Maternal and fetal factors associated with stillbirth in singleton pregnancies in 13 hospitals across six states in India: a prospective cohort study -н Boo, YY, Bora, AK, Chhabra, S, Coudhury, SS, Deka, G, Kakoty, S, Kumar, P, Mahanta, P, Minz, B, Rani, A, Rao, S, Roy, I, Solomi V, C, Verma, A, Zahir, F, Deka, R, Kurinczuk, JJ, Nair, M