Nausea and vomiting in pregnancy (NVP) is a very common medical condition in pregnancy. The severity can range from a mild to moderate course that resolves with conservative treatment or the addition of a medication, to a severe, prolonged course requiring multiple visits to the physician’s office or hospital. Early recognition and treatment of symptoms is ideal. However, signs of the condition are often times not communicated to the physician, which allows symptoms to get worse. As a result, it is extremely important to let your physician know if you are suffering from NVP.
NVP occurs in 50-90% of pregnancies. Although NVP is referred to as “morning sickness”, symptoms can occur at any time of the day and last any amount of time. Symptoms of NVP can include any of the following: nausea, gagging, retching, dry heaving, vomiting, and odor and/or food aversion. Each person usually has certain factors that trigger episodes of nausea and vomiting. NVP typically starts between 4-9 weeks of pregnancy, with a peak in symptoms at 12-15 weeks. NVP usually resolves by 20 weeks of pregnancy, although there are some patients who experience symptoms well after 20 weeks, and even up to delivery.
Hyperemesis gravidarum (HG), the most severe form of NVP, occurs in 0.3-3% of pregnancies. HG includes severe and persistent nausea and vomiting, weight loss, abnormalities in laboratory values and dehydration. If diagnosed with HG, hospital admission for intravenous fluids (IVF) and medications is often required. A patient with NVP that has been under-treated can develop HG. As a result, telling your physician that you are experiencing NVP is important.
The normal hormonal changes in pregnancy are a cause of NVP. Estrogen, hCG, progesterone and thyroid hormones all contribute to the development of symptoms; the most drastic changes occur during the first trimester. TSH, a thyroid hormone, and the pregnancy hormone, hCG, are very similar. As a result, when hCG increases as a pregnancy progresses, symptoms of an overactive thyroid, or hyperthyroidism, may develop. These symptoms most often go away as the pregnancy progresses and hCG levels reach a plateau, making treatment of the short-lived hyperthyroidism unnecessary. In addition, the more hCG a patient has circulating in their system, as seen with twins and other multiple gestations, the more severe the NVP may be.
During pregnancy, the gastrointestinal (GI) system undergoes significant changes that may contribute to the symptoms of NVP. The hormonal changes of pregnancy, mainly estrogen and progesterone, cause the GI system to slow down or speed up at different times, which causes food and drink to progress through the GI system at abnormal speeds. As a result, nausea, vomiting and constipation or diarrhea may occur. In addition, as the uterus gets bigger, the abdominal organs are pushed higher up into the abdomen and put stress on the area where the esophagus meets the stomach, or gastro-esophageal (GE) junction. This can cause heartburn, reflux, nausea and vomiting. If you already have conditions like diabetic gastroparesis, gastro-esophageal reflux disease (GERD), a history of gastric bypass surgery, or inflammatory bowel disease (IBD or IBS), you are more likely to experience more severe symptoms of NVP.
There is also a genetic factor that contributes to the development of NVP. In fact, not only is your chance increased if your mother or sister suffered form NVP, or you had NVP in a prior pregnancy, but the severity of NVP is also affected by your genetic predisposition. Genetics also play a role on the development of HG. Risk factors for the development of NVP include multiple gestations, molar pregnancy, and a positive family history of NVP. NVP and HG are also more common in women pregnant with their first child, young women, and obese women. For women who have NVP after 20 weeks of pregnancy, older age, having multiple prior births and obesity play a role. Finally, stress, lack of sleep, gastric ulcers, and migraines can play a role in the severity of NVP symptoms.
Although most patients who experience NVP feel that it is a “right of passage” everyone goes through, there can be a significant effect on family and social life, physical and mental health, employment, and finances. Many patients with NVP have to alter their day-to-day routines because of their symptoms, miss days of work, and have trouble taking care of other children and household duties. In a worst case scenario, you may develop depression and anxiety because of your inability to keep up with what you were able to do before you were pregnant, and overall, just don’t feel well at a time when you want to be happy and excited for a new pregnancy. In addition, family members and friends may tell women suffering form NVP that they should not complain about the nausea and vomiting because everyone goes through it. This approach simply allows symptoms to progress to a point where treatment may become more difficult and less effective. As a result, recognizing that “morning sickness” has become a problem and being willing to talk to your physician about it is crucial. Starting treatment sooner than later may help prevent the development of anxiety and depression, and progression of symptoms to a more advanced stage.
Although nausea and vomiting in early pregnancy is most likely due to NVP, other causes should also be considered. If your symptoms begin before 10 weeks of pregnancy, it is likely NVP. If the diagnosis of NVP or HG is made early in pregnancy, but there is poor response to initial treatment, other symptoms are present, or symptoms begin after 9-10 weeks of pregnancy, other causes of nausea and vomiting may be the reason for your symptoms.
The first opportunity to address the symptoms of NVP is during a prenatal visit. If you are experiencing symptoms before the first prenatal visit, you can call the provider’s office and ask for an earlier appointment, or talk to a nurse who can give you recommendations. It is important that you tell your provider if you are experiencing symptoms.
For some patients, lifestyle and dietary modifications will not work. Almost 10% of patients will require treatment with a prescribed medicine to treat NVP. If you think you need this form of treatment, ask your provider. There are many options available to you; some which are perfectly safe in the first trimester. Treatment with a prescribed medicine may be necessary in order to prevent your symptoms from getting out of control and affecting you and the pregnancy. Talking with your provider early on will allow them to track your symptoms and be able to decide when medication is needed.
Although NVP does not affect the developing fetus in a majority of cases, if you get to the point where you become dehydrated, lose weight and cannot get liquids or food into your system over a prolonged period of time, the pregnancy may become affected. In this case, you need to see your provider or go to the hospital for evaluation and treatment as soon as possible.
Shannon M. Clark, MD, MMS is a double board certified ObGyn and Maternal-Fetal Medicine Specialist, and founder of Babies After 35. In her roles as a clinician, educator and researcher at UTMB-Galveston, she focuses on the care of people with maternal and/or fetal complications of pregnancy. Dr. Clark has taken a special interest in pregnancy after the age of 35, which according to age alone, is considered a high-risk pregnancy.
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