On conception, the aim of Roman matrimony was procreation, rendering theories of procreative potential extremely important. Soranus suggests that women "from the ages of fifteen and fourty.. not mannish, compact, over sturdy or too flabby and very moist" and uteri as "neither very moist or dry, not too lax or constricted," were one's best shot at producer of offspring.
From a rather negative standpoint, Soranus attempts to identify outward signs of female sterility. These include: importance in the size of head and proportions of eyes and features. Small heads and eyes are always bad signs; however, not all large heads are to be interpreted as good. Protuding foreheads are especially bad.
According to Soranus, the best time for conception is "when menustration is ending and abating and when the urge and appetite for coitus are present." The couple should be sober and comfortable. The ingestions of a snack before coitus further aids conception. A pleasent state is also important during the act.
Conception leading to the successful birth of a amale heir was the goal of many married couples. Therefore, obviously theories would be created regarding the circumstances under which a desired gender might be concieved. Several important ones include the heat theory and the dominan sperm theory.
The dominant conceptive idea during the Roman times was the double seed theory. Both parents seeming to contribute to the traits of their children were viewed of both producing semen to comingle in the woman's womb, both supposedly at the time of ******. The parent with the dominant sperm contributed the more apparent characteristics.
Sorauns also believed women should be "sober during coitus" because the soul becomes "the victim of strange fantasies" during drunkeness and the offspring will resemble the mother in body and soul.
In the logic of Hippocrates, if both parents produced strong sperm, the child was to be male... and if both produced weak semen, a female child would ensue. Should one parent produce strong and one weak sperm, the gender of the child should be determines the more vivacious sperm.
According to Lucretius (On the Nature of Things 1200-1250) "When the male seed and the female seed are fussed, one partner may be dominant, overpower the other in a burst of violence. If this should be the woman then the child shall have her features and qualities. The same if the man assumes the role dominance; the children will be more like the father." Another author advised (note the incorrect estimation of a woman's ovulatory/fertile period):
"The best time for conception is when the mestrual flow has stopped. It is especially during these days that one should see if a woman is able to concieve, for they are most successful for fertility. If she does not concieve straight away, and everythig else is well with her, nothing stops her from going to her husband on other days, for the habit will excite her desire and cause her passages to open. If the ejaculate from the man runs together…