BackgroundShared decision‐making is recommended as a person‐centred approach to decision‐making in antenatal care. Little is known about the implementation of shared decision‐making in antenatal care.ObjectiveAn exploratory study to understand how shared decision‐making is implemented in antenatal clinics and whether body mass index influences maternity clinicians’ use of shared decision‐making when providing antenatal care for women.MethodsTwenty‐six antenatal clinic consultations were audio‐recorded with maternity clinicians and women with body mass index ≥ 35 kg/m2, and a comparison group of women with body mass index 18.5–24.9 kg/m2. Data were analysed quantitatively using the OPTION12 scale. Narrative case studies are presented to compare shared decision‐making behaviour related to induction of labour.ResultsTwelve clinicians and 26 pregnant women were recruited to the study. The total scores ranged from 0 to 24, with a mean score of 9 and a median of 9.5 indicating low implementation of shared decision‐making by clinicians and limited involvement of women in decision‐making. No difference was observed in OPTION12 scores in decision‐making for women by body mass index.ConclusionThis study suggests that shared decision‐making is limited in the antenatal clinic setting for all women, regardless of body mass index. Further research is required to confirm the findings of this exploratory study.Patient or Public ContributionThe perspectives of women with body mass index ≥ 35 kg/m2 informed many aspects of this study including the language/terminology adopted by researchers. A consumer group reviewed the language used in the study materials, to ensure readability and avoidance of stigmatising terminology.