Preterm Birth may have devastating Impact on Neonatal Mortality Worldwide, finds study

Preterm birth, which occurs when a baby is born before 37 weeks of gestation, is a prevalent adverse outcome during childbirth, impacting around 10% of all births globally. It is the primary contributor to neonatal deaths and ranks second among the leading causes of mortality for children under five years old worldwide.Recent population-based matched cohort study examined the associations between preterm birth (PTB) and all-cause and cause-specific mortality from birth to adulthood (up to 36 years of age) in Canada. The study used vital statistics data on live births in Canada from 1983 to 1996 and followed individuals until 2019.

Key Findings on All-Cause Mortality

Overall, the study found that individuals born preterm were at an increased risk of mortality compared to those born at term. In the unmatched cohort, the unadjusted incidence rate of all-cause mortality was higher among those born preterm, with the risk increasing as gestational age (GA) decreased. In the matched cohort, PTB was associated with an increased risk of all-cause mortality between ages 1-36 years (risk difference \[RD\]: 0.54%, risk ratio \[RR\]: 1.49). The highest RDs and RRs were observed in the first year of life (RD: 2.29%, RR: 11.61) and early childhood (ages 1-5 years, RD: 0.34%, RR: 2.79), with the lowest in ages 18-28 years (RD: 0.07%, RR: 1.13). The associations were stronger for lower GA categories.

Key Findings on Cause-Specific Mortality

For cause-specific mortality, PTB was associated with increased risks of mortality related to respiratory, circulatory, and digestive system disorders; nervous system, endocrine, and infectious diseases; cancers; congenital malformations; and conditions originating in the perinatal period. No associations were found for external causes of mortality.

Implications and Recommendations

The findings suggest that individuals born preterm, especially at lower GAs, are at increased risk of mortality from birth through their third and fourth decades of life. These associations may be partly due to underlying health determinants that affected both PTB and mortality. The results highlight the need to recognize PTB as a risk factor for mortality and to develop preventive strategies. Further follow-up studies are needed to assess potential adverse consequences of PTB into adulthood.

Concluding Remarks

In summary, this large population-based study provides comprehensive evidence on the increased risks of both short-term and long-term mortality associated with PTB, especially at lower GAs, in a North American setting. The findings emphasize the importance of addressing PTB as a major public health concern.

Key Points

1. The study examined the associations between preterm birth (PTB) and all-cause and cause-specific mortality from birth to adulthood (up to 36 years of age) in Canada, using vital statistics data on live births from 1983 to 1996.

2. The study found that individuals born preterm were at an increased risk of all-cause mortality compared to those born at term, with the risk increasing as gestational age decreased. The highest risk differences and risk ratios were observed in the first year of life and early childhood.

3. For cause-specific mortality, PTB was associated with increased risks of mortality related to respiratory, circulatory, and digestive system disorders; nervous system, endocrine, and infectious diseases; cancers; congenital malformations; and conditions originating in the perinatal period. No associations were found for external causes of mortality.

4. The findings suggest that individuals born preterm, especially at lower gestational ages, are at increased risk of mortality from birth through their third and fourth decades of life, which may be partly due to underlying health determinants that affected both PTB and mortality.

5. The results highlight the need to recognize PTB as a risk factor for mortality and to develop preventive strategies to address this public health concern.

6. Further follow-up studies are needed to assess potential adverse consequences of PTB into adulthood.

Reference –

Asma M Ahmed et al. (2024). Short-Term And Long-Term Mortality Risk After Preterm Birth. *JAMA Network Open*, 7. https://doi.org/10.1001/jamanetworkopen.2024.45871.