Growth hormone deficiency and pregnancy
AL Brackenridge1, L Breen2 & D Russell-Jones1
It is recognised that growth hormone deficiency causes disturbances in reproductive function. Indeed growth hormone has been used for ovulation induction in the treatment of subfertility in women with hypopituitarism. During normal pregnancy growth hormone is produced by the placenta (placental growth hormone). From 15 to 20 weeks gestation placental growth hormone gradually replaces pituitary growth hormone in the maternal circulation and is the main determinant of maternal IGF-1 levels. Pregnancy in women on growth hormone replacement has only previously been described twice and the optimum management is unknown. We present the case of a patient treated for growth hormone deficiency who has had two successful pregnancies.
The patient was diagnosed with pituitary dependent Cushing's disease in 1985 at the age of 20. She received a course of radiotherapy in 1986 and achieved a biochemical cure. An insulin tolerance test confirmed growth hormone deficiency and in 1996 she was commenced on growth hormone replacement.
In January 1997 she stopped her growth hormone and oral contraceptive and became pregant spontaneously in February 1997. Following delivery she felt well and did not wish to resume growth hormone. It was restarted in May 2001 because of fatigue.
She became pregnant in September 2001. During this pregnancy her growth hormone was gradually reduced and then stopped at 10 weeks gestation. IGF-1 levels were monitored throughout pregnancy. From their lowest levels at 12 weeks gestation they rose to within the normal adult range at 34 weeks and fell back after delivery to pre-treatment levels. The rise in IGF-1 levels are consistent with the placental production of growth hormone even in a growth hormone deficient woman. Experience with growth hormone treatment during pregnancy is limited and this case adds to our knowledge.