Hypophosphatemia in pregnancy: A case report

Autosomal hypophosphatemic rickets though a rare genetic disorder can lead to significant discomfort to the patient resulting in clinical deterioration and a poor quality of life. We describe a case of a 33-year-old woman G2P1001 at 6 weeks of gestation with complaints of myalgia and bony pains. Keeping her history of bony pains and fractures in mind, she was further evaluated. On evaluation, she was found to have low levels of phosphates 0.99 mg/dl (2.40-4.40) and high levels of fibroblast growth factor 23 (FGF 23) 231.70pg/ml (23.20-95.40). These biochemical parameters were suggestive of hypophosphatemic rickets and further on gene sequencing she was found to have autosomal dominant hypophosphatemic rickets (HR). During her follow-up visits, her checkup and antenatal investigations were normal. Pregnancy acts as a stressor and patients with asymptomatic ADHR may present during pregnancy for the first time with the symptoms of HR. So, a high index of suspicion is required for patients reporting musculoskeletal pains in pregnancy. Early diagnosis can help the mother have a better pregnancy experience. Phosphate and vitamin D supplementation during pregnancy can help these women reduce musculoskeletal pain symptoms. Unfortunately, this patient had a spontaneous abortion in the second trimester. The overall prevalence of ADHR is less than 1 per 1,00,000 live births. Data in pregnancy with ADHR is also minimal due to the condition's rarity. Hence, more and more studies are required in pregnancy with this disease to come to any conclusion and to find any association of ADHR with pregnancy outcomes. Genetic counselling and the need for testing in newborns if symptomatic is also an essential factor to remember when coming across such antenatal patients.