Final answer:
Obstructions in the fallopian tubes can result in female infertility. Infections and structural problems like uterine fibroids can cause scarring and blockage, preventing fertilization and implantation.
Step-by-step explanation:
Some women are infertile due to obstructions in the fallopian tubes, which can prevent the sperm from reaching the eggs for fertilization. These obstructions can be caused by infections, such as pelvic inflammatory disease or endometriosis, which can lead to scarring and blockage.
Structural problems like uterine fibroids can also hinder successful implantation in the uterus, resulting in infertility. Treatment options for this condition may include surgical procedures to remove the obstructions or in vitro fertilization.