Endometriosis and infertility: stages, egg quality and IVF pathways

What is Endometriosis and Why Does It Impair Conception?

Endometriosis is an estrogen-dependent inflammatory condition where tissue resembling the endometrium grows outside the uterine cavity—most commonly on the ovaries, fallopian tubes, pouch of Douglas, and pelvic peritoneum.

During menstrual cycles, this ectopic tissue bleeds internally with no outlet, triggering:

• Pelvic Adhesions & Anatomical Distortion: Scar tissue can kink fallopian tubes or block fimbriae from capturing ovulated eggs.
• Toxic Peritoneal Fluid: High concentrations of cytokines, prostaglandins, and reactive oxygen species impair sperm motility and egg fertilization.
• Reduced Ovarian Reserve: Endometriomas ("chocolate cysts") inside the ovary damage surrounding healthy cortical tissue and follicular reserves.
• Impaired Endometrial Receptivity: Progesterone resistance and chronic inflammatory signaling reduce the window of implantation.

To Operate or Not? The Surgical Dilemma

Women with ovarian endometriomas are frequently advised to undergo laparoscopic cystectomy before IVF. However, surgical stripping of the cyst capsule inevitably removes adjacent healthy ovarian cortex, leading to a precipitous drop in AMH and antral follicle count.

Current ESHRE guidelines advise against surgical removal of asymptomatic endometriomas smaller than 4 cm prior to IVF, unless required for severe intractable pain or safe access to retrieve other healthy follicles.

Targeted IVF Strategies for Endometriosis

• Pre-Treatment Down-Regulation: Administering a GnRH agonist depot for 1 to 3 months prior to embryo transfer quiets systemic pelvic inflammation and restores endometrial integrin expression.
• Mild / Individualized Stimulation: Avoiding aggressive gonadotropin doses protects developing oocytes from excessive oxidative stress.
• Freeze-All Protocol: Postponing embryo transfer until the hyperstimulated, estrogen-rich pelvic environment settles down ensures the lining is optimal for implantation.