Early Signs of Pregnancy
If the zygote does implant, most women experience physical signs very early that alert them to their pregnancy. The most common early indicator is missing a period, although some women notice some “spotting” that occurs during the pregnancy (anything more than this is often referred to as irregular bleeding and it may indicate a possible miscarriage). Other physical signs include breast tenderness, frequent urination, and morning sickness (see Table 12.1).
It is estimated that between 50% and 80% of all pregnant women experience some form of nausea, vomiting, or both, during pregnancy (Atanackovic et al., 2001). This sickness is due to the increase in estrogen and progesterone during pregnancy, which may irritate the stomach lining. It is often worse in the morning because there is no food in the stomach to counter its effects, although it can happen at any point during the day. Researchers now believe that morning sickness may protect the fetus from food-borne illness and chemicals in certain foods during the first trimester, which is the most critical time in development (Boyd, 2000). The lowest rates of morning sickness are found in cultures without animal products as a food staple. Some women also develop food aversions, the most common of which are to meat, fish, poultry, and eggs—all foods that can carry harmful bacteria.
In rare cases, pseudocyesis (sue-doe-sigh-EE-sis), or false pregnancy, occurs. This is a condition in which a woman believes she is pregnant when she is not. Her belief is so strong that she begins to experience several of the signs of pregnancy. She may miss her period, experience morning sickness, and gain weight.
Although the majority of cases of pseudocyesis have a psychological basis, there are some that have physical causes. For instance, a tumor on the pituitary gland may cause an oversecretion of prolactin, which in turn can cause symptoms such as breast fullness
Question: Will guys ever be able to become "pregnant"?
It is possible that today’s techniques will enable a man to carry a pregnancy to term in the near future. An embryo would have to be implanted into a man’s abdomen with the placenta and attached to an internal organ. Hormonal treatment would be necessary in order to sustain the pregnancy. In addition, the father would have to undergo a cesarean section birth. There may not be many men standing in line to carry a pregnancy, however, because the hormones needed to maintain the pregnancy can cause breast enlargement and penile shrinkage.