Barriers to prenatal care for homeless pregnant women.

Objective: The purpose of this study was to explore and describe the barriers to prenatal care for homeless pregnant women.

Design: A descriptive survey with written questionnaires.

Participants: About 183 pregnant homeless women live in Northeast Florida in any given month.

Two-breath CO(2) test detects altered dynamic cerebrovascular autoregulation and CO(2) responsiveness with changes in arterial P(CO(2)).

The new two-breath CO(2) method was employed to test the hypotheses that small alterations in arterial P(CO(2)) had an impact on the magnitude and dynamic response time of the CO(2) effect on cerebrovascular resistance (CVRi) and the dynamic autoregulatory response to fluctuations in arterial pressure. During a 10-min protocol, eight subjects inspired two breaths from a bag with elevated P(CO(2)), four different times, while end-tidal P(CO(2)) was maintained at three levels: hypocapnia (LoCO(2), 8 mmHg below resting values), normocapnia, and hypercapnia (HiCO(2), 8 mmHg above resting values). Continuous measurements were made of mean blood pressure corrected to the level of the middle cerebral artery (BP(MCA)), P(CO(2)) (estimated from expired CO(2)), and mean flow velocity (MFV, of the middle cerebral artery by Doppler ultrasound), with CVRi = BP(MCA)/MFV.