Hypophosphatemia in pregnancy: A case report

Abstract

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.