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:7/31/2015)... SHENZHEN, China , 31 de julho de 2015 ... Genômica (ICG-10, www.icg-10.org ) será realizada pela BGI de ... China . A conferência está ... inauguração em 2006, a ICG se tornou uma das ... e um dos encontros científicos mais dinâmicos, entusiastas e ...
(Date:7/31/2015)... , July 31, 2015 The 10 th ... be held by BGI from October 22-25, 2015, in ... The conference is celebrating its 10 th anniversary this ... of the world,s most influential annual meetings in the ,omics, ... enjoyable scientific gatherings. ICG-10 focuses on recent ...
(Date:7/23/2015)... , July 23, 2015 Research ... addition of the "Global Outlook of the ... offering. The global biometrics market ... public and commercial applications owing to the uptake ... witness a transformation that enhances the growth of ...
Breaking Biology News(10 mins):A 10a. Conferência Internacional sobre Genômica (ICG-10) será em outubro 2A 10a. Conferência Internacional sobre Genômica (ICG-10) será em outubro 3The 10th International Conference on Genomics (ICG-10) to Open in October 2Global Outlook of the Biometrics Industry 2015 2Global Outlook of the Biometrics Industry 2015 3
(Date:8/4/2015)...  Blueprint Medicines (NASDAQ: BPMC ), a leader ... genomically defined diseases, today announced that Jeffrey Albers ... at the 2015 Wedbush PacGrow Healthcare Conference on Tuesday, ... A live webcast of the event will be available ... website at www.blueprintmedicines.com . An archived replay of ...
(Date:8/4/2015)... Aug. 4, 2015 /PRNewswire/ -- Sinovac Biotech Ltd. (Nasdaq: ... China , today announced that it ... quarter, ended June 30, 2015, after market close on ... call on Thursday, August 13, 2015, at 8:00 a.m. ... Standard Time) to review the Company,s financial results and ...
(Date:8/3/2015)... Aug. 3, 2015  MiMedx Group, Inc. (NASDAQ: ... amniotic tissue and patent-protected processes to develop and market ... Orthopedic, Spine, Sports Medicine, Ophthalmic and Dental sectors of ... 35 th Annual Canaccord|Genuity Growth Conference in ... Chairman and CEO, William C. Taylor , President ...
(Date:8/3/2015)... 2015  Aethlon Medical, Inc. (Nasdaq: AEMD ), ... life-threatening diseases, today announced that it will host its ... on Thursday, August 13, 2015 at 4:30 p.m. Eastern ... the release of fiscal 2016 first quarter results.  A ... two hours after the call at the Investor Relations ...
Breaking Biology Technology:Sinovac to Host Conference Call to Report Second Quarter 2015 Unaudited Financial Results 2MiMedx To Present At 35th Annual Canaccord|Genuity Growth Conference 2Aethlon Medical To Host First Quarter Fiscal 2016 Investor Call on August 13, 2015 2
Cached News: