Differences in time to natural conception between women with unexplained infertility and infertile women with minor endometriosis

Hum Reprod. 2004 Jan;19(1):96-103. doi: 10.1093/humrep/deh045.


Background: Opinion remains divided as to whether finding endometriotic lesions in the absence of adhesions has an adverse effect on the likelihood of conception.

Methods: This was a retrospective study of 192 fully investigated infertile couples, followed up for up to 3 years following laparoscopy. Women studied were ovulating, <40 old years and their partners had normal sperm parameters. All 117 women with unexplained infertility and 75 with minimal/mild endometriosis without adhesive disease were managed conservatively.

Results: Women with endometriosis were found to have a lower probability of pregnancy compared with women with unexplained infertility (36% versus 55%; P<0.05). Other factors adversely associated with pregnancy were primary infertility, smoking and longer duration (>3 years) of infertility. However, the effects of duration of infertility and primary infertility were not observed to be statistically significant for women with endometriosis.

Conclusions: The findings, although undertaken in a select population undergoing laparoscopy, suggest the likelihood of pregnancy is reduced in infertile women with minimal/mild endometriosis compared with those infertile women with a normal pelvis. Duration of infertility and a previous history of pregnancy are important in predicting the likelihood of pregnancy in women with no obvious cause for their infertility (unexplained), whilst the relationship may be more complex in women with minor endometriosis

MeSH terms

  • Adult
  • Chronic Disease
  • Endometriosis / complications*
  • Endometriosis / diagnosis
  • Female
  • Fertilization*
  • Humans
  • Infertility, Female / diagnosis
  • Infertility, Female / etiology*
  • Infertility, Female / physiopathology*
  • Laparoscopy
  • Likelihood Functions
  • Maternal Age
  • Parity
  • Pregnancy
  • Prognosis
  • Proportional Hazards Models
  • Retrospective Studies
  • Smoking / adverse effects
  • Time Factors