Bone Accrual and Hormones in Response to Lactation
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This is a prospective observational trial of healthy postpartum women to investigate changes in bone density and markers of bone turnover during lactation. The study hypothesis is that women who breast-feed 5 months or more will lose bone density and subsequently regain the bone density after weaning. This study seeks to define determinants of the regain in bone density.
Condition or disease
This is a prospective observational trial enrolling healthy postpartum women, ages 20 years and older with the intent to breast-feed from the UNC outpatient obstetrical clinics and the UVA outpatient obstetrical clinics. These women were studied at 3-5 visits in the year following their delivery to assess bone density, nutritional intake, exercise, and breast-feeding choices. The number of study visits depended on the timing of return of menses and interest in participating in the follow-up study (timepoints are: immediate postpartum, 3 months postpartum, return of menses, 6 months after return of menses and follow-up visit 6 months after final visit). Blood was taken for analysis of bone-related hormones, bone turnover and calcium homeostasis markers. The study focuses on women with extended lactation (at least 5 months of lactation) whereas women who cease lactation prior to 3 months will be the primary comparison group.
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Layout table for eligibility information
Ages Eligible for Study:
20 Years and older (Adult, Older Adult)
Sexes Eligible for Study:
Accepts Healthy Volunteers:
Postpartum women from outpatient obstetrical/gynecology clinics.
age >20 at the time of delivery
singleton pregnancy and
<2 prior pregnancies that were >20 weeks gestation.
maternal rheumatologic disorders
maternal anorexia nervosa
maternal endocrinologic disorders,
medications known to affect bone density such as corticosteroids, thyroid hormone use, anticonvulsant therapy, bisphosphonates, long-term GnRH agonists use and calcitonin.