There is no reason to believe that the eggplants can start labor. To be true, it is an internet myth. This myth began with news, which started to circulate, about a restaurant called "Scalini's."
During the past 23 years, mothers of more than 300 babies have gone into labor within 48 hours after eating a dish which contained eggplant and parmesan.
The point is that neither eggplant nor parmesan can induce labor, but the dish itself perhaps could. Oregano and basil are the herbs which are suspected to induce contractions. In aromatherapy, these herbs are to be avoided during pregnancy.
There are some reasons for believing that sex can induce labor. First of all, the semen contains prostaglandins which cause the cervix to soften and prepare to open, but it is not quite clear just how many prostaglandins are needed in order to have any effect. Also, an orgasm produces the hormone oxytocin, which causes contractions.
Neither evening primrose oil or red raspberry leaf tea can actually induce labor. Some midwives may point out the reason why evening primrose is not recommended before the 36th week of pregnancy, which is the "full term", but almost all experienced sources agree that it does not do anything that the body wasn't ready to do on its own.
Evening primrose oil is a rich source of prostaglandins. As mentioned earlier, they cause the cervix to soften and prepare to open. Evening primrose oil can be taken orally, no earlier than the 34th week, and can be applied to the cervix during the 36th week. Vaginally, it can be inserted in a form of capsule, or applied as oil directly on the cervix. If it cannot be reached, Evening Primrose oil can also be absorbed through the skin or the stomach.
Red raspberry leaf tea is a Native American remedy. It helps focusing the Braxton Hicks contractions and tones the uterus. It does not cause contractions. It is contraindicated only for pregnancies with complications. Other than that, it is safe to use during the entire pregnancy.
Castor Oil to Bring on Labor is recommended. In theory, castor oil causes diarrhea and the diarrhea cramps cause sympathetic cramps of uterus.
This will not be inefficient, unless all the other conditions are optimal for labor.
Also, there has been much debate of whether this method causes babies to have pre-birth bowel movements. This is called meconium, and can be dangerous. It can cause pneumonia if the baby inhales it.
The main danger of this method is the possible dehydration of the mother, due to severe diarrhea, the loss of strength and possible breastfeeding problems due to dehydration.
Also, a dehydrated uterus is more painful. This makes the woman less able to go through a natural birth, which brings a risk of numerous interventions.