Analysis of factors influencing pregnancy rates in homologous intrauterine insemination.
OBJECTIVE
To identify predictors of pregnancy rate (PR) among women undergoing homologous IUI.


METHODS
Cross-sectional analysis of IUI cycles carried out from January 2000 to September 2002.


METHODS
Private infertility center in Alicante, Spain.


METHODS
Four hundred seventy women undergoing 1,010 cycles of IUI.


METHODS
Single IUI with ovarian stimulation using hMG.


METHODS
Preovulatory follicles (>15 mm), motile spermatozoa count, type and duration of infertility, female age, insemination timing, and cycle number.


RESULTS
Overall PR per cycle and multiple pregnancy and miscarriage rates were 9.2%, 8.6%, and 11.8%, respectively. Three significant predictors of pregnancy were identified by multiple logistic regression analysis: preovulatory follicles, spermatozoa count, and infertility duration. Interuterine insemination with three follicles almost tripled the PR with respect to only one, odds ratio (OR) = 2.89 (95% confidence interval [CI], 1.54-5.41). Compared with insemination with a motile sperm count >30 x, 20.1-30, 10.1-20, 5.1-10, and < or =5 x10(6), insemination progressively decreased the PR, from 15.3% in the highest category to 3.6% in the lowest (OR lowest/highest = 0.20 [95% CI: 0.09-0.45]), with a statistically significant dose-response trend. Infertility duration > or =3 years was marginally associated with a lower PR, OR = 0.65 (95% CI, 0.40-1.04). Overall, female age was not a significant predictor of pregnancy, and although PR slightly decreased beyond two IUI cycles and when a single IUI was performed 36-40 hours after hCG administration, results were not statistically significant.


CONCLUSIONS
Homologous IUI achieves the best results with two or three induced follicles, a high motile spermatozoa count, and infertility duration <3 years, irrespective of female age and fertility history.
Ibérico
Gilberto
G
Infertility Center, Instituto Bernabeu, Alicante, Spain.
Vioque
Jesús
J
Ariza
Nuria
N
Lozano
Jose Manuel
JM
Roca
Manuela
M
Llácer
Joaquín
J
Bernabeu
Rafael
R
D000293:Adolescent; D000328:Adult; D003362:Cost-Benefit Analysis; D003376:Counseling; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007317:Insemination, Artificial, Homologous; D008297:Male; D008423:Maternal Age; D011247:Pregnancy; D018873:Pregnancy Rate; D013997:Time Factors