Thursday, December 18, 2014
Usually, women are concerned about excess weight gain during pregnancy. However, tipping on the lighter side of the weighing scale may prove to be harmful too. Scientists from the University of Georgia found that inadequate weight gain in pregnancy could affect the survival of the male foetus in particular.
Published in the PLOS ONE journal, the study aimed to investigate the effect of weight gain during pregnancy on birth sex ratios and the sex ratios of foetal deaths. The study revealed that male foetuses have higher vulnerability to adverse conditions in the womb than female foetuses. Also, male embryos are different from female ones metabolically and exhibit different growth rates.
The scientists analysed data from the Centers for Disease Control and Prevention (CDC) Vital Statistics website, which provided information on more than 68 million singleton births in the US between 1990 and 2012. They then determined the maternal ethnicity and weight gain during pregnancy as well as the sex of the infant and its gestational age.
They found that women who gained less than 20 pounds (approx. 10 kg) during pregnancy produced a much lower proportion of male offspring than female offspring. The proportion of male offspring birth was lower even when this group was compared with women who gained more than 20 pounds. They also found that at 6 months' gestation, the rate of male foetal deaths was much higher among women who gained little weight during pregnancy than those who gained high amounts of weight.
“The correlation was a near perfect relationship where the proportion of males rose with the number of pounds women gained during gestation. To me, the tight of the relationship indicates that weight gain and sex ratio at birth are, in fact, directly related and that the relationship isn’t driven by another related variable,” said lead scientist Kristen Navara.
The scientists attribute this effect to the higher metabolic rate in male foetuses indicating a higher need of calories for successful development. Further research in this area is needed to understand the factors that contribute to maximising the chances of the foetus’s survival.
News source :-Click Here!