The loss of a pregnancy or miscarriage is something that most couples rather not think of. However, it’s important for couples to understand why miscarriages can happen, especially as it can be caused by various factors and steps can be taken to lower the risks. The common causes of miscarriage are anatomical causes (like uterine abnormality), genetic causes, immunological disorders and hormonal imbalance. In this article, I will address one of the most common types of hormonal imbalance known today – insulin resistance.

Insulin resistance is a condition whereby levels of sugar, estrogen and testosterone in the blood are raised, while progesterone levels are lowered. The result is an excess of glucose in the bloodstream, which leads to prediabetes, diabetes and other serious health disorders. In pregnancy, insulin resistance causes a variety of concerns, such as delayed fetal growth and gestational diabetes.

Several scientific studies have also found that insulin resistance can lead to miscarriage. One such study was carried out by a team of researchers at the Reproductive Medical Centre, Peking University, People’s Hospital, Beijing, China. After examining 107 patients that achieved their first pregnancy after infertility treatment, they came to the conclusion the risk of miscarriage can be directly linked to insulin resistance.

A team from the Obstruction & Gynecology Department, Babol University of Medical Science, Babol, Iran offered similar findings, when they proved that women with elevated insulin levels are at a higher miscarriage risk.  As worrying as this is, it must be noted that insulin resistance doesn’t just heighten the risk of miscarriage; in fact, it has been shown to increase the risk of multiple miscarriages.

Several published studies have confirmed this, such as one by a team from the Department of Obstetrics and Gynecology at Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou. After investigating the differences in insulin resistance between women with recurrent miscarriage and those with normal pregnancy, they concluded that insulin resistance increases the risk for recurrent miscarriage during the first trimester of pregnancy.

The crucial link between insulin resistance and recurrent miscarriage was echoed in a prospective clinical study by a team of researchers from the Department of OB & GYN, Shiraz Medical University, Iran. Their study found that 39% of women with recurrent miscarriage have abnormal oral glucose tolerance test (OGTT) results. The OCTT, which measures the body’s ability to use glucose, is often used to check for insulin resistance and gestational diabetes.

Meanwhile, a team from the Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, University of Tennessee Health Science Center, Memphis, USA concluded that 27% of women with repeat miscarriage have high fasting insulin, despite normal glucose levels.

Insulin resistance is also associated with Polycystic Ovarian Syndrome or PCOS, which is why women with PCOS struggle with infertility. The condition raises levels of estrogen and testosterone in the body, while lowering progesterone levels. This interferes with the normal development of follicles in the ovaries, causing problems with ovulation.

However, if you have PCOS or insulin resistance and wish to undergo infertility treatment, hope is not lost. There are steps you can take to improve your insulin resistance sensitivity through lifestyle changes or medical intervention, before you undergo infertility treatment. Please don’t hesitate to speak to your infertility consultant should you have any concerns about insulin resistance. Your doctor can advise you on ways to reduce your risks and increase your chances for a safe pregnancy.