Postpartum hemorrhage and its relationship to anemia and oxytocin stimulation among Navajo women

The purpose of this study was to determine if relationships existed between iron deficiency anemia (diagnosed at labor onset) and postpartum hemorrhage (PPH) and between oxytocin stimulation during labor and PPH among a select group of Navajo women. Data from the medical records of 563 Navajo Women who had vaginal deliveries of full-term, single infants at the Shiprock Indian Health Service Hospital during fiscal year 1975-76 were analyzed. All the women who met the criteria were included in the study. The following variables were analyzed with respect to postpartum hemorrhage: anemia, oxytocin stimulation (including induction and augmentation), age, and parity. The occurrence of PPH (8.7%) in this study was similar to other studies that showed a higher incidence of PPH among Navajo women compared to the general population. The occurrence of anemia was 10.2%, but this could not be compared to other research samples due to variations in both sample selection and definitions of anemia. The occurrence of oxytocin stimulation (both induction and augmentationi) was 11.8%. The occurrence of induction in this study (5.9%) was far less than that reported in the literature (13.5 - 42.1%). No comparison of qugmentation occurrence could be made due to lack of information on augmentation in the literature. When considered alone, no significant associations were found between age and PPH, between parity and PPH, or between age-and parity (for example, 18-35 year old primigravidas) and PPH. A highly significant association (p<0.0001) was shown between anemia and PPH. Significant association were seen between anemia and PPH for all parity groups and for all age groups, except for the ?17 age group. A most surprising finding was that the age-and parity group of anemic women identified as being at highest risk for PPH were those traditionally considered to be the "normal," low-risk, childbearing age and parity groups: 18 - 35 years old with parity 2-6. Before controlling for age and parity, no significant association was demonstrated between oxytocin stimulation and PPH. Significant association were fournd between oxytocin stimulation and PPH controlling for age (p < 0.03) and for parity (p < 0.01). Only one age group (18-35) (p < 0.03) and one parity group (primigravida) (p < 0.01) showed significant association between oxytocin stimulation and PPH. The age-and-parity group of exytocin-stimulated women identified as being at highest risk for PPH were 18-35 year old primigravidas: 35.7% if the women in this group had PPH. No significant association were found between type of oxytocin stimulation (induction and augmentation) and PPH, nor were those women who were both anemic and oxytocin-stimulated found to be at higher risk for PPH than all other in the study.