Preconception health and long term consequences
Written by Lucy Lines at Two Lines Fertility
What are the long term consequences of our health on our ability to conceive? I think we all know what we are ‘supposed to eat and how much we are ‘supposed’ to exercise… we’ve all read countless articles and websites encouraging us to ‘eat healthily, ‘live a healthy lifestyle’ – trying to get us all to be healthier, better and live longer… but do you know how much your health impacts your preconception? What about the health of your future babies? And your babies’ babies?
A recent series of articles published in The Lancet focused on preconception health, looking at this time in 3 different ways: firstly from a biological perspective – the weeks around conception when eggs and sperm mature, fertilisation occurs and the developing embryo forms. Secondly, looking at an individual, the preconception period starts when a woman or couple decides they want to have a baby. And finally from a public health perspective – the preconception period can relate to a sensitive phase in the life-course, such as adolescence, when health behaviours affecting diet, exercise and obesity, along with smoking and drinking, become established before the first pregnancy.
In summary, they tell us that not only does good health and lifestyle impact conception, but it also plays a major role in the health of our children.
Preconception and healthy pregnancy
A woman who is healthy at the time of conception is more likely to have a successful pregnancy and a healthy child.
Consequences of poor health can extend across generations can affect preconception health, but few people fully understand this responsibility we have as parents and future parents (not to mention grandparents!) Poor nutrition and obesity are rife among women of reproductive age, typical diets are falling far short of nutritional recommendations, especially among adolescents. I think most of us know that when we finally do get pregnant, we need to take multivitamins and eat healthily, and we get plenty of advice about this in our antenatal appointments – but many studies now show that whilst micronutrient supplementation starting in preconception and early pregnancy can correct important maternal nutrient deficiencies, the effects on child health outcomes are disappointing – starting once we are pregnant is really a bit too late – we need to start much much earlier to really impact the long term health of our children.
Did you know that the proportion of obese women globally has risen from 6% to 15% from 1975 to 2014! In many countries, including Australia, up to 50% of women are overweight when they become pregnant – and this is a real problem! Obesity is associated with increased risk of most major adverse preconception, maternal and perinatal outcomes: the inability to conceive, complications of pregnancy and delivery, congenital anomalies, stillbirth, low birth weight, unsuccessful breastfeeding and even maternal death.
Paternal obesity is not irrelevant either. It has been linked to impaired fertility by affecting sperm quality and quantity and is associated with increased chronic disease risk in offspring.
Nutrition and Pregnancy
So why are so many women considered to be obese? A typical diet in high-income countries like Australia and the UK is characterised by a high intake of red meat, refined grains, refined sugars and high-fat dairy. In the UK and Australia, more than 9 of 10 young women reported consuming fewer than five fruit and vegetable portions daily. Our diet is also lacking in several important nutrients. Analysis in the UK shows that many women of reproductive age will not be nutritionally prepared for pregnancy – 96% have an intake of iron and folate below daily recommendations for pregnancy – getting enough folate during pregnancy for the prevention of neural tube defects is almost impossible to achieve through diet alone.
Preconception & Our Biological
Looking at preconception from the purely biological perspective, the 2-3 months before and after conception, it’s easy to see that this is a critical period for optimising gamete (egg and sperm) function and early placental development. Folic acid supplementation during this time can reduce the risk of neural tube defects by as much as 70%. besides having better preconception health other benefits could include decreased risk of pre-eclampsia, miscarriage, low-birth weight, small for gestational age birth, still, birth, neonatal death and autism in children, indicating that diet and nutrition before pregnancy might change mums experience of pregnancy as well as affecting baby outcomes.
Obese women have higher circulating concentrations of all sorts of bits and pieces including inflammatory cytokines (big word for a group of cells that affect immune responses amongst other things) hormones and metabolites. These accumulate within the ovarian follicular fluid and can have a negative impact on the growth of the eggs bathing in this fluid. This has a negative impact on those eggs ability to go on and be fertilised and to grow into healthy babies. Besides, eggs from obese women are smaller and produce blastocysts with poorer potential than eggs from women of healthy weight.
Some studies have suggested that a healthy diet in the years before preconception and pregnancy (possibly as many as 3 years before!), characterised by a high intake of fruit, vegetables, legumes, nuts and fish, and low intake of red and processed meat, can be associated with reduced risk of gestational diabetes, hypertensive disorders of pregnancy and preterm birth.
Obviously, very few people will plan a pregnancy 3 years in advance, so this highlights the need for population-level interventions. Published data and findings from developmental biology, suggest that intervening to improve men and women nutritional status before preconception and pregnancy improves long term outcomes for mothers and babies.
Eggs, sperm, embryos and in utero babies exposed to poor nutrition (and by that I mean over-nutrition, undernutrition and obesity, i.e. too much or too little of the ‘good stuff’) during important phases of growth have an increased risk of non-communicable diseases in later life, including hypertension, obesity, and type 2 diabetes, atopic conditions, cancer and neurological impairment – these are long term consequences across their entire lifespan.
Did you know that we are born with all the eggs we will ever have? So that means that the eggs you are ovulating now were created before you were born when you were still growing inside your Mums tummy, so they were influenced by what your mother was doing while prior to pregnancy through preconception and when she was pregnant with you… and half of the genetic material of your potential future grandchildren is being created when you are growing your daughters… Serious food for thought…