Itching is a very common symptoms that affects almost all of us on a daily basis.
When itching, also known as pruritus, starts during pregnancy it may be persistent and last for a few weeks or months.
What causes itching during pregnancy?
There are many possible causes for itching developed during pregnancy:
- Stretched skin.
- Hormonal changes without elevated bile acids in blood.
- Cholestasis of pregnancy.
Other possible causes include, but are not limited to, dry skin (xerosis), allergic reactions, dermatological conditions (dermatoses) and liver disease.
Belly itching during pregnancy
An itchy belly may simply be caused by the skin and the tissues beneath it that stretch, stimulating receptors and nerve endings. The skin also gets dryer, but this is easily resolved by applying a moisturizer on the belly on a daily basis and avoiding drying soaps and products. Dry skin may also be caused by dehydration, but the itching in that case would not be limited to just your stomach.
Hormonal changes and itching without elevated serum bile acids
Hormonal changes during pregnancy cause skin changes in around 90% of women, 20% of which experience pruritus. Hormones often affect the pigmentation of the skin as well, causing darker spots known as melasma or chloasma, darkened genitals and armpits, darkened areola around the nipples and darkening of the linea alba in your belly; there may also be growth of body hair.
When caused by hormonal changes without evidence of cholestasis, pruritus usually starts around the third trimester when hormones are at their peak concentration and ends at the time of delivery, although it may also have an earlier onset.
Cholestasis of pregnancy and itching
Intrahepatic cholestasis of pregnancy is a condition with unclear causes, probably due to hormones and genetics; it is characterized by build-up of bile in the liver that eventually causes an increase of bile acids levels in blood. Bile is a waste product produced by the liver that transits through the gallbladder and ends up in the small intestine aiding the digestion of fats. The increase in bile acids in blood causes the itching without a rash, while a yellowish skin color and yellow eyes may be present when bilirubin levels are also elevated. Clay-colored stools may be present as well.
Itching often starts after the 28th week, in the third trimester. Most patients complain of itchy hands and feet, but it may also spread to the arms and legs; during nighttime, with less distractions, it may be felt as more severe and cause trouble falling asleep. There is no rash, but scratching may cause redness and if scratching too often and too hard some lesions may develop.
Cholestasis of pregnancy is an uncommon condition, with an occurrence of about 1-5 cases every 1,000 pregnancies in the general population; in the South American population the occurrence can be as high as 15%.
When cholestasis is diagnosed during pregnancy it is important to monitor and treat it because it is associated with increased risks for the fetus.
After delivery, the itching resolves quickly within the first few days, while jaundice and elevated bile acids may take up to 4-6 weeks to normalize.
How is the cause of itching diagnosed during pregnancy?
The first step for any diagnosis is the medical consult. Your specialist will take you family and medical history which may already give useful information on the possible cause. A physical exam is usually included to check for skin abnormalities that may indicate dermatological conditions, allergic reaction, response to irritants, or other causes.
To rule out or confirm cholestasis of pregnancy, the doctor may prescribe some blood tests:
- Liver function test or hepatic panel. This may include serum levels of bilirubin, albumin, AST (GOT) and ALT (GPT).
- Serum bile acids test. This may include total bile acids and the individual acids levels as well, such as cholic acid, deoxycholic acid and chenodeoxycholic acid.
- Viral Hepatitis test.
- Epstein-Barr virus test.
- Cytomegalovirus test.
Cholestasis of pregnancy diagnosis and treatment
Cholestasis in pregnant women is suspected when itching is present without any skin rash, besides the one that may be caused by the scratching response to pruritus. Elevated bile acids levels in blood are the main indicator (> 10 umol/L). Up to 60% have abnormal AST and ALT results, while around 20% have elevated serum bilirubin. Jaundice, or yellowish skin, may be present and is caused by hyperbilirubinemia.
When cholestasis of pregnancy is diagnosed, treatment is indicated to minimize the risk of complications for the fetus which include preterm labor, low birth weight, fetal distress and in rare cases even death.
Ursodeoxycholic acid (UDCA) is the first line treatment. It is an oral medication that lowers bile acid levels and is effective at treating the itching; it is usually started at 300 mg twice a day, but it may be increased to 600 mg if symptoms persist. Antihistamine and steroids may be used to treat the pruritus as well, but usually they are not needed.
Early delivery may be advised and will be induced around the 37th-38th week depending on fetal development.
If you experience persistent, generalized, itching during pregnancy, it is important to inform your healthcare provider: they will advise you on all the possible causes, homemade remedies, and in case they are indicated they will schedule further testing and treatment.
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S Chakravarti – Oxford University Hospital, Sep 2017
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SD Craigo – Society for Maternal-Fetal Medicine, Mar 2012
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B Adhikari, MAB Khan – StatPearls, Jan 2021
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S Kang et al – McGraw-Hill, 2019