Obstetric Cholestasis (Intrahepatic Cholestasis of Pregnancy)

The diagnosis is a blood result, not a symptom

Itching gets you tested. Numbers get you diagnosed. The RCOG says you will be offered liver function tests and a bile acid test, and makes an important point about how they behave: "Your bile acid levels can be abnormal even if your liver function tests are normal", and "some women may have itching for days or weeks before their blood tests become abnormal. If your itching persists and no other cause is found, your liver function tests and bile acids should be repeated."

Your skin is also examined to check whether something else - eczema, for instance - explains the itch, and the RCOG notes you may have more than one condition. If your symptoms are unusual, start very early in pregnancy, or do not settle after birth, you may be offered more blood tests, a liver scan and referral to a liver specialist to rule out another cause.

For context on how selective that testing is: the RCOG says itching affects "25 in 100 women (25%)" in pregnancy, while ICP affects "about 7 in 1000 women (less than 1%)" in the UK, rising to "up to 15 in 1000 women (1.5%)" among women of Indian-Asian or Pakistani-Asian origin.

The three bands, quoted exactly

Green-top Guideline No. 43 was rewritten in 2022 and the banding is the part that changed clinical practice most. The guideline states: "ICP is defined as: mild (peak bile acids 19-39 micromol/L), moderate (peak bile acids 40-99 micromol/L) and severe (peak bile acids 100 micromol/L or more)."

Note the word peak. It is your highest recorded bile acid level that places you, not your most recent one, which is why repeat testing matters and why a single reassuring result does not downgrade you.

What each band says about stillbirth risk

These are the RCOG's own words, and they are worth reading as written rather than summarised, because the differences between the bands are large:

• Mild (19 to 39 micromol/L): "If your bile acid levels are between 19 and 39 micromol/L (mild ICP) and you do not have any other risk factors, the chance of you having a stillbirth is no different to someone who doesn't have ICP."
• Moderate (40 to 99 micromol/L): "If your bile acid levels are between 40 and 99 micromol/L (moderate ICP), and you do not have any other risk factors, then the chance of you having a stillbirth is similar to someone who doesn't have ICP until you are 38-39 weeks' pregnant."
• Severe (100 micromol/L or more): "If your bile acid levels are 100 micromol/L or more (severe ICP), your chance of having a stillbirth is higher than someone who does not have ICP. Around 3 in 100 women with severe ICP have a stillbirth after 36 weeks of pregnancy."

The RCOG adds a qualifier that applies to all three: "If you have other factors (such as gestational diabetes and/or pre-eclampsia) or are having a multiple pregnancy (twins or triplets) you may have a higher chance of stillbirth and this may affect when your healthcare team recommend that you give birth." The key points section states the position bluntly: "Only women with severe ICP have an increased risk of stillbirth."

The monitoring you get - and the monitoring you do not

Once diagnosed, "you should be under the care of an obstetrician. Your blood tests will usually be repeated after one week and an individualised plan of care will be made for you." Some women's levels return to normal without treatment, and the team may then reconsider whether the diagnosis stands.

Here is the sentence that surprises most people, and it is worth quoting because it saves unnecessary appointments: "You do not need any additional scans of the baby because you have ICP." Extra growth scans are not part of ICP care by itself. What the RCOG does ask is that you "keep a close eye on your baby's movements and if you are worried, you should go to your local maternity unit for a checkup straight away".

Whether you are advised to give birth in a consultant-led unit with a neonatal unit depends on your bile acid levels.

Treatment: what it does and what it does not

The honest version, from the RCOG: "Treatments to improve your itching are of limited benefit." Emollients such as aqueous cream with or without menthol, antihistamines to help you sleep, cool baths and loose cotton clothing are the practical measures offered.

On ursodeoxycholic acid, the guideline is careful: it "may slightly reduce itching in a small number of women", and "may reduce your chance of giving birth prematurely but it does not prevent stillbirth". The wider statement is starker: "There is no treatment available that helps your baby or that will make your bile acid levels better." A daily dose of vitamin K is recommended for a small number of women, because ICP can rarely affect blood clotting, but "most women will not need this".

Timing of birth by band

For a single baby with no other complications, the RCOG sets out these options:

• 19 to 39 micromol/L: "Planned birth by the time of your due date (40 weeks) may be considered." With no other risk factors you may also choose to wait for labour, because your stillbirth risk is no different from someone without ICP.
• 40 to 99 micromol/L: "Planned birth at 38-39 weeks' gestation may be recommended."
• 100 micromol/L or more: "Planned birth at 35-36 weeks' gestation may be recommended."

Induction, planned caesarean and waiting for labour are all discussed as options. The RCOG is explicit that "you do not need to have a planned caesarean birth just because you have ICP". In labour, continuous CTG monitoring is advised if your bile acids are more than 100 micromol/L or you have other risk factors. ICP does not restrict your pain relief options.

Follow-up, recurrence and contraception

Symptoms improve after birth, but "it can take several weeks for your blood tests to return to normal". At your 6-week postnatal check your team should confirm the itching has gone and arrange blood tests to confirm liver function and bile acids have normalised. If they have not, you may be referred for further investigation.

There is "an increased chance that you will have ICP again in future pregnancies", so liver function and bile acids should be checked at the start of any future pregnancy. On contraception, the guidance is specific rather than restrictive: ICP "does not affect your choice of contraception once your liver blood tests and bile acids have returned to normal", but "if you take an estrogen containing contraceptive such as the combined pill and develop itching you should see your healthcare professional immediately for review". HRT remains possible in future.