Estimating the incidence of unintended births and pregnancies at the sub-state level to inform program design

PLoS One. 2020 Oct 15;15(10):e0240407. doi: 10.1371/journal.pone.0240407. eCollection 2020.

Abstract

Objectives: Unintended (mistimed or unwanted) pregnancies occur frequently in the United States and have negative effects. When designing prevention programs and intervention strategies for the provision of comprehensive birth control methods, it is necessary to identify (1) populations at high risk of unintended pregnancy, and (2) geographic areas with a concentration of need.

Methods: To estimate the proportion and incidence of unintended births and pregnancies for regions in Missouri, two machine-learning prediction models were developed using data from the National Survey of Family Growth and the Missouri Pregnancy Risk Assessment Monitoring System. Each model was applied to Missouri birth certificate data from 2014 to 2016 to estimate the number of unintended births and pregnancies across regions in Missouri. Population sizes from the American Community Survey were incorporated to estimate the incidence of unintended births and pregnancies.

Results: About 24,500 (34.0%) of the live births in Missouri each year were estimated to have resulted from unintended pregnancies: about 25 per 1,000 women (ages 15 to 45) annually. Further, 40,000 pregnancies (39.7%) were unintended each year: about 41 per 1,000 women annually. Unintended pregnancy was concentrated in Missouri's largest urban areas, and annual incidence varied substantially across regions.

Conclusions: Our proposed methodology was feasible to implement. Random forest modeling identified factors in the data that best predicted unintended birth and pregnancy and outperformed other approaches. Maternal age, marital status, health insurance status, parity, and month that prenatal care began predict unintended pregnancy among women with a recent live birth. Using this approach to estimate the rates of unintended births and pregnancies across regions within Missouri revealed substantial within-state variation in the proportion and incidence of unintended pregnancy. States and other agencies could use this study's results or methods to better target interventions to reduce unintended pregnancy or address other public health needs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Birth Rate
  • Databases, Factual
  • Female
  • Humans
  • Incidence
  • Middle Aged
  • Missouri
  • Pregnancy
  • Pregnancy, Unplanned*
  • Program Development*
  • Young Adult

Grants and funding

The authors are affiliated with Mathematica, an independent research organization. Mathematica received funding from Missouri Foundation for Health (MFH) to conduct the study (contract number 17-0203-PUP-17). Funding was used to support direct and indirect costs of conducting the study through Mathematica as an organization, which supports the salaries and materials for authors to conduct the research. MFH did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.