Brazil's Missing Infants: Zika Risk Changes Reproductive Behavior.

Area of Science:

• Epidemiology
• Public Health
• Reproductive Health

Background:

• Zika virus epidemics pose significant population health risks.
• Studies suggest Zika virus impacts fecundity and is linked to congenital anomalies.
• Understanding the interplay between Zika risk, public awareness, and reproductive behavior is crucial.

Purpose of the Study:

• To analyze the biological effects of Zika infection on fertility.
• To assess the impact of public awareness of Zika risk on reproductive behavior.
• To quantify the effects of the Zika epidemic on birth cohort size.

Main Methods:

• Utilized causal inference techniques with vital statistics data.
• Analyzed spatiotemporal variations in Zika risk and public health messaging.
• Compared birth cohort size reductions with timing of Zika risk and awareness.

Main Results:

• A significant reduction in birth cohort size (approx. one-quarter) was observed 18 months post-peak Zika risk.
• This reduction coincided with public health advisories for childbearing delay, not solely biological impacts.
• Behavioral effects on childbearing delay were more pronounced in more-educated and older women.

Conclusions:

• The Zika epidemic led to substantial strategic changes in reproductive behavior, with women delaying childbirth.
• Biological reductions in fecundity were small and not statistically significant.
• Informed reproductive decisions, particularly among educated and older women, significantly influenced birth rates during the epidemic.