Understanding the Recommended Two-Year Wait Between Pregnancies

World Health Organization Guidelines

The World Health Organization (WHO) recommends a two-year interval between pregnancies. This timeframe raises questions regarding its necessity and implications for maternal and child health.

Trends in Maternal Age

The average age of first-time mothers is increasing, with women in Canada and the United States typically giving birth for the first time between the ages of 26 and 29. A 2020 article from Forbes highlighted that financial considerations are a significant factor in this delay. According to a survey conducted by SoFi and Modern Fertility, 60% of women cited insufficient funds to start a family, while 51% expressed a desire to earn a higher salary before having children.

Research on Interpregnancy Intervals

The WHO’s recommendation stems from research conducted in 2005, which suggested that a two-year wait between childbirth and subsequent pregnancies may reduce the risk of adverse outcomes such as preterm births, low birth weight, and small-for-gestational-age births. Recently, an international study analyzed data from women across four high-income countries—Finland, Norway, Australia, and the United States—spanning 36 years to evaluate safe interpregnancy intervals.

The findings indicated that shorter intervals (less than six months) may lead to spontaneous preterm births. Conversely, longer intervals (more than five years) were associated with both preterm births and small-for-gestational-age outcomes. The study revealed that both short (less than a year) and long (over five years) waits had an increased risk of these adverse outcomes compared to the recommended 18-24 months.

Considerations for Future Pregnancies

It is essential to note that the studies did not account for the mother’s health prior to or during the interpregnancy period. As a result, these findings suggest that the strict recommendation of an 18-24 month wait may not be necessary for women in developed countries. The research also indicated that longer intervals (3-5 years) could similarly increase risks of preterm births and small-for-gestational-age births.

In conclusion, while there is no one-size-fits-all answer regarding the ideal time to wait between pregnancies, various factors must be considered. It is crucial for women to consult their healthcare providers to determine the best approach for their individual circumstances.

References

1) Mathews, T., & Hamilton, B. (2016). Mean age of mothers is on the rise: United States, 2000-2014. National Center of Health Statistics, Hyattsville, MD.
2) Statistics Canada. (n.d.). Table 13-10-04018-01: Crude birth rate, age-specific fertility rates and total fertility rates (live births). Retrieved 07 22, 2021, from Statistics Canada: https://doi.org/10.25318/1310041801-eng
3) Stahl, A. (2020, 05 01). New Study: Millennial women are delaying having children due to their careers. Retrieved 07 21, 2021, from Forbes.com: https://www.forbes.com/sites/ashleystahl/2020/05/01/new-study-millenial-women-are-delaying-having-children-due-to-their-careers/?sh=6c1135d276a
4) Tessema, G., Marinovich, M., Haberg, S., Gissler, M., Mayo, J., Nassar, N., et al. (2021). Interpregnancy intervals and adverse birth outcomes in high income countries: An international cohort study. PLoS ONE , 16 (7), e0255000.