Choosing when to have a baby is an important decision for expecting parents. The due date often depends on factors outside of the parents’ control, but some research suggests that the week a baby is born may impact their lifelong health and development. This article will explore what the healthiest week is for a baby to be born based on risks of prematurity, seasonal health concerns, and optimal developmental windows.
Risks of Premature Birth
Babies born more than 3 weeks before their due date are considered premature. The earlier a baby is born, the higher the risks they face for complications and long-term health problems. According to the March of Dimes, babies born at full term (39-40 weeks) have the lowest risks for serious health issues.
Some problems associated with premature birth include:
- Respiratory distress: Underdeveloped lungs can cause breathing difficulties and require oxygen support.
- Low birth weight: Preemies often weigh less than 5 pounds 8 ounces.
- Feeding difficulties: Weak sucking reflexes and immature GI systems.
- Jaundice: Liver not fully matured to process bilirubin.
- Infection: Weaker immune system puts preemies at higher infection risk.
- Brain bleeds: Bleeding in the brain is more likely the earlier a baby is born.
- Cerebral palsy: May be caused by bleeds in the brain.
- Developmental delays: More likely to face delays in motor skills, speech, cognition.
- Vision and hearing problems: Higher incidence of vision/hearing issues.
The last few weeks of pregnancy are critical for brain, lung, and organ maturation. The risks decline steadily the closer a baby gets to full term. While specialized neonatal intensive care has greatly improved outcomes for preemies, avoiding an early delivery is still ideal if possible.
Seasonal Health Concerns
Some research indicates babies born at certain times of year may be exposed to particular health risks based on seasonal viruses and environmental factors. However, the evidence is still inconclusive about how much impact season of birth has on lifelong health.
Cold and Flu Season
Babies born during peak cold and flu season (fall and winter) may be more susceptible to catching viruses in their first few months. However, studies offer mixed conclusions about whether birth season affects risk for respiratory infections:
- A 2015 study found winter births correlated with more hospitalizations for RSV bronchiolitis in infants. But spring births were not linked to fewer infections.
- A 2016 review reported inconclusive evidence connecting birth month with respiratory infections.
- A 2018 study found fall birth was associated with higher risk of flu hospitalization before age 10.
While the data is uncertain, parents may want to take extra precautions against flu and cold exposure in the first winter if baby is born September-December.
Allergies and Asthma
Some research indicates babies born in high pollen months may be more likely to develop conditions like asthma, eczema, and seasonal allergies later on. Possible theories are:
- Early allergen exposure programs fetus’s immune system to be overly sensitive.
- Moms’ exposure to pollen during pregnancy impacts development of fetal immune system.
- Fall babies hit peak allergy seasons at younger, more susceptible ages.
However, many studies contradict the season of birth theory. More research is still needed to determine if birth timing truly impacts allergy/asthma risk.
Sunlight Exposure and Vitamin D
Babies born in winter months may have an increased risk for vitamin D deficiency since they have less sunlight exposure in early infancy. Vitamin D is critical for bone development and long-term health. To compensate:
- Expose baby to moderate, indirect sunlight daily when possible.
- Give infant vitamin D supplements if advised by pediatrician.
However, infants born in summer also need sun protection to lower skin cancer risks. Overall, there are strategies parents can use any time of year to optimize vitamin D levels.
Optimal Developmental Windows
Research on school performance and athletic ability indicates that babies’ neurological development may be affected by age relative to peers. The optimal time to be born for success in school and sports appears to be at the start of the academic year.
Academic Achievement
The majority of studies find a significant advantage in school for children born September through November compared to the rest of the year. Reasons why fall-born babies tend to have higher test scores and grades include:
- Being oldest in class cohort, with nearly 1 year maturity edge over summer-born peers.
- More developed mentally and physically compared to younger classmates.
- Highest confidence levels by being most skilled in early grades.
- Teacher perception of better performance capabilities.
However, a 2017 Danish study found no test score differences based on birth month. More research is still needed to confirm theories on the impact of age differences within a class.
Athletic Performance
Multiple studies reveal a trend of higher sports achievement for children born early in the enrollment cut-off year. Athletes born in the first quarter have an advantage in size, strength, and coordination over their younger competitors. For example:
- A study of German youth soccer found 60% of players on elite teams were born in the first 3 months of year.
- A Canadian study found hockey players born in the first half of year were overrepresented on youth elite teams.
- Another study found a majority of junior elite tennis players had January-March birthdays.
The performance gap likely persists into adulthood professional athletics. While talent still matters, physical maturity gives older athletes an edge during development.
Conclusion
Based on the risks of prematurity, seasonal health concerns, and timing of developmental windows, the healthiest weeks for a baby to be born appear to be:
Full Term, September – November
The ideal scenario is for babies to reach full gestational maturity (39-40 weeks) with birthdates falling in the early fall months. This combination of timing optimizes health in infancy while setting up children for success later in athletics and academics compared to peers.
However, babies born outside of the September-November window can still thrive with attentive parenting, quality healthcare, and school support. Child development involves many factors, including genetics, environment, and chance. But expecting parents may gain small advantages by planning conceptions and due dates with seasonal considerations in mind.
References
Banner Health. (n.d.). What are the long-term effects of premature birth? https://www.bannerhealth.com › healthcareblog › what-are-the-long-term-effects
Centers for Disease Control and Prevention. (2022, August). Preterm birth. https://www.cdc.gov/reproductivehealth/maternalinfanthealth/pretermbirth.htm
Dossett, L. A., Swiger, C. M., & Carias, D. M. (2020). Does Season of Birth Place Children at Risk for Disease? Global pediatrics, 6(1), 2333794X1989917. https://doi.org/10.1177/2333794X19899177
Harvard Medical School. (2009, December). A baby’s birthday: Timing conception. https://www.health.harvard.edu/blog/a-babys-birthday-timing-conception-20091215663
Jülicher, Birgit, and Alexander Gaglianone. “Does Being Young For One’s Grade Impair Long-Term Outcomes?,” 2022. http://ftp.iza.org/dp15161.pdf.
March of Dimes. (n.d.). Full term pregnancy. https://www.marchofdimes.org/pregnancy/what-is-full-term.aspx
Muscatello, D. J., Newall, A. T., Dwyer, J. J., & Macintyre, C. R. (2018). Birth seasonality and influenza hospitalisation trends in New South Wales, Australia, 1990-2009. Epidemiology and infection, 146(13), 1653–1660. https://doi.org/10.1017/S0950268818001665
Paranjothy S, Dunstan F, Watkins WJ, Hyatt M, Demmler JC, Lyons RA. (2015). Gestational age, birth weight, and risk of respiratory hospital admission in childhood. Pediatrics. 2013 Dec;132(6):e1562-9. doi: 10.1542/peds.2013-1737. Epub 2013 Nov 18. PMID: 24240654.
Roberts, Michelle. (2017, August 11). Being the eldest child is a health advantage, study finds. BBC News. https://www.bbc.com/news/health-40891023