Balancing the risk of recurrent thromboembolism and pre-existing osteoporosis in pregnancy

In summary, our 31-year-old patient with hypogonadotrophic hypogonadism has severe osteoporosis caused by chronic oestrogen deficiency. Her GnRH deficiency can be overcome using ovulation induction therapy. However, if she becomes pregnant there is a small risk of recurrent thromboembolism because of her previous cerebral thrombosis. This risk is hard to quantify but would undoubtedly increase if her mobility were impaired. The metabolic and mechanical alterations of pregnancy may compromise her weakened skeleton and increase the risk of a second major fracture. Her skeletal status precludes the use of standard heparin. Fractionated low molecular weight heparins would be the prophylactic agent of choice, possibly switching to low-dose warfarin for the second trimester. Alternative prophylaxis using low-dose aspirin may be suitable, although this is not proven. The difficulty in this case is that pregnancy and the prophylactic measures designed to protect the patient may prove to be detrimental. The case also highlights the vital role of prepregnancy counselling and interdisciplinary consultation between obstetrician, haematologist and endocrinologist in order to steer the safest course through this therapeutic minefield.