Obesity and Pregnancy

2 April 2021

Obesity and Pregnancy

photo credit: ID: 99358731, Kreangkrai Indarodom, dreamstime.com

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.