While overall rates of unintended pregnancy have declined across previous decades, rates have remained highest among those with low incomes, at younger ages, and among racial or ethnic minority groups. Unintended pregnancy has been associated with worse measures of health and welfare for parents, infants, and children.
Reducing unintended pregnancy is a Healthy People 2030 public health priority. While multiple factors contribute to unintended pregnancies, contraception provides an effective preventive health strategy. The safety and effectiveness of contraceptive methods have been well-established and clinical recommendations from medical and public health organizations have provided guidance to patients and clinicians.

Understanding relationships between unintended pregnancy and health can inform clinical practice and health policy; however, estimates of these associations specific to current US populations are lacking. The aim of this systematic review and meta-analysis was to estimate associations of unintended pregnancy with key maternal and infant health outcomes during pregnancy and post partum in epidemiologic observational studies relevant to clinical practice and public health in the US.
Epidemiologic studies relevant to US populations that compared key maternal and infant health outcomes for unintended vs intended pregnancies and met prespecified eligibility criteria were included after investigators' independent dual review of abstracts and full-text articles.
Investigators abstracted data from publications on study methods, participant characteristics, settings, pregnancy intention, comparators, confounders, and outcomes; data were validated by a second investigator. Prenatal depression, postpartum depression, maternal experience of interpersonal violence, preterm birth, and infant low birth weight were taken as objectives.

Thirty-six studies (N = 524 522 participants) were included (14 cohort studies rated good or fair quality; 22 cross-sectional studies); 12 studies used large population-based data sources.
Compared with intended pregnancy, unintended pregnancy was significantly associated with higher odds of depression during pregnancy (23.3% vs 13.9%) and post partum (15.7% vs 9.6), interpersonal violence (14.6% vs 5.5%), preterm birth (9.4% vs 7.7%), and infant low birth weight (7.3% vs 5.2%). Results were similar in sensitivity analyses based on controlling for history of depression for prenatal and postpartum depression and on study design and definition of unintended pregnancy for relevant outcomes. Studies provided limited sociodemographic data and measurement of confounders and outcomes varied.
Compared with intended pregnancy, unintended pregnancy was significantly associated with adverse maternal and infant outcomes in this systematic review and meta-analysis of 36 epidemiologic observational studies.
Results of the meta-analysis were generally consistent with previous reviews. Published narrative reviews without quantitative estimates of associations described higher rates of perinatal depression with unintended pregnancy. A narrative review of unintended pregnancy and interpersonal violence or abuse also described higher rates with unintended pregnancy. Most previous reviews evaluated maternal health behaviors rather than health outcomes and concluded that few studies were available to determine relationships between unintended pregnancy and psychosocial health or psychological outcomes.
The health outcomes highlighted in this review serve as markers of health and well-being during pregnancy and post partum, and their higher incidence with unintended pregnancy is important to clinical practice and public health. Reducing preterm birth, increasing depression screening in pregnancy, and reducing different types of violence are objectives of Healthy People 2030. Prevention of unintended pregnancy, also an objective of Healthy People 2030, may play a role in improving these national health indicators.
In this systematic review and meta-analysis of epidemiologic observational studies relevant to US populations, unintended pregnancy, compared with intended pregnancy, was significantly associated with adverse maternal and infant outcomes.
Source: Heidi D. Nelson, MD, MPH; Blair G. Darney, PhD; Katherine Ahrens; JAMA. 2022;328(17):1714-1729. doi:10.1001/jama.2022.19097