Prenatal Care
The absence of prenatal care has been associated with higher rates of preterm births. Analysis of 15,627,407 live births in the United States in 1995–1998 concluded that the absence of prenatal care carried a 2.9 (95%CI 2.8, 3.0) times higher risk of preterm births. This same study found statistically significant relative risks of maternal anemia, intrapartum fever, unknown bleeding, renal disease, placental previa, hydramnios, placenta abruption, and pregnancy-induced hypertension with the absence of prenatal care. All these prenatal risks were controlled for other high-risk conditions, maternal age, gravidity, marital status, and maternal education. The absence of prenatal care prior to and during the pregnancy is primarily a function of  socioeconomic factors (low family income and education), access to medical consultations (large distance from the place of residence to the healthcare unit and transportation costs), quality of healthcare, and social support. Efforts to decrease rates of preterm birth should aim to increase the deficits posed by the aforementioned barriers and to increase access to prenatal care. Diagnosis
Placental alpha microglobulin-1
Placental alpha microglobulin-1 (PAMG-1) has been the subject of several investigations evaluating its ability to predict imminent spontaneous preterm birth in women with signs, symptoms, or complaints suggestive of preterm labor. In one investigation comparing this test to fetal fibronectin testing and cervical length measurement via transvaginal ultrasound, the test for PAMG-1 (commercially known as the PartoSure test) has been reported to be the single best predictor of imminent spontaneous delivery within 7 days of a patient presenting with signs, symptoms, or complaints of preterm labor.
This altitude is known as Armstrongs Line. In practice bodily fluids do not boil off at this altitude. This is because the skin and outer organs have enough strength to withstand this pressure, thus pressure inside the body would be significantly higher—however, nitrogen bubbles are starting to form, creating a hazard. Prevention
To prevent ebullism, a pure oxygen (O2) atmosphere was used in early space flights to eliminate nitrogen in the blood. There are major fire hazards associated with using pure O2 as a breathing gas, which was central to the death of three astronauts in a fire during a ground test with Apollo 1. Nonetheless, NASA continued to use a nominally pure oxygen atmosphere throughout the Apollo Program but switched to air for the follow-on Space Transport System "Space Shuttle". Russian cosmonauts used pure oxygen before changing to a higher-pressure nitrox mixture, leading to incompatibility problems in 1975 on the Apollo-Soyuz Test Project. Space suits are often pressurized to several psi lower than stations capsules or shuttles and since they still use pure O2, an acclimation period is common in the airlock to remove nitrogen and other gases from the bloodstream. Etymology
The term "space ebullism" was introduced by Captain Julian E. Ward in his paper "The True Nature of the Boiling of Body Fluids in Space", published in Aviation Medicine in October 1956. It was suggested "because the word ebullism does not connote the addition of heat to produce vapor." It comes from Latin ebullire, meaning "to bubble out, or to boil up."