Improved Menstrual Function in Obese Women With Polycystic Ovary Syndrome After Behavioural Modification Intervention

A Randomized Controlled Trial

Emma Oberg; Sebastian Gidlöf; Ivika Jakson; Marja Mitsell; Petra Tollet Egnell; Angelica Lindén Hirschberg


Clin Endocrinol. 2019;90(3):468-478. 

In This Article

Abstract and Introduction


Objective Lifestyle intervention is the recommended first-line treatment for overweight women with polycystic ovary syndrome (PCOS). However, the efficacy of lifestyle change in improving reproductive function is still unclear.

Design A randomized controlled trial (RCT) with allocation to a behavioural modification programme (intervention) or minimal intervention (control) for 4 months with a follow-up at 12 months.

Patients Sixty-eight women, aged 18-40 years, body mass index (BMI) ≥ 27 kg/m2, fulfilling all Rotterdam PCOS criteria were randomized to treatment.

Measurements The primary outcome was improved menstrual regularity. Secondary outcomes were ovulation and pregnancy rates.

Results At 4 months, the weight loss was significant in the intervention group (−2.1%, P = 0.002) and nonsignificant in the control group (−1.0%). A higher proportion of patients in the intervention group improved menstrual regularity compared to the control group, mean difference 35% (95% CI: 16-60), P = 0.003. There was no difference in ovulation rate between groups. Logistic regression analysis showed that intervention was the only predictor of improved menstrual function, OR 3.9 (95% CI: 1.3-11.9). At 12 months, a total of 54% of the women improved menstrual regularity compared to baseline (P = 0.000) and 43% (P = 0.000) had confirmed ovulation. 38% of the women wishing to become pregnant succeeded within 1 year of study completion.

Conclusions This is the first RCT in overweight women with PCOS showing efficacy in improving reproductive function following behavioural modification intervention in comparison with minimal intervention. Although extensive weight loss is difficult to achieve in these women, behavioural modification intervention can help improve reproductive function.


Polycystic Ovary Syndrome (PCOS) is a multifactorial condition characterized by menstrual disturbances, hyperandrogenism and polycystic ovarian morphology. Many women with PCOS suffer from fertility disorders and clinical manifestations of increased androgens including hirsutism and acne.[1] PCOS is also associated with metabolic consequences such as accumulation of abdominal fat, insulin resistance, hyperinsulinaemia and type 2 diabetes mellitus.[2,3] Depending on ethnicity and definition, the prevalence of PCOS ranges from 8% to 13% in the general population.[4,5]

Treatment of PCOS aims to address weight management, improve reproductive function, counteract symptoms of hyperandrogenism and prevent future metabolic complications.[6] Standard medical treatment includes combined oral contraceptives that are useful for the regulation of the menstrual cycle and to address hyperandrogenism; insulin sensitizers such as metformin, which may improve metabolic parameters as well as fertility; and anti-androgens that can alleviate the symptoms of hyperandrogenism.[6] Where fertility is the main concern assisted reproduction treatments could be needed.[6] Bariatric surgery is an effective way of achieving sustained weight loss.[7,8] However, it increases the risk of pregnancy complications such as small for gestational age, possibly neonatal mortality[8,9] and greatly augments the risk of undergoing abdominal surgery during pregnancy.[10]

Lifestyle intervention including any combination of exercise, diet and behavioural modification intervention is the recommended first-line treatment for overweight women with PCOS[11] and can offer benefits in terms of weight loss, improved hormonal parameters, decreased hirsutism and insulin resistance.[11,12] Although it is reported that ovulation may resume after only a small reduction in weight either through exercise, diet or a combination of both,[13,14] little is known about the efficacy of lifestyle intervention in improving reproductive function compared to control treatment. To our knowledge, there are only two small randomized controlled trials (RCTs) investigating menstrual function, including ovulation, as primary outcome following lifestyle intervention compared with no intervention.[16,17] These studies showed no significant improvement compared to the control group but the results indicated restoration of ovulation in patients who lost weight.[16,17] A few other controlled trials reported menstrual regularity as a secondary outcome and some demonstrated shortening of menstrual cycle intervals following lifestyle intervention[18,19] but not all.[20] It was concluded in the Cochrane review that there were insufficient data for meta-analysis on menstrual regularity and ovulation.[11]

Since the efficacy of lifestyle change in improving reproductive function is still unclear, the aim of this RCT was to evaluate the effect of behavioural modification intervention compared with control treatment on reproductive function in overweight/obese women with PCOS.