BACKGROUND: Low milk supply is a common cause of early weaning, and supply issues are associated with dysregulation of thyroid function and prolactin. However, hormone levels compatible with successful breastfeeding are not well defined, limiting interpretation of clinical lab results. In this study we sought to quantify ranges for thyroid-stimulating hormone (TSH), free thyroxine (T4), total T4, and prolactin in a cohort of exclusively breastfeeding women. MATERIALS AND METHODS: Women planning to breastfeed were recruited in the third trimester of pregnancy. Maternal endocrine function was assessed before and after a breastfeeding session at 2 and 8 weeks postpartum. We used paired t tests to determine whether values changed from the 2- to 8-week visit. RESULTS: Of 52 study participants, 28 were exclusively breastfeeding, defined as only breastmilk feeds in the prior 7 days, at both the 2- and 8-week study visits. Endocrine function changed with time since delivery: the TSH level was higher, whereas total T4, free T4, and prolactin levels were lower, at the 8-week visit than at the 2-week visit (by paired t test, p≤0.01). We found a wide range of prolactin values at the 8-week visit, with a 5th percentile value of 9 ng/dL before feeding and 74 ng/dL at 10 minutes after feeding. CONCLUSIONS: Neuroendocrine function changes during the first 8 weeks after birth, and a wide range of values is compatible with successful breastfeeding. Further studies are needed to define reference values in breastfeeding women.
BACKGROUND: Low milk supply is a common cause of early weaning, and supply issues are associated with dysregulation of thyroid function and prolactin. However, hormone levels compatible with successful breastfeeding are not well defined, limiting interpretation of clinical lab results. In this study we sought to quantify ranges for thyroid-stimulating hormone (TSH), free thyroxine (T4), total T4, and prolactin in a cohort of exclusively breastfeeding women. MATERIALS AND METHODS:Women planning to breastfeed were recruited in the third trimester of pregnancy. Maternal endocrine function was assessed before and after a breastfeeding session at 2 and 8 weeks postpartum. We used paired t tests to determine whether values changed from the 2- to 8-week visit. RESULTS: Of 52 study participants, 28 were exclusively breastfeeding, defined as only breastmilk feeds in the prior 7 days, at both the 2- and 8-week study visits. Endocrine function changed with time since delivery: the TSH level was higher, whereas total T4, free T4, and prolactin levels were lower, at the 8-week visit than at the 2-week visit (by paired t test, p≤0.01). We found a wide range of prolactin values at the 8-week visit, with a 5th percentile value of 9 ng/dL before feeding and 74 ng/dL at 10 minutes after feeding. CONCLUSIONS: Neuroendocrine function changes during the first 8 weeks after birth, and a wide range of values is compatible with successful breastfeeding. Further studies are needed to define reference values in breastfeeding women.
Authors: Elif I Ekinci; Zhong X Lu; Ken Sikaris; Intissar Bittar; Karey Y Cheong; Que Lam; Nick Crinis; Christine A Houlihan Journal: Ann Clin Biochem Date: 2013-07-19 Impact factor: 2.057
Authors: S Díaz; M Serón-Ferré; H Cárdenas; V Schiappacasse; A Brandeis; H B Croxatto Journal: J Clin Endocrinol Metab Date: 1989-05 Impact factor: 5.958
Authors: Demelza M Smeeth; Danai Dima; Lisa Jones; Ian Jones; Nick Craddock; Michael J Owen; Marcella Rietschel; Wolfgang Maier; Ania Korszun; John P Rice; Ole Mors; Martin Preisig; Rudolf Uher; Cathryn M Lewis; Sandrine Thuret; Timothy R Powell Journal: Psychoneuroendocrinology Date: 2019-04-20 Impact factor: 4.905
Authors: Jennifer Osei; Maria Andersson; Olivia van der Reijden; Susanne Dold; Cornelius M Smuts; Jeannine Baumgartner Journal: J Clin Res Pediatr Endocrinol Date: 2016-05-23