Intravenous reproductive and developmental toxicity studies of cimadronate (YM175), a novel bisphosphonate, in rats and rabbits

Pamidronate Administration During Pregnancy and Lactation Induces Temporal Preservation of Maternal Bone Mass in a Mouse Model of Osteogenesis Imperfecta

During pregnancy and lactation, the maternal skeleton undergoes significant bone loss through increased resorption to provide the necessary calcium supply to the developing fetus and suckling neonate. This period of skeletal vulnerability has not been clearly associated with increased maternal fracture risk, but these physiological conditions can exacerbate an underlying metabolic bone condition like osteogenesis imperfecta. Although bisphosphonates (BPs) are commonly used in postmenopausal women, there are cases where premenopausal women taking BPs become pregnant. Given BPs' long half-life, there is a need to establish how BPs affect the maternal skeleton during periods of demanding metabolic bone changes that are critical for the skeletal development of their offspring. In the present study, pamidronate- (PAM-) amplified pregnancy-induced bone mass gains and lactation-induced bone loss were prevented. This preservation of bone mass was less robust when PAM was administered at late stages of lactation compared with early pregnancy and first day of lactation. Pregnancy-induced osteocyte osteolysis was also observed and was unaffected with PAM treatment. No negative skeletal effects were observed in offspring from PAM-treated dams despite lactation-induced bone loss prevention. These findings provide important insight into (1) a treatment window for when PAM is most effective in preserving maternal bone mass, and (2) the maternal changes in bone metabolism that maintain calcium homeostasis crucial for fetal and neonatal bone development. © 2019 American Society for Bone and Mineral Research.

Cancer During Pregnancy: The Oncologist Overview

Although a rare and challenging condition, cancer during pregnancy should promptly be identified and treated. Not only standards of care guidelines for the underlying disease are taken into account, but also fetal safety might be weighted for clinical decisions. Frequent lack of experience and knowledge about this condition could lead to late diagnosis, imprecise management, suboptimal treatment and fetal and maternal harm. Therefore, this review aims to summarize the current evidence regarding the epidemiology, clinical presentation, diagnostic workup, staging and treatment, including novel treatment modalities for patients diagnosed with cancer during pregnancy.

Pregnancy and newborn outcomes after exposure to bisphosphonates: a case-control study

We analyzed women and newborn outcome after maternal exposure to BPs. BPs have no teratogenic effect on the 36 analyzed pregnancies compared to unexposed controls matched on women underlying diseases (either systemic disease, either "bone" disease) but some outcome differed: neonatal complications rate in systemic diseases and live birth rate in bone diseases).

INTRODUCTION

The effect of bisphosphonates (BPs) during pregnancy remains unclear. We aimed to study pregnancy outcomes in women exposed to BPs during pregnancy.

METHODS

Data for cases and controls were from the French Reference Centre of Teratogenic Agents. Cases were women who received BPs in the 6 weeks before or during a pregnancy and had systemic or bone diseases. We included two respectively matched control groups: women with systemic diseases not exposed to BPs and healthy women not exposed to BPs or any teratogenic agent. Four controls were assigned to each case.

RESULTS

Thirty-six women were exposed to BPs including 5 just before pregnancy and 30 during the first trimester; 23 had systemic diseases (systemic lupus erythematosus, n = 5; rheumatoid arthritis, n = 5; other, n = 13) and 13 had bone diseases. Rate of observed congenital malformations did not differ in women with a systemic or a bone disease compared to their respective controls (respectively 2/23 [8.7%] vs 2/92 [2.2%], p = 0.178 and 0/13 [0%] vs 0/52 [0%], p = 1.00). Among women with systemic diseases, non-specific neonatal complications were more frequent for cases (4/16 [25.0%] vs 4/64 [6.3%], p = 0.027). Among women with bone disorders, the live birth rate was lower for cases than healthy controls (8/10 [80%] vs 50/50 [100%], p = 0.025).

CONCLUSION

We found no major teratogenic effects of BPs, but rates of neonatal complications were increased for women with systemic diseases, as were spontaneous abortions for women with bone diseases likely linked to the severity of the underlying diseases and concomitant medications.

Presentation and management of osteoporosis presenting in association with pregnancy or lactation

In this review, we summarize our current understanding of the pathophysiology of fragility fractures that occur for the first time during pregnancy and lactation, and provide guidance on appropriate investigations and treatment strategies. Most affected women will have had no prior bone density reading, and so the extent of bone loss that may have occurred during pregnancy or lactation is uncertain. During pregnancy, intestinal calcium absorption doubles in order to meet the fetal demand for calcium, but if maternal intake of calcium is insufficient to meet the combined needs of the mother and baby, the maternal skeleton will undergo resorption during the third trimester. During lactation, several hormonal changes, independent of maternal calcium intake, program a 5-10 % loss of trabecular mineral content in order to provide calcium to milk. After weaning the baby, the maternal skeleton is normally restored to its prior mineral content and strength. This physiological bone resorption during reproduction does not normally cause fractures; instead, women who do fracture are more likely to have additional secondary causes of bone loss and fragility. Transient osteoporosis of the hip may affect one or both femoral heads during pregnancy but it involves localized edema and not skeletal resorption. Case reports have described the use of calcitonin, bisphosphonates, strontium ranelate, teriparatide, vertebroplasty, and kyphoplasty to treat post-partum vertebral fractures. However, the need for such treatments is uncertain given that a progressive increase in bone mass subsequently occurs in most women who present with a fracture during pregnancy or lactation.

Osteoporosis presenting in pregnancy, puerperium, and lactation

PURPOSE OF REVIEW

To describe our current state of knowledge about the pathophysiology, incidence, and treatment of osteoporosis that presents during pregnancy, puerperium, and lactation.

RECENT FINDINGS

When vertebral fractures occur in pregnant or lactating women, it is usually unknown whether the skeleton was normal before pregnancy. Maternal adaptations increase bone resorption modestly during pregnancy but markedly during lactation. The net bone loss may occasionally precipitate fractures, especially in women who have underlying low bone mass or skeletal fragility prior to pregnancy. Bone mass and strength are normally restored postweaning. Transient osteoporosis of the hip is a sporadic disorder localized to one or both femoral heads; it is not due to generalized skeletal resorption. Anecdotal reports have used bisphosphonates, strontium ranelate, teriparatide, or vertebroplasty/kyphoplasty to treat postpartum vertebral fractures, but it is unclear whether these therapies had any added benefit over the spontaneous skeletal recovery that normally occurs after weaning.

SUMMARY

These relatively rare fragility fractures result from multifactorial causes, including skeletal disorders that precede pregnancy, and structural and metabolic stresses that can compromise skeletal strength during pregnancy and lactation. Further study is needed to determine when pharmacological or surgical therapy is warranted instead of conservative or expectant management.

Bisphosphonates in patients with autoimmune rheumatic diseases: Can they be used in women of childbearing age?

Autoimmune rheumatic diseases (ARD) are prevalent in women during their childbearing age. For their treatment, high doses of corticosteroid (CS) for long-term periods are often required, increasing the risk of bone loss. According to recent guidelines, bisphosphonates (BP) should be used as first line treatment to prevent CS induced osteoporosis. However, due to their long-term release from bone and their ability to cross the placenta, it has been suggested to avoid BP in women during their fertile years. BP seem to decrease foetus bone length in pregnant animals, but not in humans, at least, when they are administered at therapeutic dosage. BP are embryo toxic in animals when used at high dosage. In a systematic literature review, we found 58 women treated with BP close before or during pregnancy, showing no related congenital malformations. However, the Unit of Clinical and Epidemiological Genetics in University of Padova collected ten cases of women treated with BP during pregnancy, reporting 20% of congenital malformations. Thus, we suggest to avoid BP during pregnancy and caution with their use in fertile women. When they have to be given before pregnancy, specific affinities of the BP have to be considered to plan the washout period beforehand.