The CHAP Trial

The CHAP Trial: Chronic Hypertension And Pregnancy

Formal Publication Title: Treatment for Mild Chronic Hypertension during Pregnancy

https://www.nejm.org/doi/full/10.1056/NEJMoa2201295 

Some general background information

  • Who did the study and who published it?

    • The CHAP Consortium - a group of institutions in the USA, with protocol approved by the National Heart, Lung, and Blood Institute (NHLBI). 

    • Recruiting took place across 61 institutions in the USA

  • Where was it published? 

    • The New England Journal of Medicine in May 2022 - hot off the press!

  • Why was the study done? 

    • Recall that after the CHIPS trial (we covered last week!), we still had some outstanding questions:

      • 1) In the wake of CHIPS, there was renewed interest in the concern about antihypertensives and growth restriction. 

      • 2) The CHIPS trial lumped together gHTN and cHTN – CHAP restricted care to true cHTN.

      • 3) While CHIPS showed looser control of HTN didn’t result in major outcomes differences, there were some non-significant differences in rates of severe blood pressures and lab abnormalities.

    • With all of these things taken together, CHAP aimed to more narrowly answer the question of whether tight versus loose control of cHTN would result in fewer adverse pregnancy outcomes. 

  • What was the research question?

    • Will a blood pressure goal of <140/90 (versus 160/105) result in a lower incidence of adverse maternal and perinatal outcomes in patients with chronic hypertension in pregnancy? 

      • → essentially the same question, but more narrowly targeted, than CHIPS. 

Methods

  • Who participated and when?

    • Recruited 

    • Eligibility: 

      • Pregnant patients with known or new cHTN and singleton pregnancy prior to 23 weeks (33w6d in CHIPS)

        • New cHTN was diagnosed based on criteria of BP 140/90 on 2 occasions at least 4 hours apart prior to 20 weeks gestation without prior diagnosis.

        • Pre-existing cHTN was defined by documented elevations in BP and previous/current antihypertensive therapy, including lifestyle modifications alone. 

      • Pregnancy dating needed to be confirmed according to ACOG criteria with ultrasound performed before randomization. 

    • Exclusion criteria:

      • Severe HTN or BP requiring more than one antihypertensive treatment;

      • Secondary cause of hypertension (i.e., renal artery stenosis);

      • Multiple gestation;

      • “Pre-specified high risk illnesses or complications that may warrant treatment at a lower BP level” - severe cardiac or renal dz as examples

      • OB conditions that increased fetal risk;

      • Contraindications to first-line antihypertensive drugs used in pregnancy

  • How was the study done?

    • BP was measured with an automated cuff (same across sites) to screening/enrollment and to guide medication adjustments, with research staff performing measurements by a specified protocol.

    • Randomized to:

      • Tight control group: goal BP < 140/90

      • Less tight group: goal BP <160/105

        • Therapy, if ongoing, was stopped in the less tight group unless severe BP developed.

        • If a severe BP was seen, the target for acute treatment was <140/90.

    • Web-based variable block randomization program.

    • Treatment was supplied as 1st line with nifedipine XL or labetalol and prescribed by trial investigators

      • Amlodipine and methyldopa were also considered if preferred by patient

      • Meds were prescribed to maximal recommended dose that was not associated with poor side effects before iniiating a second medication

      • Control group received medications in a similar fashion only if severe HTN developed.

      • Pill counts were performed to assess adherence.

  • What outcomes were they looking for?

    • Primary outcome

      • A composite of:

        • Preeclampsia with severe features occurring up to 2 weeks after birth;

        • Medically-indicated preterm birth before 35 weeks because of maternal/fetal illness (i.e., not for PPROM/PTL)

        • Placental abruption

        • Fetal/neonatal death

          • ACOG criteria were used to define preeclampsia with severe features; however, a BP of 160/100 or greater in absence of signs and symptoms of preeclampsia/proteinuria/lab abnormalities was not considered sufficient to diagnose PEC with SF.

      • The primary outcome was assessed in five pre-specified subgroups as well:

        • cHTN treatment status at baseline:

          • New diagnosis of cHTN

          • Diagnosed and receiving meds

          • Diagnosed and not receiving meds

        • Race/ethnicity

        • Diabetes status

        • Gestational age at enrollment (<14 weeks or > 14 weeks)

        • BMI (<30, 30-40, and >40).

    • A primary safety outcome was also prespecified: poor fetal growth

      • Defined as birth weight less than 10%ile for gestational age and infant sex

      • Also assessed at <5%ile.

    • Secondary outcomes were numerous:

      • Maternal death and various serious complications

      • Exposure to severe hypertension

      • Cesarean delivery

      • Any preterm birth and any serious neonatal complications/NICU stay

  • Patients were followed to 6 weeks postpartum

  • A blinded outcome adjudication committee reviewed all patient charts suspected of having primary or secondary outcomes to assess and confirm

  • 2404 patients was the intended sample size (1202 per group) to detect a reduction of 25% in the primary composite outcome, at a baseline incidence as low as 10%.

    • The discussion in the methods of how this sample size was agreed upon was very interesting and worth a look through for any of our statistics friends out there! – initially wanted to have 4700 patients but after IRB review settled upon this smaller size.

Results

  • Who did they recruit? 

    • 29,772 patients underwent screening, and 2419 subsequently underwent randomization; the final sample size for analysis was 2408, with 1208 in the active treatment arm (tighter control) and 1200 in the control arm (loose control).

    • 83 patients were lost to follow up for the complete study; 38 in the active group and 45 in the control group.

  • Baseline characteristics were similar:

    • cHTN status:

      • 56% in each arm had known cHTN and were receiving medication

      • 22% had known cHTN but were not on medication

      • 22% had newly diagnosed cHTN

    • BMI: both around 37.5

    • DM: 15.8% in each arm

    • 44.7% in each arm on aspirin therapy 

  • Labetalol was most common medication used (61.7%) followed by nifedipine (35.6%), and only 2.7% received other meds.

    • Active treatment group had more patients taking meds (88.9% for active, 24.4% for control).

    • BP also was predictably lower in the active treatment group after randomization:

      • 129.5 mmHg vs 132.6 mmHg (-3.1) systolic

      • 79.1 mmHg vs 81.5 mmHg (-2.3) diastolic

  • Outcomes

    • Primary: composite of severe preeclampsia, abruption, medically-indicated PTB < 35wk, fetal/neo death

      • 30.2% of active treatment group

      • 37.0% of control group

        • aRR 0.82, CI 0.74 - 0.92 – p<0.001

        • Number of patients needed to treat to prevent one primary outcome event: 14.7 (95% CI 9.4 - 33.7)

      • By event:

        • PEC + SF: 23.3% active vs 29.1% control

        • PTB < 35 wks: 12.2% active vs 16.7% control

      • By pre-specified subgroups:

        • The benefit seemed to be present for all pre-specified subgroups, except:

          • Newly diagnosed cHTN (RR 1.00)

          • BMI > 40 (RR 0.98)

  • Primary safety outcome: birth weight < 10%ile

    • 11.2% in active group vs 10.4% in control group

      • aRR 1.04, 95% CI 0.82 - 1.31; p=0.76.  → not statistically different!

    • For <5%ile: 5.1% vs 5.5% – also not different!

      • I.e, more aggressive treatment didn’t seem to impact rates of birth weight <10% or <5% as potentially feared.

  • Secondary outcomes:

    • Maternal: no substantial differences, except:

      • Severe-range HTN in 36.1% of active and 44.2% of control

      • Preeclampsia in 24.4% of active and 31.1% of control (RR 0.79, CI 0.69-0.89)

    • Fetal: no substantial differences, except:

      • PTB before 37 weeks: 27.5% active and 31.4% control (RR 0.87, CI 0.77-0.99)

      • Low birth weight <2500g: 19.2% active and 23.1% control (RR 0.83, CI 0.71-0.97)

  • Interesting as well that aspirin use did not seem to demonstrate a difference in development of any primary or secondary outcome… 

Conclusions and What We Do Now / What Should We Take Away

  • The authors conclude from this paper that having a target BP of 140/90 or lower was associated with better pregnancy outcomes than a target of 160/105, without any significant differences in safety outcomes for neonates.

  • Strengths:

    • A diverse, nationwide cohort with lots of patients

    • Strictly looking at chronic hypertension with early pregnancy enrollment (prior to 23 weeks)

    • Modern definitions of preeclampsia and other hypertensive disorders of pregnancy 

    • Overall results consistent with CHIPS – i.e., ~50% reduction in rates of severe-range BP, no difference in birth weight/growth restriction

  • Weaknesses:

    • High ratio of patients screened : patients enrolled – over 29k were screened for a trial size of ~2400!

      • This probably reflects a lot of vigorous selection which is a strength of this study, and importantly the demographics of those screened versus selected did not significantly differ. 

    • Left out a lot of higher risk patients: cardiac/renal disease patients, secondary hypertension, etc.

      • Additionally, in the prespecified subgroup analyses, the treatment effect was not seen in patients with BMI > 40 or patients with newly diagnosed cHTN – the study was not powered to assess these independently but may need to be seen if other strategies are better in these groups.

    • The definition of cHTN changed! – ACC/AHA in 2017 (mid-recruitment) lowered the target to 130/80. We don’t know if that might be better, or worse, as a target.

    • Only short term follow up – longer term follow up will help inform if there are any benefits ultimately with maternal or neonatal risks.

  • Interesting points:

    • NNT of 14.7 to reduce primary outcome is really excellent, especially given the other safety data provided in this trial (short-term).

    • Aspirin use was equal between groups – post hoc analysis demonstrated it did not influence primary outcome measure!

      • This study probably lends some support to the aspirin skeptics out there, but wouldn’t necessarily throw aspirin away based on this trial alone.

  • SMFM CHAP Statement: overall supportive of a target to goal BP of <140/90 based on this trial, mentioning the limitations we just went through. 

The CHIPS Trial

The CHIPS Trial: The Control of Hypertension In Pregnancy Study

Formal Publication Title: Less-Tight versus Tight Control of Hypertension in Pregnancy

https://www.nejm.org/doi/full/10.1056/nejmoa1404595

Some general background information

  • Who did the study and who published it?

    • An open, multicenter, international, randomized controlled trial. 

      • Coordinating center: University of British Columbia (go Canada again!)

    • Where was it published? The New England Journal of Medicine in 2015 

  • Why was the study done? 

    • Hypertension is common – at the time of this publication, it was estimated to affect 10% of pregnancies, with 1% being cHTN, 5-6% being gHTN, and 2-3% being preeclampsia.

    • Treatment of blood pressure at specific thresholds had not really been well defined.

      • On one hand – using antihypertensives liberally and early might help prevent maternal / fetal complications related to uncontrolled HTN.

      • On the other hand – antihypertensives might have their own consequences, as shown in other smaller studies (i.e., FGR).

  • What was the research question?

    • To compare tight versus less-tight control of non-proteinuric, non-severe hypertension in pregnancy

Methods

  • Who participated and when?

    • Subjects were recruited from March 2009 to August 2012 - 95 sites in 16 countries enrolled at least one patient.

    • Eligibility: 

      • Had non-severe, non-proteinuric preexisting hypertension or gestational hypertension

        • That’s right – they treated gHTN too! More on that later

        • Preexisting HTN defined as diagnosis pre-20 wks, gestational HTN defined as diagnosis after 20wks

      • A DBP of 90-105 if not receiving therapy, or 85-105 if already on treatment

        • BP were obtained at least 4 hours apart or at two consecutive outpatient visits, with the second measurement taken within 1 week prior to randomization.

        • Both BPs needed to be elevated to be included.

      • Live singleton fetus between 14w0d and 33w6d

    • Exclusion criteria

      • SBP of 160 or higher (but could be included later if they were treated and met all other eligibility criteria)

      • Proteinuria > 0.3mg/day on 24h, or a P:C >0.263, or a dipstic of 2+ or more

      • Used an ACE-I at or after 14 weeks

      • Had a contraindication to either trial group because of preexisting disease

        • Examples provided included pregestational diabetes or renal disease 

      • Multiple gestations, anomalies, or plans for TOP

      • Previous participation in the trial 

  • How was the study done?

    • Randomized in blocks of 2 or 4 patients using a telephone line and pager system

    • 1:1 ratio of less-tight control (defined as target DBP 100 or lower) versus tight control (target DBP 85 or lower)

      • Control of BP was expected to the target level until delivery, with a goal of between-group difference of DBP of 5mmHg (goal based on a pilot trial of the protocol).

    • Recommendation for labetalol as drug of first choice.

      • ACE-I, ARBs, renin inhibitors, and atenolol were not permitted prior to delivery.

      • No drugs were provided by the study – this was left to physician discretion. 

    • BP at subsequent prenatal visits were obtained 3x per visit. The average of the 2nd and 3rd DBPs obtained were considered to be the DBP for the visit and used for med targeting.

      • Participants also kept a diary to record this info as well as medications and co-interventions (i.e., ultrasound, clinic visit info)

    • Adherence to protocol based on a “clinically reasonable standard” was assessed within 4 weeks of randomization.

      • This isn’t totally elaborated on, but did follow to some degree blood pressure measurements in the patient’s diary and the interventions listed.

      • Thereafter, patients were seen on a schedule dictated by their doctor/midwife. 

    • A standardized questionnaire was then given to patients at 6 weeks postpartum to identify post discharge complications.

  • What outcomes were they looking for?

    • Primary outcome

      • Composite of pregnancy loss (miscarriage, ectopic, termination, stillbirth, or neonatal death) or high-level neonatal care (“greater than normal” newborn care) for more than48 hours until 28 days of life or discharge home, whichever was later.

    •  Secondary outcome

      • Maternal outcomes and complications up to six weeks postpartum, including:

        • Stroke, death, eclampsia, blindness, uncontrolled HTN, use of inotropic agents, pulmonary edema, respiratory failure, myocardial ischemia/infarction, hepatic dysfunction, hepatic hematoma or rupture, renal failure, and transfusion. 

    • Outcomes were adjudicated by a committee who were not aware of group assignments and not involved in patient’s care.

    • Additional outcomes analyzed included fetal growth and newborn complications, and incidence of severe hypertension (> 160/110) in the mother

  • Some statistics interestingness:

    • This trial had some interesting analyses that we don’t frequently see in RCTs:

      • There were multiple levels of comparisons planned, and for this reason, the alpha level for significance (i.e., p value to look for) was 0.046.

      • Similarly, for secondary outcome, p<0.01 was needed, and for the additional subsequent outcomes, p<0.001 was needed.

        • We would love to have you super statistics-minded brains email us about why these adjustments are made – it has to do with the number of comparisons made and the two interim analyses that were performed to assure safety during the trial.

Results

  • Who did they recruit? 

    • 1030 eligible women were recruited - 519 for less-tight, and 511 for tight control

      • Ultimately, one site needed to be excluded due to concerns about data integrity – so 497 patients were assigned to less-tight, and 490 to tight control.

      • Six patients were lost to follow up or withdrew so no data was available

      • 24 patients discontinued BP treatment prior to delivery, but their data was included as part of an intention-to-treat analysis

      • 10 patients (five in each group) had incomplete data after they were lost to follow up for the postpartum survey. 

      • 21 patients were found to have been ineligible after data analysis.

    • “Clinically reasonable adherence” to assigned treatment protocol was slightly worse in the less-tight group (76.6%) versus the tight group (82%).

    • Baseline characteristics were overall very similar:

      • Similar BMI, nulliparity, gestational age at randomization, gestational DM rate, smoking rate.

      • 25% in each group had gestational hypertension, whereas 75% had chronic HTN

        • 16% in the less-tight and 12% in the tight group had a severe-range BP at some point prior to enrollment (only statistical difference at p=0.049)

        • About 57% in each group were on antihypertensive meds at enrollment

    • Blood pressure was higher in the less-tight control group by average of 5.8 mmHg systolic, and 4.6 mmHg diastolic.

      • SBP: 138.8 vs 133.1 mmHg, p<0.001

      • DBP: 89.9 vs 85.3 mmHg, p<0.001

    • Antihypertensive meds were taken by fewer patients in the less-tight control group after randomization (73.4% vs 92.6%) and this continued after delivery (65.5% vs 78.3%). 

    • Labetalol was most commonly used agent (68.9% vs 68.8% between groups)

      • Four protocol violations for use of atenolol prior to delivery.

  • Outcomes

    • Primary: neonatal composite – no difference. 

      • No significant differences with respect to other perinatal outcomes for newborns, including SGA <10% or <3%, or rates of respiratory complications.

  • Secondary outcomes

  • Maternal outcomes – no difference overall but rare serious events.

    • No maternal deaths.

    • In less severe events:

      • Frequency of severe hypertension was higher in the less-tight control group than tight control group (40.6% vs 27.5%, p<0.01)

      • Higher rates of abnormal labs consistent with severe preeclampsia in less-tight group (more frequent rates of thrombocytopenia, liver enzyme elevations) – however, these did not meet prespecified limit for statistical significance (0.001 for these other outcomes)

Conclusions and What We Do Now

  • The authors conclude from this study that: 

    • Infant: “tight versus less tight control of maternal hypertension resulted in no significant difference in risk of adverse perinatal outcomes”

    • Maternal: “Less-tight control did not significantly increase risk of overall serious maternal complications.” 

      • While there was a more significant rate of severe hypertension and markers of severe preeclampsia, they didn’t meet the study’s threshold for significance (admittedly very challenging at p<0.001).

  • CHIPS is interesting in that it has dictated how we treat hypertension and allowed for “less-tight control” as the dominant paradigm in US practice:

    • In most places, treatment of hypertension prior to more significant values consistent with severe BP is not performed.

    • Gestational hypertension is not typically treated unless severe-range pressures result

      • And nowadays, that’s classified as severe preeclampsia!

  • It is interesting to think about this and the challenges with preeclampsia management – maybe we would prevent some severe preeclampsia with more aggressive treatment?

    • Those numbers are so small though, it’s hard to know.

    • But severe BP control in preeclampsia we know is very important to prevent stroke, seizures, and other complications…

  • CHIPS did provide some reassuring data in that tighter and less-tight control paradigms didn’t seem to adversely affect birth weight.

  • Given some of the limitations of CHIPS and some of these open questions, the CHAP trial was performed to better evaluate the strategy for treatment of specifically mild chronic hypertension in pregnancy. 

    • We’ll review this in a future podcast – but as a preview, it seems to favor more tight control! So perhaps a new strategy is already being employed at your institution or is incoming!

Exercise in Pregnancy

Additional reading for today in ACOG Committee Opinion 804!

What are the definitions of physical activity and exercise? 

  • Per ACOG: 

    • Physical activity: bodily movement produced by contractions of skeletal muscles in all stages of life

    • Exercise: physical activity consisting of planned, structured, and repetitive bodily movements done to improve one or more components of physical fitness 

    • Physical activity can maintain and improve cardiorespiratory fitness, reduce the risk of obesity and associated comorbidities, and results in greater longevity 

Is exercise safe in pregnancy?

  • Yes!

    •  Not just in pregnancy, but for all individuals, the US Department of Health and Human Services Physical Activity Guidelines for Americans says: 

      • At least 150 min of mod intensity aerobic activity per week

      • Recommended also in pregnancy and postpartum period 

      • Those that engaged in vigorous-intensity aerobic activity or who were physically active before pregnancy can continue those activities 

      • Few maternal conditions that would not allow aerobic exercise 

  • What are the downsides of not exercising?

    • Physical inactivity is the 4th leading risk factor for early mortality worldwide 

    • Physical inactivity and weight gain in pregnancy have been recognized as independent risk factors for maternal obesity and pregnancy related complications like GDM  

  • What are the benefits of exercising? 

    • Increased likelihood of vaginal delivery! 

    • Low incidence of: excessive weight gain, GDM, gestational hypertensive disorders, preterm birth, c-section, lower birth weight 

  • What exercises are safe? 

    • Aerobic: walking, stationary bike, aerobic exercises, dancing, stretching, water aerobics 

    • Anaerobic: resistance training (weights, elastic bands) 

    • Borg rating of perceived exertion: 6 - 20 (6 to 7 is very, very light, and 19-20 is very, very hard) 

      • Recommend moderate intensity, which is about a 13-14 (somewhat hard) 

        • About 20-30 min per day for most days of the week 

      • Also talk test: if you can talk while exerting yourself, likely not over exerting 

Note: ACOG issued a correction to this table; it should read “First Trimester, Less Than 12 Weeks Gestation.”

What are some modifications we should consider in pregnancy? 

  • Changes in pregnancy 

    • Weight gain, difference in weight distribution 

      • About 60% of pregnant patients will experience low back pain 

    • Increase in blood volume, heart rate, stroke volume, cardiac output = normal (recall our very first few episodes on physiologic changes in preg!)

      • Maintaining supine positioning after 20 weeks may lead to decrease venous return → can lead to SOB, dizziness, hypotension, etc 

    • Minute ventilation increases by 50% 

  • Other modifications: 

    • Remember to stay well hydrated, wear loose-fitting clothing, and avoid high heat and humidity (ie. hot yoga) 

    • Exercise by itself isn’t expected to increase body temp to point of concern 

  • Fetal response 

    • Studies show some minimal to mod increase in fetal heart rate by 10-30 bpm during maternal exercise 

    • Three meta-analyses show that there is minimal to no difference in birth weight 

    • However, women who continue to exercise vigorously in third trimester are more likely to deliver babies weighing 200-400g less than controls, though no increased risk of FGR 

When to stop exercising 

  • Don’t exercise if:

    • Have vaginal bleeding, abdominal pain, regular painful contractions, leaking fluid 

    • Dyspnea before exertion, dizziness, headache, chest pain

    • Muscle weakness affecting balance, calf pain or swelling  

Special considerations 

  • Obesity

    • Encourage patients to have healthy lifestyle modification in pregnancy that include physical activities and judicious diets 

    • Can start with low-intensity, short periods of exercise if not exercising already 

    • Then can build up gradually 

  • Athletes

    • Vigorous-intensity exercise even in 3rd trimester appears to be safe and healthy for most pregnancies 

    • Further research is needed for exercise intensity exceeding 90% of max heart rate  

Dermatoses of Pregnancy, feat. Dr. Laura Hanks

Here’s the RoshReview Question of the Week!

A 30-year-old G1 woman presents at 34 weeks gestation to the office with severe itching and a rash that suddenly developed across her abdomen starting around her umbilicus. The rash is mostly urticarial papules and plaques, but there are a few scattered bullae. Which of the following is required to confirm the suspected diagnosis?

Check your answer at the links above and get a special deal on RoshReview!


Today we welcome to the podcast Dr. Laura Hanks, who is an Assistant Professor in the Dept. of OB/GYN at the University of Wisconsin - Madison. She was previously in private practice in Olympia, WA, and did her residency training at the University of Rochester in New York.

Dermatoses are a pretty confusing topic — so if you have access to some textbooks through your medical school or residency libraries, Dr. Hanks bookmarked a few good chapters:

  • Gabbe’s Obstetrics. Normal and Problem Pregnancies. 8th edition. Chapter 56: Skin disease in pregnancy.  

  • Habif’s Clinical Dermatology. Chapter 6: Urticaria, Angioedema and Pruritus. 

  • Creasy and Resnik’s Maternal-Fetal Medicine. 8th edition. Chapter 69: The Skin and Pregnancy. 

What are dermatoses?

  • Dermatoses of pregnancy refers to a group of skin diseases encountered predominantly during pregnancy or immediately postpartum.

  • In general there is a lack of understanding of the pathogenesis of most of these conditions and therefore a lack of specific diagnostic criteria.

In the podcast, we use a case: 36y G1 at 22 weeks who develops severe pruritus of abdomen, spreading to thighs.

Differential Dx of Dermatoses

  • Pruritis of pregnancy (pruritis gravidarum)

    • Reported in 1.5-2% of pregnancies and occurs most frequently over the abdomen.

    • Usually just pruritus and no rash

    • Often presents in the 3rd trimester

    • Reversible form of hormonally triggered cholestasis

    • Runs in families and typically recurs in subsequent pregnancies

    • Severe pruritus with no primary skin lesions

    • Pruritus on palms and soles that later becomes more generalized

    • Itching correlates with elevated serum bile acid levels and sometimes aminotransferases

    • Bile acids can pass into fetal circulation and cause placental anoxia and cardiac depression which can preclude premature birth, stillbirth, neonatal respiratory distress syndrome, vitamin K deficiency and coagulopathy in the other and newborn.

  • Polymorphic eruption of pregnancy (PEP) or pruritic urticarial papules and plaques of pregnancy (PUPPPs)

    • Affects 1 in 130 to 1 in 300 (0.6%) in the US.

    • This often presents in the 3rd trimester or postpartum with resolution during the postpartum period more commonly in primigravidae pts

    • Abdominal distension causes damage to the connective tissue that in turn triggers an inflammatory response.

    • Associated with multiple gestation due to higher levels of progesterone, which has been shown to aggravate the inflammatory process at the tissue level.

    • Intensely pruritic urticarial rash with erythematous edematous papules and plaques that starts in the abdominal striae and spares the umbilicus. Can include urticarial and sometimes vesicular, purpuric, or targetoid lesions similar to PG or erythema multiforme. Lesions usually spare the palms and soles.

    • This is a clinical diagnosis with no lab findings and no indication for biopsies. If a biopsy is preformed it will often show a nonspecific perivascular lymphohistiocytic infiltrate +/- eosinophils

    • There are also no known risks to the fetus.

  • Impetigo herpetiformis or pustular psoriasis of pregnancy

    • Often associated with reduced calcium or Vitamin D

    • Eruption usually during 3rd trimester, most cases resolve postpartum

    • Characterized by numerous grouped, discrete, sterile pustules at the periphery of erythematous patches

    • Lesions typically originate on flexures and progress to trunk. Spares face, palms and soles.

    • Constitutional symptoms can be common including fever, malaise, diarrhea and vomiting with dehydration.

    • Lab findings include a luekocytosis, elevated erythrocyte sedimentation rate, hypocalcemia and decreased vitamin D levels

    • Risk of stillbirth and fetal abnormalities secondary to placental insufficiency

    • Maternal prognosis is very good with early diagnosis and aggressive treatment, however the increased risk of perinatal mortality may persist despite maternal treatment

    • Diagnosis is based on histopathology that shows typical features of pustular psoriasis. Direct and indirect skin immunofluorescence is negative

  • Pemphigoid gestationis

    • Unfortunately sometimes referred to has herpes gestationis, however it is not related to infection by herpesvirus. This synonym was used to refer to the grouped (herpetiform) nature of the blisters, which often are not herpetiform.

      • It is best to avoid the term herpes gestationis because of the risk for misleading patients and misinformed health care workers; not using the term avoids potentially inappropriate treatments for herpesvirus.

    • Rate in the US is 1 in 50,000 (0.002%)

    • Often presents in 2nd or 3rd trimester and sometimes postpartum (25%) with extremely pruritic, urticarial lesions that typically begin on the abdomen and trunk, that commonly involve the umbilicus. These urticarial plaques can then very quickly progress to widespread bullous lesions that may affect palms of hands and soles of feet. There is often a flare at the time of delivery with resolution during the postpartum period.

    • Lesions can be similar to PUPPs, however PUPPs lesions begin in abdominal striae and spares the umbilicus unlike PG.

    • Suggested pathogenesis is complement-fixing IgG antibodies and complement C3 react with amniotic epithelium of placental tissues and basement membrane of the skin causing an autoimmune response resulting in tissue damage and blister formation.

    • Definitive diagnosis is based on biopsies of the lesions that will show skin direct immunofluorescence shows linear deposition of IgG and C3 along basement membrane.

      • PG recognizes the same antigen as bullous pemphigoid and they do share certain features; however PG itself is confined only to pregnant women and women affected by gestational trophoblastic disease.

    • Skin histopathology shows a spongiotic epidermis and marked papillary derma edema and an eosinophilic infiltrate

    • There is an association between PG and Graves, therefore if you have a pt with PG that is an indication to check thyroid function tests

    • Given the increased risk of small for gestational age infants and preterm delivery, it is recommended to monitor growth US after diagnosis.

    • Unfortunately, there are risks to the fetus which include being born with lesions that are transient due to passive transfer of IgG1 antibodies, increased risk of SGA, preterm birth and IUFD.

  • Atopic eruption of pregnancy

    • This accounts for over 50% of pruritic dermatoses in pregnancy.

    • Most likely presents in the 1st and 2nd trimester with resolution in the postpartum period. This earlier onset may help distinguish from other dermatoses in pregnancy.

    • Features of patchy eczema and papular/prurigo lesions that are located on flexural surfaces, neck, chest, and trunk

    • Serum IgE is elevated

    • No known risk to the fetus

  • Prurigo of pregnancy

    • In the US this occurs in 1 in 300 to 1 in 450 pregnancies

    • Presents in the 2nd and 3rd trimester

    • Grouped excoriated or crusted papules over the extensor extremities and occasionally the abdomen

    • There are no laboratory findings. There may be elevated IgE levels on serologic tests. Previous reports of unfavorable fetal outcomes have not been confirmed.

  • Pruritic folliculitis of pregnancy or follicular papulopustular eruption

    • Rare, exact prevalence is unknown (~30 cases reported). Etiology remains unknown

    • Presents as pruritic follicular erythematous papules and pustules that primarily affect the trunk in the 2nd and 3rd trimester.

    • Biopsy is usually unhelpful, however histopathology is that of folliculitis. Special stains, skin immunofluorescence and serologies are negative.

    • There may be an association with decreased birthweight

  • And don’t forget derm conditions that are not unique to pregnancy!

    • Allergic contact dermatitis

    • Drug reaction

    • Atopic dermatitis or eczema

    • Erythema multiform

    • Scabies

    • Superficial fungal infections

    • Folliculitis

    • Urticaria

    • Vasculitis

    • Secondary syphilis

Habif’s Clinical Dermatology

In the case, we obtain an H&P —

  • She began itching on her upper thighs that then spread to her abdomen, chest, back and arms over several days.

  • She then experienced severe pruritus on the palms of her hands and soles of her feet. She described having to take her shoes off at work and soak them in ice baths and often sleeping with an ice pack between her hands to sooth the itching.

  • Benadryl did not seem to help neither did OTC steroid creams.

  • On exam there were numerous pink-salmon colored annula papules and plaques as well as urticaria with scale within umbilicus, flank, thighs and back. On bilateral medial aspects of feet there were pink-red vesicles with petechial border. 

What next? Dermatology referral and biopsies.

Biopsy results: Positive linear deposition of IgG and C3 antibodies along the basement membrane, suggestive of pemphigoid gestationis!

Treating Dermatoses

  • Generally, same treatment principles apply to all of the specific dermatoses of pregnancy.

    • Milder disease is treated with topical emollients, calamine lotion, cool compresses or baths, and topical corticosteroids.

      • Topical corticosteroids (e.g., hydrocortisone, triamcinolone) are classified as FDA pregnancy category C drugs in the old system, but they are still widely used during pregnancy when the possible benefits outweigh the risks for minimal percutaneous absorption.

  • Intrahepatic cholestasis of pregnancy

    • Ursodeoxycholic acid 15 mg/kg/day daily, BID or TID until delivery

  • PUPPs

    • Topical antipruritic medications, topical steroids and oral antihistamines.

    • In cases of severe pruritis, a short course of oral steroids can be used.

  • Impetigo herpetiformis

    • Systemic steroids are first-line with prednisone dose up to 60-80 mg/day

    • Calcium and vitamin D replacement as needed. Can lead to remission of eruption

  • Pemphigoid gestationis

    • The cornerstone for treatment of Pemphigoid gestationis is oral steroids. Therapy should be directed toward suppressing new lesions and relieving intense pruritus.

    • The majority of patients will respond rapidly to a relatively low-dose of prednisone (20 to 40 mg/day), however the dose may need to be uptitrated according to clinical response as high as 180 mg/day

      • Prednisone should be tapered slowly once new blister formation is suppressed

    • ~75% of patients will experience resolution or at least improvement in the late 3rd trimester, but b/c PG typically flares at delivery, steroid dose can be increased in anticipation of birth.

    • Patients at risk for prolonged or chronic PG are often older with higher parity, more widespread lesions and a history of PG in a prior pregnancy.

  • Atopic eruption of pregnancy

    • Topical steroids, antihistamines, UVB phototherapy

  • Prurigo of Pregnancy

    • Moderately potent topical steroids and oral antihistamines

    • Short course of oral steroids is rarely required

  • Pruritic folliculitis of pregnancy

    • Low-potency or midpotent topical steroids, benzolyl peroxide and UVB.

Ultimately, the patient in our podcast went on to deliver this pregnancy at 38w4d after a cesarean section for fetal indications, without any signs of neonatal blistering (can be seen in 5-10% of babies of mothers with PG!).

The patient ultimately went on to become pregnant a second time, and this time had lesions at 13 weeks. By 25 weeks, prednisone was no longer providing relief!

  • Treating refractory PG

    • A number of alternative treatments have been tested, including:

      • Intravenous immune globulin (IVIG)

      • Plasmapheresis

      • Rituximab

      • Cyclosporine A

      • Azathioprine

      • Dapsone and MTX can sometimes be used postpartum

    • With shared decision making the pt, her MFM and dermatologist elected to proceed with IVIG infusions which were 3 consecutive days every month until the end of pregnancy.

    • Her symptoms improved but never completely resolved during pregnancy and she continued the prednisone along with IVIG. She had a scheduled repeat c-section at 37w3d with stress-dose steroids given at delivery. She gave birth to a healthy male infant weighing 8lbs 1oz without any lesions.

PLOT TWIST!  The patient was Laura, and the MFM was Nick!

IVIG Infusions worked once we got them going! ;)