 The primary aim of the study is to evaluate the effect of the method of delivery vaginal delivery vs. cesarean section on oxygen saturation in the first postpartum night. The investigators hypothesize that nocturnal desaturation occurs more frequently in cesarean section compared with vaginal delivery, expressed as either the duration of SpO2 below 90 or the Oxygen Desaturation Index ODI. The ODI is defined as number of oxygen desaturations by at least 3 per hour. Furthermore, the investigators expect a higher pulse rate and a lower mean and minimum SpO2 in the cesarean section group compared with the vaginal delivery group. 