[1] HRH Princess Maha Chakri Sirindhorn Med Ctr, Obstet & Gynecol Nursing Dept, Nakhon Nayok, Thailand
[2] Mahidol Univ, Fac Nursing, Dept Obstet & Gynaecol Nursing, Bangkok 10700, Thailand
[3] Bur Hlth Promot, Dept Hlth, Nonthaburi, Thailand
[4] Mahidol Univ, Fac Nursing, Div Res Promot & Dev, Bangkok, Thailand
[5] Srinakharinwirot Univ, Fac Med, Dept Obstet & Gynecol, Nakhon Nayok, Thailand