“…Both morbidity and mortality are higher in males than in females in early life, with this di!erence persisting after adjustment for gestational age and body size, and being more marked in low birthweight and pre-term subjects (Bawkin, 1929;Ciocco, 1940;Sabin et al, 1958;Hammoud, 1965;Washburn et al, 1965;Froeschle et al, 1966;Abramowicz & Barnett, 1970;Glezen et al, 1971;Naeye et al, 1971;Paneth et al, 1982;Khoury et al, 1985;Resnick et al, 1989;Ho!man & Bennett, 1990;Zhang et al, 1991;Copper et al, 1994;Msall et al, 1993Msall et al, , 1994Synnes et al, 1994;La Pine et al, 1995;Fanaro! et al, 1995;Read et al, 1997;Stevenson et al, 1998;MacDorman & Atkinson 1998;Stoll et al, 1998).…”