Finding out a baby’s sex during pregnancy could improve their life chances, a new study from Cambridge has found.
Pregnancies of male babies are more likely to lead to complications, possibly because they grow faster in the womb and require more nutrients and oxygen than those supplied by the mother through the placenta – the temporary organ that attaches to the wall of the uterus during pregnancy to help the fetus grow and develop.
Now, scientists have found that the sex of a fetus can affect the proper functioning of the placenta as well as factors such as diet-induced maternal obesity and stress, after studying pregnancies in lab mice.
About one in 10 women is affected by pregnancy disorders, such as fetal growth restriction and pre-eclampsia – life-threatening high blood pressure for both mother and child – but these can be difficult to predict and treat.
The new research suggests that designing individual treatment plans and encouraging pregnant women to change their lifestyles based on the gender of their unborn baby could have lifelong health benefits for their children. – and mean the end of the tradition of waiting until the baby is born to find out if it’s a boy or a girl.
“Often parents don’t want to know the gender of the baby because they want it to be a surprise. But actually knowing the gender would help determine if one pregnancy may be more risky than another, because we know that certain pregnancy conditions such as pre-eclampsia and fetal growth restriction may be more common in women carrying male babies than in women,” said Dr Amanda Sferruzzi-Perri, Member of St John’s College, who conducted the research with his team from the University of Cambridge’s Department of Development Physiology and Neuroscience at the Center for Trophoblast Research.
“We’re not 100% sure why, but it could be related to the fact that male babies grow faster in the womb, so it could be that their needs for nutrients and oxygen supplied by the mother via the placenta may easily become limited, so the baby boy may not be given everything he really wants and needs to reach his full potential.
Dr. Sferruzzi-Perri’s research team revealed their findings in an article published in the journal Reproductive Biology. A second study authored in collaboration with fellow researchers from institutions around the world, which demonstrates how diet-induced maternal obesity alters placental structures and affects baby growth, including causing sex-specific alterations of the fetus, appears in the review. Acta Physiologica.
Fetal growth depends on placental function, which requires energy from mitochondria – special compartments in our cells that help convert energy taken from food into energy that cells can use as fuel. The researchers found that during a normal pregnancy in mice, the placenta reacts differently depending on whether it is supporting a female or male fetus, and works better with lighter female fetuses than with heavier male fetuses.
“The placenta has an incredible ability to alter how it forms and functions,” Dr. Sferruzzi-Perri said. “It can be seen on many levels of how cells form in the placenta, it’s genes and proteins, even its mitochondria. These can all change in response to different kinds of signals, whether in a mother who ate a sugar and fat diet, or in a pregnancy where there’s sibling rivalry when there’s more than one baby, but what I think is probably the most novel aspect, c is that the way the placenta adapts seems to depend on whether the baby is female or male.”
Studies show the importance of designing gender-specific therapies for placental insufficiency and fetal growth abnormalities, as well as personalized lifestyle interventions or therapies for obese pregnant women.
“The data we generated in the lab really showed us that we need to consider the sex of the baby when monitoring a pregnancy,” Dr. Sferruzzi-Perri said. “Therefore, perhaps treatments should be tailored based on the gender of the baby.”
Scientists already know that male and female risk of diseases such as type 2 diabetes and cardiovascular disease depends on gender – men tend to have a higher incidence of both. “Whether some of this is from early exposures is a key area that people like me and others are really eager to try to solve. is really widespread around the world, including even in developing countries where urbanization means that women have more access to sugary and fatty diets than before,” said Dr. Sferruzzi-Perri.
In the UK, more than half of pregnant women have a body mass index above the normal healthy range. This is concerning because maternal obesity increases the risk of pregnancy complications, such as miscarriage, gestational diabetes, pre-eclampsia and stillbirth. Abnormal birth weight can also lead to neurodevelopmental problems and immune disorders in childhood, as well as obesity, diabetes and heart disease in adulthood.
“We are now building more and more evidence of what to measure in the mother during pregnancy, such as her starting body mass index, her growth, her gestational weight, but also taking into account the fetal sex. routinely, clinicians consider sex when looking at ultrasound images, because sex is an important determinant of fetal growth, however, we haven’t really understood before how this might be determined; how it might interact with the environment of the mother or the way the pregnancy Our studies therefore give more information to the clinician to allow him to make more informed decisions on how to manage this pregnancy.
“A woman who has a male baby may have to adopt different living arrangements than a woman who carries a woman.”
Currently, there are very few ways to treat women with pregnancy complications other than bed rest, dietary advice, or early delivery, due to the risks of drugs passing through the placenta and affecting individual organs of the fetuses, which are very sensitive. Scientists are now trying to think of ways to design treatments that only go into the placenta.
“These therapies would increase how the placenta functions, how it grows, and even how at its mitochondria it produces energy to support fetal growth,” Dr. Sferruzzi-Perri said. “Much of this groundwork reinforces that the placenta is fundamental to a healthy pregnancy and that fetal sex is important. But by looking at the different types of genes, proteins, and cellular mechanisms, we could identify targets that could be used as biomarkers and specifically targeted in the placenta to improve outcomes for mothers and their babies.”