Hyperemesis gravidarum

Question 1

Describe hyperemesis gravidarum.

Answer 1

Hyperemesis gravidarum is characterized by severe vomiting and weight loss during pregnancy, typically starting in early pregnancy and resolving by 20 weeks’ gestation.

Question 2

What is the mechanism behind hyperemesis gravidarum?

Answer 2

Hyperemesis gravidarum is believed to be caused by the TSH-like effect of hCG, which stimulates the thyroid gland and suppresses TSH secretion.

Question 3

What are the common complications of hyperemesis gravidarum?

Answer 3

Hyperemesis gravidarum may be associated with hyponatremia, hypokalemia, low serum urea, raised hematocrit, ketonuria, and metabolic hypochloremic alkalosis. Dehydration can increase the risk of thromboembolism.

Question 4

How is hyperemesis gravidarum treated?

Answer 4

Treatment for hyperemesis gravidarum includes antiemetics, fluids, vitamin replacement, and in some cases, steroids. Thromboprophylaxis may be necessary when admitted.

Question 5

Define overt maternal hypothyroidism.

Answer 5

Overt maternal hypothyroidism is defined as a TSH level >10mIU/L with FT4 of any level, or TSH >4mIU/L with FT4 below the lower limit of the trimester-specific reference range.

Question 6

What are the common causes of overt maternal hypothyroidism?

Answer 6

Common causes of overt maternal hypothyroidism include Hashimoto’s thyroiditis, previous radioiodine therapy, previous thyroidectomy, previous post-partum thyroiditis, and hypopituitarism.

Question 7

What are the maternal complications of overt maternal hypothyroidism?

Answer 7

Maternal complications of overt maternal hypothyroidism include miscarriage and pre-eclampsia.

Question 8

What are the fetal complications of overt maternal hypothyroidism?

Answer 8

Fetal complications of overt maternal hypothyroidism include premature delivery, low birthweight, and impaired neurological development.

Question 9

Describe the preconception counseling for women on levothyroxine.

Answer 9

In women on levothyroxine, the aim is to keep TSH in the lower half of the non-pregnant reference range during preconception.

Question 10

What should be done once pregnancy is confirmed in women on levothyroxine?

Answer 10

Once pregnancy is confirmed, TFTs should be urgently checked. If not possible, the levothyroxine dose should be increased by 30% to ensure optimal early neurological development, and TFTs should be checked as soon as possible.

Question 11

How should levothyroxine be treated during pregnancy?

Answer 11

Levothyroxine should be used to treat maternal hypothyroidism during pregnancy. The aim is to keep TSH within the local normal trimester-specific range.

Question 12

What should be done post-partum for women on levothyroxine?

Answer 12

Post-partum, women on levothyroxine should return to their pre-pregnancy doses and have their thyroid function checked in 4 weeks.

Question 13

Define subclinical maternal hypothyroidism.

Answer 13

Subclinical maternal hypothyroidism is defined as a TSH level > upper limit of the trimester-specific reference range, but <10IU/L, with FT4 in the normal range.

Question 14

What are the maternal complications of subclinical maternal hypothyroidism?

Answer 14

Maternal complications of subclinical maternal hypothyroidism may include an increased risk of miscarriage, preterm birth, hypertension, and eclampsia.

Question 15

What are the fetal complications of subclinical maternal hypothyroidism?

Answer 15

Fetal complications of subclinical maternal hypothyroidism may include inconsistent evidence for effect on fetal birthweight, but no evidence of affecting fetal cognitive development.

Question 16

Is treatment recommended for subclinical maternal hypothyroidism?

Answer 16

There is no evidence that treatment with levothyroxine improves outcomes for subclinical maternal hypothyroidism, so treatment is not recommended.

Question 17

Define isolated hypothyroxinemia.

Answer 17

Isolated hypothyroxinemia is defined as a TSH level within the trimester-specific reference range, but FT4 below the lower limit for that trimester.

Question 18

Define isolated hypothyroxinemia.

Answer 18

Isolated hypothyroxinemia is defined as a TSH level within the trimester-specific reference range, but FT4 below the lower limit for that trimester.

Question 19

What are the risk factors for isolated hypothyroxinemia?

Answer 19

Risk factors for isolated hypothyroxinemia include iodine deficiency, iodine excess, and raised BMI.

Question 20

What are the fetal complications of isolated hypothyroxinemia?

Answer 20

Fetal complications of isolated hypothyroxinemia may include mild impairment in neurocognitive tests demonstrated in childhood.

Question 21

Is treatment recommended for isolated hypothyroxinemia?

Answer 21

There is no evidence that treatment with levothyroxine improves outcomes for isolated hypothyroxinemia, so treatment is not recommended.

Question 22

What are the risks associated with being euthyroid but TPO antibody positive?

Answer 22

Being euthyroid but TPO antibody positive increases the risk of miscarriage, developing overt hypothyroidism, and post-partum thyroiditis. There is also a risk of preterm birth for the fetus.

Question 23

Is treatment recommended for euthyroid but TPO antibody positive women?

Answer 23

There is no robust evidence that treatment with levothyroxine improves pregnancy rates or outcomes for euthyroid but TPO antibody positive women. However, low-dose levothyroxine can be considered in women with recurrent pregnancy loss.

Question 24

What should be done in terms of monitoring for evolving thyroid disease in euthyroid but TPO antibody positive women?

Answer 24

TFTs should be checked in the 3rd trimester and 3 months post-partum to look for evolving thyroid disease. Up to 20% of women may develop frank hypothyroidism by the 3rd trimester.

Question 25

What is the prevalence of post-partum thyroid dysfunction?

Answer 25

Post-partum thyroid dysfunction affects 5-10% of women within 1 year of delivery or miscarriage. It is 3 times more common in women with T1DM and more common in women who are TPOAb positive.

Question 26

What are the clinical presentations of post-partum thyroid dysfunction?

Answer 26

Post-partum thyroid dysfunction can present as hyperthyroidism, hypothyroidism, or hyperthyroidism followed by hypothyroidism.

Question 27

What is the prognosis of post-partum thyroid dysfunction?

Answer 27

Recurrence in future pregnancies occurs in 25% of women, and permanent hypothyroidism develops in up to 30% of women within 10 years. Annual TSH measurements are essential if treatment is withdrawn.

Question 28

How is hyperthyroidism in post-partum thyroid dysfunction managed?

Answer 28

Hyperthyroidism in post-partum thyroid dysfunction typically resolves spontaneously within 2-3 months. Propranolol may be used to control symptoms in the thyrotoxic phase.

Question 29

How is hypothyroidism in post-partum thyroid dysfunction managed?

Answer 29

Hypothyroidism in post-partum thyroid dysfunction is treated with levothyroxine if TSH >10 or TSH 4-10 with symptoms. TFTs should be rechecked every 6-8 weeks and thyroxine may be weaned off if appropriate.