To participate in these study activities, women must be willing and able to participate, be able to sign or mark a consent form, and speak one of the languages into which the consent form has been translated, including English, Nyanja, and Bemba in Zambia, and English, Shona and Ndebele in Zimbabwe.

Inclusion Criteria:

• Women who are pregnant or postpartum and experiencing obstetric hemorrhage with 2 of the following 3:

blood loss > 500 mL (at SHF, 1000 mL at RH) SBP <100 mm Hg pulse >100 bpm

Exclusion Criteria:

• Absolute exclusion criteria include: current viable third trimester intrauterine pregnancy that can be delivered in the next 20 minutes after hemorrhage begins and/or current bleeding sites above the diaphragm. Relative exclusion criteria include: a history or current clinical evidence of mitral stenosis or congestive heart failure (CHF). These must be relative contraindications that will be assessed at the time of hemorrhage and clinical judgment will need to be utilized to evaluate each case individually. Thus if the patient can be transported and delivered rapidly and is suspected or known to have valvular heart disease, she will be excluded from the study. In other cases, depending on the severity of the hemorrhage, if the patient is dyspneic in the NASG, at the SHF level, the NASG will be loosened, if that does not result in relief, the NASG will be removed. If the patients at the RH have decreasing oxygen saturation levels as demonstrated by pulse oximeter, the NASG will be loosened, if that does not result in relief, the NASG will be removed.

Women suffering obstetric hemorrhage and hypovolemic shock who have no detectable vital signs (non palpable pulse and BP) at the time of their arrival at the RH are ineligible for enrolment in the study ("non-resuscitable") if: 1) the woman does not respond to resuscitation attempts after 30 minutes and 2) more than three hours have elapsed between the start of hemorrhage and the beginning of her treatment. (As this is a clinical intervention of a potentially life saving device, the study clinicians should try the NASG on any patient if they feel it may resuscitate her; however, if the woman meets the criteria above they are ineligible for having their data entered into the study.)