Does pregnancy start at conception – when the sperm fertilizes the egg? Or does it begin one week later when the embryo implants in the uterus? According to a survey carried out by researchers from the University of Chicago and published in the American Journal of Obstetrics and Gynecology, not even doctors appear to agree.

Dr. Farr A. Curlin and team set out to determine what Ob/Gyns (obstetrician-gynecologists) thought regarding the beginning of pregnancy. They also wanted to know what measure characteristics were linked to the belief that pregnancy started at implantation instead of conception.

The researchers posted a questionnaire to 1,800 Ob-Gyns in the USA, all of them practicing their profession at that time. Their main focus was when they thought pregnancy started.

The questionnaire gave the following response options:

  • At conception (the union of the sperm and the egg, also known as fertilization)
  • When the embryo is implanted in the uterus
  • Not sure

The authors wrote that:

“Primary predictors were religious affiliation, importance of religion, and having a moral objection to abortion.”

Below are some highlighted data from their findings:

  • 66% (1154) of the doctors responded to the questionnaire
  • 57% answered – at conception
  • 28% answered – at implantation
  • 16% answered – not sure

A higher percentage of religious doctors responded “at conception”, as did those who were against abortion.

In an abstract in the journal, the authors concluded:

“Obstetrician-gynecologists’ beliefs about when pregnancy begins appear to be shaped significantly by whether they object to abortion and by the importance of religion in their lives.”

Written by Christian Nordqvist