One moment you are thrilled with the idea of being pregnant, and the next you are weeping on the couch, feeling overwhelmed. Welcome to the world of pregnancy hormones. The way hormones affect the body can be overwhelming. Learning about these hormones and how they will affect you will help make sense of your swinging emotions and the changes your body is experiencing.
Human Chorionic Gonadotropin
Human Chorionic Gonadotropin (HCG) is the main hormone that indicates pregnancy. This is the hormone that the pregnancy tests look for, both in the urine and the blood. HCG, which is made in the placenta, signals the body that pregnancy has occurred. This simple message causes all of the changes that prepare a place for the baby to grow.
HCG stops the ovulation process during pregnancy. In the early days of pregnancy, HCG levels double every two days. In high-risk pregnancies, doctors will test the mom’s blood to see if they are doubling as they should. Levels that triple or quadruple can indicate multiple pregnancies. Levels that do not double appropriately can indicate problems with pregnancy or a non-viable pregnancy.
Some doctors believe that HCG is responsible for morning sickness. Women who have high HCG levels tend to have more problems with nausea and vomiting than women who have lower levels. However, this connection has not been proven.
Early in the pregnancy, a cyst on the ovary, known as the corpus luteum, produces progesterone. This production continues until 10 weeks, when the placenta is established and takes over the production of the hormone. In early pregnancy, women have strong surges in progesterone levels. After the first trimester, these levels plateau.
Relaxing the uterus is important, because it protects the body from premature labor or contractions. However, this relaxation occurs in all smooth muscle in the body. This causes the blood vessels to also relax. Some women, as a result, will experience low blood pressure levels and periods of dizziness. Some of the gas, constipation, heartburn and acid reflux experienced during pregnancy can be linked to a relaxing of the muscles in the digestive system. Progesterone can also cause hair growth on the trunk of the body during pregnancy.
Estrogen also comes from the corpus luteum and then the placenta later in pregnancy. Estrogen triggers several bodily systems to develop in the growing baby, whether that baby is male or female. It also stimulates the baby’s adrenal gland to grow and start producing hormones. At the end of the first trimester, estrogen levels increase significantly, then plateau, just like progesterone levels. At the end of pregnancy, estrogen prepares the uterus to respond to oxytocin, another pregnancy hormone.
Estrogen is the pregnancy hormone that causes a mother’s skin and veins to change. It also sparks an increased appetite. High estrogen levels give some women the characteristic pregnancy “glow.”
In order to deliver a baby, a mother’s pelvic bones must separate significantly. Relaxin is the hormone that loosens the pelvic ligaments to allow this expansion. When a woman is pregnant, she has 10 times the normal amount of this hormone in her body. Unfortunately, the effects of relaxin affect other ligaments, so the knees, hips and shoulders may also feel looser. This can cause the hip and back pain many women experience during pregnancy.
Oxytocin is the hormone many women say causes labor, but it is actually a change in the woman’s response to oxytocin that starts labor. When the pregnancy is nearing an end, the uterus becomes more responsive to oxytocin due to estrogen. The hormone helps to stretch the cervix. After the baby is born, oxytocin stimulates milk production in the breasts. It is also responsible for the “feel good” emotions that a new mom experiences when nursing her baby.
During pregnancy, a woman’s prolactin levels increase up to 20 times their normal amounts. This hormone, combined with oxytocin, prepares the breast tissue to create and release milk for the baby. It also has a calming, tranquilizing effect on the mother.
Hormones and Emotions
None of these hormones are specifically linked to emotions. However, since hormones are neurotransmitters, these shifts and changes can cause shifts and changes in emotions as your body adjusts. If you are suffering from these emotions, don’t worry. They often level off after the first trimester as hormone levels stabilize and the body and mind adjust.
Hormones are simply a part of pregnancy. If you are expecting, embrace them and the changes they bring, because they are helping your body grow your sweet baby. Soon your baby will be in your arms, and your hormone levels will return to normal.
Cheretta A. Clerkley is a strategic marketing health care professional for Hormone Health Network and oversees patient education services and programs. These education programs focus on a wide range of health topics, including pregnancy.