Growing a baby is a monumental achievement for a woman’s body. When a woman becomes pregnant she not only grows a baby, she grows an organ, a placenta, to feed the baby while it is growing in her uterus. The challenges her body experience are not all pleasant ones. One of the most challenging is nausea and vomiting in the early months of the pregnancy. For some women it lasts the whole pregnancy.
Here are two theories why this happens.
We do know in the beginning of pregnancy a woman’s levels of hCG, human chorionic gonadotropin, rise quickly after conception. The hormone hCG is made by the placenta. Its role is to nourish the fertilized egg as it begins to grow in the uterus. Because early growth is happening at a phenomenal rate the levels are high. In fact the levels of hCG double every 48 to 72 hours in the early weeks of a pregnancy. The rising level of hCG can be measured by a blood test as early as 11 days after conception. It can be measured in the urine 12 to 14 days after conception. hCG reaches a peak between the 8th and 11th weeks of a pregnancy. The timing of the peaking of the hormone and the timing of the peaking of the nausea and vomiting many women experience is why many believe the hormone hCG is the culprit for the nausea and vomiting women experience in the first trimester.
The other hormone contributing to those first few queasy months is estrogen. Estrogen is produced by the ovaries and when a woman gets pregnant is also produced by the placenta, a double whammy of estrogen. Estrogen helps the uterus grow, maintains the lining of the uterus, and regulates other hormones during a pregnancy.
Estrogen also increases blood flow to mucous membranes. The nose, primarily mucous membrane, knows estrogen. Interestingly a study done a few years ago found that women who cannot smell, anosmia, did not suffer from nausea and vomiting during a pregnancy.
Many women know they are pregnant when suddenly smells that did not bother them previously now make them gag.
Morning sickness, which is what the nausea and vomiting of early pregnancy is commonly called, is annoying and uncomfortable, but usually not a major health issue. It is handled by a woman figuring out what she can eat, when she can eat and figures out what triggers the symptoms. It can happen in the afternoon, not just in the morning. It usually resolves by the time the second trimester begins.
Hyperemesis Gravidarum (HG) is another thing. HG is extreme and persistent nausea and vomiting. It can cause weight loss and dehydration. This can lead to metabolic imblances, ketoacidosis, nutritional disorders, anemia, physiological stress, and other awful health issues. Any woman who shows signs of dehydration such as concentrated urine or extreme thirst, unable to tolerate fluids for more than 12 hours, is dizzy, has abdominal pain should notify her doctor or midwife immediately. This can be life threatening for both the mother and the baby.
The good news is the nausea and vomiting will end.
Katie Powers, R.N., is a board-certified lactation consultant and perinatal educator at Manatee Memorial Hospital’s Family BirthPlace. Her column appears every other week in Healthy Living. Contact her at firstname.lastname@example.org.