Epidemiology of moderate preterm, late preterm and early term delivery

Respiratory distress syndrome is associated with increased morbidity and mortality in late preterm births

BACKGROUND

Respiratory distress syndrome is strongly associated with prematurity, including late preterm births. Respiratory distress syndrome has been shown to be associated with certain neonatal morbidities and mortality, but these associations are not well described among late preterm births.

OBJECTIVE

We sought to determine the association between respiratory distress syndrome and adverse neonatal outcomes among late preterm (34-36 weeks) born singleton neonates.

STUDY DESIGN

This is a retrospective cohort study using California's linked vital statistics and patient discharge data (2008-2019). We included singleton, nonanomalous births with a gestational age of 34-36 weeks. Outcomes of interest were interventricular hemorrhage, necrotizing enterocolitis, retinopathy of prematurity, neonatal sepsis, length of hospital stay, neonatal death, and infant death. Chi-square and multivariable Poisson regression analyses were used to examine the association of respiratory distress syndrome with outcomes at each gestational age. Adjusted risk ratio and 95% confidence interval values were estimated.

RESULTS

A total of 242,827 births were included, of which 11,312 (4.7%) had respiratory distress syndrome. We found that among neonates with respiratory distress syndrome, necrotizing enterocolitis was higher at 35 weeks (adjusted risk ratio, 3.97 [95% confidence interval, 1.88-8.41]) and 36 weeks (adjusted risk ratio, 4.53 [95% confidence interval, 1.45-14.13]). Intraventricular hemorrhage, retinopathy of prematurity, neonatal sepsis, and length of hospital stay were significantly higher at 34-36 weeks of gestation in neonates with respiratory distress syndrome. Neonatal death was significantly higher among neonates with respiratory distress syndrome at 35 weeks (adjusted risk ratio, 3.04 [95% confidence interval, 1.58-5.85]) and 36 weeks (adjusted risk ratio, 3.25; 95% confidence interval, 1.59-6.68). In addition, infant death was significantly higher at 35 weeks (adjusted risk ratio, 2.27 [95% confidence interval, 1.43-3.61]) and 36 weeks (adjusted risk ratio, 2.60 [95% confidence interval, 1.58-4.28]).

CONCLUSION

We found that respiratory distress syndrome was associated with intraventricular hemorrhage, retinopathy of prematurity, and sepsis at 34-36 weeks of gestation, whereas respiratory distress syndrome was associated with neonatal death, infant death, and necrotizing enterocolitis at 35 and 36 weeks. Clinicians should keep these outcomes in mind when making decisions about delivery timing, the potential benefits of antenatal steroids in pregnancies in the late preterm period, and the management of respiratory distress syndrome in late preterm neonates.

Antenatal Late Preterm Steroids: The Evolution of the ALPS Trial

The Antenatal Late Preterm Steroids (ALPS) trial was designed to address respiratory morbidity common in infants born late preterm. The study was published in April, 2016 and, shortly thereafter, changed clinical practice in obstetrics in the United States. The following chapter describes the ALPS trial study design in detail, including the background leading to the trial, the study outcomes, and the initial findings of the long-term follow-up study. The ALPS story would not be complete without Elizabeth Thom, PhD, who died before her time. Her brilliance largely contributed to the design of the ALPS trial.

Neurological development in children born moderately or late preterm: national cohort study

OBJECTIVE

To assess long term neurodevelopmental outcomes of children born at different gestational ages, particularly 32-33 weeks (moderately preterm) and 34-36 weeks (late preterm), compared with 39-40 weeks (full term).

DESIGN

Nationwide cohort study.

SETTING

Sweden.

PARTICIPANTS

1 281 690 liveborn singleton children without congenital malformations born at 32+0 to 41+6 weeks between 1998 and 2012.

MAIN OUTCOME MEASURES

The primary outcomes of interest were motor, cognitive, epileptic, hearing, and visual impairments and a composite of any neurodevelopmental impairment, diagnosed up to age 16 years. Hazard ratios and 95% confidence intervals were estimated using Cox regression adjusted for parental and infant characteristics in the study population and in the subset of full siblings. Risk differences were also estimated to assess the absolute risk of neurodevelopmental impairment.

RESULTS

During a median follow-up of 13.1 years (interquartile range 9.5-15.9 years), 75 311 (47.8 per 10 000 person years) liveborn singleton infants without congenital malformations had at least one diagnosis of any neurodevelopmental impairment: 5899 (3.6 per 10 000 person years) had motor impairment, 27 371 (17.0 per 10 000 person years) cognitive impairment, 11 870 (7.3 per 10 000 person years) epileptic impairment, 19 700 (12.2 per 10 000 person years) visual impairment, and 20 393 (12.6 per 10 000 person years) hearing impairment. Children born moderately or late preterm, compared with those born full term, showed higher risks for any impairment (hazard ratio 1.73 (95% confidence interval 1.60 to 1.87) and 1.30 (1.26 to 1.35); risk difference 4.75% (95% confidence interval 3.88% to 5.60%) and 2.03% (1.75% to 2.35%), respectively) as well as motor, cognitive, epileptic, visual, and hearing impairments. Risks for neurodevelopmental impairments appeared highest from 32 weeks (the earliest gestational age), gradually declined until 41 weeks, and were also higher at 37-38 weeks (early term) compared with 39-40 weeks. In the sibling comparison analysis (n=349 108), most associations remained stable except for gestational age and epileptic and hearing impairments, where no association was observed; for children born early term the risk was only higher for cognitive impairment compared with those born full term.

CONCLUSIONS

The findings of this study suggest that children born moderately or late preterm have higher risks of adverse neurodevelopmental outcomes. The risks should not be underestimated as these children comprise the largest proportion of children born preterm. The findings may help professionals and families achieve a better risk assessment and follow-up.

Preterm or early term birth and risk of attention-deficit/hyperactivity disorder: a national cohort and co-sibling study

PURPOSE

To examine risks of attention-deficit/hyperactivity disorder (ADHD) in preterm and early term birth survivors, and potential sex-specific differences.

METHODS

A national cohort study was conducted of all 4061,795 singletons born in Sweden in 1973-2013 who survived infancy, followed up for ADHD identified from nationwide diagnoses and medications through 2018. Poisson regression was used to compute prevalence ratios (PRs), adjusting for sociodemographic and perinatal factors. Co-sibling analyses assessed for confounding by unmeasured shared familial (genetic or environmental) factors.

RESULTS

ADHD prevalences by gestational age at birth were 12.1% for extremely preterm (22-27 weeks), 7.0% for moderately preterm (28-33 weeks), 5.7% for late preterm (34-36 weeks), 6.1% for all preterm (<37 weeks), 5.2% for early term (37-38 weeks), and 4.5% for full-term (39-41 weeks). Adjusted PRs comparing extremely preterm, all preterm, or early term versus full-term, respectively, were 2.35 (95% CI, 2.15-2.57), 1.28 (1.25-1.31), and 1.12 (1.10-1.13) among males, and 2.46 (2.17-2.78), 1.24 (1.20-1.28), and 1.08 (1.06-1.10) among females (P < .001 for each). These associations were virtually unchanged after controlling for shared familial factors. Both spontaneous and medically indicated preterm birth were associated with ADHD (adjusted PRs, 1.21; 95% CI, 1.18-1.24; and 1.39; 1.34-1.43, respectively).

CONCLUSIONS

In this large cohort, preterm and early term birth were associated with increased risks of ADHD in males and females, independently of covariates and shared familial factors.

Impact of restricting early-term deliveries on adverse neonatal outcomes: a statewide analysis

BACKGROUND

The "39-Week Rule" was adopted by the American College of Obstetricians and Gynecologists in 2009 to eliminate nonmedically indicated (elective) deliveries before 39 weeks in an effort to improve neonatal outcomes.

OBJECTIVE

Our primary objective was to quantify the effect of this policy change on adverse neonatal outcomes among a cohort of term births in South Carolina.

STUDY DESIGN

Deidentified data from all births in the state of South Carolina from 2000 to 2008 (before the 39-week rule) and from 2013 to 2017 (after statewide implementation and enforcement of the rule) were obtained from the South Carolina Revenue and Fiscal Affairs Office. Demographic data and International Statistical Classification of Diseases and Related Health Problems Ninth/Tenth Revision codes were obtained for each birth. Our primary outcome was admission to a neonatal intensive care unit. Our secondary outcomes were respiratory morbidities (including respiratory distress syndrome and transient tachypnea of the newborn), hypoxic-ischemic encephalopathy, seizure, sepsis, birth injuries, hyperbilirubinemia, hypoglycemia, and feeding difficulties. Propensity score analysis was used to control for maternal age, body mass index, race, gestational hypertension, infection, placental abruption, and gestational and pregestational diabetes mellitus. After stratification by propensity score, the Cochran-Mantel-Haenszel test was used to compare groups.

RESULTS

A total of 620,121 infants were liveborn at term during the 2 study periods. After implementation of the 39-week rule, there was a significant reduction in early-term deliveries. In adjusted analyses, neonatal intensive care unit admission was significantly more common in the postimplementation period. Respiratory morbidities were also significantly more common postimplementation. In contrast, there were significant reductions in birth injuries and hyperbilirubinemia in the postimplementation period.

CONCLUSION

Implementation of the 39-week rule was associated temporally with an increase in adverse neonatal outcomes. The outcomes intended to be reduced by the 39-week rule, including neonatal intensive care unit admission and respiratory morbidity, seem to have increased in incidence despite adherence to the proposed guidelines.

Impact of maternal age on neonatal outcomes among very preterm infants admitted to Chinese neonatal intensive care units: a multi-center cohort study

BACKGROUND

The percentage of advanced maternal age (aged over 35 years) mothers has been rising across the world, the evidence of maternal age on neonatal outcomes from low- and middle-income countries is scarce. Our objective was to evaluate the effect of maternal age on mortality and major morbidity among very preterm infants admitted to Chinese neonatal intensive care units.

METHODS

Data from a retrospective multi-center cohort of all complete care very preterm infants admitted to 57 neonatal intensive care units that participated in the Chinese Neonatal Network from January 1st to December 31st, 2019 were analyzed. Neonatal outcomes including mortality or any major morbidity, defined as necrotizing enterocolitis stage 2 or 3, moderate & severe bronchopulmonary dysplasia, severe intraventricular hemorrhage, cystic periventricular leukomalacia, severe retinopathy of prematurity, or sepsis. A multiple logistic regression model was constructed to analyze the independent association between maternal age and neonatal outcome.

RESULTS

Among 7,698 eligible newborns, 80.5% of very preterm infants were born to mothers between the ages of 21 and 35 years, with 18.0% born to mothers >35 years and 1.5% born to mothers <21 years. Higher rates of maternal hypertension, maternal diabetes, cesarean deliveries, antenatal steroid usage were noted as maternal age increased. The proportion of prenatal care, cesarean section, antenatal steroid usage and inborn for very preterm infants born to mothers <21 years was lower than those of mothers of other ages. Compared to the ages of 21-35 years group, the odds of severe intraventricular hemorrhage (adjusted odd ratio: 2.00, 95% CI: 1.08-3.71) was significantly higher in the ages of 15-20 years group. Increasing maternal age was associated with higher rates of small for gestational age and lower birth weight of very preterm infants, but no correlation between advanced maternal age and very preterm infants mortality or major morbidity.

CONCLUSIONS

Among very preterm infants, increasing maternal age was associated with higher rates of small for gestational age but not neonatal mortality or major morbidity. Young maternal age may increase the risk of severe intraventricular hemorrhage of very preterm infants.

Society for Maternal-Fetal Medicine Special Statement: Quality metrics for optimal timing of antenatal corticosteroid administration

Preterm birth is a leading cause of perinatal morbidity and mortality. Antenatal corticosteroid administration before preterm birth reduces the risks of perinatal death, respiratory morbidity, necrotizing enterocolitis, and intraventricular hemorrhage and reduces the costs of perinatal care. Antenatal corticosteroids are optimally effective when administered within 7 days before preterm birth. However, only 20% to 40% of early preterm infants receive antenatal corticosteroids within 7 days before birth, in part because it is difficult to predict the precise timing of preterm birth. Until 2020, The Joint Commission had a Perinatal Care quality metric measuring the rate of antenatal corticosteroid administration at any time before early preterm birth. This metric incentivized providers to use antenatal corticosteroids liberally. The Joint Commission retired the metric in 2020 after the rate reached more than 97% in The Joint Commission-accredited hospitals. However, the metric did not evaluate whether the timing of antenatal corticosteroid administration was optimal, that is, within 7 days of birth. A 2016 multistakeholder Cooperative Workshop recommended the development of a new quality metric to assess the rate of optimally timed antenatal corticosteroids among early preterm births. In this statement, we outline proposed specifications for such a metric and discuss potential uses, advantages, limitations, and barriers. Furthermore, we propose a balancing metric that tracks the percentage of patients treated with antenatal corticosteroids who ultimately give birth at term. We suggest that the use of these new metrics may incentivize more conservative antenatal corticosteroid timing, which could, in turn, lead to meaningfully improved outcomes for preterm neonates.

Comparison of short-term outcomes of 35-weeks' gestation infants cared for in a level II NICU vs mother-baby, a retrospective study

BACKGROUND

Late preterm infants are at high risk for medical complications and represent a growing NICU population. While 34-weeks' gestation infants are generally admitted to the NICU and 36-weeks'gestation infants stay in mother-baby, there is wide practice variation for 35-weeks'gestation infants. The objective of this study was to compare short-term outcomes of 35-weeks' gestation infants born at two hospitals within the same health system (DUHS), where one (DRH) admits all 35-weeks' gestation infants to their level II NICU and the other (DUH) admits all 35-weeks' gestation infants to mother-baby, unless clinical concern.

METHODS

We conducted a retrospective cohort analysis of 35-weeks' gestation infants born at DUHS from 2014-2019. Infant specific data were collected for birth, demographics, medications, medical therapies, LOS, ED visits and readmissions. 35-weeks' gestation infants at each hospital (DRH vs DUH) that met inclusion criteria were compared, regardless of unit(s) of care.

RESULTS

726 infants of 35-weeks' gestation were identified, 591 met our inclusion criteria (DUH -462, DRH -129). Infants discharged from DRH were more likely to receive medical therapies (caffeine, antibiotics, blood culture, phototherapy, NGT), had a 4 day longer LOS, but were more likely to feed exclusively MBM at discharge. There were no differences in ED visits; however, more infants from DUH were readmitted within 30 days of discharge.

CONCLUSIONS

Our findings suggest admitting 35-weeks' gestation infants directly to the NICU increases medical interventions and LOS, but might reduce hospital readmissions.

Sleep problems in preschool children at the child development center with different developmental status: A questionnaire survey

OBJECTIVE

To investigate the relationship between sleep problems and development in preschool children with suspected developmental delay.

METHODS

A total of 192 preschool children (mean age 4 years; 131 males, 61 females) were recruited from the Child Development Clinic, including 98 preterm children and 94 age- and sex-matched full-term children. All participants underwent evaluation of gross motor, fine motor and speech performance. All parents of all participants completed the Children's Sleep Habits Questionnaire (CSHQ). Some of the participants also underwent psychological evaluation. Correlation analysis and community network analysis were used to investigate the interactions.

RESULTS

The developmental status was: 75.5% developmental delay, 19.3% borderline development, and 5.2% normal development. Eighty-nine percent of the subjects had abnormal CSHQ scores. Age, gestational age, speech development, cognitive development, and socio-emotional development were significantly correlated with the CSHQ. Significant interactions between sleep problems and development were noted mostly in the preterm group.

CONCLUSION

High prevalence of sleep disturbances in children at the Child Development Center was noted and associated with multiple factors. Therefore, during the multidisciplinary evaluation of children with possible developmental delay, inquiring about their sleep quality and habits is strongly recommended. Mitigating sleep problems enhances the efficacy of early intervention programs.

Prostaglandins in biofluids in pregnancy and labour: A systematic review

Prostaglandins are thought to be important mediators in the initiation of human labour, however the evidence supporting this is not entirely clear. Determining how, and which, prostaglandins change during pregnancy and labour may provide insight into mechanisms governing labour initiation and the potential to predict timing of labour onset. The current study systematically searched the existing scientific literature to determine how biofluid levels of prostaglandins change throughout pregnancy before and during labour, and whether prostaglandins and/or their metabolites may be useful for prediction of labour. The databases EMBASE and MEDLINE were searched for English-language articles on prostaglandins measured in plasma, serum, amniotic fluid, or urine during pregnancy and/or spontaneous labour. Studies were assessed for quality and risk of bias and a qualitative summary of included studies was generated. Our review identified 83 studies published between 1968-2021 that met the inclusion criteria. As measured in amniotic fluid, levels of PGE2, along with PGF2α and its metabolite 13,14-dihydro-15-keto-PGF2α were reported higher in labour compared to non-labour. In blood, only 13,14-dihydro-15-keto-PGF2α was reported higher in labour. Additionally, PGF2α, PGF1α, and PGE2 were reported to increase in amniotic fluid as pregnancy progressed, though this pattern was not consistent in plasma. Overall, the evidence supporting changes in prostaglandin levels in these biofluids remains unclear. An important limitation is the lack of data on the complexity of the prostaglandin pathway outside of the PGE and PGF families. Future studies using new methodologies capable of co-assessing multiple prostaglandins and metabolites, in large, well-defined populations, will help provide more insight as to the identification of exactly which prostaglandins and/or metabolites consistently change with labour. Revisiting and revising our understanding of the prostaglandins may provide better targets for clinical monitoring of pregnancies. This study was supported by the Canadian Institutes of Health Research.

Novel oxytocin receptor antagonists for tocolysis: a systematic review and meta-analysis of the available data on the efficacy, safety, and tolerability of retosiban

OBJECTIVE

To assess the efficacy, safety, and tolerability of retosiban-a novel tocolytic unavailable in the US-in the management of preterm labor.

METHODS

We searched ClinicalTrials.Gov, MEDLINE, PubMed, SCOPUS, Web of Science, and the Cochrane Library for relevant clinical trials using the terms "retosiban" and "preterm labor" through 09/2020. We included all published randomized clinical trials (three) that compared retosiban to placebo for preterm labor, excluding conferences, books, reviews, posters, case reports, and animal studies. We analyzed homogeneous data under the fixed-effects model and heterogeneous data under the random-effects model.

RESULTS

We included all randomized clinical trials addressing this topic, which ultimately resulted in three trials with a total of 116 patients. There were no significant differences between retosiban and placebo in births at term (RR = 0.41, p = .02), births ≤7 days from the first study treatment (RR = 0.59, p = .23), or administration of rescue tocolytic (RR = 0.36, p = .07); the maternal adverse events of headache, anemia, constipation, or urinary tract infection (p > .05); or neonatal outcomes of Apgar score at 1 min (p = .88) or 5 min (p = .69), weight (p = .23), head circumference (p = .55), malnutrition (p = .27), hyperbilirubinemia (RR = 0.56, p = .21), jaundice (RR = 1.21, p = .84), respiratory distress (RR = 0.53, p = .49), or tachypnea (RR = 0.40, p = .42).

CONCLUSION

With the limited high quality evidence available, retosiban demonstrates no clear benefit over placebo in the management of preterm labor. Nevertheless, its favorable safety profile, oral bioavailability, and novel mechanism of action and the limited number of studies available for review warrant further analysis.

Preterm or Early Term Birth and Risk of Autism

OBJECTIVES

Preterm birth has been linked with increased risk of autism spectrum disorder (ASD); however, potential causality, sex-specific differences, and association with early term birth are unclear. We examined whether preterm and early term birth are associated with ASD in a large population-based cohort.

METHODS

A national cohort study was conducted of all 4 061 795 singleton infants born in Sweden during 1973-2013 who survived to age 1 year, who were followed-up for ASD identified from nationwide outpatient and inpatient diagnoses through 2015. Poisson regression was used to determine prevalence ratios for ASD associated with gestational age at birth, adjusting for confounders. Cosibling analyses were used to assess the influence of unmeasured shared familial (genetic and/or environmental) factors.

RESULTS

ASD prevalences by gestational age at birth were 6.1% for extremely preterm (22-27 weeks), 2.6% for very to moderate preterm (28-33 weeks), 1.9% for late preterm (34-36 weeks), 2.1% for all preterm (<37 weeks), 1.6% for early term (37-38 weeks), and 1.4% for term (39-41 weeks). The adjusted prevalence ratios comparing extremely preterm, all preterm, or early term versus term, respectively, were 3.72 (95% confidence interval, 3.27-4.23), 1.35 (1.30-1.40), and 1.11 (1.08-1.13) among boys and 4.19 (3.45-5.09), 1.53 (1.45-1.62), and 1.16 (1.12-1.20) among girls (P < .001 for each). These associations were only slightly attenuated after controlling for shared familial factors.

CONCLUSIONS

In this national cohort, preterm and early term birth were associated with increased risk of ASD in boys and girls. These associations were largely independent of covariates and shared familial factors, consistent with a potential causal relationship.

Late preterm births: neonatal mortality and morbidity in twins vs. singletons

OBJECTIVE

To examine the outcomes of twins and singletons in the late preterm period.

MATERIALS AND METHODS

This is a retrospective cohort study of data obtained for 165,894 births in California who delivered between 34 + 0 and 36 + 6 weeks. The primary outcome was neonatal and infant mortality. The secondary outcomes included the following neonatal morbidities: respiratory distress syndrome (RDS), intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), seizure, and sepsis. Univariate analysis was performed using chi-square test and multivariable logistic regression was used to adjust for potential confounders.

RESULTS

There were 143,891 singleton and 22,003 twin gestations included in the study. There was no difference in the primary outcome, neonatal and infant mortality between twins and singletons delivered at 34 and 36 weeks. After controlling for multiple potential confounders, significant differences in secondary outcomes of neonatal morbidity were identified. At 34 weeks, twins had significantly higher rates of IVH (aOR 2.47 (95%CI 1.08-5.64)), NEC (aOR 2.46 (95%CI 1.42-4.29)), RDS (aOR 1.60 (95%CI 1.45-1.77)), and sepsis (aOR 1.19 (95%CI 1.05-1.34)) compared to singletons. By 36 weeks, only an increased risk of RDS persisted among twins.

CONCLUSIONS

While there was no difference in mortality among twins and singletons in the late preterm period, twins may have significantly increased neonatal morbidity compared to singletons delivered between 34 + 0 and 36 + 6 weeks.

Neonatal Morbidities in Infants Born Late Preterm at 35-36 Weeks of Gestation: A Swedish Nationwide Population-based Study

OBJECTIVE

To assess risk for neonatal morbidities among infants born late preterm at 35-36 gestational weeks, early term (37-38 weeks), and late-term (41 weeks) infants, compared with full-term (39-40 weeks) infants.

STUDY DESIGN

This nationwide population-based cohort study included 1 650 450 non-malformed liveborn singleton infants born at 35-41 weeks between 1998 and 2016 in Sweden. The relative risks for low Apgar score (0-3) at 5 minutes; respiratory, metabolic, infectious, and neurologic morbidities; and severe neonatal morbidity (composite outcome) were adjusted for maternal, pregnancy, delivery, and infant characteristics.

RESULTS

Compared with infants born at 39-40 weeks, the adjusted relative risks and proportions of infants born at 35-36 weeks were higher for metabolic morbidity 7.79 (95%, 7.61 to 7.97; 33.75% vs 3.11%), respiratory morbidity 5.54 (95% CI, 5.24 to 5.85; 5.49% vs 0.75%), severe neonatal morbidity 2.42 (95% CI, 2.27 to 2.59; 3.40% versus 1.03%), infectious morbidity 1.98 (95% CI, 1.83 to 2.14; 2.53% vs 0.95%), neurologic morbidity 1.74 (95% CI, 1.48 to 2.03; 0.54% vs 0.23%), and low Apgar score 2.07 (95% CI, 1.72 to 2.51; 0.42% vs 0.12%). The risks for respiratory, severe neonatal morbidity, infectious, neurologic morbidities, and low Apgar score were highest at 35 weeks, gradually decreased until 39 weeks, and increased during 39-41 weeks.

CONCLUSIONS

Infants born late preterm at 35-36 weeks of gestation are at increased risk of neonatal morbidities, although the absolute risks for severe neonatal morbidities are low. Our findings reinforce the need of preventing late preterm delivery to decrease the burden of neonatal morbidity and help professionals and families with a better risk assessment.

Timing of Repeat Cesarean Delivery for Women with a Prior Classical Incision

OBJECTIVE

This study aimed to compare neonatal outcomes for delivery at 36 weeks compared with 37 weeks in women with prior classical cesarean delivery (CCD).

STUDY DESIGN

This was a secondary analysis of the prospective observational cohort of the Eunice Kennedy National Institute for Child and Human Development's Maternal-Fetal Medicine Unit Network Cesarean Registry. Data on cases of repeat cesarean delivery (RCD) in the setting of a prior CCD were abstracted and used for analysis. This study compared outcomes of women who delivered at 36^0/7 to 36^6/7 versus 37^0/7 to 37^6/7 weeks. The primary outcome was a composite of adverse neonatal outcomes that included neonatal intensive care unit (NICU) admission, respiratory distress syndrome (RDS), transient tachypnea of the newborn (TTN), hypoglycemia, mechanical ventilation, sepsis, length of stay ≥5 days, and neonatal death. A composite of maternal outcomes that included uterine rupture, blood transfusion, general anesthesia, cesarean hysterectomy, venous thromboembolism, maternal sepsis, intensive care unit admission, and surgical complications was also evaluated.

RESULTS

There were 436 patients included in the analysis. Women who delivered at 36 weeks (n = 176) were compared those who delivered at 37 weeks (n = 260). There were no differences in baseline characteristics. Delivery at 37 weeks was associated with a reduction in composite neonatal morbidity (24 vs. 34%, adjusted odds ratio [aOR] = 0.61 [0.31-0.94]), including a decrease in NICU admission rates (20 vs. 29%, aOR = 0.63 [0.40-0.99]), hospitalization ≥5 days (13 vs. 24%, aOR = 0.48 [0.29-0.8]), and RDS or TTN (9 vs. 19%, aOR = 0.43 [0.24-0.77]). There was no difference in adverse maternal outcomes (7 vs. 7%, aOR = 0.98 [0.46-2.09]).

CONCLUSION

Delivery at 37 weeks for women with a history of prior CCD is associated with a decrease in adverse neonatal outcomes, compared with delivery at 36 weeks.

KEY POINTS

· Classical cesarean section may have increased risk of uterine rupture in future pregnancies.. · This study compares outcomes of delivery at 370/7 to 376/7 versus 360/7 to 366/7 weeks.. · Delivery at 370/7 to 376/7 weeks was associated with decreased neonatal morbidity..

Long-term Clinical Outcome of Major Adverse Vascular Events After Hypertensive Disorders of Pregnancy

OBJECTIVE

To assess the association between hypertensive disorders of pregnancy and adverse events after pregnancy, including chronic kidney disease and major adverse cardiovascular events (cerebrovascular accident, coronary artery disease, or death).

METHODS

A nationwide, population-based cohort study was conducted analyzing women with hypertensive disorders of pregnancy identified from Taiwan National Health Insurance Research Database from 2004 to 2015. Hypertensive disorders of pregnancy were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification codes. The study cohort was comprised of women aged 20-40 years diagnosed with hypertensive disorders of pregnancy from 2006 to 2013. The comparison group comprised of four randomly selected women without hypertensive disorders of pregnancy, matched for age and index date for each woman with hypertensive disorders of pregnancy. All the women were followed from the date of cohort entry until they developed chronic kidney disease or major adverse cardiovascular events or until the end of 2015, whichever occurred first. A Cox proportional hazard model was used to estimate the risk of chronic kidney disease and major adverse cardiovascular events.

RESULTS

We identified 29,852 women with a diagnosis of hypertensive disorders of pregnancy and 119,408 matched women without hypertensive disorders of pregnancy who fit the inclusion criteria. The crude hazard ratios (HRs) were 5.22 (95% CI 4.67-5.83) and 2.26 (95% CI 1.99-2.57) for chronic kidney disease and major adverse cardiovascular events. After adjusting for potential confounders, hypertensive disorders of pregnancy was associated with a higher risk of chronic kidney disease (adjusted HR, 4.26; 95% CI 3.80-4.78), and major adverse cardiovascular events (adjusted HR, 2.15; 95% CI 1.89-2.45).

CONCLUSION

This population-based cohort study indicated that women with hypertensive disorders of pregnancy are at a higher risk of chronic kidney disease and major adverse cardiovascular events than women without hypertensive disorders of pregnancy. Further studies are required to clarify the nature of these associations and to improve public health interventions.

Association of Maternal History of Allergic Features with Preterm Pregnancy Outcomes in the Japan Environment and Children's Study

INTRODUCTION

Previous studies have reported that maternal asthma increases the risk of preterm birth. We hypothesized that inflammatory reactions caused by allergic diseases might affect the uterine environment and, subsequently, perinatal outcomes. The objective of this study was to examine the associations between allergic features among mothers and preterm pregnancy outcomes in a nationwide birth cohort.

METHODS

We analyzed data from pregnant women obtained from the Japanese Environment and Children's Study (JECS), a nationwide general birth cohort study. We used binomial and multinomial logistic regression models to examine the associations between maternal allergic features and preterm birth, threatened preterm labor (TPL), and preterm premature rupture of the membrane (PPROM).

RESULTS

A total of 97,683 pregnant women were included. Prevalence of preterm birth, TPL, and PPROM was 4.7, 19.6, and 1.2%, respectively. Maternal history of allergic diseases (asthma, allergic rhinitis, allergic conjunctivitis, food allergy, drug allergy, and contact dermatitis) increased the risk of TPL(adjusted odds ratio [aOR] = 1.11 [95% CI: 1.06-1.17], aOR = 1.12 [1.08-1.16], aOR = 1.10 [1.04-1.16], aOR = 1.17 [1.09-1.26], aOR = 1.35 [1.23-1.48], and aOR = 1.34 [1.20-1.49], respectively). Although some maternal allergic features showed a negative association with preterm birth, the variables affecting preterm birth differed according to the gestational age of the fetus (22-33 weeks vs. 34-36 weeks). There were no significant associations between maternal allergic features and PPROM.

CONCLUSION

Maternal allergic disease, except atopic dermatitis, may increase the risk of TPL. Comorbidity of maternal allergic disorders and perinatal adverse outcomes require further investigation.

Current Preterm Birth Prevention Strategies

Preterm birth remains a major issue in obstetrics. Despite efforts to reduce the incidence of preterm delivery, rates in the United States remain high at 10.2% of all live births with an incidence of 10.8% globally. Preterm birth is the leading cause of neonatal morbidity and mortality worldwide. It is also the leading cause of death in children younger than 5 years. Research into this important health topic has allowed for the identification of risk factors for preterm birth, the most important of which is a history of prior preterm birth. Cervical length screening may allow us to identify those at greatest risk of recurrent preterm birth as well as a de novo risk in women with no prior preterm birth history.

Evaluating the effect of care around labor and delivery practices on early neonatal mortality in the Global Network's Maternal and Newborn Health Registry

BACKGROUND

Neonatal deaths in first 28-days of life represent 47% of all deaths under the age of five years globally and are a focus of the United Nation's (UN's) Sustainable Development Goals. Pregnant women are delivering in facilities but that does not indicate quality of care during delivery and the postpartum period. The World Health Organization's Essential Newborn Care (ENC) package reduces neonatal mortality, but lacks a simple and valid composite index that measures its effectiveness.

METHODS

Data on 5 intra-partum and 3 post-partum practices (indicators) recommended as part of ENC, routinely collected in NICHD's Global Network's (GN) Maternal Newborn Health Registry (MNHR) between 2010 and 2013, were included. We evaluated if all 8 practices (Care around Delivery - CAD), combined as an index was associated with reduced early neonatal mortality rates (days 0-6 of life).

RESULTS

A total of 150,848 live births were included in the analysis. The individual indicators varied across sites. All components were present in 19.9% births (range 0.4 to 31% across sites). Present indicators (8 components) were associated with reduced early neonatal mortality [adjusted RR (95% CI):0.81 (0.77, 0.85); p < 0.0001]. Despite an overall association between CAD and early neonatal mortality (RR < 1.0 for all early mortality): delivery by skilled birth attendant; presence of fetal heart and delayed bathing were associated with increased early neonatal mortality.

CONCLUSIONS

Present indicators (8 practices) of CAD were associated with a 19% reduction in the risk of neonatal death in the diverse health facilities where delivery occurred within the GN MNHR. These indicators could be monitored to identify facilities that need to improve compliance with ENC practices to reduce preventable neonatal deaths. Three of the 8 indicators were associated with increased neonatal mortality, due to baby being sick at birth. Although promising, this composite index needs refinement before use to monitor facility-based quality of care in association with early neonatal mortality. Trial registration The identifier of the Maternal Newborn Health Registry at ClinicalTrials.gov is NCT01073475.

Comorbidities in children with intellectual disabilities

BACKGROUND

Intellectual disability (ID) is registered in 2%-3% of newborns. In most cases, the causes are not identifiable.

OBJECTIVE

We explored the correlation between the intellectual disability and gestational age, birth weight, Apgar score, familial diseases, congenital anomalies, and acquired medical disorders, with the aim to estimate the prevalence and severity of comorbidities in the affected children.

METHODS

Our study included 22 children with ID, and 24 with proper psychomotor development, aged 5-10 who were not considered to have ID.

RESULTS

The presence of familial disorders and CNS congenital anomalies increased the risk of ID 4.147 and 2.59 times, respectively. The risk for other congenital and noncongenital diseases was higher (7.38 and 1.4 times, respectively) in children with intellectual disability.

CONCLUSIONS

Children with intellectual disabilities have higher incidence of congenital diseases, family disorders and a higher frequency of acquired disorders during childhood. Apgar score is a sensitive predictor of morbidity regarding congenital as well as noncongenital medical conditions.

Association of Widespread Adoption of the 39-Week Rule With Overall Mortality Due to Stillbirth and Infant Death

IMPORTANCE

To improve neonatal morbidity, efforts have been made to reduce elective deliveries prior to 39 weeks' gestation, also known as the 39-week rule. Prolonging pregnancies also prolongs exposure to the risk of stillbirth. The true association of a 39-week rule with mortality is unknown and studies to date have shown conflicting results.

OBJECTIVE

To determine if widespread adoption of a 39-week rule, limiting elective deliveries prior to 39 weeks' gestation, is associated with an increase or decrease in overall mortality when considering both stillbirths and infant deaths.

DESIGN, SETTING, AND PARTICIPANTS

This historical cohort study used birth certificate and infant death certificate data in the United States to compare years before and after the adoption of the 39-week rule. Births between 2008 and 2009 were considered to be in the preadoption period (n = 7 322 234), and those between 2011 and 2012 were considered to be in the postadoption period (n = 6 972 626). Included births were singleton, nonanomalous births between 37 0/7 weeks' and 42 6/7 weeks' gestation. Statistical analysis was performed from July 19, 2016, through June 27, 2019.

EXPOSURES

The exposure of interest was the Joint Commission adoption of the 39-week rule as a quality measure.

MAIN OUTCOMES AND MEASURES

The primary outcomes of interest were stillbirth and infant death.

RESULTS

A total of 7 322 234 births (49.0% girls and 51.0% boys) were included in the preadoption period and 6 972 626 births (49.1% girls and 50.9% boys) were included in the postadoption period. Compared with the preadoption period, there was a decrease in the proportion of deliveries at 37 weeks (-0.06%) and 38 weeks (-2.5%) and an increase in the proportion of deliveries at 39 weeks (6.8%) and 40 weeks (0.2%) in the postadoption period (P < .001). The stillbirth rate increased in the postadoption cohort compared with preadoption (0.09% vs 0.10%; P < .001). The infant death rate decreased in the postadoption period compared with preadoption (0.21% vs 0.20%; P < .001). An overall mortality rate of 0.31% was calculated for the preadoption period and 0.30% for the postadoption period (P = .06). Additional analysis in a counterfactual model suggests that up to 34.2% of the difference in mortality could be associated with the 39-week rule.

CONCLUSIONS AND RELEVANCE

Stable overall perinatal mortality rates were observed in the 2-year period immediately after adoption of the 39-week rule, despite an increase in stillbirth.

Neurodevelopmental outcome of late-preterm infants: Literature review

Late-preterm infants are characterized by a birth term from 34^0/7 to 36^6/7 weeks of gestation. A foetal brain at 34^0/7 weeks of gestation weighs only 65% of the full-term newborn brain, which suggests a particular cerebral vulnerability to injury during this 6-week period. Epidemiological studies reporting the neurological outcomes of late-preterm infants exhibit large methodological heterogeneity that inhibits clarity on this issue. However, contradictory results and odds ratio values near neutral reveal probable moderate neurodevelopmental delay in late-preterm infants. This observation reflects the variable neurological outcomes of this population according to multiple perinatal factors. Therefore, the current challenge is to define efficient screening strategies to determine infants requiring specific follow-up.

Late preterm: a new high risk group in neonatology

Late preterm infants are those infants born between 34 0/7 weeks through 36 6/7 week of gestation. These are physiologically less mature and have limited compensatory responses to the extrauterine environment compared with term infants. Despite their increased risk for morbidity and mortality, late preterm newborns are often cared in the well-baby nurseries of hospital after birth and are discharged from the hospital by 2-3 days of postnatal age. They are usually treated like developmentally mature term infants because many of them are of same birth weight and same size as term infants. There is a steady increase in the late preterm birth rate in last decade because of either maternal, fetal, or placental/uterine causes. There has been shift in the distribution of births from term and post-term toward earlier gestations. Although late preterm infants are the largest subgroup of preterm infants, there has been little research on this group until recently. This is mainly because of labeling them as "near-term". Such infants were being looked upon as "almost mature", and were thought as neonate requiring either no or minimal concern. In the obstetric and pediatric practice, late preterm infants are often considered functionally and developmentally mature and often managed by protocols developed for full-term infants. Thus, limited efforts are taken to prolong pregnancy in cases of preterm labor beyond 34 weeks, moreover after 34 weeks most centers do not administer antenatal prophylactic steroids. These practices are based on previous studies reporting neonatal mortality and morbidity in the late preterm period to be only slightly higher in comparison with term infants and whereas in the current scenario the difference is significant. Late preterm infants have 2-3-fold increased risk of morbidities such as hypothermia, hypoglycemia, delayed lung fluid clearance, respiratory distress, poor feeding, jaundice, sepsis, and readmission rates after initial hospital discharge. This leads to huge impact on the overall health care resources. In this review, we cover various aspects of these late preterm infants like etiology, immediate and long-term outcome.

The impact of neonatal unit policies on breast milk feeding at discharge of moderate preterm infants: The EPIPAGE-2 cohort study

Facilitating factors and barriers to breast milk feeding (BMF) for preterm infants have been mainly studied in very preterm populations, but little is known about moderate preterm infants. We aimed to analyze hospital unit characteristics and BMF policies associated with BMF at discharge for infants born at 32 to 34 weeks' gestation. EPIPAGE-2, a French national cohort of preterm births, included 883 infants born at 32 to 34 weeks' gestation. We investigated kangaroo care in the first 24 hr, early involvement of parents in feeding support, volume of the unit, BMF information given to mothers hospitalized for threatened preterm delivery, protocols for BMF, presence of a professional trained in human lactation, unit training in neurodevelopmental care, and regional BMF initiation rates in the general population. Multilevel logistic regression analysis was used to investigate associations between unit policies and BMF at discharge, adjusted for individual characteristics and estimating odds ratios (ORs) and 95% confidence intervals (CIs). Overall, 59% (490/828) of infants received BMF at discharge (27% to 87% between units). Rates of BMF at discharge were higher with kangaroo care (adjusted OR 2.03 [95% CI 1.01, 4.10]), early involvement of parents in feeding support (1.94 [1.23, 3.04]), unit training in a neurodevelopmental care programme (2.57 [1.18, 5.60]), and in regions with a high level of BMF initiation in the general population (1.85 [1.05, 3.28]). Creating synergies by interventions at the unit and population level may reduce the variability in BMF rates at discharge for moderate preterm infants.

Impact of the 2017 ACC/AHA Guideline for High Blood Pressure on Evaluating Gestational Hypertension–Associated Risks for Newborns and Mothers

Rationale:

In 2017, the American College of Cardiology (ACC)/American Heart Association (AHA) released a new hypertension guideline for nonpregnant adults, using lower blood pressure values to identify hypertension. However, the impact of this new guideline on the diagnosis of gestational hypertension and the associated maternal and neonatal risks are unknown.

Objective:

To estimate the impact of adopting the 2017 ACC/AHA guideline on detecting gestational blood pressure elevations and the relationship with maternal and neonatal risk in the perinatal period using a retrospective cohort design.

Methods and Results:

This study included 16 345 women from China. Systolic and diastolic blood pressures of each woman were measured at up to 22 prenatal care visits across different stages of pregnancy. Logistic and linear regressions were used to estimate associations of blood pressure categories with the risk of preterm delivery, early-term delivery, and small for gestational age, and indicators of maternal liver, renal, and coagulation functions during pregnancy. We identified 4100 (25.1%) women with gestational hypertension using the 2017 ACC/AHA guideline, compared with 4.2% using the former definition. Gestational hypertension, but not elevated blood pressure (subclinical blood pressure elevation), was significantly associated with altered indicators of liver, renal, and coagulation functions during pregnancy for mothers and increased risk of adverse birth outcomes for newborns; adjusted odds ratios (95% CIs) for gestational hypertension stage 2 were 2.23 (1.18–4.24) for preterm delivery, 2.05 (1.67–2.53) for early-term delivery, and 1.43 (1.13–1.81) for small for gestational age.

Conclusions:

Adopting the 2017 ACC/AHA guideline would result in a substantial increase in the prevalence of gestational hypertension; subclinical blood pressure elevations during late pregnancy were not associated with increased maternal and neonatal risk in this cohort. Therefore, the 2017 ACC/AHA guideline may improve the detection of high blood pressure during pregnancy and the efforts to reduce maternal and neonatal risk. Replications in other populations are required.

Cyclooxygenase inhibitors for treating preterm labour: What is the molecular evidence? 1

Preterm birth (<37 weeks of gestation) significantly increases the risk of neonatal mortality and morbidity. As many as half of all preterm births occur following spontaneous preterm labour. Since in such cases there are no known reasons for the initiation of labour, treatment of preterm labour (tocolysis) has sought to stop labour contractions and delay delivery. Despite some success, the use of cyclooxygenase (COX) inhibitors is associated with maternal/fetal side effects, and possibly increased risk of preterm birth. Clinical use of these drugs predates the collection of molecular and biochemical evidence in vitro, examining the expression and activity of COX enzymes in pregnant uterine tissues with and without labour. Such evidence is important to the rationale that COX enzymes are, or are not, appropriate targets for the tocolysis. The current study systematically searched existing scientific evidence to address the hypothesis that COX expression/activity is increased with the onset of human labour, in an effort to determine whether there is a rationale for the use of COX inhibitors as tocolytics. Our review identified 44 studies, but determined that there is insufficient evidence to support or refute a role of COX-1/-2 in the onset of preterm labour that supports COX-targeted tocolysis.

Physical Exertion Immediately Before Early Preterm Delivery: A Case-Crossover Study

BACKGROUND

Occupational exertion is associated with a higher risk of preterm delivery, although studies of leisure time activities generally document reduced risks. Less is known about the risk of preterm delivery immediately following episodes of moderate or heavy physical exertion.

METHODS

We conducted a case-crossover study of 722 women interviewed during their hospital stay for early preterm delivery, defined by a gestational age before 34 weeks, and after 20 weeks. Interviews occurred between March 2013 and December 2015 in seven hospitals in Lima, Peru.

RESULTS

The incidence rate ratio (RR) of early preterm delivery was 5.82-fold higher (95% confidence interval [CI] = 4.29, 7.36) in the hour following moderate or heavy physical exertion compared with other times and returned to baseline in the hours thereafter. The RR of early preterm delivery within an hour of physical exertion was lower for exertion at moderate intensity (RR = 2.43; 95% CI = 1.50, 3.96) than at heavy intensity (RR = 23.62; 95% CI = 15.54, 35.91; P-homogeneity < 0.001). The RR of early preterm delivery was lower in the hour following moderate physical exertion among women who habitually engaged in physical exertion >3 times per week in the year before pregnancy (RR = 1.56; 95% CI = 0.81, 3.00) compared with more sedentary women (RR = 6.91; 95% CI = 3.20, 14.92; P-homogeneity = 0.003).

CONCLUSIONS

Our study showed a heightened risk of early preterm delivery in the hour following moderate or heavy physical exertion.

At the forefront of psychoneuroimmunology in pregnancy: Implications for racial disparities in birth outcomes PART 1: Behavioral risks factors

Birth prior to full term is a substantial public health issue. In the US, ˜400,000 babies per year are born preterm (<37 weeks), while>1 million are early term (37-38^6/7 weeks). Birth prior to full term confers risk both immediate and long term, including neonatal intensive care, decrements in school performance, and increased mortality risk from infancy through young adulthood. Risk for low birth weight and preterm birth are 1.5-2 times greater among African Americans versus Whites. Psychosocial stress related to being a member of a discriminated racial minority group contributes substantially to these racial disparities. Providing promising targets for intervention, depressed mood, anxiety, and poor sleep are each linked with exposure to chronic stress, including racial discrimination. A rigorous transdisciplinary approach addressing these gaps holds great promise for clinical impact in addressing racial disparities as well as ameliorating effects of stress on perinatal health more broadly. As will be reviewed in a companion paper, the mechanistic roles of physiological sequelae to stress - including neuroendocrine, inflammatory regulation, biological aging, and the microbiome - also require delineation.

Nutritional policies for late preterm and early term infants - can we do better?

Late preterm (LP) and early term (ET) infants can be considered the "great dissemblers": they resemble healthy full-term infants in appearance, but their immaturity places them at increased risk of poor short- and long-term outcomes. Nutritional requirements are greater than for full-term babies, but there are few good data on the nutritional requirements for LP and ET babies, leading to substantial variation in practice. Recent data indicate that rapid growth may be beneficial for neurocognitive function but not for body composition and later metabolic health. Breastfeeding the LP or ET infant can be challenging, and mothers of these infants may need additional support to breastfeed successfully. Future research should investigate nutritional requirements of LP and ET infants for optimal growth, addressing both short- and long-term outcomes and the potential trade-off between neurocognitive and metabolic benefits.

Epidemiology of late preterm and early term births - An international perspective

Late preterm (34-36 weeks of gestational age (GA)), and early term (37-38 weeks GA) birth rates among singleton live births vary from 3% to 6% and from 15% to 31%, respectively, across countries, although data from low- and middle-income countries are sparse. Countries with high preterm birth rates are more likely to have high early term birth rates; many risk factors are shared, including pregnancy complications (hypertension, diabetes), medical practices (provider-initiated delivery, assisted reproduction), maternal socio-demographic and lifestyle characteristics and environmental factors. Exceptions include nulliparity and inflammation which increase risks for preterm, but not early term birth. Birth before 39 weeks GA is associated with adverse child health outcomes across a wide range of settings. International rate variations suggest that reductions in early delivery are achievable; implementation of best practice guidelines for obstetrical interventions and public health policies targeting population risk factors could contribute to prevention of both late preterm and early term births.

Elective caesarean section on maternal request prior to 39 gestational weeks and childhood psychopathology: a birth cohort study in China

BACKGROUND

The recommendation of non-indicated caesarean section (CS) after 39 gestational weeks has been announced based on evidence of maternal and infant physiological effects. The potential psychological risks have not been acknowledged. This study aims to investigate emotional and behavioral problems in pre-school children born with elective CS (ECS) on maternal request prior to 39 weeks.

METHODS

Pregnant women within 12 gestational weeks between November 2008 and October 2010 were invited to participate in the China-Anhui Birth Cohort Study (C-ABCS). They were asked to complete a self-administered questionnaire respectively in 1st and 3rd trimester of pregnancy to collect basic maternal characteristics. Pregnant complications and delivery modes were abstracted from medical notes. Their singleton live births were followed up at preschool age. Strengths and Difficulties Questionnaires (SDQ) were completed by parents to assess children's emotional and behavioral problems. A total of 3319 mother-child pairs were put into the final analysis. Descriptive analysis and binary logistic regression analysis were used to assess the impact of delivery modes on abnormalities in SDQ dimensions at various gestational ages.

RESULTS

The prevalence of ECS on maternal request prior to 39 weeks, at 39-40 weeks, and after 41 weeks was 16.6, 23.7 and 15.9%, respectively. Compared with those born vaginally, children born with ECS on maternal request were more likely to have total difficult problems (RR 1.519, 95% confidence interval 1.077 to 2.142). ECS on maternal request was the independent predictor of emotional problems (3.479, 1.676 to 7.222) and total difficult problems (2.172, 1.175 to 4.016) in children born prior to 39 gestational weeks.

CONCLUSION

Children delivered by ECS on maternal request have an increased risk to have emotional and behavioral problems prior to 39 gestational weeks at preschool age. The potential psychological implication prior to 39 weeks has been added to the roster of impacts of ECS on maternal request. Further research is needed to probe the potential biological mechanisms.

Elevated blood carboxyhemoglobin levels as an early predictor of phototherapy requirement in moderate and late preterm infants

Objective: Preterm infants are prone to increased bilirubin burden and display adverse outcomes if left unmonitored; therefore, predicting an increased bilirubin production is of paramount importance.Methods: We aimed to evaluate carboxyhemoglobin (COHb) levels in moderate (GA: 32^0/7-33^6/7) and late preterm (GA: 34^0/7-36^6/7) infants to assess whether this molecule could be used as an early predictor of phototherapy requirement.Results: A total of 221 infants were enrolled in the study. On admission, carboxyhemoglobin levels of infants who received phototherapy were significantly higher than that of infants who did not require this treatment, and this difference persisted in the consecutive hours (median (min-max): 1.2% (0.3-1.7) versus 0.8% (0.4-1.1); p < .001). The initial and consecutive COHb levels showed positive correlation (r = 0.77, p < .001). In the post-hoc analysis, direct antiglobulin test positivity significantly affected phototherapy requirement (p < .001). Receiver operating characteristics analysis showed that a COHb level of ≥0.95% was found to have a sensitivity of 90% and a specificity of 88%. Multinomial logistic regression analysis demonstrated that high COHb levels on admission significantly increased the likelihood of phototherapy requirement when adjusted for covariants (adjusted odds ratio: 2.2; 95% confidence interval: 1.4-3.5; p < .001).Conclusion: Carboxyhemoglobin measurement can be simply used to predict preterm infants who will require phototherapy.

Evaluation of an intervention supporting breastfeeding among late-preterm infants during in-hospital stay

BACKGROUND

Late-preterm infants show lower breastfeeding rates when compared with term infants. Current practice is to keep them in low-risk wards where clinical guidelines to support breastfeeding are well established for term infants but can be insufficient for late-preterm.

OBJECTIVE

The aim of this study was to evaluate an intervention supporting breastfeeding among late-preterm infants in a maternity service in the Basque Country, Spain.

METHODS

The intervention was designed to promote parents' education and involvement, provide a multidisciplinary approach and decision-making, and avoid separation of the mother-infant dyad. A quasi-experimental study was conducted with a control (n=212) and an intervention group (n=161). Data was collected from clinical records from November 2012 to January 2015. Feeding rate at discharge, breast-pump use, incidence of morbidities, infant weight loss and hospital stay length were compared between the two groups.

RESULTS

Infants in the control group were 50.7% exclusive breastfeeding, 37.8% breastfeeding, and, 11.5% formula feeding at discharge, whereas in the intervention group, frequencies were 68.4%, 25.9%, and 5.7%, respectively (p=0.002). Mothers in the intervention group were 2.66 times more likely to use the breast-pump after almost all or all feeds and 2.09 times more likely to exclusively breastfeed at discharge. There were no significant differences in morbidities and infant weight loss between groups. Hospital stay was longer for infants who required phototherapy in the intervention group (p=0.009).

CONCLUSION

The intervention resulted in a higher breastfeeding rate at discharge. Interventions aimed to provide specific support among late-pretem infants in maternity services are effective.

Antecedents and Outcomes of Abnormal Cranial Imaging in Moderately Preterm Infants

OBJECTIVES

To describe the frequency and findings of cranial imaging in moderately preterm infants (born at 290/7-336/7 weeks of gestation) across centers, and to examine the association between abnormal imaging and clinical characteristics.

STUDY DESIGN

We used data from the Neonatal Research Network Moderately Preterm Registry, including the most severe early (≤28 days) and late (>28 days) cranial imaging. Stepwise logistic regression and CART analysis were performed after adjustment for gestational age, antenatal steroid use, and center.

RESULTS

Among 7021 infants, 4184 (60%) underwent cranial imaging. These infants had lower gestational ages and birth weights and higher rates of small for gestational age, outborn birth, cesarean delivery, neonatal resuscitation, and treatment with surfactant, compared with those without imaging (P < .0001). Imaging abnormalities noted in 15% of the infants included any intracranial hemorrhage (13.2%), grades 3-4 intracranial hemorrhage (1.7%), cystic periventricular leukomalacia (2.6%), and ventriculomegaly (6.6%). Histologic chorioamnionitis (OR, 1.47; 95% CI, 1.19-1.83), gestational age (0.95; 95% CI, 0.94-0.97), antenatal steroids (OR, 0.55; 95% CI, 0.41-0.74), and cesarean delivery (OR, 0.66; 95% CI, 0.53-0.81) were associated with abnormal imaging. The center with the highest rate of cranial imaging, compared with the lowest, had a higher risk of abnormal imaging (OR, 2.08; 95% CI, 1.10-3.92). On the classification and regression-tree model, cesarean delivery, center, antenatal steroids, and chorioamnionitis, in that order, predicted abnormal imaging.

CONCLUSION

Among the 60% of moderately preterm infants with cranial imaging, 15% had intracranial hemorrhage, cystic periventricular leukomalacia or late ventriculomegaly. Further correlation of imaging and long-term neurodevelopmental outcomes in moderately preterm infants is needed.

Effects of a transition home program on preterm infant emergency room visits within 90 days of discharge

OBJECTIVE

To evaluate effects of a transition home program (THP) and risk factors on emergency room (ER) use within 90 days of discharge for preterm (PT) infants <37 weeks gestation.

STUDY DESIGN

This is a prospective 3-year cohort study of 804 mothers and 954 PT infants. Mothers received enhanced neonatal intensive care unit transition support services until 90 days postdischarge. Regression models were run to identify the effects of THP implementation year and risk factors on ER visits.

RESULTS

Of the 954 infants, 181 (19%) had ER visits and 83/181 (46%) had an admission. In regression analysis, THP year 3 vs year 1 and human milk at discharge were associated with decreased risk of ER visits, whereas increased odds was associated with non-English speaking, maternal mental health disorders and bronchopulmonary dysplasia.

CONCLUSION

Enhanced THP services were associated with a 33% decreased risk of all ER visits by year 3. Social and environmental risk factors contribute to preventable ER visits.

The Canadian Preterm Birth Network: a study protocol for improving outcomes for preterm infants and their families

BACKGROUND

Preterm birth (birth before 37 wk of gestation) occurs in about 8% of pregnancies in Canada and is associated with high mortality and morbidity rates that substantially affect infants, their families and the health care system. Our overall goal is to create a transdisciplinary platform, the Canadian Preterm Birth Network (CPTBN), where investigators, stakeholders and families will work together to improve childhood outcomes of preterm neonates.

METHODS

Our national cohort will include 24 maternal-fetal/obstetrical units, 31 neonatal intensive care units and 26 neonatal follow-up programs across Canada with planned linkages to provincial health information systems. Three broad clusters of projects will be undertaken. Cluster 1 will focus on quality-improvement efforts that use the Evidence-based Practice for Improving Quality method to evaluate information from the CPTBN database and review the current literature, then identify potentially better health care practices and implement identified strategies. Cluster 2 will assess the impact of current practices and practice changes in maternal, perinatal and neonatal care on maternal, neonatal and neurodevelopmental outcomes. Cluster 3 will evaluate the effect of preterm birth on babies, their families and the health care system by integrating CPTBN data, parent feedback, and national and provincial database information in order to identify areas where more parental support is needed, and also generate robust estimates of resource use, cost and cost-effectiveness around preterm neonatal care.

INTERPRETATION

These collaborative efforts will create a flexible, transdisciplinary, evaluable and informative research and quality-improvement platform that supports programs, projects and partnerships focused on improving outcomes of preterm neonates.

Early executive function differences in infants born moderate-to-late preterm

Individuals who are born very preterm (<32weeks gestation) show differential development of prefrontal cortex structure, function, and dependent behaviors, including executive function (EF) skills, beginning during late infancy and extending into adulthood. Preschool-aged children born moderate-to-late preterm (PT; 32-36weeks gestation) show smaller discrepancies in EF development, but it is unclear whether these differences first emerge during the early childhood years, when EF is rapidly developing, or if they arise from alterations in complex cognitive skills measurable in late infancy. In the current study, we examined whether differences in complex attention, memory, and inhibition skills (precursor skills to EF) are altered in healthy infants born moderate-to-late PT at 9-months corrected age. Infants born PT demonstrated poorer memory at test following habituation than their full-term peers. Furthermore, lower gestational age at birth was associated with poorer performance on five of the six early EF tasks. Results indicate that even in the context of low medical and environmental risk, performance on the Bayley within the normal range, and no group-level differences in processing speed, infants born moderate-to-late PT show subtle alterations in cognitive skills presumed to be dependent on prefrontal cortex by 9-months of age, likely setting the stage for long-term differences in EF development.

Association of adverse birth outcomes with prenatal exposure to vanadium: a population-based cohort study

BACKGROUND

Vanadium, an important pollutant produced from anthropogenic activities, has been suggested to be embryotoxic and fetotoxic in animal studies. However, little is known about its effects on humans. We aimed to assess the association of prenatal exposure to vanadium with the risk of adverse birth outcomes in babies born to women in China.

METHODS

For this population-based cohort study, the Healthy Baby Cohort, women were recruited from three cities in Hubei Province, China. Women included in this analysis were recruited from Wuhan Women and Children Medical Care Center, Wuhan. We measured urinary concentrations of vanadium and other metals simultaneously using inductively coupled plasma mass spectrometry. We used multivariable logistic regressions, with adjustment for potential confounders, to estimate the associations of natural logarithm transformed creatinine-corrected urinary vanadium (Ln-vanadium) concentrations as continuous variables and categorised into quartiles (Q; Q1: ≤0·84 μg/g creatinine, Q2: 0·84-1·40 μg/g creatinine, Q3: 1·40-2·96 μg/g creatinine, Q4: >2·96 μg/g creatinine, with the lowest quartile set as reference) with preterm delivery, early-term delivery, low birthweight, and being small for gestational age. We applied restricted cubic spline models to evaluate the dose-response relationships.

FINDINGS

Data from 7297 women recruited between Sept 22, 2012, and Oct 22, 2014, were included in this study. Urinary Ln-vanadium concentrations showed non-linear dose-response relationships with risk of preterm delivery (S-shaped, p<0·0001) and low birthweight (J-shaped, p=0·0001); the adjusted odds ratios (ORs) for increasing quartiles of urinary vanadium were 1·76 (95% CI 1·05-2·95) for Q2, 3·17 (1·96-5·14) for Q3, and 8·86 (5·66-13·86) for Q4 for preterm delivery, and 2·29 (95% CI 1·08-4·84) for Q2, 3·22 (1·58-6·58) for Q3, and 3·56 (1·79-7·10) for Q4 for low birthweight. Ln-vanadium concentrations were linearly associated with the risk of early-term delivery (linear, p<0·0001) and being small for gestational age (linear, p=0·0027), with adjusted ORs of 1·15 (95% CI 1·10-1·21) for early-term delivery and 1·12 (1·04-1·21) for being small for gestational age per unit increase in Ln-vanadium concentrations.

INTERPRETATION

Our findings reveal a relationship between prenatal exposure to higher levels of vanadium and increased risk of adverse birth outcomes, suggesting that vanadium might be a potential toxic metal for human beings. Further studies are needed to replicate the observed associations and investigate the interaction effects of prenatal exposure to different metals on adverse birth outcomes.

FUNDING

National Key R&D Plan of China, National Natural Science Foundation of China, and Fundamental Research Funds for the Central Universities, Key Laboratory of Environment and Health.

Treatment of spontaneous preterm labour with retosiban: a phase II pilot dose-ranging study

Aims

The aims of the present study were to investigate the maternal, fetal and neonatal safety and tolerability, pharmacodynamics and pharmacokinetics of intravenous (IV) retosiban in pregnant women with spontaneous preterm labour (PTL) between 34^0/7 and 35^6/7 weeks' gestation.

Methods

In parts A and B of a three‐part, double‐blind, placebo‐controlled, multicentre study, women were randomized 3:1 (Part A) or 2:1 (Part B) to either 12‐h IV retosiban followed by a single dose of oral placebo (R‐P) or 12‐h IV placebo followed by single‐dose oral retosiban (P‐R).

Results

A total of 29 women were randomized; 20 to R‐P and nine to P‐R. An integrated analysis found that adverse events were infrequent in mothers/newborns and consistent with events expected in the population under study or associated with confounding factors. Retosiban was rapidly absorbed after oral administration, with an observed half‐life of 1.45 h. Efficacy analyses included 19 women. While not statistically significant, those receiving R‐P more frequently achieved uterine quiescence in 6 h (R‐P, 63%; 95% credible interval [CrI]: 38, 84; P‐R, 43%; 95% CrI: 12, 78) and more achieved a reduction of ≥50% in uterine contractions in 6 h (R‐P, 63%; 95% CrI: 38, 84; P‐R, 29%; 95% CrI: 4, 64). The number of days to delivery was increased in women receiving R‐P (median 26 days for R‐P vs. 13 days for P‐R).

Conclusions

Intravenous retosiban has a favourable safety and tolerability profile and might prolong pregnancies in women with PTL. The study provides the rationale and dosing strategy for further evaluation of the efficacy of retosiban in the treatment of PTL.

Recurrence of Preterm Birth and Early Term Birth

OBJECTIVE

To examine recurrent preterm birth and early term birth in women's initial and immediately subsequent pregnancies.

METHODS

This retrospective cohort study included 163,889 women who delivered their first and second liveborn singleton neonates between 20 and 44 weeks of gestation in California from 2005 through 2011. Data from hospital discharge records and birth certificates were used for analyses. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression models adjusted for risk factors.

RESULTS

Shorter gestational duration in the first pregnancy increased the risk of subsequent preterm birth (both early, before 32 weeks of gestation, and later, from 32 to 36 weeks of gestation) as well as early term birth (37-38 weeks of gestation). Compared with women with a prior term birth, women with a prior early preterm birth (before 32 weeks of gestation) were at the highest risk for a subsequent early preterm birth (58/935 [6.2%] compared with 367/118,505 [0.3%], adjusted OR 23.3, 95% CI 17.2-31.7). Women with a prior early term birth had more than a twofold increased risk for subsequent preterm birth (before 32 weeks of gestation: 171/36,017 [0.5%], adjusted OR 2.0, 95% CI 1.6-2.3; from 32 to 36 weeks of gestation: 2,086/36,017 [6.8%], adjusted OR 3.0, 95% CI 2.9-3.2) or early term birth (13,582/36,017 [37.7%], adjusted OR 2.2, 95% CI 2.2-2.3).

CONCLUSION

Both preterm birth and early term birth are associated with these outcomes in a subsequent pregnancy. Increased clinical attention and research efforts may benefit from a focus on women with a prior early term birth as well as those with prior preterm birth.

Gestational age within normal range and infants' health and temperament at 3-months of age

OBJECTIVE

To examine the association between gestational age (GA) at birth across the normal GA spectrum (37-41 weeks) and the temperament and health of 3-month old infants.

METHODS

The sample comprised 242 "low-risk" mothers and infants without chronic illnesses or severe pregnancy complications. Infant temperament was defined by three constructs: Negative Affectivity (NA), Extraversion, and Regulation, assessed by parents' reports on the Infant Behavior Questionnaire. Infants' health was defined as the number of nonroutine doctors' visits attended by the infants since their release from the hospital after birth. Analyses employed a continuous measure of GA to assess outcomes across GAs and a categorical measure (37, 38, 39-41 weeks GA) to examine contrasts.

RESULTS

Extraversion was positively related to GA primarily due to the lower scores of infants born at 37 weeks compared to infants born at 39-41 weeks GA. NA showed a similar effect. The odds of infants born at 37 weeks attending a nonroutine medical visit were 2.8 times that of infants born full-term.

DISCUSSION

Infants born at 37 weeks GA express less affect and use more nonroutine medical services than do infants born at 39-41 weeks GA. The findings underscore the importance of considering the risks of pregnancy prolongation with the developmental risk associated with early-term delivery.

Physical activity outcomes following preterm birth

Physical activity (PA) is an important mediator of health and disease. Many correlates may play an important role in explaining differences in PA between populations; however, the role of birth outcomes such as prematurity on levels of PA is relatively poorly represented in the literature. Children born preterm may be at risk for reduced levels of PA as they have increased respiratory symptoms as well as decrements in lung function and exercise capacity. Emerging evidence suggests that the effects are prevalent across the whole range of gestational age. This review summarises the current literature in regards to levels of PA in preterm-born children and also explores PA in cohorts of young adults in order to contextualise the possible impact on long term risks to respiratory health.

Betamethasone-exposed preterm birth does not impair insulin action in adult sheep

Preterm birth is associated with increased risk of type 2 diabetes (T2D) in adulthood; however, the underlying mechanisms are poorly understood. We therefore investigated the effect of preterm birth at ~0.9 of term after antenatal maternal betamethasone on insulin sensitivity, secretion and key determinants in adulthood, in a clinically relevant animal model. Glucose tolerance and insulin secretion (intravenous glucose tolerance test) and whole-body insulin sensitivity (hyperinsulinaemic euglycaemic clamp) were measured and tissue collected in young adult sheep (14 months old) after epostane-induced preterm (9M, 7F) or term delivery (11M, 6F). Glucose tolerance and disposition, insulin secretion, β-cell mass and insulin sensitivity did not differ between term and preterm sheep. Hepatic PRKAG2 expression was greater in preterm than in term males (P = 0.028), but did not differ between preterm and term females. In skeletal muscle, SLC2A4 (P = 0.019), PRKAA2 (P = 0.021) and PRKAG2 (P = 0.049) expression was greater in preterm than in term overall and in males, while INSR (P = 0.047) and AKT2 (P = 0.043) expression was greater in preterm than in term males only. Hepatic PRKAG2 expression correlated positively with whole-body insulin sensitivity in males only. Thus, preterm birth at 0.9 of term after betamethasone does not impair insulin sensitivity or secretion in adult sheep, and has sex-specific effects on gene expression of the insulin signalling pathway. Hence, the increased risk of T2D in preterm humans may be due to factors that initiate preterm delivery or in early neonatal exposures, rather than preterm birth per se.

Impact of a Transition Home Program on Rehospitalization Rates of Preterm Infants

OBJECTIVES

To evaluate the effects of a transition home program on 90-day rehospitalization rates of preterm (PT) infants born at <37 weeks gestational age implemented over 3 years for infants with Medicaid and private insurance, and to identify the impact of social/environmental and medical risk factors on rehospitalization.

STUDY DESIGN

In this prospective cohort study of 954 early, moderate, and late PT infants, all families received comprehensive transition home services provided by social workers and family resource specialists (trained peers) working with the medical team. Rehospitalization data were obtained from a statewide database and parent reports. Group comparisons were made by insurance type. Regression models were run to identify factors associated with rehospitalization and duration of rehospitalization.

RESULTS

In bivariable analyses, Medicaid was associated with more infants hospitalized, more than 1 hospitalization, and more days of hospitalization. Early PT infants had more rehospitalizations by 90 days than moderate (P = .05) or late PT infants (P = .01). In regression modeling, year 3 of the transition home program vs year 1 was associated with a lower risk for rehospitalization by 90 days (OR, 0.57; 95% CI, 0.36-0.93; P = .03). Medicaid (P = .04), non-English-speaking (P = .02), multiple pregnancies (P = .05), and bronchopulmonary dysplasia (P = .001) were associated with increased risk. Both bronchopulmonary dysplasia and Medicaid were associated with increased days of rehospitalization in adjusted analyses. The major cause of rehospitalization was respiratory illness (61%).

CONCLUSIONS

Transition home prevention strategies must be directed at both social/environmental and medical risk factors to decrease the risk of rehospitalization.

Gestational age and 1-year hospital admission or mortality: a nation-wide population-based study

Background

Describe the 1-year hospitalization and in-hospital mortality rates, in infants born after 31 weeks of gestational age (GA).

Methods

This nation-wide population-based study used the French medico-administrative database to assess the following outcomes in singleton live-born infants (32–43 weeks) without congenital anomalies (year 2011): neonatal hospitalization (day of life 1 – 28), post-neonatal hospitalization (day of life 29 – 365), and 1-year in-hospital mortality rates. Marginal models and negative binomial regressions were used.

Results

The study included 696,698 live-born babies. The neonatal hospitalization rate was 9.8%. Up to 40 weeks, the lower the GA, the higher the hospitalization rate and the greater the likelihood of requiring the highest level of neonatal care (both p < 0.001). The relative risk adjusted for sex and pregnancy-related diseases (aRR) reached 21.1 (95% confidence interval [CI]: 19.2-23.3) at 32 weeks. The post-neonatal hospitalization rate was 12.1%. The raw rates for post-neonatal hospitalization fell significantly from 32 – 40 and increased at 43 weeks and this persisted after adjustment (aRR = 3.6 [95% CI: 3.3–3.9] at 32 and 1.5 [95% CI: 1.1–1.9] at 43 compared to 40 weeks). The main causes of post-neonatal hospitalization were bronchiolitis (17.2%), gastroenteritis (10.4%) ENT diseases (5.4%) and accidents (6.2%). The in-hospital mortality rate was 0.85‰, with a significant decrease (p < 0.001) according to GA at birth (aRR = 3.8 [95% CI: 2.4–5.8] at 32 and 6.6 [95% CI: 2.1–20.9] at 43, compared to 40 weeks.

Conclusion

There’s a continuous change in outcome in hospitalized infants born above 31 weeks. Birth at 40 weeks gestation is associated with the lowest 1-year morbidity and mortality.

Effect of early-term birth on respiratory symptoms and lung function in childhood and adolescence

BACKGROUND

Early-term-born subjects, (37-38 weeks' gestation), form a large part of the population and have an increased risk of neonatal respiratory morbidity and childhood respiratory symptoms; there is a paucity of data on their later lung function. We sought to (1) compare lung function at 8-9 and 14-17 years in early-term-born children with full-term-born children (39-43 weeks' gestation); (2) assess the role of caesarean section delivery; and (3) compare respiratory symptoms and diagnosis of asthma.

METHODS

Caucasian, singleton, term births from the Avon Longitudinal Study of Parents and Children (n = 14,062) who had lung spirometry at 8-9 (n = 5,465) and/or 14-17 (n = 3,666) years were classified as early or full term.

RESULTS

At 8-9 years, standardized spirometry measures, although within the normal range, were lower in the early-term-born group, (n = 911), compared to full-term controls (n = 4,554). Delivery by caesarean section did not influence later spirometry, and the effect of early-term birth was not modified by delivery by caesarean section. At 14-17 years, the spirometry measures in the early-term group, (n = 602), were similar to the full-term group (3,064), and the rates of asthma and respiratory symptoms were also similar between the two gestation groups.

CONCLUSIONS

Early-term-born children had lower lung function values at 8-9 years compared to the full-term group, but were similar by 14-17 years of age. Delivery at early term should be avoided due to early and late morbidity. Pediatr Pulmonol. 2016;51:1212-1221. © 2016 Wiley Periodicals, Inc.

Fetal inflammation associated with minimal acute morbidity in moderate/late preterm infants

OBJECTIVE

To determine whether exposure to acute chorioamnionitis and fetal inflammation caused short-term adverse outcomes.

DESIGN

This is a prospective observational study: subjects were mothers delivering at 32-36 weeks gestation and their preterm infants at a large urban tertiary level III perinatal unit (N=477 infants). Placentae and fetal membranes were scored for acute histological chorioamnionitis based on the Redline criteria. Fetal inflammation was characterised by histological diagnosis of funisitis (umbilical cord inflammation), increased cord blood cytokines measured by ELISA, and activation of the inflammatory cells infiltrating the placenta and fetal membranes measured by immunohistology. Maternal and infant data were collected.

RESULTS

Twenty-four per cent of 32-36-week infants were exposed to histological chorioamnionitis and 6.9% had funisitis. Immunostaining for leucocyte subsets showed selective infiltration of the placenta and fetal membranes with activated neutrophils and macrophages with chorioamnionitis. Interleukin (IL) 6, IL-8 and granulocyte colony-stimulating factor were selectively increased in the cord blood of preterm infants with funisitis. Compared with infants without chorioamnionitis, funisitis was associated with increased ventilation support during resuscitation (43.8% vs 15.4%) and more respiratory distress syndrome postnatally (27.3% vs 10.2%) in univariate analysis. However, these associations disappeared after adjusting for prematurity.

CONCLUSIONS

Despite fetal exposure to funisitis, increased cord blood cytokines and activated placental inflammatory cells, we could not demonstrate neonatal morbidity specifically attributable to fetal inflammation after adjusting for gestational age in moderate and late preterm infants.