"My OB doctor is freaked out!".

Today we operated on a 30 year old female with a parathyroid tumor and high blood calcium of 11.7 mg/dl. She is 20 weeks pregnant and the high calcium is a real and direct threat to the baby. She was sent to us by her OB in Los Angeles, California. Today's operation took 18 minutes. We evaluated all four parathyroid glands showing three normal parathyroid glands and one parathyroid adenoma. She was cured, leaving the hospital 2.5 hours later to go out for a late lunch.

High Calcium and Hyperparathyroidism During Pregnancy

Almost all other cases of hyperparathyroidism and high calcium can wait a few weeks (or months) to get the patient into the operating room. However, it has been known for years that high calcium during pregnancy carries a dramatically high rate of miscarriage and fetal death.

High blood calcium during pregnancy can be very dangerous to the baby, resulting in miscarriage rates that are 5-10 times higher than normal.

Hyperparathyroidism during pregnancy usually demands a parathyroid operation to help prevent loss of the pregnancy.

Hyperparathyroidism during pregnancy is one of the very few "urgent" situations for us parathyroid surgeons.

Our practice has the world's largest experience with hyperparathyroidism during pregnancy. We published our landmark paper on this topic (see footnote). One of the primary findings of this research was that the rate of miscarriage was related to the height of the blood calcium (shown in this graph). Once the calcium level reached 11.4 mg/dl, the chance of miscarriage was 50%, increasing to nearly 80% when the calcium was over 12.5 mg/dl. This evidence helped us stratify which pregnant woman with only slightly elevated calcium levels can be observed during the pregnancy (to have the parathyroid tumor removed after the baby is born), versus those who need to be taken to the operating room within a few days to decrease the risk to the baby. It appears that decreasing mom's blood calcium into the normal range provides a dramatic reduction in miscarriage-expected to be back to normal. These young women are at a much higher risk of pre-eclampsia and eclampsia, but this risk is reduced or eliminated with cure of the hyperparathyroidism.

It was interesting to note that most of these women had one or more previous miscarriages, and they had high calcium for years which was not appreciated for it's danger. Fourteen of the women in this study had 3 or more miscarriages in the past 6 years, all of whom had a successful full-term pregnancy once their parathyroid tumor was removed.

The literature would suggest that a baby born to a mother who has elevated calcium can be born hypo-parathyroid (too little or zero parathyroid glands). There are a number of case reports of this in the medical literature, however we have never seen this and frankly, we think this fear is FAR overstated. Theoretically a high blood calcium in the mother can cause the parathyroid glands within the fetus to not develop, or to develop poorly, but again, the real risk of this is very low in our opinion. There is also a fear that the baby may have low blood calcium levels during his/her first few days of life. This may occur and thus all babies born to mothers with hyperparathyroidism should have their calcium levels checked at the time of birth, and then at 12 and 24 hours of life. If the calcium level is normal at that point, the baby will be fine forever and fear of hypoparathyroidism in the baby can be eliminated-forever. In reality, the incidence of hypoparathyroidism (and low blood calcium) is extremely small. Even temporary low blood calcium for a day or two is quite uncommon. Thus, get the baby's blood calcium measured for 24 hours and then send mom and baby home to have a great life. Even in the very rare case when the baby's calcium is low for a day or two, the baby should have parathyroid glands that can take over and maintain normal calcium levels for life. Obviously, measuring PTH in the baby can help settle any questions.

The bottom line, young women need to get their hyperparathyroidism fixed BEFORE they can get pregnant. If they are pregnant and have high blood calcium, they can be observed if the calcium levels remain below 11.0 mg/dl. If the calcium levels ever rise over 11.0 mg/dl, or the patient has other risks for eclampsia, or if the patient has a history of previous miscarriages, then an operation during pregnancy is warranted. Although the literature suggests that an operation should be timed for the first week or so of the second trimester, our research (see footnote) suggest that earlier may be better in some, if not all circumstances. Obviously we need to get the problem fixed prior to the miscarriage, and this will often happen in the early part of the second trimester.

Sestamibi scans are probably not recommended in pregnant patients, but the real risks of this are probably very small (or non-existent). However, we do NOT perform sestamibi scans on pregnant patients. We perform the exact same operation we perform on all our patients, which is a quick assessment of all four parathyroid glands. This usually takes less than 20 minutes total operative time. We still send pregnant patients home within a few hours of the operation after documentation of fetal hear tones (provided the pregnancy is that advanced). We are very careful to put the moms on supplemental oral calcium (as we do ALL our patients), as a bout of low calcium must be avoided.