnancies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40748-021-00135-5.

Association of antenatal corticosteroids with morbidity and mortality among preterm multiple gestations: meta-analysis of observational studies

OBJECTIVE

This meta-analysis aimed to assess the efficacy of antenatal corticosteroids (ACS) on morbidity and mortality among preterm multiple pregnancies.

METHODS

The PubMed, Embase, Web of Science and Cochrane Library databases were searched for studies investigating the outcomes among preterm multiple gestations following to ACS, from their inception to 1 November 2020. Two authors independently performed the study selection, risk of bias assessment and data extraction. The primary outcomes were respiratory distress syndrome (RDS) and mortality and secondary outcomes included intraventricular haemorrhage (IVH), periventricular leukomalacia (PVL), necrotising enterocolitis, retinopathy of prematurity and bronchopulmonary dysplasia. Pooled ORs were obtained using random effects models. Subgroup analyses were performed to explain heterogeneity by ACS completeness, administration-to-delivery intervals (≤7 days) and single or multicentre.

RESULTS

A total of 16 observational studies with 36 973 newborns were included in the meta-analysis. ACS treatment was associated with a reduction in RDS (OR 0.66; 95% CI 0.54 to 0.82; I2=91.4%; p<0.001), mortality (OR 0.64; 95% CI 0.50 to 0.81; I2=85.9%; p<0.001), IVH (OR 0.67; 95% CI 0.54 to 0.83; I2=77.4%; p<0.001) and PVL (OR 0.65; 95% CI 0.47 to 0.92; I2=75.5%; p<0.001). Subgroup analyses showed ACS completeness, administration-to-delivery interval and multicentre study affected these associations.

DISCUSSION

ACS may be beneficial for reducing the risks of RDS, mortality, IVH and PVL among preterm multiple gestations. The efficacy of ACS could be affected by ACS completeness and administration-to-delivery. More robust evidence on the efficacy of ACS treatment among multiple gestations is warranted.

Preterm Neonatal Mortality and Its Determinants at a Tertiary Hospital in Western Uganda: A Prospective Cohort Study

Background

Prematurity contributes greatly to the neonatal mortality burden in sub-Saharan Africa. This study evaluated the proportion of preterm neonatal death, medical conditions at admission, and determinants of mortality of preterm neonates in the neonatal intensive care unit (NICU) of a tertiary hospital in Western Uganda.

Materials and Methods

A prospective cohort study of 351 consecutively enrolled preterm neonates was conducted from March to June 2019. Interviewer-administered questionnaires and physical assessment of neonates were used to obtain socio-demographic and clinical data for mothers and their preterm neonates. Descriptive statistics for participants’ characteristics were generated, while bivariate and multivariate logistic regression models were fitted so as to establish the determinants of mortality outcome. A p-value <0.05 was considered statistically significant.

Results

In-hospital neonatal mortality of 31.6% (95% CI: 26.9–36.7) was noted, with 65.8% of deaths occurring within 72 hours from admission. The most common medical conditions at admission were: hypothermia (67.2%), respiratory distress syndrome (43.0%), small for gestational age (15.7%), and perinatal asphyxia (14.5%). Under multivariate regression modelling, maternal age ≥35 years (AOR: 4.5; 95% CI: 1.35–15.31), no antenatal care (AOR: 4.7; 95% CI: 1.05–21.21), >4 ANC visits (AOR: 5.3; 95% CI: 1.88–15.21), neonatal resuscitation (AOR: 3.4; 95% CI: 1.66–6.82), outborn status (AOR: 2.3; 95% CI: 1.20–4.50), singleton pregnancy (AOR: 3.7; 95% CI: 1.74–7.89), <28 weeks’ gestation (AOR: 12.0; 95% CI: 2.24–64.27), and male sex (AOR: 2.0; 95% CI: 1.04–3.74), respiratory distress syndrome (AOR: 2.6; 95% CI: 1.22–5.70), apnea (AOR: 6.2; 95.5% CI: 1.09–35.38), hypothermia (AOR: 2.3; 95% CI: 1.09–4.92), and small for gestational age (AOR: 4.7; 95% CI: 2.06–10.74) were significantly associated with mortality.

Conclusion and Recommendations

In-hospital mortality of preterm neonates was high. We identified various maternal and neonatal risk factors, indicating a need for stakeholders to enhance efforts towards prevention of preterm-associated complications and optimize facility-based continuum of care.

Neurodevelopmental Outcome and Adaptive Behavior in Preterm Multiples and Singletons at 1 and 2 Years of Corrected Age

Background

Recent literature has investigated the role of multiple birth on neurodevelopmental outcomes of premature infants, especially extremely preterm ones. Multiple gestations are often associated to increased neurodevelopmental disability. Actually, research findings are controversial.

Objective

To compare the neurodevelopmental and behavioral outcomes of multiples and singletons in a cohort of preterm infants ≤28 weeks gestational age at 1 and 2 years of corrected age.

Methods

The study included 86 infants, born from January 2014 to September 2017 and enrolled in the follow-up program provided at authors’ Institution. Exclusion criteria included: major brain lesions and malformations, severe neuro-sensorial deficits, genetic syndromes, single-twin survivors. Thirty four multiples were compared to 52 singletons, using the Griffiths Mental Development Scales and the Child Behavior Checklist 1½–5. Statistical analysis was based on ANOVA techniques to test group differences. A p < 0.05 was considered statistically significant.

Results

The neurodevelopmental outcomes of multiples and singletons at 1 and 2 years of corrected age did not significantly differ at a general level (p > 0.05). Multiples showed significantly lower mean scores than singletons at 1 year in Locomotor (87.15 ± 11.94 vs. 92.48 ± 11.59) and Personal-Social (84.88 ± 10.25 vs. 89.63 ± 8.19) subscales. Considering the behavioral outcomes, higher rates of externalizing problems were observed in multiples at 2 years (54.27 ± 9.64 vs. 49.31 ± 10.39).

Conclusion

The slightly lower neurodevelopmental outcome showed by multiples, especially in the gross-motor and personal-social domains at 1 year, might be related to the specific environmental condition they experience. Multiple birth may affect mother’s sensitivity to infant’s needs and infant’s acquisition of emotional and behavioral regulation. This affects the separation process and the acquisition of the independent walking and other gross-motor skills. Being multiples might also induce an hyperstimulation and this could explain their higher vulnerability to externalizing problems (impulsiveness, hyperactivity, attention deficits). Additionally, males are more affected by the multiple condition than females.

Neurodevelopmental outcome of preterm twins at 5 years of age

BACKGROUND

Twins are considered to be at an increased risk for perinatal mortality and morbidities, but it is unclear whether preterm twins are at an increased risk for poor developmental outcomes when compared to preterm singletons. Our aim was to compare the neurodevelopmental outcome of preterm twins vs singletons at 5 years of age.

METHODS

Very low birth weight and very low gestational age infants (twins n = 66, singletons n = 157) were recruited as a part of the PIPARI project in the Turku University Hospital, covering a regional population. Cognitive development, neuropsychological performance, and neurodevelopmental impairments (including cerebral palsy, hearing deficit, visual impairment, and intellectual disability) were evaluated at 5 years of age.

RESULTS

Twins and singletons had otherwise similar perinatal background factors, except for the higher proportion of preterm rupture of membranes in singletons. Twins had cognitive and neuropsychological outcomes that were otherwise comparable with singletons, but they had a slightly lower verbal intelligence quotient (estimate -5.81, 95% CI -11.14 to -0.48, p = 0.03). Being a twin was not a risk for neurodevelopmental impairments.

CONCLUSIONS

Our study shows that, contrary to a common hypothesis, the overall neurodevelopment of very preterm twins does not significantly differ from that of preterm singletons.

Characteristics, management and outcomes of very preterm triplets in 19 European regions

OBJECTIVE

To describe obstetrical care and in-hospital outcomes in very preterm triplet pregnancies in a European multiregional cohort.

METHODS

Data from a prospective population-based study of very preterm births between 22 + 0 and 31 + 6 weeks of gestation in 19 regions from 11 European countries participating in the EPICE project in 2011/2012 were used to describe triplet pregnancies and compare them with twins and singletons.

RESULTS

Triplets constituted 1.1% of very preterm pregnancies (97/8851) and 3.3% of very preterm live births (258/7900); these percentages varied from 0% to 2.6% and 0% to 6% respectively across the regions. In-hospital mortality after live birth was 12.4% and did not differ significantly from singletons or twins or by birth order. However, 28.9% of mothers with a triplet pregnancy experienced at least one neonatal death. Ninety percent of live-born triplets were delivered by cesarean. Vaginal delivery was associated with an Apgar score of less than 7, but not with in-hospital mortality.

CONCLUSIONS

The prevalence of very preterm triplets varies across European regions. Most triplets were born by cesarean and those born vaginally had lower Apgar scores. Overall, in-hospital mortality after live birth was similar to singletons and twins.

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.

Outcomes following a comprehensive versus a selective approach for infants born at 22 weeks of gestation

OBJECTIVE

To examine outcomes at two institutions with different approaches to care among infants born at 22 weeks of gestation.

STUDY DESIGN

Retrospective, cohort study (2006-2015). Enrollment was limited to mother-infant dyads at 22 weeks of gestation. Proactive care was defined as provision of antenatal corticosteroids and neonatal resuscitation and intensive care. One center (Uppsala, Sweden; UUCH) provided proactive care to all mother-infant dyads (comprehensive center); the other center (Nationwide Children's Hospital, USA; NCH) initiated or withheld treatment based on physician and family preferences (selective center). Differences in outcomes between the two centers were evaluated.

RESULT

Among 112 live-born infants at 22 weeks of gestation, those treated at UUCH had in-hospital survival rates higher than those at NCH (21/40, 53% vs. 6/72, 8%; P < 0.01). Among the subgroup of infants receiving proactive care (UUCH: 40/40, 100%; NCH: 16/72, 22%) survival was higher at UUCH than at NCH (21/40, 53% vs. 3/16, 19%; P < 0.05).

CONCLUSION

Even when mother-infant dyads were provided proactive care at NCH (selective center), survival was lower than infants provided proactive care at UUCH (comprehensive center). Differences between the approaches to care at the two centers at 22 weeks of gestation merits further investigation.

Morbidity and mortality of very low birth weight multiples compared with singletons

BACKGROUND

Previous studies comparing the neonatal outcome of very low birth weight (VLBW) multiples and singletons have suggested a worse outcome for multiples at gestational ages on the limits of viability.

OBJECTIVES

The objective of this study is to determine the neonatal mortality and morbidity of VLBW multiples compared to singletons.

METHODS

This is a retrospective study including all infants registered in the Spanish network for infants under 1500 g (SEN1500), over a 12-year period (from 2002 to 2013). Mortality and major morbidities were compared between singletons and multiples.

RESULTS

About 32,770 infants were included: 21,123 singletons (64.5%) and 11,647 multiples (35.5%), with a mean gestational age of 29.5 weeks (22-38), and mean birth weight of 1115 g (340-1500). When adjusted by other perinatal factors, multiple pregnancy has a significantly higher risk of mortality than singleton pregnancy (odds ratio (OR) 1.15; IC 95% 1.05-1.26, p = .002), but not a higher risk of major morbidity or composite adverse outcome. In the subgroup of infants born before 26 weeks, multiples showed a higher risk of mortality (63.9% versus 51%, OR 1.7; 95% CI 1.47-1.96) and a higher risk of composite adverse outcome (88.9% versus 81.5%, OR 1.82, 95% CI 1.28-2.24).

CONCLUSIONS

In preterm infants born with less than 1500 g, multiple pregnancy is a prognostic factor that can slightly increase mortality. Extremely preterm infants born before 26 weeks have a greater risk of mortality and major morbidity if they come from a multiple pregnancy.

Multifetal pregnancy reduction of triplets to twins compared with non-reduced triplets: a meta-analysis

The current systematic review and meta-analysis evaluate the perinatal outcomes in twin pregnancies following multifetal pregnancy reduction (MPR) compared with non-reduced triplet pregnancies. All studies comparing perinatal outcome of twin pregnancies following MPR to non-reduced triplet pregnancies were considered. MEDLINE, non-indexed MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and Web of Science were searched for relevant published articles up to August 2016. The search yielded 653 publications of which 92 were assessed for eligibility. A total of 24 studies met the inclusion criteria. Overall, the outcomes of pregnancies following MPR were better compared with expectantly managed triplets. The MPR group delivered at a later gestational age and was less likely to be delivered before 32 or 28 weeks' gestation. Newborns in the MPR group had significantly higher birthweight at delivery (mean difference 500 g [95% CI 439.95, 560.04]). Rates of pregnancy loss before 24 weeks' gestation and overall infant survival were comparable between the groups. This meta-analysis suggests that MPR of triplet pregnancies to twins is associated with improved perinatal outcome compared with non-reduced triplets. Should primary prevention of high order multiple pregnancy fail, MPR is an appropriate alternative to minimize the perinatal morbidity and mortality of triplet pregnancies.

Fetal and neonatal outcomes of preterm infants born before 32 weeks of gestation according to antenatal vs postnatal assessments of restricted growth

BACKGROUND

Fetal growth restriction is defined using ultrasound parameters during pregnancy or as a low birthweight for gestational age after birth, but these definitions are not always concordant.

OBJECTIVE

The purpose of this study was to investigate fetal and neonatal outcomes based on antenatal vs postnatal assessments of growth restriction.

STUDY DESIGN

From the EPIPAGE 2 population-based prospective study of very preterm births in France in 2011, we included 2919 singleton nonanomalous infants 24-31 weeks gestational age. We constituted 4 groups based on whether the infant was suspected with fetal growth restriction during pregnancy and/or was small for gestational age with a birthweight <10th percentile of intrauterine norms by sex: 1) suspected with fetal growth restriction/small for gestational age 2) not suspected with fetal growth restriction/small for gestational age 3) suspected with fetal growth restriction/not small for gestational age and 4) not suspected with fetal growth restriction/not small for gestational age. We estimated relative risks of perinatal mortality and morbidity for these groups adjusting for maternal and neonatal characteristics.

RESULTS

We found that 22.2% of infants were suspected with fetal growth restriction/small for gestational age, that 11.4% infants were not suspected with fetal growth restriction/small for gestational age, that 3.0% infants were suspected with fetal growth restriction/not small for gestational age, and that 63.4% infants were not suspected with fetal growth restriction/not small for gestational age. Compared with infants who were not suspected with fetal growth restriction/not small-for-gestational-age infants, small-for-gestational-age infants suspected and not suspected with fetal growth restriction had higher risks of stillbirth or termination of pregnancy (adjusted relative risk, 2.0 [95% confidence interval, 1.6-2.5] and adjusted relative risk, 2.8 [95% confidence interval, 2.2-3.4], respectively), in-hospital death (adjusted relative risk, 2.8 [95% confidence interval, 2.0-3.7] and adjusted relative risk, 2.0 [95% confidence interval, 1.5-2.8], respectively), and bronchopulmonary dysplasia (adjusted relative risk, 1.3 [95% confidence interval, 1.2-1.4] and adjusted relative risk, 1.3 [95% confidence interval, 1.1-1.4], respectively), but not severe brain lesions. Risks were not increased for infants suspected with fetal growth restriction but not small-for-gestational-age.

CONCLUSION

Antenatal and postnatal assessments of fetal growth restriction were not concordant for 14% of very preterm infants. In these cases, birthweight appears to be the more relevant parameter for the identification of infants with higher risks of adverse short-term outcomes.

Morbidity and mortality among very preterm singletons following fertility treatment in Australia and New Zealand, a population cohort study

BACKGROUND

Due to high rates of multiple birth and preterm birth following fertility treatment, the rates of mortality and morbidity among births following fertility treatment were higher than those conceived spontaneously. However, it is unclear whether the rates of adverse neonatal outcomes remain higher for very preterm (<32 weeks gestational age) singletons born after fertility treatment. This study aims to compare adverse neonatal outcomes among very preterm singletons born after fertility treatment including assisted reproductive technology (ART) hyper-ovulution (HO) and artificial insemination (AI) to those following spontaneous conception.

METHODS

The population cohort study included 24069 liveborn very preterm singletons who were admitted to Neonatal Intensive Care Unit (NICU) in Australia and New Zealand from 2000 to 2010. The in-hospital neonatal mortality and morbidity among 21753 liveborn very preterm singletons were compared by maternal mode of conceptions: spontaneous conception, HO, ART and AI. Univariate and multivariate binary logistic regression analysis was used to examine the association between mode of conception and various outcome factors. Odds ratio (OR) and adjusted odds ratio (AOR) and 95% confidence interval (CI) were calculated.

RESULTS

The rate of small for gestational age was significantly higher in HO group (AOR 1.52, 95% CI 1.02-2.67) and AI group (AOR 2.98, 95% CI 1.53-5.81) than spontaneous group. The rate of birth defect was significantly higher in ART group (AOR 1.71, 95% CI 1.36-2.16) and AI group (AOR 3.01, 95% CI 1.47-6.19) compared to spontaneous group. Singletons following ART had 43% increased odds of necrotizing enterocolitis (AOR 1.43, 95% CI 1.04-1.97) and 71% increased odds of major surgery (AOR 1.71, 95% CI 1.37-2.13) compared to singletons conceived spontaneously. Other birth and NICU outcomes were not different among the comparison groups.

CONCLUSIONS

Compared to the spontaneous conception group, risk of congenital abnormality significantly increases after ART and AI; the risk of morbidities increases after ART, HO and AI. Preconception planning should include comprehensive information about the benefits and risks of fertility treatment on the neonatal outcomes.

[Epidemiology and risk factors of preterm birth]

OBJECTIVE

To synthesize the available evidence regarding the incidence and several risk factors of preterm birth. To describe neonatal outcomes according to gestational age and to the context of delivery.

MATERIALS AND METHODS

Consultation of the Medline database.

RESULTS

In 2010, 11% of live births (15 million babies) occurred before 37 completed weeks of gestation worldwide. About 85% of these births were moderate to late preterm babies (32-36 weeks), 10% were very preterm babies (28-31 weeks) and 5% were extremely preterm babies (<28 weeks). In France, premature birth concerns 60,000 neonates every year, 12,000 of whom are born before 32 completed weeks of gestation. Half of them are delivered after spontaneous onset of labor or preterm premature rupture of the membranes, and the other half are provider-initiated preterm births. Several maternal factors are associated with preterm birth, including sociodemographic, obstetrical, psychological, and genetic factors; paternal and environmental factors are also involved. Gestational age is highly associated with neonatal mortality and with short- and long-term morbidities. Pregnancy complications and the context of delivery also have an impact on neonatal outcomes.

CONCLUSION

Preterm birth is one of the leading cause of the under-five mortality and of neurodevelopmental impairment worldwide; it remains a major public health issue.

Antenatal Corticosteroid Therapy Before 24 Weeks of Gestation: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the effectiveness of antenatal corticosteroids compared with placebo or no treatment in neonates born before 24 weeks of gestation.

DATA SOURCES

We searched MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Cochrane Central Register of Controlled Trials databases from 1990 to March 13, 2015, and ClinicalTrials.gov.

METHODS OF STUDY SELECTION

Studies considered were published randomized or quasirandomized controlled trials and observational studies that compared outcomes between neonates who received or did not receive antenatal corticosteroids born before 24 weeks of gestation.

TABULATION, INTEGRATION, AND RESULTS

We performed duplicate independent assessment of the title and abstracts, full-text screening, inclusion of articles, and data abstraction. We performed meta-analyses using random-effects models and quality assessment with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. There were 17 observational studies, and our primary outcome, mortality to discharge in neonates receiving active intensive treatment, had a total of 3,626 neonates. The adjusted odds of mortality to discharge were reduced by 52% in the antenatal corticosteroid group compared with the control group (crude adjusted odds ratio [OR] 0.45, 95% confidence interval [CI] 0.36-0.56; adjusted OR 0.48, 95% CI 0.38-0.61; mortality to discharge 58.1% [intervention] compared with 71.8% [control]) with a "moderate" quality of evidence based on the GRADE system. There were no significant differences between the groups for severe morbidity.

CONCLUSION

The available data, all observational, show reduced odds of mortality to discharge in neonates born before 24 weeks of gestation who received antenatal corticosteroids and active intensive treatment. Antenatal corticosteroids should be considered for women at risk of imminent birth before 24 weeks of gestation who choose active postnatal resuscitation.

Is artificial reproductive technology a risk factor for retinopathy of prematurity independent of the generation of multiple births?

PURPOSE

There is some debate regarding whether artificial reproductive technology (ART) constitutes an independent risk factor for retinopathy of prematurity (ROP). We wanted to assess the prevalence of ART in multiple birth infants seen for ROP screening and whether or not ROP was identified or treated, in order to evaluate whether ART contributes a risk factor for ROP independent of the generation of multiple births.

METHODS

A retrospective audit was performed of all multiple birth babies admitted to a tertiary neonatal unit who met the UK ROP screening criteria (<32 weeks gestational age [GA] and/or <1,501 g birthweight [BW]).

RESULTS

A total of 205 babies met our criteria, of whom 87.3% were twins. A total of 39.5% were born following ART. A total of 30.5% of the non-ART group developed ROP vs 34% of the ART group (p = 0.837). Stage 3 ROP developed in 5.1% of non-ART babies and 6% of ART babies. A total of 8.5% of non-ART babies and 10% of ART babies required treatment for ROP. Logistic regression demonstrated that ART was not independently associated with development of ROP.

CONCLUSIONS

Artificial reproductive technology multiple birth babies make up a considerable proportion of the ROP screening burden and their number is likely to increase as ART is increasingly available and utilized. We found no significant difference between the numbers of babies developing ROP in the ART vs non-ART groups, but the numbers are small. The estimated odds of developing ROP are slightly higher in the ART babies, so our data do not rule out a possible association.

Trends in Morbidity and Mortality of Extremely Preterm Multiple Gestation Newborns

OBJECTIVES

To examine the risk of mortality and major morbidities in extremely preterm multiple gestation infants compared with singletons over time.

METHODS

This is a retrospective study of 15,402 infants born ≤27 weeks' gestation, admitted to NICUs in the Australian and New Zealand Neonatal Network from 1995 to 2009. Mortality and major morbidities were compared between singletons and multiples across three 5-year epochs.

RESULTS

Extreme preterm multiples were more likely to have lower birth weight; higher maternal age; and higher rates of assisted conception, antenatal steroid use, and cesarean delivery compared with singletons. The mortality rate was significantly higher in multiples compared with singletons even as there was a trend of decreasing gestational-age stratified mortality in multiples over the time period investigated. The rates of major morbidities or composite adverse outcomes were not different between multiples and singletons across all epochs. The adjusted odds ratio (AOR) for mortality in multiples was significantly higher in multiples compared with singletons (AOR 1.20, 95% confidence interval [CI] 1.08-1.34). There were no differences in the adjusted odds for poor outcomes in multiples compared with singletons in the most recent epoch: mortality (AOR 1.00, 95% CI 0.84-1.19), major morbidity (0.95, 95% CI 0.81-1.10), and composite adverse outcome (0.96, 95% CI 0.83-1.11).

CONCLUSIONS

Over the 15-year period, the odds for mortality in extremely preterm NICU infants of multiple gestation was significantly higher compared with singletons. The adjusted odds of poor outcomes in multiples were not significantly different from that of singletons in the most recent epoch.

Preterm infant outcomes in New South Wales and the Australian Capital Territory

AIM

This study aimed to provide updated information on gestation-specific hospital outcomes of extreme to very preterm infants admitted to neonatal intensive care units.

METHODS

A population-based retrospective cohort study of infants born between 23(+0) and 31(+6) weeks gestation and admitted to a network of neonatal intensive care units between 2007 and 2011 in a well-defined geographic area of New South Wales and the Australian Capital Territory. Main outcome measures were survival and major morbidities prior to hospital discharge.

RESULTS

Of 4454 infants included, hospital survival rates based on gestational age alone were 27%, 59%, 76%, 85%, 91% and over 95% at 23, 24, 25, 26, 27 and 28-31 weeks, respectively. Survival rates for each week up to 29 weeks gestation differed by at least 5% when perinatal risk factors including birthweight percentile, exposure to antenatal steroids, birth outside a tertiary hospital and gender were included in the survival estimation. All the major outcome figures were then simplified and displayed in a simple, easy-to-understand preterm outcome table for counselling purposes.

CONCLUSION

We report the latest hospital outcomes of extreme to very preterm infants in New South Wales and the Australian Capital Territory. Survival rates based on gestational age alone may not provide the true estimate as the survival for these infants can vary based on the presence or absence of other relevant perinatal factors.

Neurodevelopmental outcomes of preterm singletons, twins and higher-order gestations: a population-based cohort study

OBJECTIVE

To study the neurodevelopmental outcomes of multiple (twins, triplets, quads) compared with singleton extremely preterm infants <29 weeks gestation.

DESIGN

Population-based retrospective cohort study.

SETTING

A network of 10 neonatal intensive care units in a geographically defined area of New South Wales and the Australian Capital territory.

PATIENTS

1473 infants <29 weeks gestation born between 1 January 1998 and 31 December 2004.

INTERVENTION

At 2-3 years of corrected age, a neurodevelopmental assessment was conducted using either the Griffiths Mental Developmental Scales or the Bayley Scales of Infant Development II.

MAIN OUTCOME MEASURE

Moderate-severe functional disability was defined as developmental delay (Griffiths Mental Developmental Scales General Quotient or Bayley Scales of Infant Development-II Mental Development Index >2 SDs below the mean), moderate cerebral palsy (unable to walk without aids), sensorineural or conductive deafness (requiring amplification) or bilateral blindness (visual acuity <6/60 in the better eye).

RESULTS

Of the 1081 singletons and 392 multiples followed-up, singletons demonstrated higher rates of systemic infections, steroid treatment for chronic lung disease and birth weight <10th percentile. Moderate-severe functional disability did not differ significantly between singletons and multiples (15.8% vs 17.6%, OR 1.14; 95% CI 0.84 to 1.54; p=0.464). Further subgroup analysis of twins, higher-order gestations, 1st-born multiples, 2nd or higher-born multiples, same and unlike gender multiples, did not demonstrate statistically higher rates of functional disability compared with singletons.

CONCLUSIONS

Premature infants from multiple gestation pregnancies appear to have comparable neurodevelopmental outcomes to singletons.

Prematurity and twinning

AIM OF THE STUDY

Newborns from multiple pregnancies are increasing in number and demonstrate a higher perinatal morbidity and mortality compared to singletons. Prematurity is the main reason for most neonatal diseases in twins, but other variables may play a role and their prenatal evaluation may improve the overall outcome.

MAIN FINDINGS

Prematurity is six times more frequent in twins and therefore birth weight is significantly lower compared to singletons. Thus, twins are more exposed to prematurity related diseases (respiratory, cardiovascular, infectious, etc.) and to long-term complications (especially neurological disabilities).

RESULTS

It is very difficult to estimate the increased risk of neonatal morbidity related to twinning independently to the increased risk of prematurity and therefore to interpret data on morbidity rates, in particular regarding the neurodevelopmental outcome.

CONCLUSION

Prevention of preterm birth is a primary goal in managing multiple pregnancies, together with prophylaxis with corticosteroids in order to improve foetal lung maturity. Accurate risk assessment strategies and adequate obstetrical-neonatological management of multiple pregnancies may reduce the increasing need for neonatal intensive care and for health resources in the long-term follow-up that has been observed over the last decades.

The effect of IVF pregnancies on mortality and morbidity in tertiary unit

BACKGROUND

There are several studies that have shown an increased risk of premature birth and developmental abnormalities with in vitro fertilization (IVF); however, the data on preterm mortality and morbidity are limited.

AIM

Our aim is to investigate whether IVF had an effect on the mortality and morbidity in neonates admitted to the neonatal intensive care unit.

METHODS

A total of 940 term and preterm babies who were admitted to the intensive care unit over a period of 2 years were enrolled. Of these, 121 babies were born after IVF and 810 were born after a natural conception and 9 were born after ovulation induction. Of these, 112 preterm babies were born after IVF and 405 preterm babies were born after a natural conception.

RESULTS

In the IVF group, the gestational age and birth weight were significantly lower than in the non-IVF group. Additionally, in the IVF group, multiple births were significantly higher than in the non-IVF group. IVF pregnancies increase preterm delivery but did not increase preterm mortality, and preterm morbidity did not differ among groups, except for intraventricular hemorrhage (IVH). Gestational age was shown to be the primary risk factor for IVH using a logistic regression analysis. Also when newborns at gestational age <32 weeks were compared using regression analysis, gestational age was the major risk factor for IVH.

CONCLUSION

IVF appears to be associated with premature delivery and the known risks associated with prematurity.

Clinical features and short-term outcomes of triplet pregnancies in Japan

OBJECTIVE

To review clinical features and short-term outcomes of triplet pregnancies among Japanese women.

METHODS

A retrospective analysis was carried out among 320 Japanese women with triplet pregnancies (8 monochorionic, 75 dichorionic, and 150 trichorionic triplets; 87 with unknown placental chorionicity) who delivered at 22 gestational weeks or more between January 2005 and December 2008.

RESULTS

Delivery was by cesarean for 315 (98%) women. Gestational age at delivery was 32.3±2.8 weeks (mean±SD) and 33.2 weeks (median), and 97%, 61%, and 14% of women delivered at less than 37, less than 34, and less than 30 gestational weeks, respectively. For live-born infants, mean birth weight was 1762±437 g, 1608±396 g, and 1406±380 g for the heaviest, middle, and lightest triplet, respectively. Eighteen (5.6%) women experienced perinatal mortality (3 triplets for 1 woman, 2 triplets for 4 women, and 1 triplet for 13 women). Perinatal mortality was 25 deaths per 1000 deliveries, and decreased with increasing number of chorionic membranes (125, 44, and 20 per 1000 mono-, di-, and trichorionic triplet deliveries, respectively).

CONCLUSION

Short-term outcomes were good among triplet pregnancies in Japan. The data may be useful for counseling Japanese women with triplet pregnancies.

Twins born over weekends: are they at risk for elevated infant mortality?

OBJECTIVE

To assess the impact of the day of birth on twin mortality in a population sample.

METHODS

We analyzed weekend versus weekday twin births from the United States national twin birth data for the periods 1989-2002. We computed adjusted hazard ratios (HR) and 95% confidence intervals (CI) to assess the association between infant mortality and weekday of birth using the Cox proportional hazards model.

RESULTS

The crude rates for all types of mortality were found to be significantly higher for twins born on weekends than on weekdays. After adjustment, only post-neonatal mortality risk was higher on weekends as compared to weekdays [Hazards ratio (HR)=1.19, CI: 1.04, 1.36]. Twins of white mothers were at greater risk for neonatal death (HR=1.16, CI: 1.08, 1.24) but were less likely to experience post-neonatal death (HR=0.68, CI: 0.64, 0.76) as compared to twins of black mothers. We found an interaction between maternal age and weekday of birth. Twins born on weekends to teenage mothers (age<18) had a 35% greater risk for neonatal death (HR=1.35, CI: 1.06, 1.71) while those born on weekends to older mothers did not show elevated risk for any of the mortality indices.

CONCLUSION

Increased risks for post-neonatal death are significantly higher amongst twins born on weekends as compared to weekdays. Further research is required to identify the detailed differences in structure and procedures that result in the disadvantage associated with weekend birth.