IntroductionThis document is used to gain a better understanding of preterm birth and the causes of preterm birth as they relate to genetics and environmental effects. It will also examine what premature birth means for the growth and development of the affected child throughout his or her life. A normal human gestation period lasts approximately 40 weeks from the start of the last menstrual period until delivery. Any labor that begins before the 37th week of pregnancy is considered preterm labor. Preterm birth is the leading cause of infant death and long-term difficulties such as neurological damage and disability in children. Late preterm birth refers to babies born from the 34th week of pregnancy until before the 37th week. Over 70% of babies defined as preterm are born during this period. (nichd)According to Zhou, preterm birth is the leading cause of infant death worldwide, but the underlying causes remain mostly unknown (Zhou 1). The health of a baby at the time of birth is influenced by many factors. These include, but are not limited to, the mother's maternal health, her education, behavior, and exposure to environmental pollution (inequality at birth). This is a huge problem that affects our understanding of the causes of preterm birth and therefore how we can respond to it. In general, preterm births can be classified as spontaneous or medically indicated due to a complication of the mother or fetus during pregnancy. (Medscape 2). Spontaneous preterm labor is difficult to study because it happens so quickly. Medically indicated preterm birth due to such complications can be studied using genetic and environmental causes. Genetic Causes Genetic causes include racial disparities and familial inheritance...... middle of paper ......r. Patients heterozygous for the IL-4(-590T) allele have a higher risk factor for preterm birth (Medscape). The IL-6 polymorphism, on the other hand, leads to an increase in the amount of IL-6 which actually decreases the risk of preterm birth when in the homozygous state. Genetic causes are not only found in cytokines but also in non-cytokine gene polymorphisms. MMPs are linked to the rupture of amniotic membranes. One study analyzed MMP levels in the amniotic membranes of African American women compared to white women when they were exposed to endotoxin stimuli. The membranes of African American women produced more MMP-9. Polymorphisms in MMP-9 may be more common in African American women than white women, could explain the enhanced expression, and also explain why African American women have higher levels of PPROM (Medscape).