Researchers from the Brazilian Federation of Gynecology and Obstetrics Associations Commission for Endocrine Gynecology looked at the following theories for boosting chances of pregnancy:
1. Women are more fertile as they age – MYTH
Although a woman may feel healthy in her forties, her fertility will not be in the same state as in her thirties, Brazilian researchers said.
They said the evidence of age that impedes fertility is not unanimous. But data shows that between 25 and 27 years old who try to get pregnant in 12 cycles have a success rate of around 80 percent.
The figure, on the other hand, is closer to the figure of 50 percent for people aged 40 to 45 years.
This is according to two studies, one led by Boston University School of Public Health in 2017, published in the American Journal of Obstetrics and Gynecology, and another led by Princeton University in 1986, published in Science.
2. Men are less fertile as they age – TRUE
The effect of a man's age on reproduction is less clear, according to the researchers – scientists are trying to fathom the low point.
However, the Brazilian team said that there are & # 39; clear directions & # 39; are that older fathers have lower quality sperm. That's on the back of two 2018 studies, one of which was led by the University of Campinas, published in fertility and sterility.
Studies have shown that men under the age of 25 are the most fertile and that among these men 95 percent of their sperm has no DNA damage – a figure that drops to 80 percent at the age of 35.
This was highlighted in a comprehensive review by the Center for Reproductive Medicine in Cleveland, Ohio, published in the journal Reproductive Biology and Endocrinology in 2015.
3. Women have a & # 39; fertile window & # 39; – TRUE
The authors said, although not impossible, the chances of conception are very low outside the & # 39; fertility window & # 39 ;.
They said the best chance of pregnancy is six days before the ovulation day, according to a 2002 study by the National Institute of Environmental Health Sciences. Ovulation day falls two weeks before a bleeding.
The team said having sex hoping to become pregnant even one day after that day is meaningless.
4. Lubricants kill semen – TRUE
Lubricants can boost the antics of the bedroom, but they do nothing for sperm's ability to swim, the researchers said.
& # 39; Multiple lubricants have been shown in multiple studies to adversely affect sperm motility at different concentrations & # 39 ;, the authors say.
Sperm begins to swim slower after 15 minutes of exposure to lubricants, a 1996 study by researchers at the Southwestern Medical Center at the University of Texas at Dallas showed, the findings published in a magazine that is no longer available.
Strangely enough, mustard oil seems to work well as a lubricant, because when the sperm is exposed to it, it remains hyperactive and the ability to swim is not reduced.
That is according to a study by the State University of New York Upstate Medical University in 2014, published in Fertility and Stertility.
The Brazilian researchers added that findings such as these suggest that canola, baby or mustard oil is preferred as a lubricant because they do not significantly affect sperm motility & # 39 ;.
5. Gender closer to ovulation will father a boy – MYTH
A popular belief that the Brazilian team often hears is that the gender of a baby depends on when it was made during the woman's cycle.
Sex closer to the ovulation day would increase the chance of a boy, and sex farther away from the ovulation day would favor a girl.
But the Brazilian team claims that there is limited and controversial evidence to support this.
They said: & # 39; There are a small number of studies, most of which were conducted more than 15 years ago, in small groups of patients, and that have produced conflicting results. & # 39;
6. Diet will increase female fertility – MYTH
A woman can have products that are deemed & # 39; fertility stimulus & # 39; for the best chance of getting pregnant.
But the Brazilian team said there is not enough evidence to support that diet – vegetarian, low-fat, or supported with, for example, herbal supplements – will help.
Even among the most studied nutrients, vitamin D and folic acid, there is not enough robust science, the team said.
However, folic acid is important for the development of a healthy baby, and women trying to conceive should use it for that reason, the NHS says.
7. Diet will stimulate male fertility – TRUE
The sperm of the man can be damaged by obesity and poor lifestyle choices, there is increasing evidence.
Consuming too much alcohol, caffeine, red meat and processed meat, sugar and total dairy products can dramatically reduce the chances of pregnancy, the authors said, including studies of which one is published in the Journal of Endocrinology of The University of Adelaide in 2017.
On the other hand, regular consumption of fish and seafood, poultry, grains, fruits and vegetables, and low-fat dairy products can improve sperm, according to a group of studies.
8. Smoking affects the fertility of men and women – TRUE
Smoking is generally unhealthy, which, according to science, can affect fertility.
For women there is evidence that smoking reduces the chance of pregnancy and increases the chance of miscarriage and an earlier menopause.
For men, smoking can affect sperm quality at DNA level, according to various studies, including a 2018 study by the University of Hassan II Casablanca, published in Andrologia.