Primary hyperparathyroidism (PHPT) in Pregnancy

Primary hyperparathyroidism in pregnancy is of concern primarily for its potential effect on the fetus and neonate. 

Complications of primary hyperparathyroidism in pregnancy include:

• Spontaneous abortion, low birth weight, supravalvular aortic stenosis, and neonatal tetany:

  • The latter condition is a result of fetal parathyroid gland suppression by high levels of maternal calcium, which readily cross the placenta during pregnancy.

  • Infants with this condition, used to hypercalcemia in utero, have functional hypoparathyroidism after birth and can develop hypocalcemia and tetany in the first few days of life.

Calcium levels vary in the pregnant patient due to the physiological changes that occur.

• Carella and Gossain stated that calcium concentrations greater than 10.1 mg/dL during the second or third trimester should prompt an evaluation of PHPT.

In a retrospective patient series in the Norman Parathyroid Clinic in Florida, investigators examined pregnant patients with fetal loss and PHPT:

• They found that patients with calcium levels of 10.7 mg/dL were associated with pregnancy loss, but most pregnancies continued to term.

• Calcium levels  greater than 11.4 mg/dL were associated with higher levels of fetal loss, and 72% of fetal loss occurred at or above this level.

Surgery is the definitive treatment for PHP.T

• However, since surgery for PHPT has inherent potential risks for the pregnant patient, it is often viewed as the last resort.

• However, given the increasing evidence that supports a higher morbidity and mortality associated with calcium levels of  greater than 11.4 mg/dL, surgical intervention is recommended in patients with levels  greater 11.0 mg/dL, particularly in patients with prior pregnancy loss.

Gestational age plays a role in determining surgical candidacy:

• Traditionally, surgery is reserved for patients in the second trimester, given the higher risk in the first and third trimesters.

• First-trimester surgery is avoided due to incomplete organogenesis, and third-trimester surgery has been discouraged because it is associated with a higher risk of preterm labor.

  • In addition, there is a reported 58% fetal mortality associated with third-trimester parathyroidectomy.

  • This mortality rate includes all postoperative complications for the infant, such as premature delivery, intrauterine growth retardation, infant hypocalcemia, neonatal death, and stillbirth.

  • It is impossible to differentiate surgical complications from complications of prolonged hypercalcemia related to the underlying disease process.

Rodrigo Arrangoiz MS, MD, FACS

Cirugía Oncológica