Departments of Obstetrics and Gynecology (M.J., T.H., Y.N.), and Hygiene (K.T., T.T.), School of Medicine, Kyorin University, Mitaka City, Tokyo 181, Japan
Abstract
Early detection of declining female fertility is important for
effective prevention and treatment of infertility. Age, serum
concentration of FSH in the early follicular phase (basal FSH), and the
clomiphene citrate (CC) challenge test correlate only with large
declines in fertility. We serendipitously discovered that by a novel
mechanism bioelectric impedance (BEI) sensitively reflects early
fertility decrements. BEI was measured between the right and left arms
by the tetrapolar method before and during ovarian stimulation for
in vitro fertilization (IVF). In a stepwise multiple
logistic regression analysis of five factors (BEI on luteal day 4 prior
to the IVF cycle [BEI-L4], age, basal FSH, body height, and body mass
index), BEI-L4 alone was a significant predictor (P < 0.05)
of achievement of pregnancy by IVF in 148 women (74 pregnant and 74
nonpregnant). BEI showed a nadir on the day of administration of hCG in
the pregnant but not the nonpregnant group. Serum concentrations of
VEGF during ovarian stimulation were significantly higher in the
pregnant group, but not those of 17ß-estradiol and progesterone. The
CC challenge test revealed no significant difference between 11
pregnant and 15 nonpregnant women. The clinical usefulness of BEI was
evaluated in 272 consecutive IVF cycles. Rate of pregnancy was
significantly higher (P<0.01) in IVF cycles with BEI-L4
600
than <600
(44% and 26% in 149 and 123 cycles,
respectively). When BEI-L4 was
600
, pregnancy rates were
constantly high irrespective of age and basal FSH. In prediction of
nonpregnancy, sensitivity of BEI-L4 (0.52) was significantly
(P<0.05) higher than those of age and basal FSH (0.39 and
0.046, respectively). BEI, which is easy, noninvasive, and inexpensive,
predicts female fertility more sensitively than age and basal FSH,
probably reflecting angiogenic capacity of reproductive organs.