Summary

In this Study Session, you have learned that:

• Estrogen and progesterone are the main pregnancy hormones.
• High level of progesterone causes some internal structures to increase in size, including the uterus which grows about five times its normal size at full term.
• The expected increase in weight of the mother in an average pregnancy is 9-12 kg.
• A higher circulating blood volume is required to provide extra blood flow through the placenta to the fetus in order supply the fast growing fetus with adequate nourishment and oxygen.
• One of the reasons for iron supplementation during pregnancy is the red cells are diluted in the much larger volume of blood plasma, causing physiological anaemia.
• During pregnancy, many women get short of breath because the growing baby crowds the mother's lungs leaving less space for the lungs to expand and contract. Indigestion is also common as the mother's stomach is pushed higher up.
• The muscles in the walls of the gastrointestinal system relax slightly during pregnancy resulting in the slowing down of the rates at which food moves along the gut of the mother maximising absorption of nutrients into the mother's blood. This is advantageous for the fetus, but the mother may experience nausea or constipation.
• Needing to urinate often is normal, especially in the first and last months of pregnancy, because the uterus presses more on bladder at this time. At night, the bladder fills more quickly as fluid (oedema) that collected in the legs during the day is re-absorbed.
• Due to the changes in the woman's hormones, the mechanical stretching of her growing abdomen, breasts and thigh can cause stretch marks in the skin of these areas during pregnancy ending up in brown pigmentation and increased sweating which may disappear after childbirth.
• In the second trimester, the breasts begin to produce colostrum, a yellowish secretion that thickens as pregnancy progresses. It is rich in proteins and maternal antibodies, and should always be fed to the newborn right after delivery.