Pregnancy-Associated Osteoporosis: Does the Skeleton Recover?

Abstract

Osteoporosis in pregnancy is a rare clinical problem of unknown cause. If the bone loss results from the pregnancy alone it should improve toward normal after delivery; in contrast, where bone density was low before pregnancy, due to some other secondary cause, significant postpartum improvement might not be expected. Thirteen women (age 23-37 years) with pregnancy-associated osteoporosis presenting with either pain in the back and vertebral collapse (8 subjects) or pain in the hip (5 subjects) had consecutive dual-energy X-ray absorptiometry measurements of bone mineral density (BMD) for up to 8 years after an affected pregnancy. The BMD results were expressed as a Z-score in relation to an age-matched mean. The mean initial (0-6 months postpartum) BMD was low in both groups and at both sites. In the back pain group the mean spine Z-score (Ll-L4) was -3.34 (range -2.25 to -4.66) and mean total hip Z-score was -2.41 (range -1.44 to -3.82). In the hip pain group the mean spine Z-score was -2.00 (range -1.48 to -2.65) and mean hip Z-score was -2.19 (range -1.12 to -3.26). Subsequent mean hip and spine BMD increased significantly toward the lower end of the normal range. We conclude that a reversible part of the bone loss is related to the pregnancy itself. A low BMD before pregnancy cannot be excluded. Knowledge that the bone density increases after an affected pregnancy, combined with the known rarity of recurrent symptoms in subsequent pregnancies, is important in prognosis.

ENDOCRINOLOGY IN PREGNANCY: Bone metabolic changes during pregnancy: a period of vulnerability to osteoporosis and fracture

“…Consistent with the transitory condition of the process, bone density tends to recover in most, but not all, cases after delivery (78) (Fig. 4), an observation that may explain the low rate of recurrence in subsequent pregnancies (2,79,80).…”

Maternal Mineral and Bone Metabolism During Pregnancy, Lactation, and Post-Weaning Recovery

“…Serum chemistries and calciotropic hormone levels are usually unremarkable. However, bone loss is likely a factor in pregnancy-related vertebral fractures, because the BMD is usually low at presentation (475,713,849,1005), and it spontaneously improves afterward (259,433,713). In the few cases where bone biopsies were done, mild osteoporosis was observed (849,850,1005).…”

“…Pregnancy-associated osteoporosis typically occurs in a first pregnancy, higher parity does not increase the risk, and fractures usually do not recur in subsequent pregnancies (243,259,475,666,713). These observations imply that in many cases reversible factors (such as nutritional deficiencies) may have been corrected after the first pregnancy.…”

“…Individual cases have reported spontaneous improvements in bone density by 20 -70% (29,433,713,811,928), so pharmacological therapy may be reasonably withheld for 12-18 mo to determine the magnitude of spontaneous recovery (501). An anti-remodeling agent such as a bisphosphonate or denosumab might blunt the spontaneous bone formation that is expected during the post-weaning interval.…”

A Rare Cause of Low Back Pain in Pregnancy: Pregnancy Associated Osteoporosis

“…Emzirme süresince kemik döngüsü artar, süt yolu ile kalsiyum kaybedilmesine karşın idrarla atılan kalsiyum miktarı azalır (5,17). Emzirmeyi kesip sadece kalsiyum ve D vitamini takviyesi verilen olguların lomber KMY değerlerinde 8-18 ayda %6, 2-4 yıllık süre de %9,5 artış tespit edilmiştir (12,18). Bizim olgumuzun da idrarda kalsiyum miktarı normalden düşük bulundu.…”