Survival rate of extremely low birthweight infants and its effect on the amendment of the Eugenic Protection Act in Japan

Neurological outcomes and associated perinatal factors in infants born between 22 and 25 weeks with active care

OBJECTIVES

To elucidate the outcomes of periviable infants receiving active care (AC) and explore perinatal factors associated with neurodevelopmental outcomes.

METHODS

This is a single-center retrospective study on infants born at 22-25 weeks of gestation, all of whom received AC. A developmental quotient (DQ) ≥ 85 at corrected 18 months was judged as normal.

RESULTS

Fifty-seven infants were included in the study. The survival rates at discharge were 83%, 86%, 93%, and 93% at 22, 23, 24, and 25 gestational weeks, respectively. The overall percentage of normal DQ was 26/47 (55%). Acidemia in the arterial blood gas measured within 6 h after birth was identified as a factor significantly associated with subnormal DQ.

CONCLUSIONS

Not only high survival rates, but also favorable neurodevelopmental outcomes may be achieved by AC in periviable infants. Moreover, impaired neurodevelopmental outcomes may be associated with early postnatal acidemia following initial resuscitation.

Buy-in and breakthroughs: the Overton window in neonatology for the resuscitation of extremely preterm infants

To understand the future of neonatology, it is important to reflect upon the past and the factors that lead to significant advances in the field. In this article, we explore the evolving landscape of neonatology and the shifting practices in the resuscitation of extremely premature infants, with a particular focus on societal influences that have driven these changes. Using the political policy concept of an Overton Window, we explore how breakthroughs move from unthinkable to acceptable practice and how the increasing involvement of parents and their advocacy efforts have played a pivotal role in that progress. In the era of expanded shared decision making, it is crucial that we apply that same approach to setting priorities in our field, acknowledging the crucial perspectives of both parents and former premature infants in shaping the future of neonatology.

Effect of national guidance on survival for babies born at 22 weeks' gestation in England and Wales: population based cohort study

Objectives

To explore the effect of changes in national clinical recommendations in 2019 that extended provision of survival focused care to babies born at 22 weeks' gestation in England and Wales.

Design

Population based cohort study.

Setting

England and Wales, comprising routine data for births and hospital records.

Participants

Babies alive at the onset of care in labour at 22 weeks+0 days to 22 weeks+6 days and at 23 weeks+0 days to 24 weeks+6 days for comparison purposes between 1 January 2018 and 31 December 2021.

Main outcome measures

Percentage of babies given survival focused care (active respiratory support after birth), admitted to neonatal care, and surviving to discharge in 2018-19 and 2020-21.

Results

For the 1001 babies alive at the onset of labour at 22 weeks' gestation, a threefold increase was noted in: survival focused care provision from 11.3% to 38.4% (risk ratio 3.41 (95% confidence interval 2.61 to 4.45)); admissions to neonatal units from 7.4% to 28.1% (3.77 (2.70 to 5.27)), and survival to discharge from neonatal care from 2.5% to 8.2% (3.29 (1.78 to 6.09)). More babies of lower birth weight and early gestational age received survival focused care in 2020-21 than 2018-19 (46% to 64% at <500g weight; 19% to 31% at 22 weeks+0 days to 22 weeks+3 days).

Conclusions

A change in national guidance to recommend a risk based approach was associated with a threefold increase in 22 weeks' gestation babies receiving survival focused care. The number of babies being admitted to neonatal units and those surviving to discharge increased.

Active care of infants born between 22 and 26 weeks of gestation does not follow consensus expert recommendations

AIM

To determine the relationship between clinical practice and publication of an Australian consensus statement for management of extremely preterm infants in 2006.

METHODS

A population-based study using linked data from New South Wales, Australia for births between 22 + 0 and 26 + 6 weeks of gestation between 2000 and 2011.

RESULTS

There were 4746 births of whom 2870 were liveborn and 1876 were stillborn. Of the live births, 2041 (71%) were resuscitated, 1914 (67%) were admitted into a neonatal intensive care unit (NICU) and 1310 (46%) survived to hospital discharge. Thirty-nine (2%) stillbirths were resuscitated but none survived. No 22-week infant survived to hospital discharge. Fewer 23-week gestation infants were resuscitated between 2004 (52%) and 2005 (20%) but resuscitation rates increased by 2008 (44%). There was no difference at other gestations. Adjusted odds ratio (OR) for resuscitation was increased by birthweight (OR: 1.01), tertiary hospital birth (OR: 3.4) and Caesarean delivery (OR: 11.3) and decreased by rural residence (OR: 0.4) and male gender (OR: 0.7).

CONCLUSION

Expert recommendations may be shaped by clinical practice rather than the converse, especially for 23-week gestation infants. Recommendations should be revised regularly to include clinical practice changes.

Limit of viability in Japan: ethical consideration

Viability means "the quality or state of being able to live, grow and develop." Limit of viability has been changed along with the advancement of perinatal and neonatal medicine. The viability limit defined in the Japanese Motherhood Protection Act was amended from 24 to 22 completed weeks of gestation in 1991 based on the survival rate of extremely preterm infants. Survival rates of infants at 22 and 23 weeks' gestation born between 2002 and 2004 in Japan were 31% and 56%, respectively. Though medical data are the most important means to define viability, socio-economical and ethical factors should be also considered, especially when we discuss the group of marginally viable infants. We think there are two different categories of viability limits, one from biological survival limit and another from social agreement of providing active medical intervention. Currently in Japan, the former viability definition based on purely medical data is 22 completed weeks and the latter definition is the social consensus of about 24-28 weeks' gestation.

Ethical considerations in the management of infants born at extremely low gestational age

With ongoing improvements in technology and the understanding of neonatal physiology, there has been increasing debate regarding the gestational age and birth weight limits of an infants' capability of sustaining life outside the womb and how this is to be determined. The objective of this review was to address this issue with an analysis of current data (following the introduction of surfactant therapy in 1990) from published studies of survival in extremely low gestational age infants. We found that survival was possible at 22 completed weeks of gestation but only in < 4% of live births reported. Survival increased from 21% at 23 weeks gestational age to 46% at 24 weeks gestational age. Historically, despite continual advances in neonatology, the mortality at 22 weeks has not improved over the past three decades. Combining the data from studies on survival with evidence from developmental biology, we believe that it is not worthwhile to pursue aggressive support of infants born at < 23 weeks gestational age. Given the complicated issues related to morbidity and mortality in infants born at 22 to 25 weeks gestational age and the ethical implications of the available evidence, we propose the need for a consensus derived framework to help in decision-making.

Evidence of selection bias in preterm survival studies: a systematic review

OBJECTIVE

To determine by how much selection bias in preterm infant cohort studies results in an overestimate of survival.

DESIGN

Systematic review of studies reporting survival in infants less than 28 weeks of gestation published 1978-1998. Studies were graded according to cohort definition: A, stillbirths and live births; B, live births; C, neonatal unit admissions. Proportions of infants surviving to discharge were calculated for each week of gestation.

RESULTS

Sixty seven studies report data on 55 cohorts (16 grade A, 23 grade B, 16 grade C). Studies that are more selective report significantly higher survival between 23 and 26 weeks of gestation (grade C > grade B > grade A, p < 0.01), exaggerating survival by 100% and 56% at 23 and 24 weeks respectively.

CONCLUSION

To minimise the potential for overestimating survival around the limits of viability, future studies should endeavour to report the outcome of all pregnancies for each week of gestation (terminations, miscarriages, stillbirths, and all live births).

Overview of sudden infant death syndrome in Japan

In spite of rapid medical advancement in the care of infants and children, not only the general public but also many medical personnel have remained unaware of sudden infant death syndrome (SIDS) until very recently in Japan. In 1981, a research project team on SIDS financed by the Ministry of Health and Welfare was founded. Current incidence of SIDS is estimated to be about 0.5 per 1000 live births. The SIDS Family Association was organized in 1993 in Japan and began to publicize the social importance of SIDS and to support SIDS families by training befrienders. A series of article on current achievements from SIDS research projects and from the SIDS Family Association are submitted to this issue. The present paper summarizes the status of SIDS in Japan by overviewing the activities of the research team and the SIDS Family Association.