Ronald M. Cyr, MD


September 01, 2010

In This Article

Hippocratic Teachings

Mauriceau described the 2 principal signs attributed to Hippocrates (460 BC-ca. 370 BC):

Book 5, Aphorism 42: The woman pregnant with a boy has good color; but if it is a girl, she is pale.

Book 5, Aphorism 48: The male fetus is usually inclined to the right side, the female to the left.

These beliefs were passed down in obstetric texts until the 1800s. In 1771, Professor D. De la Brousse affirmed his faith in Hippocrates's Aphorism 48 and correctly predicted the sex in 27 of 30 cases by palpating the maternal pulse. He theorized that the inclination of the fetus toward one side exerts pressure on the ipsilateral abdominal blood vessels and diminishes the mother's pulse on that side. Thus, the side on which the fetus lies has a fainter pulse; because a male fetus usually lies to the right, a weaker right pulse predicts a boy.[5]

In addition, a woman carrying a boy was often said to seem happier, more energetic, have less nausea, be aware of movement earlier, have her right nipple become larger and firmer than the left, and have thicker milk.

Mauriceau was skeptical of those who linked conception during various lunar phases with fetal sex. He also discredited the idea that boys were produced by sperm from the right testicle by describing the case of a man who had both a son and a daughter after losing his right testicle during a hernia operation.

Ambroise Paré (1510-1590), the "father" of French surgery, described all the traditional signs mentioned above and acknowledged the natural superiority of males over females, but he also offered the following admonishment:

It is by God's Will that males and females are produced. It seems to me unwise for husbands to blame their wives or girlfriends for producing girls. For it is not within the power of man or woman to conceive a male or a female at will. [6]

The notion that the mother determines the infant's sex was prevalent throughout the ages and explains why nobles were quick to discard women who could not bear sons. As late as 1900, the London obstetrician E. Rumley Dawson combined this belief with the Hippocratic tradition and published a theory on sex determination:

The sex of the fœtus is not due to the male parent, but depends on which ovary supplied the ovum which was fertilised, and so became the fœtus. I find that a male fœtus is due to fertilisation of an ovum that came from the right ovary, and a female fœtus is due to fertilisation of an ovum that came from the left ovary. This I shall now proceed to prove. [7]

Despite Mauriceau's doubts about the accuracy of the various methods in vogue, he showed a keen understanding of human nature when he gave the following advice to midwives who insisted on predicting the fetal sex:

I would first ascertain the couple's wishes before making a recommendation, and then predict the opposite. In this way, if the midwife is right (even if only by chance), she will be judged to be a skilful woman; if the guess is wrong (as will happen one out of two times) the couple will be happy to get what they wanted and be much less critical, since we tend to be well disposed when an unexpected gift comes our way.[4]


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