HOME >> BIOLOGY >> NEWS
Embryos that implant in uterus 'late' prove more likely to die in first weeks of pregnancy

Researchers at the National Institute of Environmental Health Sciences said today that fertilized human eggs that implant late are less likely to survive.

The road to birth is a perilous one. These same NIEHS scientists showed in 1988 (New England Journal of Medicine, 319, pp 189-94) that 25 percent of fertilized eggs fail to survive six weeks -- so early that most mothers did not know they had been pregnant. Only daily urine testing for shifting traces of a hormone called hCG confirmed these pregnancies and their loss. The 25 percent early loss, when added to the clinical miscarriages that occur later, means that at least one-third of all embryos fail.

Today, the researchers reported they have found that the lost fetuses tend to be those that implant late. (NEJM, June 10.) The implantation of the fertilized egg in the wall of the uterus is necessary for the nourishment and growth of the fetus. Surviving pregnancies implanted only about one day earlier, on average, than the non-survivors: 10.5 days v. 9.1 days from fertilization to implantation. But the day-by-day trend was clear. If a fertilized egg implanted by the ninth day, it had only a 13 percent chance of loss. The risk rose to 26 percent if the implantation was on the tenth day, 52 percent on the eleventh day, and 82 percent thereafter. All three implantations after day 12 ended in early loss. There was no association in the NIEHS study between late implantation and the clinical miscarriages that occurred later in pregnancy.

NIEHS' Allen J. Wilcox, M.D., Ph.D., Donna Baird, Ph.D., and Clarice R. Weinberg, Ph.D., said their study could not determine the mechanisms at work. They speculate that embryos that implant more slowly may be imperfect in some way. Thus, they said, "the uterus may be receptive to pregnancy only during a limited time-window, shutting out defective embryos that get there too late. This would spare a mother the physiologic burden of supp
'"/>

Contact: Bill Grigg
grigg@niehs.nih.gov
301-402-3378
NIH/National Institute of Environmental Health Sciences
10-Jun-1999


Page: 1 2

Related biology news :

1. First Dinosaur Embryo Skin Discovered -- Unhatched Embryos Are First Ever Found Of Giant-Plant Eating Dinosaurs
2. Who Needs Flowers? Transgenic Plants Sprout Embryos On Leaves
3. At Lifes Most Sensitive Stage, Embryos Cope With Stress
4. University of Pittsburgh medical center among first to implant heart assist device
5. Medical implants work better when you rough them up, study finds
6. DCI donor services begins distribution of tissue implants
7. Researchers model embryo implantation and tumour metastasis in fruit flies
8. Injectable tissue implant could repair ravages of breast cancer surgery
9. Improving bone implant technology
10. Researchers envision intelligent implants
11. Rutgers researchers test polymer reliability for medical implants

Post Your Comments:
(Date:11/11/2014)... , Nov. 11, 2014  Forensicon, Inc., a ... is pleased to announce the promotion of Yaniv ... of Digital Forensics. In Schiff,s new role as Director, ... team of digital forensics examiners and provide leadership within ... Photo - http://photos.prnewswire.com/prnh/20141110/157719 Schiff ...
(Date:11/7/2014)... -- Leading Biometric companies aim to provide consumers ... transactions.  Companies in focus today are: NXT-ID, Inc. (NASDAQ: ... ), Google Inc. (NASDAQ: GOOG ), Microsoft Corporation ... EBAY ) and MasterCard Inc. (NYSE: MA) NXT-ID, ... authentication company focused on the growing mobile commerce is pleased ...
(Date:11/6/2014)... Medicine, Inc, a Baltimore-based bioinformatics company focused on ... a research collaboration with the international leader in ... CSBR). , "There are many companies utilizing advances ... TumorGraft technology is unique in a way that ... vast amounts of valuable data. Our bioinformatic analysis ...
Breaking Biology News(10 mins):Yaniv Schiff Promoted to Director of Digital Forensics at Forensicon, Inc. 2Universal Authentication Methods Provide More Secure Operations for Biometrics Devices - Company Joins FIDO Alliance for Consumer Protection 2Universal Authentication Methods Provide More Secure Operations for Biometrics Devices - Company Joins FIDO Alliance for Consumer Protection 3Universal Authentication Methods Provide More Secure Operations for Biometrics Devices - Company Joins FIDO Alliance for Consumer Protection 4Universal Authentication Methods Provide More Secure Operations for Biometrics Devices - Company Joins FIDO Alliance for Consumer Protection 5Universal Authentication Methods Provide More Secure Operations for Biometrics Devices - Company Joins FIDO Alliance for Consumer Protection 6Insilico Medicine, Inc announces research collaboration with Champions Oncology, Inc 2
(Date:11/22/2014)... MA (PRWEB) November 21, 2014 ... key investors will gather on December 3rd at ... Biotech Conferences series. GeneticRx will take place at ... Medical School and will discuss the present and ... therapy, exon skipping, and gene editing—as well as ...
(Date:11/22/2014)... The “Chiral Chromatography Columns Market by type ... Plastic), by Application [GC, LC (HPLC, UHPLC, Flash ... analyses and studies the major market drivers, restraints, ... and Rest of the World. , Browse 90 ... 135 pages and in-depth TOC on “Chiral Chromatography ...
(Date:11/21/2014)... 2014 , Todd Martensen ... Mariano Rodríguez es elegid vicepresidente senior de desarrollo ... está en marcha para comenzar de forma rápida la comercialización ... reciente aprobación en Europa   , ... anunciar los siguientes nombramientos: Todd Martensen ...
(Date:11/21/2014)... CA (PRWEB) November 20, 2014 Author ... Short Walk to the Other Side” published as ... “Award-Winning Finalist in the “Fiction: Short Story” category of ... Jeffrey Keen, President and CEO of USA Book News, ... mainstream and independent publishers, including Simon & Schuster, Penguin, ...
Breaking Biology Technology:Pioneering Academics and Key Industry Leaders to Discuss Rare Diseases and the Emergence of New Genetic Medicines at Genetic Rx on December 3rd 2Chiral Chromatography Columns Market worth $87.8 Million by 2018 - New Research Report by MarketsandMarkets 2Chiral Chromatography Columns Market worth $87.8 Million by 2018 - New Research Report by MarketsandMarkets 3Chiral Chromatography Columns Market worth $87.8 Million by 2018 - New Research Report by MarketsandMarkets 4Chiral Chromatography Columns Market worth $87.8 Million by 2018 - New Research Report by MarketsandMarkets 5KLOX Technologies anuncia sus nombramientos ejecutivos 2KLOX Technologies anuncia sus nombramientos ejecutivos 3KLOX Technologies anuncia sus nombramientos ejecutivos 4KLOX Technologies anuncia sus nombramientos ejecutivos 5Mystic Ink 's Short Story Collection “A Short Walk to the Other Side” Honoring Ray Bradbury Praised As Award-Winning Finalist In USA Best Book Awards 2Mystic Ink 's Short Story Collection “A Short Walk to the Other Side” Honoring Ray Bradbury Praised As Award-Winning Finalist In USA Best Book Awards 3Mystic Ink 's Short Story Collection “A Short Walk to the Other Side” Honoring Ray Bradbury Praised As Award-Winning Finalist In USA Best Book Awards 4
Cached News: