A recent research, carried out by New Zealand's Auckland University, has revealed that women in long term relationships tend to give birth to healthier babies and have safer pregnancy, as opposed to women who rush into relationships, who expose themselves to a risk of problem filled pregnancies and delivering unhealthy babies.

As per the findings of the study, women who get pregnant within days or weeks of meeting their baby's biological father are three times more prone to suffering from pre-eclampsia or pregnancy induced high blood pressure, which could be life threatening, and giving birth to smaller babies. On the other hand, women who have been with their partner for a minimum of six months are less at risk of suffering from high BP and giving birth to undersized babies.

Experts believe that the difference is that in the case of a long term relationship, there is a longer exposure to the biological father's sperm which helps in boosting the mother's immune system. Lead author of the research Dr. Larry Chamley shared that the female immune system was strengthened by "exposure to paternal antigens - beneficial antibodies in the male sperm".

The study has been detailed in the Journal of Reproductive Immunology. Results were adjusted based on the participating women's lifestyle and background and factors such as weight, general health and smoking habits.