Survival of pre-viable preterm infants in the United States: a systematic review and meta-analysis

Research priorities for the most premature babies born <25 weeks' gestation: results of an international priority setting partnership

OBJECTIVE

The James Lind Alliance (JLA) Most Premature Babies Priority Setting Partnership aimed to identify the most important areas for research for infants born <25 weeks' gestation.

DESIGN

Employing standardised JLA methodology, questions for research were sought from stakeholders via an online survey. Summary questions were formed and checked against existing evidence, with unanswered questions compiled into a second shortlisting survey for prioritisation by stakeholders. A stakeholder consensus workshop was held to determine the top 10 research priorities.

PARTICIPANTS

People with lived experience of neonatal intensive care, including parents/carers of preterm infants and adults born preterm, and healthcare professionals caring for preterm infants across Australia, New Zealand and the UK.

MAIN OUTCOME MEASURE

The top 10 research priorities for infants born <25 weeks' gestation.

RESULTS

From 844 questions received from the initial survey, 81 summary questions were formed, of which 80 were unanswered and included in the second shortlisting survey. The 19 top-ranked questions were taken to the final prioritisation workshop, where the top 10 research priorities were determined by people with lived experience and healthcare professionals. The most important research question identified was 'What can be done in the neonatal intensive care unit to improve long-term health and developmental outcomes?'. Other important areas for research included antenatal interventions and neonatal care at birth, preventing intraventricular haemorrhages, managing pain, postnatal corticosteroid treatment and supporting families.

CONCLUSIONS

This study identified the most important areas of research for infants born <25 weeks' gestation, as determined jointly by stakeholders. These findings should be used to guide future research and funding aimed at improving meaningful outcomes for these infants and their families.

Survival outcomes among periviable infants: a systematic review and meta-analysis comparing different income countries and time periods

Background

Periviable infants are a highly vulnerable neonatal group, and their survival rates are considerably affected by patient-, caregiver-, and institution-level factors, exhibiting wide variability across different income countries and time periods. This study aims to systematically review the literature on the survival rates of periviable infants and compare rates among countries with varied income levels and across different time periods.

Methods

Comprehensive searches were conducted across MEDLINE, Embase, CENTRAL, and Web of Science. Cohort studies reporting survival outcomes by gestational age (GA) for periviable infants born between 22 + 0 and 25 + 6 weeks of gestation were considered. Paired reviewers independently extracted data and assessed the risk of bias and quality of evidence. Data pooling was achieved using random-effects meta-analyses.

Results

Sixty-nine studies from 25 countries were included, covering 56,526 live births and 59,104 neonatal intensive care unit (NICU) admissions. Survival rates for infants born between 22 and 25 weeks of GA ranged from 7% (95% CI 5-10; 22 studies, n = 5,658; low certainty) to 68% (95% CI 63-72; 35 studies, n = 21,897; low certainty) when calculated using live births as the denominator, and from 30% (95% CI 25-36; 31 studies, n = 3,991; very low certainty) to 74% (95% CI 70-77; 48 studies, n = 17,664, very low certainty) for those admitted to NICUs. The survival rates improved over the two decades studied; however, stark contrasts were evident across countries with varying income levels.

Conclusion

Although the survival rates for periviable infants have improved over the past two decades, substantial disparities persist across different economic settings, highlighting global inequalities in perinatal health. Continued research and collaborative efforts are imperative to further improve the global survival and long-term outcomes of periviable infants, especially those in Low- and Middle-Income Countries.

Systematic review registration

PROSPERO, CRD42022376367, available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022376367.

Age of Viability: Clarifying Prenatal Documentation and Definitions in India's Contemporary Medical Landscape

The concept of foetal viability has evolved significantly and has been influenced by advancements in neonatal care and legal frameworks. This review explores the complexities of defining foetal viability in India's contemporary medical landscape, particularly in light of the recent extension of the Medical Termination of Pregnancy (MTP) Act to 24 weeks. The article examines the confusion surrounding the classification of extreme preterm births, Medical Termination of Pregnancy (MTP) Act, and prenatal documentation during sonography. It addresses the challenges in distinguishing between preterm birth and abortion and proposes solutions to standardize definitions and practices.

Impact of preterm birth on muscle mass and function: a systematic review and meta-analysis

Individuals born preterm present lower exercise capacity. Along with the cardiopulmonary responses and activity level, muscle strength is a key determinant of exercise capacity. This systematic review aimed to summarize the current knowledge on the impact of preterm birth on skeletal muscle mass and function across the lifespan. The databases PubMed, MEDLINE, EBM, Embase, CINAHL Plus, Global Index Medicus, and Google Scholar were searched using keywords and MeSH terms related to skeletal muscle, preterm birth, and low birth weight. Two independent reviewers undertook study selection, data extraction, and quality appraisal using Covidence review management. Data were pooled to estimate the prematurity effect on muscle mass and function using the R software. From 4378 studies retrieved, 132 were full-text reviewed and 25 met the inclusion/exclusion criteria. Five studies presented a low risk of bias, and 5 had a higher risk of bias due to a lack of adjustment for confounding factors and presenting incomplete outcomes. Meta-analyses of pooled data from homogenous studies indicated a significant reduction in muscle thickness and jump test (muscle power) in individuals born preterm versus full-term with standardized mean difference and confidence interval of - 0.58 (0.27, 0.89) and - 0.45 (0.21, 0.69), respectively.    Conclusion: Overall, this systematic review summarizing the existing literature on the impact of preterm birth on skeletal muscle indicates emerging evidence that individuals born preterm, display alteration in the development of their skeletal muscle mass and function. This work also highlights a clear knowledge gap in understanding the effect of preterm birth on skeletal muscle development. What is Known: • Preterm birth, which occurs at a critical time of skeletal muscle development and maturation, impairs the development of different organs and tissues leading to a higher risk of comorbidities such as cardiovascular diseases. • Preterm birth is associated with reduced exercise capacity. What is New: • Individuals born preterm display alterations in muscle mass and function compared to individuals born at term from infancy to adulthood. • There is a need to develop preventive or curative interventions to improve skeletal muscle health in preterm-born individuals.

Neonatal outcomes of early preterm births according to the delivery indications

OBJECTIVE

To compare the neonatal outcomes of early preterm births according to delivery indications and determine the obstetric risk factors associated with adverse outcomes.

METHODS

We retrospectively studied pregnancies delivered between 22 + 0 and 26 + 6 weeks at the tertiary center between April 2013 and April 2022. Stillbirths, elective termination of pregnancy, and multifetal pregnancies were excluded. Patients were classified into two groups according to delivery indications: spontaneous preterm birth (sPTB) due to premature rupture of membranes (PROM), preterm labor, or acute cervical insufficiency; and indicated preterm birth (iPTB). Obstetric and neonatal outcomes were compared between the groups.

RESULTS

Of the 121 neonates, 73 % (88/121) underwent sPTB. The overall survival rates were 73 % and 49 % in the sPTB and iPTB groups, respectively (p = 0.017). Multivariate logistic regression analysis was performed with adjustment for gestational age at delivery, fetal growth restriction, cesarean section, histological chorioamnionitis, and funisitis. Moreover, in the 1-year follow-up, the proportion of body mass below the third percentile was significantly higher in the iPTB-group than in the sPTB-group (53 % vs. 20 %, p = 0.019). Furthermore, diagnoses of developmental delay and cerebral palsy were slightly higher in the iPTB-group (33 % and 20 %, respectively) than in the sPTB-group (27 % and 9 %, respectively); however, this difference was not statistically significant.

CONCLUSIONS

In early preterm births, iPTB was associated with a higher neonatal mortality than sPTB.

Trends in Active Treatment of Live-born Neonates Between 22 Weeks 0 Days and 25 Weeks 6 Days by Gestational Age and Maternal Race and Ethnicity in the US, 2014 to 2020

IMPORTANCE

Birth in the periviable period between 22 weeks 0 days and 25 weeks 6 days' gestation is a major source of neonatal morbidity and mortality, and the decision to initiate active life-saving treatment is challenging.

OBJECTIVE

To assess whether the frequency of active treatment among live-born neonates in the periviable period has changed over time and whether active treatment differed by gestational age at birth and race and ethnicity.

DESIGN, SETTING, AND PARTICIPANTS

Serial cross-sectional descriptive study using National Center for Health Statistics natality data from 2014 to 2020 for 61 908 singleton live births without clinical anomalies between 22 weeks 0 days and 25 weeks 6 days in the US.

EXPOSURES

Year of delivery, gestational age at birth, and race and ethnicity of the pregnant individual, stratified as non-Hispanic Asian/Pacific Islander, non-Hispanic Black, Hispanic/Latina, and non-Hispanic White.

MAIN OUTCOMES AND MEASURES

Active treatment, determined by whether there was an attempt to treat the neonate and defined as a composite of surfactant therapy, immediate assisted ventilation at birth, assisted ventilation more than 6 hours in duration, and/or antibiotic therapy. Frequencies, mean annual percent change (APC), and adjusted risk ratios (aRRs) were estimated.

RESULTS

Of 26 986 716 live births, 61 908 (0.2%) were periviable live births included in this study: 5% were Asian/Pacific Islander, 37% Black, 24% Hispanic, and 34% White; and 14% were born at 22 weeks, 21% at 23 weeks, 30% at 24 weeks, and 34% at 25 weeks. Fifty-two percent of neonates received active treatment. From 2014 to 2020, the overall frequency (mean APC per year) of active treatment increased significantly (3.9% [95% CI, 3.0% to 4.9%]), as well as among all racial and ethnic subgroups (Asian/Pacific Islander: 3.4% [95% CI, 0.8% to 6.0%]); Black: 4.7% [95% CI, 3.4% to 5.9%]; Hispanic: 4.7% [95% CI, 3.4% to 5.9%]; and White: 3.1% [95% CI, 1.1% to 4.4%]) and among each gestational age range (22 weeks: 14.4% [95% CI, 11.1% to 17.7%] and 25 weeks: 2.9% [95% CI, 1.5% to 4.2%]). Compared with neonates born to White individuals (57.0%), neonates born to Asian/Pacific Islander (46.2%; risk difference [RD], -10.81 [95% CI, -12.75 to -8.88]; aRR, 0.82 [95% CI, [0.79-0.86]), Black (51.6%; RD, -5.42 [95% CI, -6.36 to -4.50]; aRR, 0.90 [95% CI, 0.89 to 0.92]), and Hispanic (48.0%; RD, -9.03 [95% CI, -10.07 to -7.99]; aRR, 0.83 [95% CI, 0.81 to 0.85]) individuals were significantly less likely to receive active treatment.

CONCLUSIONS AND RELEVANCE

From 2014 to 2020 in the US, the frequency of active treatment among neonates born alive between 22 weeks 0 days and 25 weeks 6 days significantly increased, and there were differences in rates of active treatment by race and ethnicity.

Maternal and neonatal outcomes of expectantly managed pregnancies with previable preterm premature rupture of membranes

PURPOSE

This study aimed to describe the maternal and fetal outcomes associated with expectant management following previable preterm premature rupture of membranes (PPROM) before 24 weeks of gestation. We also analyzed the risk estimates of potential confounders to clarify whether these variables are contributed to the risk of postnatal mortality among these neonates.

METHODS

This retrospective cohort study included all pregnant patients who experienced previable PPROM before 24 weeks of gestation at a tertiary maternal-fetal medicine center. We used the neonatal data from birth until discharge.

RESULTS

A total of 128 women were enrolled. The survival to discharge rate was 60.9%. The median latency period (80 vs. 20 days, respectively, p < 0.001) was significantly longer, the median gestational week at delivery (34 vs. 25 weeks, respectively, p < 0.001) and median birth weight (2100 vs. 710 g, p < 0.001) was significantly higher in the survivor group than the non-survivor group. Surviving neonates had significantly lower frequencies of anhydramnios at any time during the latency period than the non-survivor neonates (38.4% vs. 86.0%, respectively, p < 0.001).

CONCLUSION

This study demonstrated an opposite correlation between the duration of latency period and gestational age at PPROM with earlier membrane rupture in pregnancies having a longer latency period, which additionally clarifies the higher gestational age at delivery. The antepartum factors that increased the possibility of postnatal mortality within our study included the gestational week at delivery, duration of the latency period, anhydramnios at any time during the latency period, and birth weight.

Nitrate in Drinking Water during Pregnancy and Spontaneous Preterm Birth: A Retrospective Within-Mother Analysis in California

BACKGROUND

Nitrate is a widespread groundwater contaminant and a leading cause of drinking water quality violations in California. Associations between nitrate exposure and select adverse birth outcomes have been suggested, but few studies have examined gestational exposures to nitrate and risk of preterm birth (before 37 wk gestation).

OBJECTIVE

We investigated the association between elevated nitrate in drinking water and spontaneous preterm birth through a within-mother retrospective cohort study of births in California.

METHODS

We acquired over 6 million birth certificate records linked with Office of Statewide Health Planning and Development hospital discharge data for California births from 2000-2011. We used public water system monitoring records to estimate nitrate concentrations in drinking water for each woman's residence during gestation. After exclusions, we constructed a sample of 1,443,318 consecutive sibling births in order to conduct a within-mother analysis. We used separate conditional logistic regression models to estimate the odds of preterm birth at 20-31 and 32-36 wk, respectively, among women whose nitrate exposure changed between consecutive pregnancies.

RESULTS

Spontaneous preterm birth at 20-31 wk was increased in association with tap water nitrate concentrations during pregnancy of 5 to <10mg/L [odds ratio (OR)=1.47; 95% confidence interval (CI): 1.29, 1.67] and ≥10mg/L (OR=2.52; 95% CI: 1.49, 4.26) compared with <5mg/L (as nitrogen). Corresponding estimates for spontaneous preterm birth at 32-36 wk were positive but close to the null for 5 to <10mg/L nitrate (OR=1.08; 95% CI: 1.02, 1.15) and for ≥10mg/L nitrate (OR=1.05; 95% CI: 0.85, 1.31) vs. <5mg/L nitrate. Our findings were similar in several secondary and sensitivity analyses, including in a conventional individual-level design.

DISCUSSION

The results suggest that nitrate in drinking water is associated with increased odds of spontaneous preterm birth. Notably, we estimated modestly increased odds associated with tap water nitrate concentrations of 5 to <10mg/L (below the federal drinking water standard of 10mg/L) relative to <5mg/L. https://doi.org/10.1289/EHP8205.

Regional Contribution of Previable Infant Deaths to Infant Mortality Rates in the United States

OBJECTIVE

Lack of standardization of infant mortality rate (IMR) calculation between regions in the United States makes comparisons potentially biased. This study aimed to quantify differences in the contribution of early previable live births (<20 weeks) to U.S. regional IMR.

STUDY DESIGN

Population-based cohort study of all U.S. live births and infant deaths recorded between 2007 and 2014 using Centers for Disease Control and Prevention's (CDC's) WONDER database linked birth/infant death records (births from 17-47 weeks). Proportion of infant deaths attributable to births <20 vs. 20 to 47 weeks, and difference (ΔIMR) between reported and modified (births ≥20 weeks) IMRs were compared across four U.S. census regions (North, South, Midwest, and West).

RESULTS

Percentages of infant deaths attributable to birth <20 weeks were 6.3, 6.3, 5.3, and 4.1% of total deaths for Northeast, Midwest, South, and West, respectively, p < 0.001. Contribution of < 20-week deaths to each region's IMR was 0.34, 0.42, 0.37, and 0.2 per 1,000 live births. Modified IMR yielded less regional variation with IMRs of 5.1, 6.2, 6.6, and 4.9 per 1,000 live births.

CONCLUSION

Live births at <20 weeks contribute significantly to IMR as all result in infant death. Standardization of gestational age cut-off results in more consistent IMRs among U.S. regions and would result in U.S. IMR rates exceeding the healthy people 2020 goal of 6.0 per 1,000 live births.

Periviability: A Review of Key Concepts and Management for Perinatal Nursing

One of the most complex clinical problems in obstetrics and neonatology is caring for pregnant women at the threshold of viability. Births near viability boundaries are grave events that carry a high prevalence of neonatal death or an increased potential for severe lifelong complications and disabilities among those who survive. Compared with several decades ago, premature infants receiving neonatal care by today's standards have better outcomes than those born in other eras. However, preterm labor at periviability represents a more complex counseling and management challenge. Although preterm birth incidence between 20/7 and 25/7 weeks has remained unchanged, survival rates at earlier gestational ages have increased as perinatal and neonatal specialties have become more adept at caring for this at-risk population. Women face difficult choices about obstetric and neonatal interventions in light of uncertainties around survival and outcomes. This article reviews current neonatal statistics in reference to short- and long-term outcomes, key concepts in obstetric clinical management of an anticipated periviable birth, and counseling guidance to ensure shared-decision making.

Women born with very low birth weight have similar menstrual cycle pattern, pregnancy rates and hormone profiles compared with women born at term

BACKGROUND

Individuals born very preterm or with very low birth weight (VLBW) have a reduced likelihood to reproduce according to population-based register studies. Extremely low-birth weight born adults had a lower reproduction rate for both men and women in a follow-up study.

AIM

To investigate if being born with VLBW is associated with differences in the reproductive health, i.e. age of menarche, menstrual cycle pattern, pregnancy rates and hormone profile compared with women born at term.

METHODS

A prospective long-term follow-up of a cohort of live-born VLBW children and their controls studied repeatedly since birth and now assessed at 26-28 years of age. Of the totally 80 girls enrolled from birth 49 women (24 VLBW women and 25 controls) participated in the current follow-up. The women's anthropometric data and serum hormone levels were analysed.

RESULTS

The reproductive hormone levels, including Anti-Mullerian Hormone, did not differ significantly between VLBW women and their controls. Both groups reported menstrual cycle irregularities and pregnancies to the same extent but the VLBW women reported 1.5 years later age of menarche. The VLBW subjects had a catch-up growth within 18 months of birth but remained on average 5 cm shorter in adult height. There were no significant differences in BMI, sagittal abdominal diameter, blood pressure or in their answers regarding life style between the VLBW women and the controls.

CONCLUSION

No differences in the reproductive hormone levels were found between VLBW women and their controls. Although age at menarche was somewhat higher in the VLBW group menstrual cycles and pregnancy rates were similar in the VLBW and control groups. Further follow-up studies are required to elucidate the health outcomes of being born VLBW.

Survival and Impairment of Extremely Premature Infants: A Meta-analysis

CONTEXT

Survival of infants born at the limit of viability varies between high-income countries.

OBJECTIVE

To summarize the prognosis of survival and risk of impairment for infants born at 22 + 0/7 weeks' to 27 + 6/7 weeks' gestational age (GA) in high-income countries.

DATA SOURCES

We searched 9 databases for cohort studies published between 2000 and 2017 in which researchers reported on survival or neurodevelopmental outcomes.

STUDY SELECTION

GA was based on ultrasound results, the last menstrual period, or a combination of both, and neurodevelopmental outcomes were measured by using the Bayley Scales of Infant Development II or III at 18 to 36 months of age.

DATA EXTRACTION

Two reviewers independently extracted data and assessed the risk of bias and quality of evidence.

RESULTS

Sixty-five studies were included. Mean survival rates increased from near 0% of all births, 7.3% of live births, and 24.1% of infants admitted to intensive care at 22 weeks' GA to 82.1%, 90.1%, and 90.2% at 27 weeks' GA, respectively. For the survivors, the rates of severe impairment decreased from 36.3% to 19.1% for 22 to 24 weeks' GA and from 14.0% to 4.2% for 25 to 27 weeks' GA. The mean chance of survival without impairment for infants born alive increased from 1.2% to 9.3% for 22 to 24 weeks' GA and from 40.6% to 64.2% for 25 to 27 weeks' GA.

LIMITATIONS

The confidence in these estimates ranged from high to very low.

CONCLUSIONS

Survival without impairment was substantially lower for children born at <25 weeks' GA than for those born later.

Neurodevelopmental Outcomes in Infants With Birth Weight ≤500 g at 3 Years of Age

OBJECTIVES

To determine neurodevelopmental outcomes at 3 years of age in children born with a birth weight (BW) of ≤500 g.

METHODS

Infants who were born with a BW of ≤500 g from 2003 to 2012 in the Neonatal Research Network of Japan and survived to discharge from the NICU were eligible in this study. The study population consisted of 460 children (56.7% of 811 surviving infants) who were evaluated at 36 to 42 months of age. Neurodevelopmental impairment (NDI) was defined as having cerebral palsy, visual impairment, hearing impairment, or a developmental quotient score of <70.

RESULTS

The overall proportion of NDI was 59.1% (95% confidence interval [CI]: 54.6%-63.5%). The trend revealed no significant change during the study period. In a multivariate modified Poisson regression analysis, NDI was associated with severe intraventricular hemorrhage (adjusted risk ratio [RR]: 1.42; 95% CI: 1.19-1.68; P < .01), cystic periventricular leukomalacia (adjusted RR: 1.40; 95% CI: 1.13-1.73; P < .01), severe necrotizing enterocolitis (adjusted RR: 1.31; 95% CI: 1.07-1.60; P < .01), surgical ligation for patent ductus arteriosus (adjusted RR: 1.29; 95% CI: 1.09-1.54; P < .01), and male sex (adjusted RR: 1.19; 95% CI: 1.01-2.40; P = .04).

CONCLUSIONS

This cohort showed that neurodevelopmental outcomes of infants with a BW of ≤500 g have not improved from 2003 to 2012. Multivariate analysis revealed that severe intracranial hemorrhage and cystic periventricular leukomalacia were the strongest risk factors for NDIs. Our data suggested that measures aimed at reducing neurologic morbidities will be important for improving outcomes of infants with a BW of ≤500 g.

The Effect of Comprehensive Medical Care on the Long-Term Outcomes of Children Discharged from the NICU with Tracheostomy

Background:

Survival of infants with complex care has led to a growing population of technology-dependent children. Medical technology introduces additional complexity to patient care. Outcomes after NICU discharge comparing Usual Care (UC) with Comprehensive Care (CC) remain elusive.

Objective:

To compare the outcomes of technology-dependent infants discharged from NICU with tracheostomy following UC versus CC.

Methods:

A single site retrospective study evaluated forty-three (N=43) technology-dependent infants discharged from NICU with tracheostomy over 5½ years (2011-2017). CC provided 24-hour accessible healthcare-providers using an enhanced medical home. Mortality, total hospital admissions, 30-days readmission rate, time-to-mechanical ventilation liberation, and time-to-decannulation were compared between groups.

Results:

CC group showed significantly lower mortality (3.4%) versus UC (35.7%), RR, 0.09 [95%CI, 0.12-0.75], P=0.025. CC reduced total hospital admissions to 78 per 100 child-years versus 162 for UC; RR, 0.48 [95% CI, 0.25-0.93], P=0.03. The 30-day readmission rate was 21% compared to 36% in UC; RR, 0.58 [95% CI, 0.21-1.58], P=0.29). In competing-risk regression analysis (treating death as a competing-risk), hazard of having mechanical ventilation removal in CC was two times higher than UC; SHR, 2.19 [95% CI, 0.70-6.84]. There was no difference in time-to-decannulation between groups; SHR, 1.09 [95% CI, 0.37-3.15].

Conclusion:

CC significantly decreased mortality, total number of hospital admissions and length of time-to-mechanical ventilation liberation.

Early Mortality and Morbidity in Infants with Birth Weight of 500 Grams or Less in Japan

OBJECTIVE

To assess the short-term prognosis of Japanese infants with a birth weight (BW) of ≤500 g.

STUDY DESIGN

Demographic and clinical data were reviewed for 1473 live born infants with a BW ≤500 g at gestational age ≥22 weeks who were treated in the 204 affiliated hospitals of the Neonatal Research Network of Japan between 2003 and 2012.

RESULTS

Survival to hospital discharge occurred in 811 of 1473 infants (55%; 95% CI 53%-58%). The survival rates of BW ≤300 g, 301-400 g, and 401-500 g were 18% (95% CI 10%-31%), 41% (95% CI 36%-47%), and 60% (95% CI 57%-63%), respectively. In a multivariable Cox proportional hazards analysis, antenatal corticosteroid use (adjusted hazard ratio: 0.68; 95% CI 0.58-0.81; P < .01), cesarean delivery (0.69; 95% CI 0.56-0.85; P < .01), advanced gestational age per week (0.94; 95% CI 0.89-0.99; P = .02), BW per 100-g increase (0.55; 95% CI 0.49-0.64; P < .01), Apgar score ≥4 at 5 minutes (0.51; 95% CI 0.43-0.61; P < .01), and no major congenital abnormalities (0.38; 95% CI 0.29-0.51; P < .01) were associated with survival to discharge. Despite the improved survival rate over the 10-year study period (from 40% in 2003 [95% CI 30%-51%] to 68% in 2012 [95% CI 61%-75%]), at least 1 severe morbidity was present in 81%-89% of the survivors.

CONCLUSIONS

Improvements in perinatal-neonatal medicine have improved the survival, but not the rate of major morbidities, of infants with a BW ≤500 g in Japan.

County-level Variation in Infant Mortality Reporting at Early Previable Gestational Ages

BACKGROUND

Infant mortality rate (IMR), or number of infant deaths per 1000 livebirths, varies widely across the US While fetal deaths are not included in this measure, reported infant deaths do include those delivered at previable gestations, or ≤20 weeks gestation. Variation in reporting of these events may have a significant impact on IMR estimates.

METHODS

This retrospective analysis used US National Center for Health Statistics 2007-2013 data from 2391 US counties. Counties were categorised by US region, demographic characteristics, and state-level fetal death reporting requirements. County percentage of fetal deaths among all 17-20 week fetal and infant deaths was evaluated using multivariable linear regression. County-level characteristics were then included in multivariable linear regression to determine the associated change in county IMR.

RESULTS

County percentage of deaths at 17-20 weeks reported as fetal ranged from 0% to 100% (mean 63.7%). Every 1 point increase in this percentage was associated with a 0.02 point decrease in county IMR (95% confidence interval (CI) 0.02, 0.03). When county IMRs were recalculated holding the percentage of fetal vs. infant deaths at 17-20 weeks constant at 63.7%, results suggest that the predicted gap in county IMR between Northeast and Midwest regions would narrow by 0.45 points.

CONCLUSIONS

Variable reporting of previable fetal and infant deaths may compromise the validity of county IMR comparisons. Improved consistency and accuracy of fetal and infant death reporting is warranted.

Epidemiology of Periviable Births: The Impact and Neonatal Outcomes of Twin Pregnancy

This article discusses a study that estimated the prevalence of twin live births in the United States that were delivered in the periviable (20-25 weeks) gestational age, and compared changes in twin neonatal mortality and morbidity rates between 2005 and 2013 overall, and at periviable gestations. Although the decline in twin neonatal mortality rates at 23 and 24 weeks is encouraging, and suggests advancement in the neonatal care of these extremely small twins, the concomitant increase in neonatal morbidity at 23 weeks is concerning. Efforts to understand if twins delivered at periviable gestations suffer from long-term consequences of neurodevelopmental and cognitive deficits remain important.

Trends in Overall Mortality, and Timing and Cause of Death among Extremely Preterm Infants near the Limit of Viability

Objective

To investigate the trends in mortality, as well as in the timing and cause of death, among extremely preterm infants at the limit of viability, and thus to identify the clinical factors that contribute to decreased mortality.

Methods

We retrospectively reviewed the medical records of 382 infants born at 23–26 weeks’ gestation; 124 of the infants were born between 2001 and 2005 (period I) and 258 were born between 2006 and 2011 (period II). We stratified the infants into two subgroups–“23–24 weeks” and “25–26 weeks”–and retrospectively analyzed the clinical characteristics and mortality in each group, as well as the timing and cause of death. Univariate and multivariate logistic regression analyses were done to identify the clinical factors associated with mortality.

Results

The overall mortality rate in period II was 16.7% (43/258), which was significantly lower than that in period I (30.6%; 38/124). For overall cause of death, there were significantly fewer deaths due to sepsis (2.4% [6/258] vs. 8.1% [10/124], respectively) and air-leak syndrome (0.8% [2/258] vs. 4.8% (6/124), respectively) during period II than during period I. Among the clinical factors of time period, 1-and 5-min Apgar score, antenatal steroid identified significant by univariate analyses. 5-min Apgar score and antenatal steroid use were significantly associated with mortality in multivariate analyses.

Conclusion

Improved mortality rate attributable to fewer deaths due to sepsis and air leak syndrome in the infants with 23–26 weeks’ gestation was associated with higher 5-minute Apgar score and more antenatal steroid use.

Major determinants of survival and length of stay in the neonatal intensive care unit of newborns from women with premature preterm rupture of membranes

OBJECTIVE

To assess the predictors of outcome in terms of length of stay in the neonatal intensive care unit (NICU) and survival of neonates from women with preterm premature rupture of membranes (PPROM).

METHODS

A population-based retrospective study including 331 singleton pregnant women with PPROM at 24-34 gestational weeks between January 2013 and December 2015 was conducted. Gestational age at delivery, birth weight, route of delivery, newborn gender, maternal age, oligohydramnios, premature retinopathy (ROP), necrotising enterocolitis (NEC), sepsis, fetal growth retardation (FGR), intracranial hemorrhagia (ICH), bronchopulmonary dysplasia (BPD), respiratory distress syndrome (RDS), primary pulmonary hypertension (PPH), congenital cardiac disease (CCD), patent ductus arteriosus (PDA), use of cortisol (betamethasone) and maternal complications including gestational diabetes, preeclampsia and chorioamnionitis were used to predict neonatal outcomes in terms of length of stay in the NICU and survival.

RESULTS

In linear regression analyses, birth weight, ROP, CCD, BPD, PDA, NEC and preeclampsia were significant confounders for length of stay in the NICU. Among them, birth weight was the most powerful confounder for prolongation of the NICU stay (t: -6.43; p < 0.001). In multivariate logistic regression analyses, birth weight, PDA, ROP and PPH were significantly correlated with neonatal survival. PPH was the most powerful confounder in neonatal survival (β: 7.22; p = 0.005).

CONCLUSION

Prematurity-related complications are the most important problems for which precautions should be taken. Therefore, premature deliveries should be avoided to prevent infection and to prolong the latent period in cases of PPROM in order to decrease prematurity-related outcomes.

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.

Neonatal and maternal outcomes following midtrimester preterm premature rupture of the membranes: a retrospective cohort study

Background

Preterm premature rupture of membranes (PPROM) complicates 1 % of all pregnancies and occurs in one third of all preterm deliveries. Midtrimester PPROM is often followed by spontaneous miscarriage and elective termination of ongoing pregnancies is offered in many countries. The aim of this retrospective descriptive cohort study was to investigate the natural history of midtrimester PPROM in a jurisdiction where termination of pregnancy in the absence of maternal compromise is unavailable.

Methods

Cases of midtrimester PPROM diagnosed between 14 and 23 + 6 weeks’ gestation during April 2007 to June 2012 were identified following a manual search of all birth registers, pregnancy loss registers, annual reports, ultrasound reports, emergency room registers and neonatal death certificates at Cork University Maternity Hospital - a large (circa 8500 births per annum) tertiary referral maternity hospital in southwest Ireland. Cases where delivery occurred within 24 h of PPROM were excluded.

Results

The prevalence of midtrimester PPROM was 0.1 % (42 cases/44,667 births). The mean gestation at PPROM was 18 weeks. The mean gestation at delivery was 20 + 5 weeks, with an average latency period of 13 days.

Ten infants were born alive (23 %; 10/42). The remainder (77 %; 32/42) died in utero or intrapartum. Nine infants were resuscitated. Two infants survived to discharge. The overall mortality rate was 95 % (40/42).

Five women had clinical chorioamnionitis (12 %; 5/42) but 69 % demonstrated histological chorioamnionitis. One woman developed sepsis (2.4 %; 1/42). Other maternal complications included requirement of intravenous antibiotic treatment (38 %; 17/42), retained placenta (21 %, 9/42) and post-partum haemorrhage (12 %; 5/42).

Conclusions

This study provides useful and contemporary data on midtrimester PPROM. Whilst fetal and neonatal mortality is high, long-term survival is not impossible. The increased risk of maternal morbidity necessitates close surveillance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-0813-3) contains supplementary material, which is available to authorized users.

Antenatal Counseling Regarding Resuscitation and Intensive Care Before 25 Weeks of Gestation

The anticipated birth of an extremely low gestational age (,25 weeks) infant presents many difficult questions, and variations in practice continue to exist.Decisions regarding care of periviable infants should ideally be well informed,ethically sound, consistent within medical teams, and consonant with the parents' wishes. Each health care institution should consider having policies and procedures for antenatal counseling in these situations. Family counseling may be aided by the use of visual materials, which should take into consideration the intellectual, cultural, and other characteristics of the family members. Although general recommendations can guide practice, each situation is unique; thus, decision-making should be individualized. In most cases, the approach should be shared decision-making with the family, guided by considering both the likelihood of death or morbidity and the parents' desires for their unborn child. If a decision is made not to resuscitate,providing comfort care, encouraging family bonding, and palliative care support are appropriate.

A moving line in the sand: a review of obstetric management surrounding periviability

Periviable birth poses numerous clinical and ethical challenges for the practicing clinician. We review the data surrounding the administration of corticosteroids for fetal lung maturity, antibiotics in the case of preterm premature rupture of membranes, magnesium sulfate for cerebral palsy prophylaxis, fetal monitoring, and cesarean delivery. The ethical complexities of patient counseling are also reviewed with a recommendation toward shared decision making between patient and physician.