Obesity and Pregnancy

2 April 2021

Obesity and Pregnancy

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Overweight and obesity are defined as abnormal or excessive fat accumulation that poses a risk to health of the individual. For women, it can increase your risk of infertility, increase complications in pregnancy and increase adverse consequences for mother and child.

Some women with obesity have elevated levels of insulin and insulin resistance, causing a hormonal imbalance which can lead of excess androgens that can prevent ovulation from occurring. Without ovulation, a woman cannot fall pregnant. Obesity in pregnancy can mean it takes longer for you to fall pregnant. It has been shown that for women with BMI (body mass index) from 29kg/m2, the chance of conception falls by 4% every year for every 1kg/m2 gained. (Stubert et al, 2018)

The risks of miscarriage and recurrent early miscarriages were also significantly higher for obese women (Lashen et al, 2004). During pregnancy, the relative risks for gestational diabetes and pre-eclampsia (elevated blood pressure) increases by 10% when there is a 10% increase in pre-pregnancy BMI. (Shummers et al, 2015). Congenital malformation risks have also been shown to have a strong correlation with maternal obesity. These include heart defects, orofacial cleft and limb malformations.(Stubert et al, 2018).

Preventative measures to achieve a normal BMI is important to allow for successful conception and an uncomplicated pregnancy to achieve success with a healthy mother and healthy baby.

Please book an appointment for further discussion about weight management in preparation for a pregnancy or during pregnancy or please talk to your own doctor.


Lashen, H, Fear, K, & Sturdee, DW, 2004, ‘Obesity is associated with increased risk of first trimester and recurrent miscarriage: matched case control study’, Human Reproduction, 19(7): 1644 1646.

Shummers, L, Hutcheon, JA, Bodnar, LM, Lieberman, E & Himes, K, 2015, Risk of adverse pregnancy outcomes by prepregnancy body mass index: A population-based study to inform prepregnancy weight loss counselling’, Obstetrics & Gynaecology, 125(1): 133-143.

Stubert, J, Reister, F, Hartmann, S & Janni W, 2018, ‘The risks associated with obesity in pregnancy’, Deutsches Ärzteblatt International, 115: 276–83.

Is obesity linked to our genes?

9 April 2021

Is obesity linked to our genes?

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Many factors have been given for influencing body weight in humans. These include the built environment, medical conditions, human behavior, medications, but increasingly there is a strong association of a genetic role in obesity. In a landmark study, Stunkard et al 1986 found that there was a correlation between the weight of Danish adoptees and the body mass index (BMI) of their biological parents that was statistically significant, particularly for their mothers. Furthermore, he found that there was no correlation between the weight of adoptees and their adoptive parents and that this was applicable across all weight classes, not just the obese adoptees, but also those who were thin. (Stunkard et al, 1986)

Mutations in genes alone, which occur slowly, cannot explain the obesity epidemic that has occurred in the past few decades around the world. It Australia, there has been a 11.3% rise in the prevalence of obesity in Australia from 1980 to 2000 which is 2.5 times increase, over 20 years. (Cameron et al, 2003) Interest is growing in the role of the environment and the gene-environment interaction in the increase prevalence of obesity and obesity related comorbidities. Epigenetics the activation or deactivation of gene expression across certain tissues without DNA sequence changes to the genome. It is thought that through this mechanism, environmental chemicals, gut microbiota modifications and poor nutritional intake can have an impact on metabolism and contribute to obesity and its comorbidities. (Thaker VV, 2017).

If you have any questions please book an appointment or talk to your doctor.


Stunkard, AJ, Sørensen, TI, Hanis, C, Teasdale, TW, Chakraborty, R, Schull, WJ, & Schulsinger, F, 1986, ‘An adoption study of human obesity’, The New England journal of medicine, 314(4): 193–198.

Cameron, AJ, Zimmet, PZ, Dunstan, DW, Dalton M, Shaw, JE, Welborn, TA, Owen, N, Salmon, J & Jolley, D, 2003, ‘Overweight and obesity in Australia: the 1999-2000 Australian Diabetes, Obesity and Lifestyle Study (AusDiab)’, Medical Journal of Australia, 178 (9): 427- 432.

Thaker V. V. (2017). ‘Genetic and epigenetic causes of obesity’ Adolescent medicine: state of the art reviews,28(2), 379–405.