A 33 year old gravida 2 para 1 female presents for prenatal care at 35 weeks gestation. She was previously seen at 8 weeks gestation for her only prenatal visit. She has had weight gain of only 21 pounds during her pregnancy, but reports her appetite has been good. She has experienced heat intolerance and fatigue for several months. Her heart rate is 112, blood pressure is 124/86 mm Hg. On examination, she has fullness in her neck and exhibits a fine tremor. You should advise this patient that her child will be at risk for which of the following complications ?
a. Thrombocytopenia
b. Macrocephaly
c. Heart failure
d. Heart block
e. Constipation
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C is the answer
C. Heart failure
Choice C
please why C
Answer: C
This patient has evidence of maternal hyperthyroidism. Maternal hyperthyroidism will put a developing fetus at risk of neonatal thyrotoxicosis as a result of maternal thyroid stimulating immunoglobulins that cross the placenta. Neonatal thyrotoxicosis can result in high-output heart failure. The condition resolves within 2 to 4 months in most cases, as the high concentrations of thyroid stimulating immunoglobulins diminishes.
Thrombocytopenia is not related to hyperthyroidism. Macrocephaly is not a complication of thyrotoxicosis, for which this fetus is at risk. Constipation and heart block are associated with low thyroid states.
Summary: Maternal hyperthyroidism results in production of excess thyroid stimulating immunoglobulins that cross the placenta and can result in neonatal thyrotoxicosis in the neonate.
Reference: Ross, D. S. (2014, June 19). Overview of thyroid disease in pregnancy. Retrieved January 9, 2015, from http://www.uptodate.com/contents/overview-of-thyroid-disease-in-pregnancy?source=search_result&search=maternal+hyperthyroidism&selectedTitle=1~150