In normal pregnancy, as discussed in Chapter 4 (p. 72), progesterone blocks aldosterone action, and thus there are very high aldosterone levels (Appendix, p. 1258). Accordingly, the diagnosis of hyperaldosteronism during pregnancy can be diicult. Since renin levels are suppressed in pregnant women with hyperaldosteronism, a plasma aldosterone-to-renin activity ratio may be helpful for diagnosis (Kamoun, 2014). Hypertension worsens as pregnancy progresses, and medical management includes potassium supplementation and antihypertensive therapy. In many cases, hypertension responds to spironolactone, but 3-blockers or calcium-channel blockers may be preferred because of the potential fetal antiandrogenic efects of spironolactone. Mascetti and coworkers (201r1) reported successful use of amiloride in a pregnant woman. Use of eplerenone, a selective aldosterone-receptor antagonist, has also been reported (Cabassi, 2012). Laparoscopic tumor resection is curative (Eschler, 2015; Miller, 2012).
The pituitary enlarges impressively during pregnancy, predominately from lactotrophic cellular hyperplasia induced by estrogen stimulation (Chap. 4, p. 68). Several pituitary disorders can also complicate pregnancy.
These adenomas are found often in nonpregnant women since the advent of widely available serum prolactin assays. Serum levels <25 pg/mL are considered normal in nonpregnant women (Nlotivala, 2011). Adenoma symptoms and indings include amenorrhea, galactorrhea, and hyperprolactinemia. Tumors are classiied arbitrarily by their size measured by CT or MR imaging. A micro adenoma is :;10 mm, and a macro adenoma is >10 mm. Treatment for microadenomas is usually with bromocriptine, a dopamine agonist and powerful prolactin inhibitor, which frequently restores ovulation. For suprasellar macroadenomas, most recommend surgical resection before pregnancy is attempted (Araujo, 2015).
In a pooled analysis of more than 750 pregnant women with prolactinomas, only 2.4 percent with microadenomas developed symptomatic enlargement during pregnancy (Molitch, 2015). Symptomatic enlargement of macroadenomas, however, is more frequent and was found in 21 percent of 238 pregnant women. Schlechte (2007) also reported that 15 to 35 percent of suprasellar macroadenomas have tumor enlargement that causes visual disturbances, headaches, and diabetes insipidus. Nonfunctioning adenomas can also cause symptoms of pituitary expansion in pregnancy (Lambert, 2017).
Pregnant women with microadenomas should be queried regularly for headaches and visual symptoms. Those with macroadenomas are followed more closely and have visual field testing during each trimester. CT or MR imaging is recommended only if symptoms develop (Fig. 58-7). Serial serum prolactin levels serve little use because of normal rises during pregnancy (Appendix, p. 1259). Symptomatic tumor enlargement should be treated immediately with a dopamine antagonist. he safety of bromocriptine in pregnancy is well established. The safety profile is less well known for cabergoline, which is increasingly used in nonpregnant women because it is better tolerated and more efective. Cabergoline is generally considered safe for use in pregnancy (Araujo, 2015; Auriemma, 2013). Lebbe and colleagues (2010) described 100 pregnancies exposed to cabergoline and found no adverse efects. Similar indings were reported in 85 exposed Japanese pregnant women (Ono, 2010). Surgery is recommended for women with no response.