BackgroundResearch indicates expectant and new mothers use the Internet, specifically social media, to gain information and support during the transition to parenthood. Although parents regularly share information about and photos of their child or children on Facebook, researchers have neither explored the use of Facebook to share pregnancy-related information nor investigated factors that influence such sharing.ObjectiveThe aim of this study was to address a gap in the literature by exploring the use of Facebook by pregnant women. Specifically, the study examined the use of Facebook to share pregnancy-related information, as well as any association between prenatal attachment and the aforementioned aspects of sharing pregnancy-related information on Facebook.MethodsPregnant women who were at least 18 years of age were recruited for participation in the study through posts and paid advertisements on Facebook and posts to professional organization listservs. Individuals interested in participating were directed to a secure Web-based survey system where they completed the consent form and the survey that focused on their current pregnancy. Participants completed the Maternal Antenatal Attachment Scale and answered questions that assessed how often they shared pregnancy-related information on Facebook, who they shared it with, why they shared it, and what they shared.ResultsA total of 117 pregnant women completed the survey. Descriptive statistics indicated that the pregnancy announcement was most commonly shared (75/108, 69.4%), with most women sharing pregnancy-related information on Facebook less than monthly (52/117, 44.4%) with only family and friends (90/116, 77.6% and 91/116, 78.4%, respectively) and for the purpose of involving others or sharing the experience (62/107, 57.9%). Correlation and regression analyses showed that prenatal attachment, in general, was positively and significantly related to all aspects of sharing pregnancy-related information at the P<.05 level, with the exception of sharing because of expectations. Quality of attachment, which involves the positive feelings the woman has about her unborn child, was significantly associated with sharing to involve others or share the pregnancy (t8,93=2.654 , P=.009). In contrast, after controlling for other variables, the strength or preoccupation component of prenatal attachment was significantly associated with frequency of sharing (t8,100=2.554 , P=.01), number to types of information shared (t8,97=2.605 , P=.01), number of groups with whom shared (t8,99=3.467, P=.001), and sharing to get advice (χ28=5.339 , P=.02).ConclusionsPregnant women in this study used Facebook for a variety of reasons, demonstrating the use of the social media platform during pregnancy for supportive and informational purposes. Overall, the results of this study are likely to be useful to professionals who are seeking alternative methods for providing intervention, information, and support to pregnant women via social media in our technology-driven society.