Prospective Evaluation of Maternal Liver Fat Content and Blood Flow during Pregnancy using MRI
This will be a prospective observational study of pregnant women who present for prenatal care at The University of Texas Southwestern Medical Center and Parkland Health and Hospital System. All information will be obtained and stored in a newly formed centralized electronic database. That information will be deidentified prior to storage, and kept on an encrypted, password protected computer.
Two cohorts of patients will be identified at their initial first trimester prenatal visit. The first cohort will consist of primigravid women of normal weight, defined as a BMI between 18.5 and 24.9, without known medical or liver co-morbidities. The second cohort will consist of twenty overweight primigravid women, defined as a BMI greater than or equal to 25 without known medical or liver co-morbidities. A complete history and physical will be taken at initial presentation to exclude pre-existing liver disease, moderate or heavy alcohol use (defined as [AND]amp;gt;20gm of alcohol a week), severe malnutrition, risk factors for insulin resistence and hepatotoxic drug use. If clinical inclusion criteria is met, the patient will be offered enrollment and informed consent obtained. Labs will then be added on to the patients[AND]amp;apos; new OB labs (standard of care), which include liver function assay, hepatitis serologies, serum ferritin, and Hgb A1c for a total of an additional 10 mL. If these labs return abnormal then the patient will be excluded and her treating physician notified. If normal, she will be given an MRI appointment. An MRI will be performed at 10-16 weeks, 26-20 weeks, 36-40 weeks, within 1 week podt poartum and 12 weeks post partum. Since MRI protocol is to have the patient fasting, we will check fasting lipids at the time of the initial MRI performed at 10-16 weeks for a total of 10 mL additional blood. At the time of the subsequent MRI exams, which are performed at 26-30 weeks, 36-40 weeks, within 1 week post-partum and 12 weeks postpartum, fasting lipids, liver function tests, and serum ferritin will be drawn for a total of 5 additional blood draws of 10 mL each for study purposes. If the patient delivers before the third trimester scan, then she will have study labs added on to her labor and delivery admission labs. All additional lab draws will be done by a designated research nurse. During the 36-40 week MRI, as the gravid uterus will be within the imaged field of view, the fetal hepatic fat content will also be assessed simultaneously. The MRIs performed will not include the use of gadolinium. All imaging studies will be interpreted by a single radiologist investigator. Data collected includes quantitative assessment of hepatic fat by body MRI and phase contrast measurement of maternal blood flow in mL/min. T2 relaxation time and apparent diffusion coefficient of the liver are also calculated as a surrogate of parenchymal edema and perfusion. Anatomical data will be obtained regarding liver size. In addition, surrounding organ anatomy and physiology across pregnancy will be assessed if included in the imaging volume.
- maternal age 18-30 years
- first pregnancy
- BMI within one of the two cohorts, 18.5-24.9 or > 25.