GI in Pregnancy: GI in Pregnancy: Viral Hepatitis

0:00Welcome to Board Pearls. This is episode four of six of the GI in Pregnancy chapter, in the Special Populations and Acute or Supportive Care module. This episode is viral hepatitis in pregnancy, with the decisions that belong to pregnancy itself. The first patient has chronic hepatitis B found at her first prenatal visit. Her case shows what viral load triggers treatment, when treatment starts and with which drug, what her baby must receive and how fast, whether cesarean delivery helps, and when her treatment can stop. Her negative hepatitis C test shows how hepatitis C is screened for and why it isn't treated in pregnancy. The second patient has acute hepatitis with fever and very high liver enzymes in the third trimester. Her case shows how hepatitis A, hepatitis E, and herpes simplex are weighed, why the travel history decides the danger of hepatitis E, and why herpes simplex, the liver failure without jaundice, is treated before it's confirmed.

0:56Here's the first patient. A thirty-year-old woman has her first prenatal visit at ten weeks. She was born in a country where hepatitis B is common and has never been tested. Her hepatitis B surface antigen, HBsAg, is positive, her hepatitis B virus, HBV, DNA is three point two million international units per milliliter, and her alanine aminotransferase, ALT, is mildly raised. Her hepatitis C antibody is negative.

1:26She has chronic hepatitis B with a high viral load, found the way it should be, by screening. Every pregnancy is screened for HBsAg, and HBV DNA is measured in women who test positive, because the risk of transmission to the baby follows the mother's viral load. Chapter eighteen covers hepatitis B in full, and these are the rules for her pregnancy.

1:47Her viral load decides whether she's treated and when. A mother with HBV DNA above two hundred thousand international units per milliliter gets tenofovir disoproxil fumarate starting at twenty-eight to thirty-two weeks. Tenofovir alafenamide has less pregnancy data, and lamivudine and telbivudine are obsolete. Her three point two million is far above the threshold, so she's treated, and she starts at twenty-eight to thirty-two weeks rather than now, because transmission happens at delivery and the goal is a low viral load at that moment.

2:22Her baby's protection is planned now, so it doesn't depend on someone remembering at birth. Every exposed infant gets hepatitis B immunoglobulin, HBIG, and the first dose of hepatitis B vaccine within twelve hours of birth, which together cut transmission to under five percent. Her tenofovir lowers the risk before delivery, and HBIG with vaccine protect the baby after it.

2:46Two common worries don't change her baby's risk. Cesarean delivery doesn't reduce transmission, so she's told a cesarean won't help. Breastfeeding is safe once the baby has had HBIG and vaccine. Amniocentesis is avoided when possible.

3:00Why her tenofovir was started decides when it can stop. Antiviral therapy given only to prevent transmission can stop at delivery or up to six weeks afterward, with ALT monitored for six months, because flares after delivery are common. Women with advanced fibrosis continue therapy for their own liver. So if her fibrosis assessment is reassuring, her tenofovir stops after delivery with six months of ALT checks, and if she has advanced fibrosis, it continues.

3:30Her negative hepatitis C antibody comes from universal screening. All pregnant women are screened for hepatitis C at the first prenatal visit, under guidance from the American Association for the Study of Liver Diseases, AASLD, the Infectious Diseases Society of America, IDSA, the Centers for Disease Control and Prevention, CDC, and the United States Preventive Services Task Force, USPSTF, updated in response to the opioid epidemic.

3:59Had her test been positive, with detectable RNA, her pregnancy would be managed around transmission rather than treatment. Vertical transmission of hepatitis C virus, HCV, is about five percent without human immunodeficiency virus, HIV, and ten to fifteen percent with HIV coinfection, which impairs cellular immunity and allows higher viremia. Delivery mode doesn't affect transmission, so cesarean isn't indicated for HCV alone. Invasive fetal monitoring, episiotomy, and prolonged rupture of membranes are avoided, because they expose the baby's blood and mucosa to maternal blood. Breastfeeding is safe unless there's nipple trauma or HIV coinfection.

4:40She wouldn't be treated during pregnancy. Direct-acting antivirals aren't approved in pregnancy in the United States because safety data are limited, so treatment is given before conception or after delivery. Ribavirin is highly teratogenic, because it disrupts nucleic acid synthesis, and it's absolutely contraindicated, with both women and men using two forms of contraception for six months after the last dose. HCV RNA is rechecked after delivery, because up to ten percent of women clear the virus spontaneously, and treatment follows if it persists.

5:13Her baby would be tested on a schedule set by maternal antibody. Antibody testing in an infant isn't useful until passively transferred maternal immunoglobulin G, IgG, has cleared, so a positive antibody at six weeks reflects the mother, not infection. The right tests are HCV RNA at two to six months and HCV antibody after eighteen months.

5:35Now the second patient. A twenty-seven-year-old woman is thirty weeks pregnant with three days of fever, sore throat, and myalgias, then right upper quadrant pain. Her ALT is two thousand four hundred, about thirty times normal, but her bilirubin is only one point four, and she has no rash. She hasn't traveled.

5:53She has acute hepatitis in the third trimester, and her pattern, a very high ALT with little jaundice after a febrile illness, means herpes simplex hepatitis until proven otherwise. Because that diagnosis must be treated immediately, her treatment starts while the other viral causes are tested for.

6:12Disseminated herpes simplex virus, HSV, infection in pregnancy causes liver failure without jaundice: transaminases twenty-five to forty times normal with a bilirubin below three. The vesicular rash is absent in about half of cases, which is why HSV is so often missed at first, and about a quarter of disseminated HSV cases occur in pregnancy. Her very high transaminases, near-normal bilirubin, fever, and upper respiratory symptoms fit, and her missing rash doesn't argue against it.

6:42So she's treated before the result returns. Empirical intravenous acyclovir is started before HSV polymerase chain reaction, PCR, results in any pregnant patient with acute hepatitis, especially with fever and upper respiratory symptoms, because the disease progresses quickly and waiting for confirmation risks fulminant hepatic failure. Untreated mortality is about thirty to fifty percent, and empirical acyclovir lowers it substantially. Acyclovir is well studied and safe in every trimester. A liver biopsy, if one were done, would show patchy necrosis, minimal inflammation, and viral inclusions. She starts intravenous acyclovir tonight, with her PCR sent alongside, rather than waiting for a result or a rash.

7:26Hepatitis A is part of her viral workup, and in pregnancy it behaves as it does in anyone else. Its incidence and course in pregnancy match the general population. Acute infection can be associated with preterm labor and premature rupture of membranes, but outcomes for mother and baby are generally good. The vaccine is inactivated and safe in pregnancy, as is post-exposure immunoglobulin. If a mother is infected within two weeks of delivery, her infant receives hepatitis A immunoglobulin for passive protection.

7:56Hepatitis E is the other virus her workup includes, and her travel history decides how dangerous it would be. Genotypes one and two are fecal-oral, water-borne strains endemic in South and Central Asia, sub-Saharan Africa, and Mexico, and they cause maternal mortality of a fifth to a third in the third trimester, with about three thousand stillbirths a year worldwide. Genotype three, the zoonotic strain of industrialized countries, acquired from undercooked pork and game, causes a generally self-limited illness without that severity in pregnancy. Viral loads are higher in pregnancy whatever the genotype, and the severity of genotypes one and two is attributed to nutritional cofactors such as folate deficiency and to the Th2 shift of pregnancy, which reduces cellular immunity and impairs clearance.

8:41So third-trimester jaundice two weeks after returning from South Asia suggests genotype one or two and a risk of fulminant failure, while the same illness after eating undercooked pork in the United States suggests genotype three and a milder course. Ribavirin and interferon-alpha work against hepatitis E virus, HEV, outside pregnancy, but both are contraindicated in it, ribavirin as a teratogen and interferon as an abortifacient. So treatment is supportive, with attention to fluid balance and coagulopathy and intensive care unit, ICU, admission for fulminant cases, as chapter nineteen covers further. With no travel, she's unlikely to have the dangerous genotypes.

9:24Here are the traps the boards set in these patients. Starting tenofovir in the first trimester when the goal is preventing transmission. Using a viral load threshold other than two hundred thousand. Missing the twelve-hour window for HBIG and vaccine. Recommending cesarean delivery for HBV or HCV. Discouraging breastfeeding in HBV or uncomplicated HCV. Stopping antiviral therapy without six months of ALT monitoring. Treating HCV during pregnancy, or giving ribavirin. Testing an infant for HCV antibody too early. Missing the travel history that marks dangerous HEV. And waiting for a rash or a PCR result before starting acyclovir.

10:06So, start to finish. For hepatitis B, every pregnancy is screened, tenofovir disoproxil fumarate is given from twenty-eight to thirty-two weeks when HBV DNA is over two hundred thousand, and every exposed newborn gets HBIG and vaccine within twelve hours. Cesarean doesn't help, breastfeeding is allowed, and ALT is watched for six months after tenofovir stops. For hepatitis C, every pregnancy is screened, treatment waits until after delivery, ribavirin is avoided, RNA is rechecked after delivery, and the infant is tested for HCV RNA at two to six months.

10:42For acute hepatitis in pregnancy, hepatitis A is generally benign and its vaccine is safe, and hepatitis E genotypes one and two, from endemic regions, cause high mortality in the third trimester. Very high transaminases with little jaundice and fever mean HSV until proven otherwise, and intravenous acyclovir starts immediately.

11:04Episode five is pre-existing liver disease in pregnancy.

11:08For the full chapter, the practice vignettes, and the topic-tagged question bank, head to board pearls dot com. You'll find the rest of the series on Apple Podcasts, Spotify, or wherever you listen to podcasts. That brings us to the end of episode four of six of chapter thirty-five, and I'll see you in the next one.