New study establishes when pregnancy starts

41 lasted at least six weeks past the last menstrual cycle, and the other 48 ended in early loss, the scientist said. Among pregnancies lasting six weeks or more, the first detectable rise in the level of a hormone known as chorionic gonadotropin (hCG) -- an indicator of successful attachment of a fertilized egg to the uterus wall -- occurred six to 12 days after ovulation.

"The risk of early loss was strongly related to the time of implantation," the authors wrote. "Early loss was least likely when implantation occurred by the ninth day (13 early losses among 102 pregnancies, or 13 percent) rising to 26 percent (14 of 53 pregnancies) when implantation occurred on the 10th day, 52 percent (12 of 23) on the 11th day and 82 percent (9 of 11) with implantation after day 11."

Three pregnancies in which the first rise in hormone occurred after day 12 ended by themselves.

"This study was first intended to identify the proportion of pregnancies that were lost very early before women knew they were pregnant," Wilcox said. "But we also were able to look at the date on which pregnancy could first be detected in relation to ovulation.

"The first detection of pregnancy is really the first detection of hCG, which rises very rapidly once the fertilized egg attaches to the uterus. That's in fact the most hidden event of pregnancy and has never been seen before."

Fertilization begins about a week earlier when egg and sperm unite, he said. Many fertilized eggs, however, never succeed in clinging to the uterine wall where they can grow into an embryo, fetus and, eventually, a baby.

"This is the first really concrete information we have about when pregnancy starts in humans - how long after fertilization does pregnancy begin," Wilcox said. "It probably has implications for assisted reproduction -- the way medicine is able to manipulate reproductive processes to encourage pregnancy - possibly by increasing the nar

Contact: David Williamson
University of North Carolina at Chapel Hill

Page: 1 2 3

Related biology news :

1. Student science contest participation influences study, career choices, alumni say
2. New study shows hope for treating inhalant abuse
3. International study findings link acne-like rash to effectiveness of new targeted cancer treatment
4. Cigarette smoke causes breaks in DNA and defects to a cells chromosomes, Pitt study finds
5. New study indicates arsenic could be suitable as first-line treatment in type of leukaemia
6. Phase II trials of second-generation antisense cancer drug planned following successful early study
7. Preclinical safety study shows adipose-derived stem cells improve heart function after heart attack
8. Indiana University, EPA to study airborne PCBs
9. K-State, other universities to study how climate affects plant evolution
10. USC study links historical increases in life span to lower childhood exposure to infection
11. Washington University in St. Louis leads group studying aging process

Post Your Comments:

(Date:11/17/2015)... 17, 2015 Paris ... --> Paris , qui s,est ... DERMALOG, le leader de l,innovation biométrique, a inventé le ... et empreintes sur la même surface de balayage. Jusqu,ici, ... l,autre pour les empreintes digitales. Désormais, un seul scanner ...
(Date:11/17/2015)... , Nov. 17, 2015 Pressure BioSciences, Inc. ... the development and sale of broadly enabling, pressure cycling ... sciences industry, today announced it has received gross proceeds ... million Private Placement (the "Offering"), increasing the total amount ... or more additional closings are expected in the near ...
(Date:11/12/2015)... Nov. 12, 2015  A golden retriever that stayed ... dystrophy (DMD) has provided a new lead for treating ... the Broad Institute of MIT and Harvard and the ... . Cell, pinpoints a protective ... the disease,s effects. The Boston Children,s lab of ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... Malaysia , Nov. 24, 2015  Asia-Pacific ... contract research organisation (CRO) market. The trend of ... in lower margins but higher volume share for ... capacity and scale, however, margins in the CRO ... Organisation (CRO) Market ( http://www.frost.com/sublib/display-report.do?id=P86A-01-00-00-00&src=PR ), finds ...
(Date:11/24/2015)... SAN DIEGO , Nov. 24, 2015 Halozyme Therapeutics, ... Jaffray Healthcare Conference in New York on ... Dr. Helen Torley , president and CEO, will provide a ... New York at 1:00 p.m. ET/10:00 a.m. ... communication and investor relations, will provide a corporate overview. --> ...
(Date:11/24/2015)... ... November 24, 2015 , ... ... year and one of the premier annual events for pharmaceutical manufacturing: 2015 Annual ... November 2015, where ISPE hosted the largest number of attendees in more than ...
(Date:11/24/2015)... -- --> --> ... Market by Product & Services (Primer, Probe, Custom Oligos, ... End-User (Research, Pharmaceutical & Biotech, Diagnostic Labs) - Global ... expected to reach USD 1,918.6 Million by 2020 from ... 10.1% during the forecast period. Browse 183 ...
Breaking Biology Technology:
Cached News: