About the Authors

Catherine Y. Spong

spongc@mail.nih.gov

Affiliation National Institute of Child Health and Human Development, Bethesda, Maryland, United States

Competing Interests

The author has declared that no competing interests exist.

Author Contributions

Wrote the first draft of the manuscript: CS. ICMJE criteria for authorship read and met: CS. Agree with manuscript results and conclusions: CS.