Italian research reveals a new twist in the battle of the sexes

New research from Italy reveals that mother nature tries very hard to compensate for the fact that male foetuses and newborns are more fragile than females by allowing significantly more boys to be conceived at a time of year when conditions for pregnancy and birth are optimal.

Evidence that males are more fragile than females and that fewer males are conceived in sub-optimal conditions is not new. What is new in research published (Thursday 27 March) in Human Reproduction[1] is the extent to which nature tries to level the playing field to give boys a sporting chance.

In the first study designed specifically to focus on sex ratio (the proportion of boys to girls) at conception as opposed to at birth[2] Dr Angelo Cagnacci and his team from the gynaecology unit at the Policlinico of Modena found that 535 males were conceived in the 'best' month for conception as against 465 females, while only 487 males were conceived for 513 females in the 'worst' month[3]. (The normal sex ratio is 511 males to 489 females out of every 1,000 conceptions that produce a birth).

Dr Cagnacci explained that seasonal variations in reproduction have been described before, and a higher conception rate should indicate conditions more favourable for pregnancy and newborn survival for both boys and girls. This seasonal variation is different in different latitudes because it is linked to the length of daytime hours and environmental temperature. Optimum conditions are daytime of 12 hours and a mean temperature of 12C, so maximum conception rates occur at opposite times in regions equidistant from the equator but located in different hemispheres.

"In this study of over 14,000 births at our institute over a six year period, the lowest conception rates were from March to May and the highest from September to November. What is fascinating is the degree of disparity in sex ratio that the numbers of boys conceived compared with girls was so much higher in the favou

Contact: Margaret Willson
European Society for Human Reproduction and Embryology

Page: 1 2 3

Related biology news :

1. Italian research links diet with endometriosis risk
2. Researchers say US military accidentally introduced tree pathogen to Italian estate
3. Italian study finds traffic pollution affects male fertility
4. European experts slam new Italian fertility proposals
5. Italian wolves havent gone to the dogs--yet
6. Leader in cancer treatment and prevention research honored
7. UT Southwestern receives $1.78 million grant for obesity research as part of NIH Roadmap initiative
8. Scientists to prototype cyberinfrastructure for research and education access to ocean observatories
9. Belgian researchers explore revolutionary approach to angiogenesis
10. Award winning researchers reveal potential new role for Glivec
11. New research shows plants can shuffle and paste gene pieces to generate genetic diversity

Post Your Comments:

(Date:6/3/2016)... , June 3, 2016 ... Management) von Nepal ... und Lieferung hochsicherer geprägter Kennzeichen, einschließlich Personalisierung, ... führend in der Produktion und Implementierung von ... der Ausschreibung im Januar teilgenommen, aber Decatur ...
(Date:5/24/2016)... superior patient care by providing unparalleled technology to leaders of the medical imaging industry. ... recently added to the range of products distributed by Ampronix. Photo - ... ... ... ...
(Date:5/3/2016)...  Neurotechnology, a provider of high-precision biometric identification ... Identification System (ABIS) , a complete system for ... can process multiple complex biometric transactions with high ... face or iris biometrics. It leverages the core ... MegaMatcher Accelerator , which have been used in ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... 24, 2016 Epic Sciences unveiled a ... susceptible to PARP inhibitors by targeting homologous recombination ... The new test has already been incorporated into ... cancer types. Over 230 clinical trials ... pathways, including PARP, ATM, ATR, DNA-PK and WEE-1. ...
(Date:6/23/2016)... , ... June 23, 2016 , ... ... release of its second eBook, “Clinical Trials Patient Recruitment and Retention Tips.” Partnering ... retention in this eBook by providing practical tips, tools, and strategies for clinical ...
(Date:6/23/2016)... , June 23, 2016 /PRNewswire/ - FACIT has ... Ontario biotechnology company, Propellon Therapeutics Inc. ... and commercialization of a portfolio of first-in-class WDR5 ... targets such as WDR5 represent an exciting class ... in precision medicine for cancer patients. Substantial advances ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... (Yeast and Mold) microbial test has received AOAC Research Institute approval 061601. , ... tests introduced last year,” stated Bob Salter, Vice President of Regulatory and Industrial ...
Breaking Biology Technology:
Cached News: