PCOS & Breastfeeding – Two studies

Resumption of ovarian function during lactational amenorrhoea in breastfeeding women with polycystic ovarian syndrome: endocrine aspects.

Hum Reprod. 2001 Aug;16(8):1603-10

Sir-Petermann T, Devoto L, Maliqueo M, Peirano P, Recabarren SE, Wildt L.

Division of Endocrinology, Department of Internal Medicine, School of Medicine, University of Chile, Santiago, Chile. tsir@entelchile.net

BACKGROUND: The aim of this study was to evaluate the changes in gonadotrophin concentrations and the dynamics of the episodic fluctuations of circulating LH during night-time, in fully breastfeeding normal women and in those with polycystic ovarian syndrome (PCOS) during lactational amenorrhoea and after weaning, in order to provide insights into the onset of this syndrome. Additionally, ovarian activity was evaluated by ultrasound examination and steroid concentrations.

METHODS: Twelve lactating PCOS (LPCOS) women and six normal lactating (NL) women of similar age were selected. On the 4th and 8th week postpartum (PP) and eight weeks after weaning, blood samples were collected every 10 min (10.00–20.00h). Gonadotrophin concentrations were determined in all samples. Steroid hormones were measured in one fasting sample and ovarian morphology was assessed by ultrasound.

RESULTS: On the 8th week PP, LH pulse frequency was higher and FSH concentrations were lower in LPCOS women compared with NL women, and steroid hormone concentrations remained low, except for androstenedione which was higher in LPCOS patients. After weaning, similar differences were observed between both groups. PCOS patients also showed enlarged ovaries with a PCOS pattern in the three study periods.

CONCLUSIONS: The enlarged ovaries associated with higher androstenedione concentrations suggest that PCOS is a primary ovarian defect, making it difficult to establish if the abnormal LH pattern observed in these women is primary or secondary to the ovarian dysfunction.

====
Resumption of ovarian function during lactational amenorrhoea in breastfeeding women with polycystic ovarian syndrome: metabolic aspects.

Hum Reprod. 2001 Aug;16(8):1598-602.

Maliqueo M, Sir-Petermann T, Salazar G, Perez-Bravo F, Recabarren SE, Wildt L.

Division of Endocrinology, Department of Internal Medicine, San Juan de Dios Hospital, School of Medicine, University of Chile, Santiago, Chile.

BACKGROUND: Polycystic ovarian syndrome (PCOS) is a common endocrine-metabolic disorder in women, a high percentage of whom exhibit peripheral insulin resistance. After delivery, in normal women, lactation imposes a metabolic adaptation, the impact of which on the insulin resistance of PCOS patients is not known. The aim of this study was to evaluate the effect of lactation on insulin resistance, glucose and insulin metabolism, and sex hormone-binding globulin (SHBG) and insulin-like growth factor binding protein-1 (IGFBP)-1 concentrations in fully breast-feeding normal and PCOS women during the postpartum period (lactational amenorrhoea) and also after weaning.

METHODS: Twelve lactating PCOS (LPCOS) women and six normal lactating (NL) women of similar age and body mass index (BMI) were selected for the study. At the 4th and the 8th week postpartum (pp), and 8 weeks after weaning, a 2 h, 75 g oral glucose tolerance test (oGGT) was performed, followed by an insulin tolerance test 2 days later. For the oGGT, glucose and insulin were measured in each sample and SHBG and IGFBP-1 were determined in the fasting sample.

RESULTS: During lactation, fasting insulin levels were similar in both groups. In LPCOS women 2 h insulin concentrations were significantly higher, and SHBG and IGFBP-1 concentrations were significantly lower, than those observed in NL women. In both groups, insulin sensitivity evaluated by the insulin tolerance test was not modified. After weaning, in LPCOS women, SHBG and IGFBP-1 concentrations remained lower and insulin concentrations remained higher than those observed in NL women ( P < 0.05 ). CONCLUSIONS: In PCOS women, insulin resistance is not modified during lactation. Lactation has a transitory beneficial effect on insulin levels and biological markers of insulin resistance.