A Proactive Approach to Neonates Born at 23 Weeks of Gestation

In the grey zone-survival and morbidities of periviable births

OBJECTIVE

To compare the survival and morbidities of infants born between 22 0/7-25 6/7 weeks of gestation.

STUDY DESIGN

This observational cohort study consisted of 187 eligible infants liveborn at a single, Level III Neonatal Intensive Care Unit (NICU) between June 1, 2009, and December 31, 2016, in Cleveland, Ohio. Infants with recognized syndromes or major congenital malformations were excluded from the review.

RESULT

The rate of survival to discharge for NICU-admitted infants born at 22- and 23- week was 56% and 54% respectively at our institution. There was no trend observed between gestational ages and incidence of necrotizing enterocolitis (NEC), patent ductus arteriousus (PDA), sepsis, or severe intraventricular hemorrhage (IVH- Grade 3 or 4). The infants born at 22 weeks had a higher incidence of retinopathy of prematurity (ROP) as compared to 25 weeks gestation (p < 0.001). The need for home oxygen was significantly higher in the smallest infants 70% at 22 weeks, 62% and 60% at 23 and 24 weeks versus 33% at 25 weeks gestation (p < 0.007). Those born at 22 weeks had the same rate of survival to discharge with severe IVH as those born at 23 weeks but required fewer VP shunts (p > 0.52).

CONCLUSIONS

The course of extremely preterm infants shows no difference between those born at 22 and 23 weeks of gestation in our NICU with regards to both mortality and short-term morbidities, although they differed marginally from 24 week gestation infants and significantly from those born at 25 weeks gestation.

Perspectives on developing and sustaining a small baby program

The Small Baby Program at Nationwide Children's Hospital was launched in 2004 in response to a need for better care for infants born extremely preterm. Standardization of care, decreased variability, multidisciplinary support, and robust research and quality improvement have allowed us to greatly improve our outcomes. In addition to the numerous medical and technological advances during this time, a strong commitment to kangaroo care and family-centered care have been integral to the growth and success of our program. The following review of the program aims to highlight the above areas while detailing the specific processes that have contributed to its ongoing success. Key areas of focus have been on respiratory management, neurodevelopmental care, and nutritional optimization. The implementation and continued refinement of the Small Baby Program has allowed us to improve the survival of extremely preterm infants, decrease certain morbidities, and improve long-term neurodevelopmental outcomes.

Development of a small baby unit to improve outcomes for the extremely premature infant

Survival and outcomes for extremely premature (EP) infants have improved and even infants born at 23 and 24 weeks that were previously considered non-viable are now routinely surviving. This review describes our particular institution's basis for and process of creating and sustaining a small baby program for a quaternary, referral-based neonatal intensive care unit. Through multi-disciplinary collaboration, small baby guidelines were developed that established uniform care and optimized evidence-based practice for the care of this unique patient population. A focus on parent-centered care while removing noxious stimuli for the patient has improved neurodevelopmental outcomes. Data collection, quality improvement, and ongoing research are incorporated in the small baby program to establish and sustain best practices and outcomes for the EP patient. Through the establishment of a small baby unit, we have improved survival, decreased short-term morbidities, and improved neurodevelopmental outcomes for the EP infant in our region.

Neonatal Outcomes and Maternal Characteristics in Monochorionic Diamniotic Twin Pregnancies: Uncomplicated versus Twin-to-Twin Transfusion Syndrome Survivors after Fetoscopic Laser Surgery

Preterm birth remains a major complication of fetal laser surgery (FLS) due to twin-to-twin transfusion syndrome (TTTS).

OBJECTIVES

We tested the hypothesis that neonatal outcomes in fetuses born at >24 weeks are worse in TTTS survivors compared to uncomplicated monochorionic diamniotic (MCDA) twins.

METHODS

196 patients with TTTS treated with laser therapy and 91 uncomplicated MCDA gestations were compared. Neonatal outcomes included respiratory distress syndrome (RDS), transient tachypnea of the newborn (TTN), bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, and neonatal death. Risk factors assessed were TTTS, maternal age, maternal body mass index, race, premature prolonged rupture of membranes, stage of TTTS, parity, and gestational age (GA) at delivery.

RESULTS

GA at delivery was lower in the TTTS group (31.0 ± 4.6 vs. 33.5 ± 2.4 weeks, p < 0.001). RDS and TTN occurred at higher rates in the TTTS than in the uncomplicated MCDA group. After multivariate logistic regression, the only factor significantly associated with the composite adverse outcome was GA at delivery (OR 0.61; 95% CI: 0.58-0.7).

CONCLUSION

TTTS twins treated with FLS are deliver 2.5 weeks earlier than uncomplicated MCDA twins. Respiratory complications were significantly higher in TTTS twins and were mainly the consequence of the early GA at delivery.

Reduced rate of treated retinopathy of prematurity after implementing lower oxygen saturation targets

OBJECTIVE

To evaluate an implementation of lower oxygen saturation targets with retinopathy of prematurity (ROP) as primary outcome, in infants at the lowest extreme of prematurity.

STUDY DESIGN

Retrospective cohort including infants born at 22-25 weeks of gestation in 2005-2015 (n = 325), comparing high (87-93%) and low (85-90%) targets; infants transferred early were excluded from the main analysis to avoid bias.

RESULTS

Overall survival was 76% in high saturation era, and 69% in low saturation era (p = .17). Treatment-requiring ROP was less common in low saturation group (14% vs 28%, p < .05) with the most prominent difference in the most immature infants. Including deceased infants in the analysis, necrotizing enterocolitis was more frequent in low saturation era (21% vs 10%, p < .05).

CONCLUSIONS

Implementing lower saturation targets resulted in a halved incidence of treatment-requiring ROP; the most immature infants seem to benefit the most. An association between lower oxygenation and necrotizing enterocolitis cannot be excluded.

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.

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

OBJECTIVE

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

STUDY DESIGN

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

RESULT

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

CONCLUSION

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

Public Health Implications of Very Preterm Birth

With advanced perinatal care and technology, survival among infants born very preterm (<32 weeks gestation) has improved dramatically over the last several decades. However, adverse medical and neurodevelopmental outcomes for those born very preterm remains high, particularly at the lowest gestational ages. Public health plays a critical role in providing data to assess population-based risks associated with very preterm birth, addressing disparities, and identifying opportunities for prevention, including improving the health of reproductive-age women, before, during, and after pregnancy.

Short interpregnancy interval increases the risk of preterm premature rupture of membranes and early delivery

OBJECTIVES

Preterm premature rupture of membranes (PPROM) is a major contributor to overall preterm birth (PTB) rates. A short interpregnancy interval (IPI) is a well-known risk factor for PTB. It is unknown if a short IPI specifically affects the risk of developing PPROM in a subsequent pregnancy. We sought to determine the association between IPI and the risk of PPROM in a subsequent pregnancy.

METHODS

A retrospective cohort study using the Missouri birth certificate database of singleton births from 2003 to 2013 was conducted. A short IPI (delivery of the prior pregnancy to conception of the index pregnancy) was defined as ≤6 months. IPI >6 months was categorized into two groups: IPI 7-23 months and IPI ≥24 months. PPROM was defined as premature rupture of membranes between 16⁰ and 36⁶ weeks. Multivariable logistic regression was conducted to determine the association between IPI and PPROM while controlling for maternal age, race, body mass index (BMI), education level, use of social services (Medicaid insurance, food stamps, or participation in the WIC [Women, Infants, and Children] program), tobacco use, and history of PTB. Secondary outcome included the gestational age at delivery, categorized into five subgroups (≤24⁰, 24¹-28⁰, 28¹-32⁰, 32¹-34⁰, and 34¹-36⁶ weeks).

RESULTS

474,957 subjects with singleton gestations had data available to calculate the IPI. Of these, 1.4% (n = 6797) experienced PPROM. IPI ≤6 months was significantly associated with an increased risk of developing PPROM compared with patients with IPI ≥24 months (odds ratio (OR) 1.80, 95% CI 1.70-1.90, p < .001). A higher proportion of women with IPI ≤6 months delivered between 28¹ and 32⁰ weeks compared to the other two IPI groups (27.0 versus 15.0 and 16.4%, p < .001). Individual maternal factors associated with an increased risk of PPROM included advanced maternal age, African American race, BMI <18.5 kg/m², BMI ≥30 kg/m², use of social services, tobacco use, and a prior PTB.

CONCLUSION

Our data demonstrate that an IPI of ≤6 months is significantly associated with an increased risk of developing PPROM in the subsequent pregnancy. Of greater clinical relevance is that these women were more likely to deliver between 28¹ and 32⁰ weeks as compared with women with a longer IPI. Novel to this study is the establishment of a specific link between a short IPI and PPROM with subsequent early delivery. Several maternal demographic factors known to be associated with PTB risk were also found to be associated with an increased risk of PPROM. Further studies are necessary to elucidate plausible biologic mechanisms ultimately leading to the development and implementation of preventive and therapeutic strategies for this high-risk cohort.

Explaining the recent decrease in US infant mortality rate, 2007-2013

BACKGROUND

The US infant mortality rate has been steadily decreasing in recent years as has the preterm birth rate; preterm birth is a major factor associated with death during the first year of life. The degree to which changes in gestational age-specific mortality and changes in the distribution of births by gestational age have contributed to the decrease in the infant mortality rate requires clarification.

OBJECTIVE

The objective of the study was to better understand the major contributors to the 2007-2013 infant mortality decline for the total population and for infants born to non-Hispanic black, non-Hispanic white, and Hispanic women.

STUDY DESIGN

We identified births and infant deaths from 2007 and 2013 Centers for Disease Control and Prevention National Vital Statistics System's period linked birth and infant death files. We included all deaths and births for which there was a reported gestational age at birth on the birth certificate of 22 weeks or greater. The decrease in the infant mortality rate was disaggregated such that all of the change could be attributed to improvements in gestational age-specific infant mortality rates and changes in the distribution of gestational age, by week of gestation, using the Kitagawa method. Sensitivity analyses were performed to account for records in which the obstetric estimate of gestational age was missing and for deaths and births less than 22 weeks' gestation. Maternal race and ethnicity information was obtained from the birth certificate.

RESULTS

The infant mortality rates after exclusions were 5.72 and 4.92 per 1000 live births for 2007 and 2013, respectively, with an absolute difference of -0.80 (14% decrease). Infant mortality rates declined by 11% for non-Hispanic whites, by 19% for non-Hispanic blacks, and by 14% for Hispanics during the period. Compared with 2007, the proportion of births in each gestational age category was lower in 2013 with the exception of 39 weeks during which there was an increase in the proportion of births from 30.1% in 2007 to 37.5% in 2013. Gestational age-specific mortality decreased for each gestational age category between 2007 and 2013 except 33 weeks and >42 weeks. About 31% of the decrease in the US infant mortality rate from 2007 through 2013 was due to changes in the gestational age distribution, and 69% was due to improvements in gestational age-specific survival. Improvements in the gestational age distribution from 2007 through 2013 benefited infants of non-Hispanic white women (48%) the most, followed by infants of non-Hispanic black (31%) and Hispanic (14%) women.

CONCLUSION

Infant mortality improved between 2007 and 2013 as a result of both improvements in the distribution of gestational age at birth and improvements in survival after birth. The differential contribution of improvements in the gestational age distribution at birth by race and ethnicity suggests that preconception and antenatal health and health care aimed at preventing or delaying preterm birth may not be reaching all populations.