Pregnancy Intention, Changes in Pregnancy Intention, and Pregnancy Incidence among Female Nurses in North America

• Type of Material: Article
• Authors: Siwen Wang, Harvard T.H. Chan School of Public Health; Lidia Minguez-Alarcon, Channing Division of Network Medicine; Melissa P Capotosto, Boston College; Makiko Mitsunami, Harvard T.H. Chan School of Public Health; Audrey Gaskins, Emory University; Brittany M Charlton, Channing Division of Network Medicine; Jaime E Hart, Channing Division of Network Medicine; Janet W Rich-Edwards, Channing Division of Network Medicine; Jorge E Chavarro, Harvard T.H. Chan School of Public Health
• Language: English
• Date: 2023-05-03
• Publisher: American Medical Association.
• Publication Version: Final Published Version
• Copyright Statement: 2023 Wang S et al. JAMA Network Open.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1001/jamanetworkopen.2023.11301
• Title of Journal or Parent Work: JAMA Network Open
• Volume: 6
• Issue: 5
• Start Page: E2311301
• End Page: E2311301
• Grant/Funding Information: This study was supported by grants U01HL145386 (to Dr Chavarro), R24ES028521 (to Dr Chavarro), and P30 ES000002 (support to Dr Hart) from the US National Institutes of Health.
• Keywords: Humans; Adult; Pregnancy; Cohort Studies; North America; Female; Incidence; Intention; Prospective Studies
• Research Categories: Health Sciences, Nutrition; Health Sciences, Epidemiology

Abstract

Importance: Pregnancy intention assessment is a key element of preconception and contraceptive care. The association between a single screening question and the incidence of pregnancy is unknown. Objective: To prospectively evaluate the dynamics of pregnancy intention and pregnancy incidence. Design, Setting, and Participants: This prospective cohort study (the Nurses' Health Study 3) was conducted from June 1, 2010, to April 1, 2022, in 18376 premenopausal, nonpregnant female nurses aged 19 to 44 years. Main Outcomes and Measures: Pregnancy intention and pregnancy status were assessed at baseline and approximately every 3 to 6 months thereafter. Cox proportional hazards regression models were used to estimate the association between pregnancy intention and pregnancy incidence. Results: A total of 18376 premenopausal, nonpregnant women (mean [SD] age, 32.4 [6.5] years) participated in the study. At baseline, 1008 women (5.5%) were trying to conceive, 2452 (13.3%) were contemplating pregnancy within 1 year, and the remaining 14916 (81.2%) were neither trying to conceive nor thought they would be pregnant within 1 year. A total of 1314 pregnancies were documented within 12 months of pregnancy intention assessment. The cumulative incidence of pregnancy was 38.8% in women actively trying to conceive (median [IQR] time to pregnancy, 3.3 [1.5-6.7] months), 27.6% in women contemplating pregnancy (median [IQR] time to pregnancy, 6.7 [4.2-9.3] months), and 1.7% in women neither trying to conceive nor contemplating pregnancy (median [IQR] time to pregnancy, 7.8 [5.2-10.5] months) among those who became pregnant. Women who were actively trying to conceive were 23.1 times (95% CI, 19.5-27.4 times) and women who were contemplating pregnancy were 13.0 times (95% CI, 11.1-15.2 times) more likely to conceive within 12 months than women who were neither attempting nor contemplating pregnancy. Among women contemplating pregnancy at baseline who did not get pregnant during follow up, 18.8% were actively trying and 27.6% were not trying by 12 months. Conversely, only 4.9% of women neither trying to conceive nor contemplating pregnancy within 1 year at baseline changed pregnancy intention during follow up. Conclusions and Relevance: In this cohort study of reproductive-aged nurses in North America, pregnancy intention was highly fluid among women who were contemplating pregnancy but relatively stable among women trying to conceive and women who were neither trying to conceive nor contemplating pregnancy. Pregnancy intention was strongly associated with pregnancy incidence, but the median time to pregnancy points to a relatively short time window to initiate preconception care..