Polycystic ovary syndrome, glucose metabolism disturbances and daytime sleepiness in women with a history of preterm birth

Abstract

Objective

The present thesis is based on three papers where the aims are to answer the following questions:

1. Do women with a history of preterm birth have increased prevalence of PCOS and disturbed glucose metabolism (Paper I)?

2. Can AMH replace ovarian morphology in the diagnosis of PCOS (Paper II)?

3. Is EDS, and hence the risk of OSA, higher in women with PCOS (Paper III)?

Study design

The study is designed as a cross sectional, case-control study. Women from the Namsos Hospital district with previous preterm birth (n = 133) were compared with controls with term births (n = 129). All three papers are based on the same cohort of women. In paper I, 19 women in the case group and 2 women in the control group are excluded because of a history of twin births.

Methods

All included women had a clinical examination and a trans-vaginal ultrasound examination. Fasting blood samples were drawn and oral glucose tolerance tests (OGTT) were performed. Hirsutism was evaluated by the modified Ferriman – Gallwey (FG) score. The PCOS diagnosis were set according to the Rotterdam criteria (PCOSR), the Androgen Excess and PCOS Society criteria (PCOS-AES) and by replacing PCOM with AMH as one out of three diagnostic criteria. All participants filled in the Epworth sleepiness scale (ESS) questionnaire.

Main outcomes

1. The prevalence of PCOS and diabetes (study 1)

2. The serum levels of AMH (study 2)

3. The total ESS score (study 3)

Results

1. Twenty-nine of 114 women (25.4%) met the PCOS-R criteria among women with preterm birth, compared with 18 of 127 (14.2%) among controls (p = 0.03). Eight (7.1%) women were diagnosed with diabetes in the preterm group compared to none in the control group (p < 0.01). Hirsutism was present in 34 (29.8%) women with preterm birth compared to 12 (9.4%) in the control group (p < 0.01).

2. Among the 262 participants, 56 met the PCOS-R criteria and 44 the PCOS-AES criteria. When replacing PCOM with AMH, the specificity and sensitivity for identifying PCOS were 97.1% and 94.6% according to the PCOS-R criteria and 97.2% and 95.5% according to the PCOS-AES criteria at an AMH cut-off value of 20 pmol/L.

3. No differences were found in ESS score between PCOS women and non-PCOS women. There were no correlations between ESS score and androgen, glucose and insulin levels, body mass index (BMI) or waist-hip ratio.

Conclusions

The prevalence’s of PCOS, diabetes and hirsutism are increased among women with a history of preterm birth. Endocrine and/or metabolic factors may therefore be involved in the pathogenesis of preterm birth. Women who have experienced preterm delivery seem to have a markedly increased risk of PCOS and diabetes. AMH may be a good substitute for PCOM in diagnosing PCOS both according to the PCOS-R and the PCOS-AES criteria. Sensitivity and specificity is high at low AMH levels. According to the ESS score, PCOS women in this cohort did not have EDS. An increased risk of OSA based on EDS was not found.