{
    "abstract": "The objective of the study was to determine the normal changes in the plasma concentrations of protein C and protein S that occur during each trimester of pregnancy.\nThe study was a prospective cross-sectional study of 91 normal pregnant women who had plasma concentrations of protein C and protein S measured during the first, second, and third trimesters.\nThere was no statistically significant change in antigenic or functional protein C levels during normal pregnancy. Total protein S levels also remained unchanged. Free protein S levels fell significantly from first to second trimesters (0.45 U/ml mean to 0.26 U/ml mean, p < 0.001), but no further fall occurred during the third trimester.\nThe second-trimester fall in free protein S levels is a physiologic pregnancy adaptation. Women with a thromboembolic event appearing for the first time during pregnancy should have investigations for protein S deficiency delayed until the postpartum period, to avoid misdiagnosis and treatment.",
    "authors": [
        {
            "affiliation": "Department of Obstetrics and Gynecology, University of Ottawa, Ontario, Canada.",
            "firstname": "W",
            "initials": "W",
            "lastname": "Faught"
        },
        {
            "affiliation": null,
            "firstname": "P",
            "initials": "P",
            "lastname": "Garner"
        },
        {
            "affiliation": null,
            "firstname": "G",
            "initials": "G",
            "lastname": "Jones"
        },
        {
            "affiliation": null,
            "firstname": "B",
            "initials": "B",
            "lastname": "Ivey"
        }
    ],
    "conclusions": null,
    "copyrights": null,
    "doi": "10.1016/0002-9378(95)90104-3",
    "journal": "American journal of obstetrics and gynecology",
    "keywords": [],
    "methods": null,
    "publication_date": "1995-01-01",
    "pubmed_id": "7847526",
    "results": "There was no statistically significant change in antigenic or functional protein C levels during normal pregnancy. Total protein S levels also remained unchanged. Free protein S levels fell significantly from first to second trimesters (0.45 U/ml mean to 0.26 U/ml mean, p < 0.001), but no further fall occurred during the third trimester.",
    "title": "Changes in protein C and protein S levels in normal pregnancy.",
    "xml": "<Element 'PubmedArticle' at 0x788503675620>"
}