Rates of preterm birth vary between different populations and ethnic groups. Epidemiologic
studies have suggested that the incidence of preterm birth is also higher in pregnancies
carrying a male fetus; the male: female difference is greater in earlier preterm pregnancy.
Placental or chorion trophoblast cells from pregnancies with a male fetus produced more pro-
inflammatory TNFα in response to LPS stimulation and less anti-inflammatory IL-10 and
granulocyte colony stimulating factor (G-CSF) than cells from pregnancies with a female�…