Associate Professor, Maternal-Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences


Christian M. Pettker, MD

Intrahepatic cholestasis of pregnancy (ICP) occurs in the second and third trimesters of pregnancy and is characterized by pruritus and elevated serum bile acid concentrations. Its incidence has been estimated to range from 0.3% to 15% in various populations, with most estimates from 0.3% to 0.5%.

 While ICP poses little risk for women, it does confer risk to the fetus. The persistence and intensity of associated pruritis are uncomfortable, and the increased risk of stillbirth is a significant concern to both patients and health care professionals.

What is the differential diagnosis of pruritis in pregnancy?

Pruritis is a common complaint in pregnancy.

 In ICP, itching is often generalized but predominantly affects the palms of the hands and the soles of the feet, is worse at night, and is generally not associated with a rash.

 The most frequent pathologic causes of pruritus specific to pregnancy include atopic eruption of pregnancy, polymorphic eruption of pregnancy, pemphigoid gestationis, and ICP.

Q|How should a woman with pruritus in pregnancy be evaluated?

A detailed history and physical examination are imperative in making the diagnosis of ICP. In the process of taking the history and performing the physical examination, it is appropriate to consider and assess for other causes of pruritus without a rash 

. ICP should be considered in a woman who develops new-onset pruritus without a rash in the second half of pregnancy.

In evaluating a patient for other potential causes for pruritus, one should assess the onset, extent, severity, aggravating and alleviating factors, timing, medical history, medications (eg, narcotics), allergies, past medical/family history of atopy (eg, eczema, allergic rhinitis, asthma), amount of bathing, household contacts, pets, and travel history. Sexual history and any history of intravenous drug use should be assessed to ascertain the patient’s risk of hepatitis and HIV. A history of ICP in any prior pregnancies should be assessed as well.

Other significant signs and symptoms to assess include recent changes in weight, appetite, skin or eye color (jaundice), and sleep habits. Excessive fatigue, insomnia, malaise, and abdominal pain and colic are not common with ICP. If present, evaluation for other causes of pruritis and hepatic disease may be warranted.

The physical examination should assess for the presence of rashes, excoriations, papules, plaques, or bullae. Although ICP is not associated with a rash, the intensity of the pruritus can lead to the development of excoriations or prurigo nodularis, which may be mistaken for a rash.

 Dark urine and jaundice are not common with ICP and suggest other hepatic diseases.

Q|What laboratory evaluation is recommended for a pregnant woman with pruritis in whom ICP is suspected?

We recommend measurement of serum bile acid levels and liver transaminases in patients with suspected ICP (GRADE 1B).

 Mass spectrometry and liquid chromatography can evaluate for total and fractionated (cholic, chenodeoxycholic, and deoxycholic acid) bile acids. Total bile acids also can be assessed by enzymatic assay. Although the enzymatic assay does not provide fractionated bile acid levels, fractionated levels have limited utility, and the most clinically useful value is the total bile acid level.

The clinical diagnosis of ICP is based on pruritus symptoms and supported by the presence of elevated total serum bile acid levels and the absence of diseases associated with similar laboratory findings and symptoms. A serum total bile acid concentration of greater than 10 micromol/L often is used to diagnose ICP, although the data are limited and the diagnostic accuracy has been questioned.

 Increases in transaminases (eg, alanine aminotransferase and aspartate aminotransferase) can also sometimes be seen in ICP, although elevated transaminases are not necessary for the diagnosis. 

Although bile acid levels can be affected by a postprandial state, random bile acids can be used to diagnose ICP and are typically more convenient for the patient and practitioner than fasting bile acids. 

 lists other causes of ICP and elevated bile acid concentrations. Particularly in women with elevated bile acids before the second trimester of pregnancy, other etiologies should be considered.

Q|Are particular women or populations at risk for ICP?

Women with preexisting hepatobiliary disease are reported to be at higher risk for ICP. Patients with a history of ICP are at risk for recurrence. ICP has been associated with multiple gestations and advanced maternal age, and familial clustering of cases of ICP also suggests a genetic component.

 ICP likely results from both environmental and hormonal influences in women who are genetically susceptible.

Q|What are the complications of cholestasis of pregnancy?

ICP is associated with several adverse perinatal outcomes, including stillbirth, meconium-stained amniotic fluid, and preterm birth (both spontaneous and iatrogenic). Data suggest that the risk of stillbirth with ICP is associated with the total bile acid concentration,

 although some level of risk may still be present even with low bile acid concentrations.

Women with ICP and bile acid levels ≥40 micromol/L have been reported to have increased risks of adverse perinatal outcomes, including preterm birth, asphyxia or respiratory distress syndrome, and meconium-stained amniotic fluid.

 Increased rates of both indicated and spontaneous preterm birth are reported with ICP, with the incidence of prematurity varying greatly among studies. Pregnancies complicated by spontaneous preterm birth have been reported to have an earlier onset of pruritus, and the prevalence of spontaneous preterm birth increases with higher total bile acid concentrations.

 There also is evidence that patients with ICP are at increased risk for preeclampsia.

Q|What is the recommended treatment for cholestasis of pregnancy?

We recommend that ursodeoxycholic acid (UDCA) be used as the first-line agent for the treatment of maternal symptoms of ICP (GRADE

Three meta-analyses have summarized the data from randomized trials and have reported benefits in improving maternal symptoms.

 Compared with placebo or alternative agents (eg, cholestyramine or S-adenosyl methionine), UDCA is more effective in relieving pruritus and improving laboratory abnormalities and has no known adverse fetal effects. The typical starting dose for UDCA is 10 to 15 mg/kg per day, which can be divided into doses taken 2 or 3 times daily. Typical regimens are 300 mg taken 2 or 3 times daily or 500 mg twice daily. A decrease in pruritus usually is seen within 1 to 2 weeks. If pruritis is not relieved, the dose can be titrated to a maximum of 21 mg/kg per day. Biochemical improvement is usually seen within 3 to 4 weeks.

Alternative drugs, such as S-adenosyl methionine and cholestyramine, can be considered for patients who cannot take UDCA or have continued symptoms on the maximum dosage. It has been reported that rifampin can be combined with UDCA for refractory cases of ICP with improvement in pruritis.16 Antihistamines such as diphenhydramine or hydroxyzine also have been used for pruritis, although these may have limited benefit. Topical antipruritics (eg, menthol creams, calamine lotion) are also of limited use, given that itching is typically widespread. To date, none of these alternative treatments have been evaluated in randomized controlled trials.

Q|Is serial serum bile acid testing beneficial?

In patients with ICP, bile acid levels can increase during pregnancy and may increase rapidly near term. Given that higher serum total bile acid concentrations have been associated with adverse perinatal outcomes in some studies, repeat bile acid measurement has been suggested as potentially useful in guiding management. Follow-up laboratory testing may help guide delivery timing, especially in severe cases, but serial testing (eg, weekly) is not recommended.

Q|How should a pregnant woman with itching and normal bile acids be managed?

The pruritus in ICP can precede the rise in serum bile acids by several weeks. Therefore, if symptoms persist and no other explanation for pruritis exists, measurement of the total bile acid concentration and serum transaminases should be repeated. If UDCA is started empirically at the time testing is performed and before results are available, it is possible that elevated bile acid or transaminase levels may never be detected.

Q|Is antepartum testing indicated for patients with ICP?

We suggest that patients with a diagnosis of ICP begin antenatal fetal surveillance at a gestational age when delivery would be performed in response to abnormal fetal testing or at the time of diagnosis if the diagnosis is made later in gestation (GRADE 2C).

 The observed increased risk of stillbirth with ICP has prompted most practitioners to perform antenatal testing in this setting. However, the efficacy of antepartum fetal testing to prevent stillbirth in the setting of ICP is unknown. Several studies and case reports have reported stillbirth occurring within a few days of a reactive nonstress test.

 Antepartum fetal testing in ICP may not be useful because the mechanism of stillbirth is thought to be a sudden event rather than a chronic placental vascular process.

Recent clinical trials and meta-analyses support fetal surveillance with substantially lower rates of adverse perinatal outcomes compared with earlier reports, potentially due to more intensive monitoring with fetal surveillance and late-preterm or early-term delivery.

 The optimal frequency of testing is unknown and may be determined by criteria such as comorbidities or bile acid levels (eg, more frequent for total bile acid levels of 100 micromol/L or more). Due to the higher risk of stillbirth, patients with ICP should be placed on continuous fetal monitoring in labor.

Q| When should women with a diagnosis of cholestasis be delivered?

While the risk for late stillbirth is avoided with an early planned delivery, this must be weighed against risks to the neonate related to prematurity. The timing of delivery should be approached using risk stratification based on patient-specific factors, including total bile acid levels, in a shared decision-making model. 

We recommend that patients with total bile acid levels ≥100 micromol/L be offered delivery at 36 0/7 weeks of gestation, given that the risk for stillbirth increases substantially around this gestational age (GRADE 1B). We recommend delivery between 36 0/7 and 39 0/7 weeks of gestation for patients with intrahepatic cholestasis of pregnancy and total bile acid levels <100 micromol/L (GRADE 1C). 

Delivery timing for women with total bile acid levels <100 micromol/L should be individualized; it is reasonable for patients with bile acid levels of <40 micromol/L to be managed toward the later end of this time range, given the low risk for stillbirth seen in the studies referenced above, while women with total bile acid levels of ≥40 micromol/L should be considered for earlier delivery.

Delivery between 34 and 36 weeks of gestation can be considered in women with ICP, total bile acid levels of ≥100 micromol/L, and any of the following:

excruciating and unremitting maternal pruritus not relieved with pharmacotherapy;

a prior history of stillbirth before 36 weeks of gestation due to ICP with recurring ICP in the current pregnancy; or

preexisting or acute hepatic disease with clinical or laboratory evidence of worsening hepatic function.

Any patient delivered for ICP prior to 36 weeks of gestation should be extensively counseled about the absence of definitive evidence that the maternal and fetal benefits of delivery outweigh the potential morbidity of prematurity. 

We recommend antenatal corticosteroids for fetal lung maturity for patients delivered before 37 0/7 weeks of gestation if not previously treated (GRADE 1A).

For patients with early-term pregnancies (37 to 38 weeks of gestation) with pruritis suggestive of ICP, no rash, and no bile acid results yet available to confirm the diagnosis, management should be based on shared decision-making that involves a discussion of the uncertainty of the diagnosis, the risks of ICP vs early-term delivery, and the values and preferences of the patient. 

Diagnostic certainty, and thus advice about delivery management, is improved if there are elevated transaminases or a history of ICP in prior pregnancies, and it may be reasonable to deliver in the absence of bile acid results in these situations. 

We recommend against preterm delivery at <37 weeks of gestation in patients with a clinical diagnosis of ICP without laboratory confirmation of elevated bile acids (GRADE 1B).

The risk of recurrence of ICP in subsequent pregnancies may be as high as 90%, although data are insufficient to counsel patients on specific ranges.

 Some data also suggest that patients with a history of ICP are at higher risk for developing later hepatobiliary disease, particularly within the first year after the diagnosis of ICP. Given the risk for hepatitis C in these patients and the availability of an effective treatment, some experts advocate for routine testing for hepatitis C in patients with ICP.

It is important to consider reevaluation of liver function test results after delivery in patients with persistent pruritis or other signs or symptoms of a hepatobiliary disease, such as right upper quadrant pain or jaundice. If serologic study results remain abnormal, the patient should be referred to a liver specialist for evaluation for another underlying condition. 

1.Wikström Shemer E, Marschall HU, Ludvigsson JF, Stephansson O. Intrahepatic cholestasis of pregnancy and associated adverse pregnancy and fetal outcomes: a 12-year population-based cohort study. BJOG 2013;120:717-23.

2.Kenyon AP, Tribe RM, Nelson-Piercy C, et al. Pruritus in pregnancy: a study of anatomical distribution and prevalence in relation to the development of obstetric cholestasis. Obstet Med 2010;3:25-9.

3.Bechtel MA, Plotner A. Dermatoses of pregnancy. Clin Obstet Gynecol 2015;58:104-11.

4.Ambros-Rudolph CM, Glatz M, Trauner M, Kerl H, Müllegger RR. The importance of serum bile acid level analysis and treatment with ursodeoxycholic acid in intrahepatic cholestasis of pregnancy: A case series from central europe. Arch Dermatol 2007;143:757-62.

5.Egan N, Bartels A, Khashan AS, et al. Reference standard for serum bile acids in pregnancy. BJOG : 2012;119:493-8.

6.Manzotti C, Casazza G, Stimac T, Nikolova D, Gluud C. Total serum bile acids or serum bile acid profile, or both, for the diagnosis of intrahepatic cholestasis of pregnancy. Cochrane Database Syst Rev 2019;7:Cd012546.

7.Pataia V, Dixon PH, Williamson C. Pregnancy and bile acid disorders. Am J Physiol Gastrointest Liver Physiol 2017;313:G1-g6.

8.Brouwers L, Koster MP, Page-Christiaens GC, et al. Intrahepatic cholestasis of pregnancy: maternal and fetal outcomes associated with elevated bile acid levels. Am J Obstet Gynecol 2015;212:100 e1-7.

9.Kawakita T, Parikh LI, Ramsey PS, et al. Predictors of adverse neonatal outcomes in intrahepatic cholestasis of pregnancy. Am J Obstet Gynecol 2015;213:570 e1-8.

10.Cui D, Zhong Y, Zhang L, Du H. Bile acid levels and risk of adverse perinatal outcomes in intrahepatic cholestasis of pregnancy: A meta-analysis. J Obstet Gynaecol Res 2017;43:1411-20.

11.Ovadia C, Seed PT, Sklavounos A, et al. Association of adverse perinatal outcomes of intrahepatic cholestasis of pregnancy with biochemical markers: results of aggregate and individual patient data meta-analyses. Lancet 2019;393:899-909.

12.Williamson C, Hems LM, Goulis DG, et al. Clinical outcome in a series of cases of obstetric cholestasis identified via a patient support group. BJOG 2004;111:676-81.

13.Bacq Y, Sentilhes L, Reyes HB, et al. Efficacy of ursodeoxycholic acid in treating intrahepatic cholestasis of pregnancy: a meta-analysis. Gastroenterology 2012;143:1492-501.

14.Gurung V, Middleton P, Milan SJ, Hague W, Thornton JG. Interventions for treating cholestasis in pregnancy. Cochrane Database Syst Rev 2013;2013:Cd000493.

15.Kong X, Kong Y, Zhang F, Wang T, Yan J. Evaluating the effectiveness and safety of ursodeoxycholic acid in treatment of intrahepatic cholestasis of pregnancy: A meta-analysis (a prisma-compliant study). Medicine (Baltimore) 2016;95:e4949.

16.Liu J, Murray AM, Mankus EB, Ireland KE, Acosta OM, Ramsey PS. Adjuvant Use of Rifampin for Refractory Intrahepatic Cholestasis of Pregnancy. Obstet Gynecol 2018;132:678-81.

17.Alsulyman OM, Ouzounian JG, Ames-Castro M, Goodwin TM. Intrahepatic cholestasis of pregnancy: perinatal outcome associated with expectant management. Am J Obstet Gynecol 1996;175:957-60.

18.Herrera CA, Manuck TA, Stoddard GJ, et al. Perinatal outcomes associated with intrahepatic cholestasis of pregnancy. The Journal of Maternal-Fetal & Neonatal Medicine 2018;31:1913-20.

19.Lee RH, Incerpi MH, Miller DA, Pathak B, Goodwin TM. Sudden fetal death in intrahepatic cholestasis of pregnancy. Obstet Gynecol 2009;113:528-31.

20.Sentilhes L, Verspyck E, Pia P, Marpeau L. Fetal death in a patient with intrahepatic cholestasis of pregnancy. Obstet Gynecol 2006;107:458-60.

21.Chappell LC, Bell JL, Smith A, et al. Ursodeoxycholic acid versus placebo in women with intrahepatic cholestasis of pregnancy (PITCHES): a randomised controlled trial. Lancet 2019;394:849-60.

22.Wijarnpreecha K, Thongprayoon C, Sanguankeo A, Upala S, Ungprasert P, Cheungpasitporn W. Hepatitis C infection and intrahepatic cholestasis of pregnancy: A systematic review and meta-analysis. Clin Res Hepatol Gastroenterol 2017;41:39-45.

Articles

Intrahepatic cholestasis of pregnancy (ICP) occurs in the second and third trimesters of pregnancy and is characterized by pruritus and elevated serum bile acid concentrations.

Society for Maternal-Fetal Medicine Consult Series #53: Intrahepatic Cholestasis of Pregnancy

Experts debate the use of "pregnant women" and "pregnant persons." 

Listen Now: Building and Sustaining a Gender-Affirming Medical Care Environment

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Join Senior Editor Angie DeRosa as Sarah J. Kilpatrick, MD, PhD; and Christian M. Pettker, MD debate noun use. 

Board Members Debate Noun Use: Pregnant Woman or Pregnant Person? 

As obstetricians we commit ourselves to a job that consists mostly of bringing life to the world. These celebrations offer such joy in our work. Less often we are shepherds of loss. We help a couple through miscarriage or stillbirth and support families with the loss of a newborn, for example. These moments are most devastating for patients and their families, but they are also full of grief for us. We are never prepared for, nor do we completely recover from, the loss of a mother. Mothers are young. Mothers are the foundations of a family. Most of the time, the loss of a mother is sudden and unexpected. It leaves an empty space unlike any other. Most obstetricians can recite the names of every mother we helped take care of, but lost.

’s maternal mortality series and to share our experiences. When we were asked to write, we accepted without a second thought; it is easy to write about people we think about on most days. We hope that reflecting on these lives and how we have been changed by them can help our colleagues reflect on their own experiences. We also aim to help motivate a movement to improve efforts to prevent maternal mortality. Our reflection on these cases cannot dwell purely on the profound sadness of it all or how we might have wanted it to go differently. From each case we need to grow and change and get better for the next woman that comes through our door.

During a low point in training, during a time of loss, one of our mentors offered important words of encouragement in this context: “You will be changed by this event. You will either be better from it, or worse from it. But you are the one who chooses which it will be.” In trying to make things better, and in a spirit of fellowship for our colleagues reading this, we are sharing our stories. 


We paused in the hallway halfway between triage and the operating room (OR), so she could kiss her kids. “We will take good care of her,” I remember saying to the two scared, sleepy looking faces. They were in pajamas and attached to their dad. One was about a year younger than my daughter and one was about a year older. 

“She lost a lot of blood,” her husband said again. I nodded, said “I know” and tried to sound reassuring. “We have blood on the way, but the most important thing right now is that we get her into the operating room.” And off we went. It was 5:45 am.

By the time the case started, I had two chiefs operating with me. Thank goodness for change of shift. We worked quickly to get in, acutely aware of how quickly blood was coming out from below. The woman was scheduled to be seen for the first time the next day by maternal-fetal medicine (MFM), but I knew at minimum she had a bleeding previa and two prior cesareans. Anesthesia was transfusing, the cell saver was being assembled, oncology was on their way, my back-up was coming. I was supported. This was the way it was supposed to work. 

Yet despite my amazing team, a very prepared hospital, and my years of training, 90 minutes later I was giving chest compressions. And despite a trauma surgeon, two gynecologic oncologists, and a critical care boarded MFM all by my side, a few minutes after 8 am, I was telling that scared man, now father of three, that he was a single parent. 

Six hours later, after debriefing with the many residents, nurses, and specialists who shared in this tragedy with me, I was back home. My family was the same, my house was the same, but nothing would ever be quite the same. I took a healthy young woman into the OR to deliver her baby and she died on my OR table in my care. 

As I learned more about my patient in the days that followed her death, from the neonatal intensive care unit doctors who took care of her 32-weeker, from hospital staff who knew her as a friend, and from her family who spoke at her funeral, I was bothered most by the fact that we did not have the chance to know one another. I hated that our entire patient-doctor relationship was defined by that night. I wanted her to know the kind of doctor I was. I wanted the opportunity to answer her questions and concerns. I wanted to reassure her that even in the brief moments we had together, I understood how much she loved her children, and I would have done anything to have her case end differently. I wanted then and now to be able to reach out to her family, to see her kids, to tell them in person how sorry I was.  And yet because of the Health Insurance Portability and Accountability Act, the medical legal system, and perhaps most importantly because of a brief moment of eye contact between her husband and me at the funeral, I have stayed away. I am a caregiver but I continue to care in this instance in silence. 

Now almost a decade out from this tragedy, I continue to think about this woman, her daughter, and her family almost every day. In the early years, what used to surprise me most was that I barely knew this woman or her family and yet I thought about them not only at work when I was counseling, operating, and teaching, but at home when I was tucking my kids in, laughing with my husband, or admiring a sunrise. As the years have passed, I have become more comfortable with how frequently my thoughts drift to her and her family. Her story has become part of my story even though our endings were so different. 

For my part, I have been exceptionally lucky. This tragedy could have led to self-doubt and a disdain for the uncertainty and powerlessness of obstetrical care. Perhaps because of the amazing team who got me through that night, I continue to believe that I kept my promise and that we took good care of this mom. I continue to love obstetrics, especially the most challenging deliveries, which push us all to be better. I will forever feel vulnerable because of that night, but I feel honored to be with families at these most dangerous and intimate moments.


She came to our practice after finding out the worst and best information a woman can hear. A neurologist told her the bad news that she had suspected: Her symptoms indeed were signs that the disease that took her mother would also slowly but soon take her life, too. At the same time, she found out she was pregnant. The neurologist and our MFM team were uncertain if she would live through her pregnancy. She was certain she would try. She wanted to be a mother, she wanted her husband to be a father, and she wanted to give life to her child.

With her first visit to our practice she set into motion a transformation of our service. We spent weeks coordinating her care and planning her admission. We assembled all of the specialists and all of the nursing units for regularly scheduled morning meetings planning for her pregnancy. At a certain point she and her husband wanted to join the meetings. Despite our trepidation at this request, based on a paternalistic fear that we would have trouble discussing openly some of the scarier parts of her care, we accepted this challenge. And together we planned for the joy of birth but also for all of the frightening moments she might encounter to get there.  

We took care of the woman for four months in the hospital-she was in the ICU all of those days-progressively losing her strength to move, talk, and breathe. With each week we added another specialty to our meetings, to support her feeding or to plan her tracheostomy and ventilator management. But at the same time, we tried to commit to all of the normal aspects of childbirth, too. Our lactation team visited her in the third trimester to discuss her plans for breastfeeding.  The labor and maternity nurses threw her a baby shower in the intensive care unit. One of my highest honors as an obstetrician was to be invited; it remains, and will probably always be, the only baby shower I have attended. She was committed to becoming well again and having as normal an experience as possible. She believed there would be a cure for her disease in her lifetime.

Her plan was for a vaginal birth and despite her weakness we believed it was medically possible. At term, when we found out that her baby was in breech presentation, she requested an external cephalic version. We tried, but failed, and she ended up with a cesarean that included skin-to-skin, breastfeeding, and rooming-in, even in the ICU.  She left the hospital with her husband and her baby, to go live and die at home.

She was able to see her child’s first birthday. As a result, she avoided becoming a “maternal mortality” “pregnancy-related death” statistic. Admittedly, when we talk about efforts to reduce maternal mortality we are not talking about preventing cases like this.  But despite all we were able to do for her, those who took care of this family experienced profound loss because she did not live long enough. For me and my colleagues, years later even, this still has all of the sadness of a maternal loss.

All the way through the end, she felt blessed and had no regrets. I think she knew how much she touched and influenced each of her caregivers.  Her courage and strength were something that built strength in our hospital’s service and made us so much better at taking care of complicated patients. Our introspection on her care and her life was important for our thinking about how to build a patient-centered destination hospital for the highest-risk pregnancies. Realizing how often complex patients at our hospital could be helped by this level of coordination, this work became a regularly occurring meeting that continues monthly to this day. What she started for us continues to amaze me. New specialties join our meetings all the time, though this is hardly challenging in a tertiary care center. It is when a family member, a church leader, an attorney, a conservator, or a patient joins us for these meetings that I am convinced we would not be meeting our patients’ true needs if our patient had not blessed us with her experience.

I think about her regularly. Certainly, each meeting of the Proactive Care group generates memories of our first meetings working together. But I also think about her every time I work harder to support a vaginal birth or the breastfeeding goals of a woman who faces smaller but still important challenges related to her medical problems or social issues. Most of all, I think of her strength and courage and her commitment to getting better in the face of her inevitable death. This makes me stronger, too.

Two physicians recount their experiences of losing a patient.

Memorials to two mothers

Obstetricians have been trying to link the fetal heart rate (FHR) with fetal health since the invention of the modified stethoscope by Pinard in the 1870s. Practical application of intrapartum FHR assessment, however, required the development of an electronic fetal monitoring (EFM) system based on the fetal ECG by Drs. Edward Hon and Orvan Hess at Yale in the late 1950s. Their discovery allowed for precise estimations of FHR baselines and periodic changes in a continuous fashion. Within a decade, clinicians throughout the United States had adopted EFM.

Unfortunately, the inconvenient truth about EFM is that it was introduced before its efficacy could be confirmed by hard-core research. Developed primarily to reduce the occurrence of cerebral palsy (CP) and intrapartum stillbirth, its value in preventing these outcomes has never been proven. In fact, it’s the secondary benefit of fetal monitoring-providing a convenient way to supervise several patients at one time-and our fear of litigation that are the primary reasons it survives. So EFM remains perhaps the most prominent example of universal adoption of a medical technology before its verification.

The shortcomings of electronic FHR monitoring 

The available data suggest that continuous intrapartum EFM does not perform much better than the intermittent auscultation of Pinard. A Cochrane meta-analysis that included over 37,000 patients, for instance, concluded that while its application cut neonatal seizures in half (RR 0.50; 95% CI, 0.31–0.80), it failed to affect perinatal mortality or CP rates. The same meta-analysis also revealed that continuous EFM increased cesarean (RR 1.16; 95% CI, 1.01–1.32) and operative vaginal (RR 1.16; 95% CI, 1.01–1.32) deliveries. In fact, as ACOG reports, the false-positive rate of EFM for CP exceeds 99%, with as few as 1 to 2/1,000 fetuses with nonreassuring patterns developing CP.

The specificity of EFM may be improved with fetal scalp stimulation and scalp pH. A heart rate acceleration stimulated by digital pressure on the fetal scalp is highly correlated with a normal fetal pH (negative likelihood ratio 0.08; 95% CI, 0.02–0.41), although its absence is not always associated with acidosis in the setting of a worrisome tracing. Scalp pH testing can be employed at this point with a value of <7.20 (mixed venous) typically used as an indication for delivery, although its use appears to be rapidly decreasing across the country. 

Because of the false-positive rates of these approaches, additional methods of assessing fetal status in labor have been introduced under more rigorous testing, with mixed results. Fetal pulse oximetry has been compared to EFM in several clinical trials but the research to date shows no difference in overall cesarean delivery rates, although fewer of them were performed for nonreassuring fetal status (RR 0.68; 95% CI, 0.68–0.99). These studies also didn’t show differences in any maternal or neonatal outcomes. More promising is the STAN fetal heart monitor, an FDA-approved device that takes Dr. Hon’s original technology of monitoring the fetal ECG and uses specialized software to examine specific changes in the ECG related to fetal hypoxemia. Its use is suggested only in higher-risk patients who are likely to develop metabolic acidosis, rather than as a substitute for standard EFM. The most recent Cochrane review of STAN, which incorporated nearly 10,000 patients, showed reduced rates of metabolic acidosis and neonatal encephalopathy as well as operative vaginal deliveries without influencing cesarean rates.

Unfortunately, none of these tests has proven to be universally applicable and traditional EFM is here to stay. With this in mind, we are pressed to improve EFM interpretation to increase its usefulness and accuracy. The NIH/NICHD recognized this in 1997 and convened a workshop to provide a consensus on definitions related to EFM interpretation.This publication standardized terms for baseline rates (normal, tachycardia, bradycardia), variability, accelerations, decelerations, and contraction patterns. In our opinion, these guidelines provided a common interpretation paradigm-a way to speak a common language. Many institutions, including our own, mandated the use of the NICHD criteria on their L&D floors and through credentialing examinations for all providers involved in inpatient care of pregnant patients. However, the 1997 criteria had its limitations; for instance, it did not clarify the terms “reassuring” or “nonreassuring” or clearly explain the appropriate management for abnormal patterns. 

In April 2008, the NICHD directed a second workshop to revisit its 1997 recommendations; updated definitions and interpretation standards were published in September 2008.Here are some of the key points: 

 GENERAL CONSIDERATIONS included highlighting the dynamic and contextual nature of EFM interpretation. The authors stressed that a particular assessment is only limited to its specific time period. The workshop also emphasized the poor positive predictive value of EFM: While the presence of accelerations and/or variability reliably predicts the absence of fetal metabolic acidemia, the absence of accelerations and/or variability does not predict acidemia. 

UTERINE CONTRACTIONS are now quantified as the number of contractions present in a 10-minute window, averaged over 30 minutes, with normal representing five or fewer contractions in 10 minutes and tachysystole meaning five or more contractions in 10 minutes. The terms hyperstimulation and hypertonus, which are referred to in ACOG Practice Bulletin No. 70, are discouraged. 

 if they occur with 50% or more of uterine contractions in any 20-minute window and as 

 if they occur with less than 50% of uterine contractions in any 20-minute window. Otherwise the same definitions for early, late, and variable decelerations as well as normal FHR baseline and variability remain. 

A THREE-TIER INTERPRETATION SYSTEM was introduced in 2008 to aid in reading, communicating, and managing FHR tracings:

 a. CATEGORY I (NORMAL): Strongly predictive of normal fetal acid-base status; may be followed in a routine manner. These tracings include 

▶ baseline rate 110–160 bpm ▶ moderate variability ▶ absent, late, or variable decelerations ▶ early decelerations may or may not be present ▶accelerations may or may not be present   b. CATEGORY II (INDETERMINATE): Not predictive of abnormal fetal acid-base status but require evaluation, continued surveillance, and reevaluation, taking into account the clinical context.

 c. CATEGORY III (ABNORMAL): Predictive of abnormal fetal acid-base status; require prompt evaluation and management. Include either: 

▶ absent baseline FHR variability with: 

The best way to learn these categories is to learn the definitions of I and III; all other tracing types fall into category II’s grey zone. In reality, a large proportion of tracings are neither ‘reassuring’ nor ‘nonreassuring.’ In fact, the time may have arrived for us to abandon these terms. In the first place, using two systems and five terms can only make interpretation and communication confusing. Moreover, the new tripartite system allows more ‘wiggle room’ by creating a category that neither connotes normality nor mandates immediate delivery. 

It is left to the caregiver to decide upon appropriate management of category II tracings but category III tracings warrant prompt delivery. It is also unclear how the legal profession will view the change in language given their frequent misuse of the terms ‘reassuring’ and ‘nonreassuring.’ 

We hope that these new guidelines will improve communication on L&D and applaud the efforts of the workshop to continue the discourse on EFM. We encourage you to learn these new definitions and incorporate them into your practice as they become a standard of care. It’s clear, however, that we need more technology and research to improve our assessments of fetal health in labor. While improving the way we talk about fetal assessment is good, finding a better tool for such assessment would be better. ◀

DR. PETTKER is Assistant Professor, Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, and Medical Director of the Labor and Birth Unit, Yale-New Haven. DR. LOCKWOOD, Editor in chief, is Anita O’Keefe Young Professor and Chair, Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT. 

Alfirevic Z, Devane D, Gyte GM. Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour. Cochrane Database Syst Rev. 2006;(3):CD006066. doi:10.1002/14651858.CD006066. 

American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 70. Intrapartum fetal heart rate monitoring. Obstet Gynecol. 2005;106:1453-1460. 

Skupski DW, Eglinton GS. Intrapartum fetal stimuluation tests: a meta-analysis. Obstet Gynecol. 2002;100:830. 

East CE, Chan FY, Colditz PB, et al. Fetal pulse oximetry for fetal assessment in labour. Cochrane Database Syst Rev. 2007;(2): CD004075. doi:10.1002/14651858.CD004075. 

Neilson JP. Fetal electrocardiogram (ECG) for fetal monitoring during labour. Cochrane Database Syst Rev. 2006;(3):CD000116. doi:10.1002/14651858.CD000116. 

Electronic fetal heart rate monitoring: research guidelines for inter-pretation. National Institute of Child Health and Human Development Research Planning Workshop. Am J Obstet Gynecol. 1997;177:13851390. 

Macones GA, Hankins GD, Spong CY, et al. The 2008 National Institute of Child Health and Human Development workshop report on electronic fetal monitoring: update on definitions, interpretation, and research guidelines. Obstet Gynecol. 2008;112:661-666. 

The NIH/NICHD has released new guidelines on electronic fetal heart rate assessment. Two experts summarize the new standards and explain their value.

Christian M. Pettker, MD

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