Difficult human childbirth is often explained to be the outcome of long term evolutionary hanges in the genus Homo resulting in an‘obstetrical dilemma,’defined as the compromise between the need for a large pelvis in birthing large brained babies and a narrow pelvis for the mechanics of bipedal locomotion (Washburn, 1960). The ‘obstetrical dilemma’ is argued to result in the risk of cephalopelvic disproportion and injury (Washburn, 1960). Current research challenges the premise of the obstetrical dilemma by considering the effects ecological factors have on the growth of the bony human pelvis (Wells et al., 2012; Wells, 2015, Stone, 2016; Wells, 2017). This thesis tests Wells et al.’s (2012) assertion that environmental factors, such as agricultural diets, compromise pelvic size and morphology and potentially affect human childbirth. The skeletal samples examined in this study are from medieval English populations with long established agricultural diets. Bony pelvic metrics analyzed are from the St. Mary Spital assemblage, and demographic and pathological data from St. Mary Spital were compared to the East Smithfield Black Death cemetery assemblage. The results show that there is some evidence for a relationship between chronic stress and compromised pelvic shape and size in both men and women, however the evidence is not conclusive that younger women with compromised pelvic dimensions were at an increased risk of obstructed labour and maternal mortality during childbirth. This suggests that childbirth was not likely a significantly elevated cause of death among younger women in medieval London as a result of cephalopelvic disproportion. The concept of a single obstetrical dilemma is flawed, as multiple obstetrical dilemmas other than cephalopelvic disproportion through pelvic capacity constrains are present, including ecological and nutritional stressors, childbirth practices and technologies, sanitation ractices, and social and gender inequality / Graduate