The enigma of spontaneous preterm birth.
John I
JI
Takayama
Nobutake
N
Matsuo
D019049:Developed Countries; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008423:Maternal Age; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data; D047928:Premature Birth / Q000453:epidemiology* / Q000209:etiology; D027724:Reproductive Techniques, Assisted; D012307:Risk Factors; D014481:United States / Q000453:epidemiology