Navigation Links
Weight gain between first and second pregnancies associated with increased odds of male second child
Date:9/24/2007

Boston, MA -- A slightly greater number of males than females are born worldwide every year. In recent decades, although there are still more baby boys born than girls, there has been an apparent decline in the ratio of male to female newborns in several industrialized countries, including Canada, Denmark, England, Germany, Japan and the United States. That has led researchers to ask: Are there any factors that can influence the probability of giving birth to a baby boy or girl? A new study from the Harvard School of Public Health (HSPH) and Karolinska Institutet in Stockholm, Sweden, found that mothers who experienced an increase in weight from the beginning of the first pregnancy to the beginning of the second pregnancy may be slightly more likely to give birth to a baby boy during their second pregnancy. The study appears online September 24, 2007 in the journal Fertility & Sterility.

The results are provocative because few biological factors are known in humans to influence the chances of either conceiving or carrying to term a baby boy or girl. Our study suggests that maternal nutritional factors might play a role, said Eduardo Villamor, assistant professor of international nutrition at HSPH and lead author of the study.

Some prior studies had looked at what factors might influence the sex ratio, but evidence of causality has been weak. Parental smoking, for example, has been associated with both lower and higher sex ratios. Maternal nutritional status had been studied, but there was little evidence to support a causal relationship with the sex ratio. One of the hypotheses that the authors of this study wanted to test was whether the increase in maternal obesity in several industrialized countries could play a role in the declining sex ratio. Their study found the opposite--maternal weight gain seemed to favor the birth of boys.

The study population, drawn from the Swedish Birth Registry, included 220,889 women who had successive
'/>"/>

Contact: Todd Datz
tdatz@hsph.harvard.edu
617-432-3952
Harvard School of Public Health
Source:Eurekalert

Page: 1 2

Related biology news :

1. Research may provide new link between soft drinks and weight gain
2. Leptin-signaling Protein Maintains Normal Body Weight And Energy Balance In Mice
3. Weight control protein may yield antiobesity drugs
4. Eating, body weight regulated by specific neurons
5. An essential regulator of body weight revealed
6. Engineers discover why toucan beaks are models of lightweight strength
7. Weighting cancer drugs to make them hit tumors harder
8. Its not fair! We are programmed to resist weight loss
9. Just like us, social stress prompts hamsters to overeat, gain weight
10. Very low birth weight linked to reduced quality of life in pre-school children
11. 76 percent of workers older than 60 years of age are overweight or obese
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:7/11/2014)... Janeiro, Brazil- In the brains of all vertebrates, ... allows an electric or chemical signal to be ... synapses, which are the most abundant type of ... formation is crucial for learning, memory, perception and ... synapses critical for brain function. For instance, ...
(Date:7/10/2014)... Colo. , June 27, 2014  The ... the National Institute of Standards and Technology (NIST) ... of its academic research and forensic science expert ... The Board is an element of the NIST,s ... members are among the first appointments made to ...
(Date:7/10/2014)... 30, 2014  Aware, Inc. (NASDAQ: AWRE ... previously announced on June 26, 2014 that its Board ... $1.75 per share, or approximately $40 million in total.  ... 2014 and a payment date of July 24, 2014.  ... had set an ex-dividend date for this special cash ...
Breaking Biology News(10 mins):Blame it on the astrocytes 2Ten Members of the American Academy of Forensic Sciences Appointed to Forensic Science Standards Board (FSSB) 2Ten Members of the American Academy of Forensic Sciences Appointed to Forensic Science Standards Board (FSSB) 3NASDAQ Sets Ex-Dividend Date for Aware, Inc.'s Special Cash Dividend of $1.75 Per Share 2
... Physicists, chemists and engineers at the University of Pennsylvania ... of patchy particles, using charged, self-assembling molecules that may ... and perhaps be used in small batteries that store ... electrical charges of calcium ions just like the ...
... retinal prosthesis and fetal tissue transplant, restored some vision ... at Neuroscience 2009, the annual meeting of the Society ... news on brain science and health, may lead to ... an engineered protein restored vision in an animal model ...
... researchers from the United States, Korea, and France has sequenced ... E. coli bacteria, one used to study evolution ... practical applications. The findings will help guide future research and ... classical research that is the foundation of our understanding of ...
Cached Biology News:Penn team uses self-assembly to make molecule-sized particles with patches of charge 2Experimental treatments restore partial vision to blind people 2Genomes of 2 popular research strains of E. coli sequenced 2Genomes of 2 popular research strains of E. coli sequenced 3
(Date:7/10/2014)... 2014 OMICS Group’s 5th International conference ... August, 2014 at Double Tree by Hilton Beijing, China ... in Analytical & Bioanalytical research methods only to facilitate ... this occasion, Dr. Srinubabu Gedela, MD of OMICS Group ... a remarkable one in bringing a unique and international ...
(Date:7/10/2014)...  Kainos Capital, a firm specializing in acquiring and ... has acquired the Slim-Fast brand from Unilever. Unilever will ... the transaction were not disclosed. Slim-Fast is ... markets ready-to-drink shakes, powders, bars and snacks to retail ... in the United Kingdom and ...
(Date:7/10/2014)... may help in the fight against terrorism with the ... of explosives with the use of light and special ... and Actuators B: Chemical , the researchers describe a ... concentrations as low as 6.3 ppm (parts per million). ... minutes. , "Traditionally explosives detection has involved looking for ...
(Date:7/10/2014)... our laptops and electric vehicles could store more energy ... help of a sponge-like silicon material. , Researchers ... used in one of the battery,s electrodes, as silicon ... of graphite. A paper describing the material,s performance as ... Nature Communications . , "Silicon has long been sought ...
Breaking Biology Technology:A Critical Review of Analytical Techniques for Improved Living Standards 2A Critical Review of Analytical Techniques for Improved Living Standards 3A Critical Review of Analytical Techniques for Improved Living Standards 4Kainos Capital Acquires Slim-Fast From Unilever 2Detecting trace amounts of explosives with light 2Silicon sponge improves lithium-ion battery performance 2Silicon sponge improves lithium-ion battery performance 3
... /Xinhua-PRNewswire-FirstCall/ -- China Medical,Technologies, Inc. (the "Company") ... device company that develops, manufactures and markets ... it will report selected,unaudited financial numbers including ... for the second fiscal quarter ended September ...
... Inc. ("Carna"),announced on October 27, 2008, the signing ... ("SUBC"). Under the terms of this,Agreement, SUBC will ... China., With China,s emergence as a strong ... companies have now established,research and production facilities in ...
... value and cost-effectiveness of spinal cord stimulation, ... BSX ) today welcomed an announcement by ... (NICE) recommending,the use of spinal cord stimulation (SCS) ... final guidance, NICE confirmed that,SCS is both safe ...
Cached Biology Technology:China Medical Technologies Announces Reporting Dates for the September Quarter Results and Addresses Investor Inquiries 2China Medical Technologies Announces Reporting Dates for the September Quarter Results and Addresses Investor Inquiries 3Carna Biosciences Signs Distribution Agreement with Shanghai Universal Biotech Company 2UK's NICE Recommends Spinal Cord Stimulation for Patients with Chronic Neuropathic Pain 2UK's NICE Recommends Spinal Cord Stimulation for Patients with Chronic Neuropathic Pain 3UK's NICE Recommends Spinal Cord Stimulation for Patients with Chronic Neuropathic Pain 4UK's NICE Recommends Spinal Cord Stimulation for Patients with Chronic Neuropathic Pain 5