Pregnant women who smoke could be harming the fertility of their daughters as scientists fear cigarette smoke has gender-bending hormones which can ‘masculinise girls’
- Scientists looked at how much testosterone babies had been exposed to in utero
- They found a significant difference in baby girls whose mothers smoked
- It is not clear how this may affect fertility in their future
Pregnant women who smoke could be damaging the fertility of their daughters, scientists fear.
Researchers believe tobacco contains gender-bending toxins which ‘masculinise’ girls while they are developing in the womb.
Daughters of mothers who smoked showed signs of having had high exposure to testosterone, the primary male sex hormone, a study found.
This may have consequences for their chances of conceiving over a life-time, the experts warned.
Women naturally produce small amounts of testosterone, but too much could cause to cause infertility as one of many problems.
Turkish researchers claim the same findings were not seen in boys or babies whose mothers didn’t smoke.
Pregnant women who smoke may be harming the fertility of their daughters because the cigarette toxins could have gender-bending properties, scientists fear
Smoking during pregnancy is widely known to be bad for the health of both mother and baby.
It’s the latest study to highlight the dangers of smoking on infants. Robust evidence already links it to premature birth – a leading cause of death and disability.
Yet some women persist, with figures showing one in ten British women are lighting up until childbirth.
Dr Deniz Ozalp Kizilay and colleagues at Cigli State Training Hospital studied more than 100 newborns – 56 females and 64 males.
Their mothers, who had smoked during pregnancy, filled out a questionnaire on their habits.
Babies whose mothers hadn’t smoked before or during pregnancy, or been exposed to second hand smoke, were included in the study for comparison.
Scientists measured anogenital distance (AGD), which is the space between the midpoint of the anus to a point of the genitalia.
AGD is a medical measurement of testosterone levels and reproductive health over life, with its length depending on testosterone levels during foetal development.
However, there are limited studies which have delved into how AGD is affected by maternal smoking.
Female newborns exposed to prenatal smoke had a significantly larger AGD length.
The more cigarettes a mother reported smoking daily, the longer the AGD, the scientists said.
Dr Kizilay said: ‘AGD is an important biomarker of foetal androgen exposure and intrauterine masculinization.
‘This significant increase in AGD in girls exposed to maternal smoking may be an indicator of excessive testosterone exposure that poses a risk for short and long-term health problems, including metabolism and fertility.
‘To our knowledge this is the first time that the unfavourable effects of prenatal smoke exposure on AGD, as a marker of testosterone exposure, has been demonstrated in female newborns.’
The findings suggest what has previously been suspected that the thousands of toxins in cigarettes have endocrine disrupting properties.
The endocrine system is made from a collection of glands that produce hormones regulating processes in the body, such as growth and development, reproduction, sleep, and mood.
Dr Kizilay said: ‘Our results do suggest that girls have higher testosterone exposure but not how this relates to reproductive function.’
The team plan to research the long-term effects of high testosterone exposure in the same group of baby girls to see if it does indeed affect their future fertility.
Their findings are being presented today at the 58th Annual European Society for Paediatric Endocrinology Meeting in Vienna.
In 2017 by Aberdeen University also found girls exposed to tobacco while still growing in the womb are more likely to have a miscarriage.
The damaging effects of cigarettes in utero also heightens their chance of going on to give birth prematurely, according to the findings published in the journal Human Reproduction Open.
Boys’ fertility may also be at risk, with studies finding both maternal and paternal smoking may reduce sperm quality in offspring.
WHAT ARE THE DANGERS OF A MOTHER SMOKING WHILE PREGNANT?
Cigarettes can restrict the essential oxygen supply to the baby. As a result, their heart has to beat harder every time the mother smokes
Increased risk of complications in pregnancy and birth
Less likely to have a healthier pregnancy and a healthier baby
Increased risk of stillbirth
Baby more likely to be born too early and have to face the additional breathing, feeding and health problems that often go with being premature.
Baby more likely to be born underweight: babies of women who smoke are, on average about 8oz lighter than other babies. This means they’re more likely to struggle keeping warm and are more prone to infection
Increased risk of cot death
Each year, smoking during pregnancy in the UK causes an estimated:
2,200 premature births