Influenza vaccination during pregnancy and influencing factors in Korea: A multicenter questionnaire study of pregnant women and obstetrics and gynecology doctors.

Background: Although the World Health Organization and health authorities in most countries recommend that pregnant women receive inactivated influenza virus vaccines, coverage remains low. This study aimed to investigate (1) the proportion of pregnant women who received an influenza vaccination and influencing factors and (2) the proportion of obstetrics and gynecology (OBGYN) doctors who routinely recommend influenza vaccination to pregnant women and influencing factors.

Methods: Two separate, anonymized questionnaires were developed for physicians and pregnant and postpartum women and were distributed to multicenters and clinics in South Korea. The proportions of women who received influenza vaccination during pregnancy and OBGYN doctors who routinely recommend the influenza vaccine to pregnant women were analyzed. Independent influencing factors for both maternal influenza vaccination and OBGYN doctors' routine recommendations to pregnant women were analyzed using log-binomial regression analysis.

Results: The proportion of self-reported influenza vaccination during pregnancy among 522 women was 63.2%. Pregnancy-related independent factors influencing maternal influenza vaccination were "(ever) received information about influenza vaccination during pregnancy" (OR 8.9, 95% CI 4.17-19.01), "received vaccine information about from OBGYN doctors" (OR 11.44, 95% CI 5.46-24.00), "information obtained from other sources" (OR 4.38, 95% CI 2.01-9.55), and "second/third trimester" (OR 2.41, 95% CI 1.21-4.82).. Among 372 OBGYN doctors, 76.9% routinely recommended vaccination for pregnant women. Independent factors effecting routine recommendation were "working at a private clinic or hospital" (OR 5.33, 95% CI 2.44-11.65), "awareness of KCDC guidelines" (OR 3.11, 95% CI 1.11-8.73), and "awareness of the 2019 national free influenza vaccination program for pregnant women" (OR 4.88, 95% CI 2.34-10.17). OBGYN doctors most commonly chose 'guidelines proposed by the government or public health (108, 46%) and academic committees (59, 25%), as a factor which expect to affect the future recommendation CONCLUSION: This study showed that providing information about maternal influenza vaccination, especially by OBGYN doctors, is crucial for increasing vaccination coverage in pregnant women. Closer cooperation between the government and OBGYN academic societies to educate OBGYN doctors might enhance routine recommendations.