BACKGROUND: Obesity in childbearing women is associated with poorer pregnancy and birth outcomes, particularly caesarean section, compared with normal-weight women. The high caesarean section rate may reflect care and outcomes which occur at the time surrounding the first birth. AIM: To describe the birth outcomes of extremely obese pregnant women (body mass index [BMI] of 40 or more) experiencing their first birth. METHODS: Clinical audit was used to systematically review the care and birth outcomes of all extremely obese pregnant women experiencing their birth at one study site during a 2-year period in 2009 and 2010. Fifty participants birthed during the study period. Data were collected from booking to discharge from the maternity service and included variables such as model of care, number of appointments, and obstetric and neonatal outcomes. Descriptive statistics were used to describe and synthesize the data. Inferential statistics were used to draw inferences about the population. RESULTS: Obese women rarely had contact with a midwife, except at booking, receiving a standard model of care provided by numerous caregivers, most often inexperienced medical staff. More than half of the obese women experienced a caesarean section (56%), 2.3 times that of normal-weight primiparous women who birthed at the study site during the same period (24.2%). This was despite 64% experiencing normal pregnancy free from any complication. For women who planned to labor, birth intervention including induction of labor, augmentation for slow labor, epidural, and continuous cardiotocography was high. Caesarean occurred most often for "failure to progress" and "failed induction." CONCLUSION: Clinical audit was useful in determining information, which suggests current maternity care provision is not meeting the needs of extremely obese women experiencing their first birth. IMPLICATIONS FOR PRACTICE: The development of effective, targeted antenatal care designed to meet the needs of extremely obese women is recommended as are strategies to keep birth normal.