Beware-Fast food may lead to delayed pregnancy & infertility

Smoking and obesity, have consistently been associated with a longer time to pregnancy, TTP or infertility, but the role of preconception diet in women remains poorly studied.Indulging more on fast food and eating fewer fruits could lengthen your duration of becoming pregnant and decrease your chances of conceiving within a year, according to a new research published in the journal Human Reproduction.

The study was conducted by Claire Roberts, a professor at University of Adelaide, and colleagues to determine the association between preconception dietary intake and reduced fecundity as measured by a longer time to pregnancy (TTP).

Several lifestyle factors including obesity and smoking have consistently been associated with a longer TTP or infertility, but the role of preconception diet in women remains poorly studied. Healthier foods or dietary patterns have been associated with improved fertility, however, these studies focused on women already diagnosed with or receiving treatments for infertility, rather than in the general population.

This research was carried out in women recruited to the multi-centre Screening for Pregnancy Endpoints (SCOPE) study between 2004 and 2011. Of the 5598 women, the majority (5258, 94%) received no fertility treatments before conception and 340 did.

The researchers introspected 5598 women in Australia, New Zealand, the UK and Ireland about their diet. The women, who had not had a baby before, were interviewed by research midwives during their first antenatal visit.

Among all the couples in the study, 468 (8%) couples were classified as infertile and 2204 (39%) conceived within a month. When the researchers looked at the impact of diet on infertility, they found that in women with the lowest intake of fruit, the risk of infertility increased from 8% to 12%, and in those who ate fast food four or more times a week, the risk of infertility increased from 8% to 16%.

Compared to women who ate fruit three or more times a day in the month before conception, women who ate fruit less than one to three times a month took half a month longer to become pregnant. Similarly, compared to women who never or rarely ate fast food, women who consumed fast food four or more times a week took nearly a month longer to become pregnant.

The findings show that eating a good quality diet that includes fruit and minimizing fast food consumption improves fertility and reduces the time it takes to get pregnant," said Dr. Roberts.

First author Dr Jessica Grieger, post-doctoral research fellow at the University of Adelaide, said: "We recommend that women who want to become pregnant should align their dietary intakes towards national dietary recommendations for pregnancy. Our data shows that frequent consumption of fast foods delays time to pregnancy."

During the first antenatal visit at around 14-16 weeks' gestation, midwives collected information about the time it took to become pregnant and the women's diet. This included details of their diet in the month before conception, and how frequently they consumed fruit, green leafy vegetables, fish and fast foods. Fast foods included burgers, pizza, fried chicken and chips that were bought from take-away or fast food outlets. Fast foods eaten at home (bought from supermarkets, for example) were not included in the data collected and so consumption of this type of food is likely to be under-reported.

Dr Grieger said: "Most of the women did not have a history of infertility. We adjusted the relationships with pre-pregnancy diet to take account of several factors known to increase the risk of infertility, including elevated body mass index [BMI] and maternal age, smoking and alcohol intake. As diet is a modifiable factor, our findings underscore the importance of considering preconception diet to support timely conception for women planning pregnancy."

Limitation of the study includes the fact that collection of dietary data relied on retrospective recall and evaluated a limited range of foods. Paternal dietary data were not collected and the potential for residual confounding cannot be eliminated.

"For any dietary intake assessment, one needs to use some caution regarding whether participant recall is an accurate reflection of dietary intake. However, given that many women do not change their diet from pre-pregnancy to during pregnancy, we believe that the women's recall of their diet one month prior to pregnancy is likely to be reasonably accurate," said Dr Grieger.

"Lower intake of fruit and higher intake of fast food in the preconception period were both associated with a longer TTP," concluded the researchers. The researchers also found that while intake of fruit and fast foods affected time to pregnancy, pre-pregnancy intake of green leafy vegetables or fish did not.

For more information click on the link: https://doi.org/10.1093/humrep/dey079