Short summary

This study examined the blood pressure of pregnant women with PCOS compared to controls in Odense Child Cohort.  

Rationale

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder, affecting 8-13% of women during the reproductive age (1). PCOS is defined by the Rotterdam criteria based on two of the following criteria: Oligo- or anovulation, biochemical or clinical hyperandrogenism, and polycystic ovaries (2). Obesity is closely related to insulin resistance and inflammation (3), and the risk of hypertension (HT) could be associated with body mass index (BMI) (4, 5). Two recent Scandinavian prospective studies confirmed higher systolic and diastolic blood pressure (BP) in premenopausal women with PCOS (6, 7). In a Danish register-based study, young women with PCOS had an odds ratio (OR) of 1.7 for development of CVD including HT (8). 

In normal pregnancy, BP is typically lower during first trimester than the remaining pregnancy due to reduced peripheral resistance, despite increased maternal blood volume and 30-50% higher cardiac output (9, 10). Maternal volume expansion leads to higher BP during 2nd and 3rd trimester, and BP peaks around gestational age (GA) 30-34 weeks (10). Maladaptation to hemodynamic changes can cause pregnancy induced HT (PIH) (10). PIH is defined as the development of BP ? 140/90 mmHg after GA 20 weeks in at least two separate measurements more than 4 hours apart (11). PIH can potentially progress to preeclampsia, which is responsible for more than 70,000 maternal deaths worldwide each year (11). 

Limited data are available regarding BP levels during pregnancy in PCOS. Two studies reported higher 24 hour BP during each trimester of pregnancy (12) and higher BP during 3rd trimester of pregnancy (13) in women with PCOS compared to controls, but only 22 (12) and 33 (13) women with PCOS were included in the studies. Some studies reported higher risk of PIH in women with PCOS compared to controls (12, 14-21), whereas this could not be confirmed in other studies (22-24). The studies differed according to included study populations, and many studies were conducted in selected study cohorts of women with PCOS (12, 14-24). It remains to be established, whether PCOS is an individual risk factor for elevated BP and/or PIH during pregnancy. 

The aim of the present study was to examine BP prospectively throughout pregnancy in women with PCOS and controls. We hypothesized that BP was higher in women with PCOS than controls and the prevalence of PIH could be associated with BMI. 

Description of the cohort

Odense Child Cohort is an ongoing single-center prospective cohort. Pregnant women residing in the municipality of Odense were recruited between January 2010 and December 2012. Among 6,707 pregnancies, 4,017 women received information regarding the study cohort, and 2,874 were included. Of the 2,197 eligible women 9.1% (200/2,197) had a diagnosis of PCOS and 90.9% (1,997/2,197) were controls. 

Data and biological material

Blood pressure. Maternal characteristics (age, BMI, ethnicity ect.)

Collaborating researchers and departments

Department of Endocrinology and Metabolism, Odense University Hospital, 

Department of Environmental Medicine, University of Southern Denmark, 

Charité – Universitätsmedizin Berlin

Odense Child Cohort, Hans Christian Andersen Children's Hospital, Odense University Hospital

Department of Gynecology and Obstetrics, Odense University Hospital

Experimental and Clinical Research Center, a joint cooperation between Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité-Universitätsmedizin Berlin

DZHK (German Centre for Cardiovascular Research), 

• Dorte Glintborg, DrMed, PhD
• Professor Marianne Andersen, DrMed, PhD
• Professor Jan Stener Jørgensen, DrMed, PhD
• Richard Christian Jensen, DrMed, PhD
• Anna Birukov, MSc
• Henriette Boye Kyhl, MSc