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David Grenache, Ph.D.
Salt Lake City, UT
Recent Activity
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This blog has covered the topic of gestational diabetes mellitus several times. Recent big news in this arena is the recommendation from the U.S. Preventative Services Task Force (USPSTF) that all pregnant women be screened for gestational diabetes mellitus (GDM) after 24 weeks of gestation. The USPSTF is an "independent... Continue reading
Posted Jan 29, 2014 at The Pregnancy Lab
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The rapid assessment of pregnancy status is important in urgent health care settings. Determining if a woman is pregnant or not is necessary to: Determine if symptoms such as abdominal pain, vaginal bleeding, and/or vomiting are due to pregnancy; Prevent fetal exposure to sources of radiation (x-ray, CT, scan, etc);... Continue reading
Posted Oct 24, 2013 at The Pregnancy Lab
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Today's post is by a guest author, Ian Schwartz, M.D. Dr. Schwartz is an assistant professor of emergency medicine at the Yale University School of Medicine and the former medical director of the adult emergency department at the Yale-New Haven Hospital in New Haven, CT. Here, he provides his perspective... Continue reading
Posted Oct 2, 2013 at The Pregnancy Lab
A recent post on this blog described the inability of qualitative point-of-care (POC) hCG tests to detect hCG when it was present in urine or serum at a concentration that should, according to the test manufacturer, always be detected. The inability of these devices to detect hCG is a serious... Continue reading
Posted Sep 10, 2013 at The Pregnancy Lab
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Today's post is by a guest author, Dina N. Greene, Ph.D. Dr. Greene is a Scientific Director at Northern California Kaiser Permanente Regional Laboratories in Berkeley, CA. She discovered that qualitative hCG tests may not be as analytically sensitive as we all have come to believe and she shares her... Continue reading
Posted Aug 29, 2013 at The Pregnancy Lab
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I'm beginning to wonder what could possibly come next. Last month, Swiss Precision Diagnostics (via its Procter & Gamble partner) unveiled its newest product in consumer diagnostics: the Clearblue Advanced Pregnancy Test with Weeks Estimator. This urine hCG test determines pregnancy status but also provides an estimate of the number... Continue reading
Posted Jun 9, 2013 at The Pregnancy Lab
We have written about nonivasive prenatal testing (NIPT) on this blog several times. Because they are so new, the landscape around these tests is continually evolving. The American College of Obstetricians and Gynecologists (ACOG) published guidelines on these tests in December of last year. Just this week, the American College... Continue reading
Posted Apr 8, 2013 at The Pregnancy Lab
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This post is by a guest author, Douglas Stickle, Ph.D. Dr. Stickle is a professor in the Department of Pathology at Thomas Jefferson University and the director of chemistry and point-of-care testing at Jefferson University Hospitals in Philadelphia, PA. Rupture of membranes (ROM) is the term used to describe the... Continue reading
Posted Mar 5, 2013 at The Pregnancy Lab
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In a previous post I described the clinical performance of DNA-based screening tests for fetal aneuploidies like Down syndrome. Overall, these tests have excellent detection rates (~99%) with very low false-positive rates (~0.2%). In other words, these tests are about 99.0% sensitive and 99.8% specific. With performance like that one... Continue reading
Posted Jan 6, 2013 at The Pregnancy Lab
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The use of biochemical screening tests to identify pregnant women who are at high risk of having a fetus with Down syndrome is well established. Biochemical screening began nearly 30 years ago and, over the years, the tests have evolved and improved. Now there’s a new kid on the screening... Continue reading
Posted Dec 11, 2012 at The Pregnancy Lab
Today was an interesting day at work. A genetic counselor I work with emailed me that a pregnant patient wanted to have "every single Down syndrome screening test that was available." While this was problematic in and of itself (more about that later), this patient also planned to have an... Continue reading
Posted Nov 26, 2012 at The Pregnancy Lab
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A neural tube defect (NTD) is a birth defect of the spinal cord and/or brain. The term is used to describe a group of disorders that occur very early in pregnancy and can be mild to severe or even fatal. During the first 3 weeks of pregnancy, specific cells fuse... Continue reading
Posted Nov 1, 2012 at The Pregnancy Lab
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I have just returned from the annual meeting of the AACC where I attended a very interesting debate on the diagnosis of gestational diabetes mellitus (GDM). I've written about the current controversy in diagnosing GDM before and you can read about those here and here. Basically, the controversy boils down... Continue reading
Posted Jul 22, 2012 at The Pregnancy Lab
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Today's post is by a guest author, Patrick Kyle, Ph.D. Dr. Kyle is the Director of Analytical Toxicology and an Associate Director of Clinical Chemistry at the University of Mississippi Medical Center in Jackson, MS. He discovered a curious phenomenon when the lamellar body count is performed on a specific... Continue reading
Posted May 23, 2012 at The Pregnancy Lab
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A short while back, a colleague asked Ann and me if we were aware of any need to have a critical value for hCG tests. Our colleague had been asked by a physician to implement one in his laboratory because the physician had “missed” a molar pregnancy diagnosis due to... Continue reading
Posted Apr 23, 2012 at The Pregnancy Lab
I’ve written several times about qualitative hCG tests in this blog. As a reminder, qualitative tests can be performed using urine or serum samples. Urine tests can be performed close to the patient or even at home because the urine sample requires no special processing. However, when serum is the... Continue reading
Posted Mar 27, 2012 at The Pregnancy Lab
I've written about ectopic pregnancy a few times now (see this and this). The use of hCG testing in the evaluation of a woman with a suspected ectopic pregnancy is invaluable. For many years doctors have relied upon the concept of a "discriminatory zone." That is, an hCG concentration above... Continue reading
Posted Feb 21, 2012 at The Pregnancy Lab
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Ann recently posted about massively parallel genomic sequencing using maternal blood as a screening test for Down syndrome. In it, she described a recently published, multi-center clinical study that validated this molecular test in just over 1,600 women. The test detected 98.6% of the Down syndrome fetuses and had a... Continue reading
Posted Jan 29, 2012 at The Pregnancy Lab
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David has written previously about the different types of screening tests for Down syndrome (trisomy 21). Although these tests have certainly gotten better over time, even the best among them is subject to less than perfect sensitivity (90%) and a false positive rate of between 2 and 5%. Given the... Continue reading
Posted Jan 20, 2012 at The Pregnancy Lab
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The most common cause of life-threatening infections in newborns comes from a bacteria known as Streptococcus agalactiae (more commonly referred to as group B streptococcus or GBS). This was stressed in a recent meta-analysis that reported that GBS infection remains an important, global cause of infant mortality. The overall infection... Continue reading
Posted Jan 6, 2012 at The Pregnancy Lab
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David has written about preeclampsia in the past, but I thought I'd talk about some specific studies that have been published on that topic. Recall that preeclampsia is when a pregnant woman develops high blood pressure and protein in the urine after the 20th week of pregnancy and it is... Continue reading
Posted Dec 15, 2011 at The Pregnancy Lab
Hyperemesis gravidarum (HG) is severe vomiting during pregnancy and it occurs in approximately 0.2% of all pregnancies. Interestingly, many patients with HG may display clinical and biochemical symptoms of hyperthyroidism. The name "transient hyperthyroidism of hyperemesis gravidarum" (THHG), has been adopted to describe the syndrome of transient hyperthyroidism in pregnancy... Continue reading
Posted Dec 7, 2011 at The Pregnancy Lab
I’ve blogged about fetal lung maturity (FLM) tests before but this is exciting news! The Clinical and Laboratory Standards Institute (CLSI) has just published a document that provides guidance to labs that wish to perform the lamellar body count as a test for fetal lung maturity. Disclaimer: I participated in... Continue reading
Posted Dec 1, 2011 at The Pregnancy Lab
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Hypothyroidism affects about 2% of all women but occurs in only about 0.5% of pregnant women. The discrepancy is probably due to the known association between hypothyroidism and infertility. Other causes of inadequate thyroid function during and after pregnancy include iodine deficiency, Hashimoto’s disease, thyroidectomy, radioactive iodine treatment, and subacute.... Continue reading
Posted Nov 18, 2011 at The Pregnancy Lab
I’ve written about the use of hCG testing in the evaluation of patients with suspected ectopic pregnancies. As a reminder, the diagnostic tests used in the work-up of a woman with symptoms of an ectopic pregnancy include a combination of transvaginal ultrasound and the laboratory measurement of serum hCG concentrations.... Continue reading
Posted Nov 7, 2011 at The Pregnancy Lab