Jh. Check et al., ORIGIN OF 1ST TRIMESTER 17-HYDROXYPROGESTERONE LEVELS AS DETERMINED IN PREGNANCIES BY DONOR OOCYTE FERTILIZATION, Gynecologic and obstetric investigation, 36(3), 1993, pp. 136-140
The study presented herein measured 17-hydroxyprogesterone (17-OHP) le
vels in women with ovarian failure who conceived by transfer of embryo
s which resulted from donor oocyte fertilization. A significant increa
se in 17-OHP during the first trimester was seen compared to baseline
nonpregnant levels. The 17-OHP levels increased from a baseline averag
e of 47.7 +/- 9.7 ng/dl to a first-trimester average of 175.8 +/- 80.6
ng/dl in the donor oocyte recipients vs. 63.0 +/- 38.0 ng/dl baseline
to 295.0 +/- 83.9 ng/dl first-trimester in the control group. Initial
ly these data may appear to contradict previous findings demonstrating
a lack of 17-OHP secretion by the first-trimester placenta. However,
by comparing the first-trimester progesterone (P) levels of normal pre
gnant women, and also measuring 17-OHP in patients with natural menopa
use and surgical menopause given exogenous P we concluded the followin
g about the origin of first-trimester sera 17-OHP levels: hydroxylatio
n of P to 17-OHP by the ovaries, some secretion by the first trimester
placenta; and also increased adrenal conversion of P to 17-OHP. Contr
ibuting to the total serum 17-OHP level is the fact that there is cros
s-reactivity with P to 17-OHP.