The prevalence of unplanned pregnancy ending in birth, associated factors, and health outcomes

STUDY QUESTION: What are associated factors of unplanned pregnancies ending in birth? SUMMARY ANSWER: Pregnancies that were less planned were associated with women of lower socio-economic status (SES), an unhealthier lifestyle before and during the pregnancy, more stress, and less social support. WHAT IS KNOWN ALREADY: In Europe, the prevalence of unplanned pregnancy leading to birth varies. Unplanned pregnancy is more common among socially disadvantaged women, and associated with adverse pregnancy outcomes. STUDY DESIGN, SIZE, DURATION: In a cross-sectional study, 517 women were recruited from May through September 2015. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women were recruited from six hospitals in Flanders, Belgium. Data from self-report and medical records were collected during the first 5 days postpartum. The validated London Measure of Unplanned Pregnancy was used to collect data regarding pregnancy planning. Data were analysed with Mann-Whitney U tests, Kruskal-Wallis tests, and multiple linear regression analysis. MAIN RESULTS AND THE ROLE OF CHANCE: The majority of the pregnancies (83%) ending in birth were planned, 15% were ambivalent, and 2% unplanned. Women who are multigravida (95% CI -0.30 to -0.02), less well educated (95% CI 0.07-0.85), single or having a non-cohabiting relationship (95% CI 0.01-2.53), having history of drug abuse (95% CI -2.07 to -0.35), and experiencing intimate partner violence (95% CI -3.82 to -1.59) tended to have a significantly higher risk of a less planned pregnancy. Less planned pregnancies were significantly associated with initially unwanted pregnancies (P < 0.001), no folic acid or vitamin use before pregnancy (P < 0.001), lower number of prenatal visits (P = 0.03), smoking during pregnancy (P < 0.001), more stress (P = 0.002), lower relationship satisfaction (P = 0.001), and less social support (P < 0.001). Less planned pregnancies were also significantly associated with hyperemesis (P < 0.001) and shorter duration of delivery (P = 0.03). No differences were found in neonatal outcomes. LIMITATIONS, REASONS FOR CAUTION: The prevalence of unplanned pregnancies is probably underestimated due to over-representation of women with higher SES in this study. Women's emotions may have influenced the answer to certain questions. Owing to the cross-sectional design, no causal relationships could be established. WIDER IMPLICATIONS OF THE FINDINGS: This study emphasizes the importance of targeting socially disadvantaged women in the prevention of unplanned pregnancies.