How High Planes Fly. Planes equipped with jet engines fly at greater altitudes than propeller-driven aircraft. These include commercial flights, cargo jets and even private passenger jets. The air traffic control tower usually assigns a cruising altitude of up to 39,000 feet, but long flights are typically assigned higher altitudes. By keeping these planes at assigned altitudes, air traffic control creates invisible stacked highways in the sky, keeping enough air space between the flights.
Blockage to or damage in the fallopian tube is one of the causes of infertility. Fallopian tubes play an important role in ovulation, as well as conception. Once the female egg is released from the ovary, one of the fallopian tubes (i.e. the fimbriae) picks up the egg and pushes it to pass through the tube.
Chlamydia infection can cause permanent damage to the fallopian tubes in a woman and can lead to future infertility and an increase risk of ectopic pregnancy. Chlamydia infection during pregnancy also increases a woman's risk of preterm labor and of having a baby with low birth weight. Lymphogranuloma venereum is another type of STD that is common in the developing world and is caused by a different strain of the Chlamydia bacteria.