Antenatal immunisation intentions of expectant parents: Relationship to immunisation timeliness during infancy.

Background: Most women decide about infant immunisation during pregnancy. However, we have limited knowledge of the immunisation intentions of their partners. We aimed to describe what pregnant women and their partners intended for their future child's immunisations, and to identify associations between parental intentions and the subsequent timeliness of infant immunisation.

Methods: We recruited a cohort of pregnant New Zealand (NZ) women expecting to deliver between April 2009 and March 2010. The cohort included 11% of births in NZ during the recruitment period and was generalisable to the national birth cohort. We completed antenatal interviews independently with mothers and partners. We determined immunisation receipt from the National Immunisation Register and defined timely immunisation as receiving all vaccines (scheduled at 6-weeks, 3- and 5-months) within 30 days of their due date. We described independent associations of immunisation intentions with timeliness using adjusted odds ratios (OR) and 95% confidence intervals (CI).

Results: Of 6172 women, 5014 (81%) intended full immunisation, 245 (4%) partial immunisation, 140 (2%) no immunisation and 773 (13%) were undecided. Of 4152 partners, 2942 (71%) intended full immunisation, 208 (5%) partial immunisation, 83 (2%) no immunisation and 921 (22%) were undecided. Agreement between mothers and partners was moderate (Kappa=0.42). Timely immunisation occurred in 70% of infants. Independent of their partner's intentions, infants of pregnant women who decided upon full immunisation were more likely to be immunised on time (OR=7.65, 95% CI: 4.87-12.18). Independent of the future mother's intentions, infants of partners who had decided upon full immunisations were more likely to be immunised on time (OR=3.33, 95% CI: 2.29-4.84).

Conclusions: During pregnancy, most future parents intend to fully immunise their child; however, more partners than mothers remain undecided about immunisation. Both future mothers' and future fathers' intentions are independently associated with the timeliness of their infant's immunisations.