High Alkaline Phosphatase (ALP) in Pregnancy: Causes, Symptoms, Diagnosis and Treatment 

Introduction

Has it ever happened that during a routine prenatal check-up, you glanced through your blood test report and noticed that your alkaline phosphatase (ALP) level was higher than the normal range? 

We understand that seeing an abnormal test result during pregnancy can be worrying, but in many cases, a rise in ALP is a normal part of pregnancy. It normally happens as your body supports your baby’s growth and development. However, sometimes elevated ALP levels may be linked to an underlying condition that requires medical attention^1,2.

This article explains why ALP can rise during pregnancy, when a high result may need closer review, what symptoms to watch for, how doctors usually investigate it, and what management may involve. 

What Is ALP?

ALP is an enzyme that is found in several tissues of the body, especially the liver, bones, intestines, kidneys, and placenta. ALP is one of the blood markers doctors use to get clues about liver, bone, and pregnancy-related changes³. 

During pregnancy, the placenta makes its own form of ALP. As the placenta grows, more of this ALP enters the mother’s bloodstream. This rise is usually most noticeable in the second and third trimesters^4,5. Because ALP can also come from the liver and bones, doctors do not interpret the high level on its own. They look at your pregnancy stage, symptoms, and other blood test results before deciding whether more tests are needed². 

What Is the Normal ALP Range in Pregnancy?

ALP levels normally increase as pregnancy progresses. Therefore, ALP levels that would be considered high in non-pregnant adults may be completely normal during pregnancy^6,7. 

Note: Reference ranges differ between laboratories and may also differ by trimester. Your doctor will compare your result with your stage of pregnancy, your symptoms, and other tests included in the routine liver function test panel, such as bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), and sometimes bile acids. 

Causes of High ALP in Pregnancy

As a general rule, a mild or moderate rise in ALP late in pregnancy is often expected. A result that is rising very quickly, is much higher than expected for the trimester, or appears with symptoms such as itching, jaundice, severe headache, vision changes, abdominal pain, high blood pressure, or reduced baby movements should be discussed promptly with a doctor. 

The common causes of high ALP during pregnancy include: 

• Normal pregnancy: The most common cause is increased production of ALP by the placenta. Levels gradually rise during pregnancy and return to normal within a few weeks after delivery^4,5.

Other related causes may include: 

• Pregnancy-related complications: Very high or rapidly rising ALP has sometimes been reported in pregnancies with placental insufficiency (when the placenta cannot provide enough oxygen and nutrients to the baby), preeclampsia (a pregnancy complication characterised by high blood pressure and signs of organ damage), foetal growth restriction (FGR) (a condition in which the baby grows more slowly than expected in the womb), or preterm birth (delivery before 37 completed weeks of pregnancy)⁶. This does not mean ALP alone causes these problems, or that high ALP is a marker of FGR, preeclampsia, placental insufficiency, or preterm birth. 

Note: There is no specific ALP level that can reliably predict pregnancy complications or indicate that delivery is needed. 

• Liver conditions: Conditions such as intrahepatic cholestasis of pregnancy (ICP), hepatitis, bile duct blockage, or other liver problems can raise ALP. Doctors usually look for other clues as well, such as itching without a rash, jaundice, dark urine, pale stools, or abnormal liver function tests^2,8. 
• Bone-related causes: Because ALP is also made by bone cells, vitamin D deficiency, osteomalacia, Paget’s disease, a recent bone injury, or other conditions that increase bone turnover may raise ALP^2,8.
• Certain medications: Some medicines (like anticonvulsants) may increase ALP levels⁹.
• Less common causes: Rarely, kidney disease, certain intestinal disorders, or cancers involving the liver or bones can also raise ALP levels². These are uncommon during pregnancy and are usually investigated only if you have other symptoms or abnormal test results. 

Symptoms Associated with High ALP in Pregnancy

High ALP itself usually does not cause symptoms. If symptoms are present, they are more likely to come from the condition causing the ALP rise. Possible symptoms include²:

• Tiredness 
• Nausea or vomiting 
• Reduced or no appetite 
• Persistent itching 
• Yellowing of the skin or eyes (jaundice) 
• Dark-coloured urine or pale stools 
• Pain in the upper right side of the abdomen 
• Bone pain, joint pain, or tenderness 
• Muscle weakness or frequent fractures 
• Swelling of the ankles and legs 

How Is High ALP in Pregnancy Diagnosed?

High ALP during pregnancy is usually detected through an ALP blood test. This test measures the level of ALP in your blood and helps determine whether the increase is a normal pregnancy-related change or a sign of an underlying condition².

If the result is higher than expected, your doctor may order additional tests to understand where the ALP is coming from. These may include liver tests, bilirubin, GGT, bile acid testing if itching suggests ICP, vitamin D or calcium tests if a bone cause is suspected, blood pressure checks, urine testing for protein, and ultrasound or foetal monitoring when there are concerns about the baby’s growth or well-being. 

Treatment of High ALP in Pregnancy

An increase in ALP alone does not need treatment or extra monitoring of the baby. Many pregnant people do not need treatment because the rise is expected and related to the placenta. If tests suggest another cause, your doctor will treat that condition rather than the ALP level itself. Management may include: 

• Liver conditions: ICP, hepatitis, or bile duct problems may need medicines, repeat blood tests, and closer monitoring of both you and your baby. In ICP, doctors commonly check bile acid levels because these help guide care¹⁰.
• Bone disorders: If elevated ALP is due to vitamin D deficiency or another bone condition, management may include vitamin D and calcium supplements, dietary changes, or other therapies recommended by your doctor¹¹. 
• Preeclampsia or other pregnancy-related complications: These conditions require prompt medical management, which may include blood pressure control, close monitoring of the mother and the foetus, and, in some cases, early delivery if medically necessary¹². 
• Medication-related elevation: If a medication is suspected to cause high ALP levels, your doctor may review your treatment and recommend a safer alternative if appropriate⁹. However, you should never stop or change any medication without medical advice. 
• Regular follow-up: Repeat blood tests and foetal monitoring may be recommended to ensure that both the mother and the foetus remain healthy throughout the pregnancy. 

Important: Do not try to lower ALP on your own or stop any medicine without medical advice. The safest next step is to ask your doctor whether your ALP level fits your stage of pregnancy and whether any follow-up tests are needed. 

Tips for a Healthy Pregnancy

While high ALP in pregnancy is often a normal part of pregnancy, following a healthy lifestyle can support your overall well-being and your baby’s development. Here are some simple tips to help you have a healthy pregnancy¹³:

• Aim for healthy weight gain during pregnancy based on your pre-pregnancy weight. Your doctor can guide you on the recommended weight gain. 
• Eat a balanced, nutrient-rich diet that includes plenty of fruits, vegetables, whole grains, lean proteins, and low-fat dairy or other calcium-rich foods. 
• Choose foods rich in folate, iron, calcium, and protein, and take prenatal vitamins or supplements only as recommended by your doctor. 
• Drink ample water and stay well hydrated throughout the day. 
• Eat high-fibre foods, such as whole grains, fruits, vegetables, and beans, to help avoid constipation. 
• Stay physically active by aiming for at least 150 minutes of moderate-intensity physical activity each week, such as brisk walking, unless your doctor advises otherwise. 
• Avoid alcohol and foods that may increase the risk of foodborne illness, including raw or undercooked meat, poultry, seafood, fish high in mercury, and unpasteurised soft cheeses. 
• Get enough rest and manage stress by maintaining a regular sleep schedule and seeking support from family and friends when needed. 
• Attend all prenatal check-ups and follow your doctor’s advice throughout your pregnancy. 

When Should You Consult a Doctor?

You should contact your doctor promptly if a high ALP result comes with symptoms that may suggest a liver, bone, or pregnancy-related problem. Seek urgent care if you notice any of the following^2,14: 

• Persistent or severe itching 
• Yellowing of the skin or eyes (jaundice) 
• Dark-coloured urine or pale stools 
• Severe or persistent pain in the upper right side of your abdomen 
• Persistent nausea or vomiting that does not improve 
• Bone pain or frequent fractures 
• A severe headache that does not go away or gets worse 
• Blurred vision 
• Swelling of the face or hands 
• High blood pressure 
• Trouble breathing 
• Reduced or absent foetal movements 
• Vaginal bleeding or leaking of fluid 

Note: Even if you do not have any symptoms, attend all your scheduled prenatal appointments and discuss any abnormal blood test results with your doctor. 

Also Read: Complete Pregnancy Test List Trimester-By-Trimester for Indian Mothers 

Conclusion

If your ALP is high during pregnancy, especially in the later months, it is often a normal change caused by the growing placenta. A high ALP level alone does not mean that the placenta is not working properly, and it does not by itself indicate a pregnancy complication or the need for early delivery. However, ALP can also increase due to liver or bone problems, certain medicines, or other pregnancy-related conditions. Your doctor will consider your symptoms and other test results to understand what the raised ALP level means. 

Regular prenatal check-ups, timely blood tests, and immediate attention to any warning symptoms can help ensure the health of both you and your baby. If you have concerns about your ALP levels or your pregnancy, speak with your doctor for appropriate advice and care. 

Frequently Asked Questions(FAQs)

References

1. Ferro B, Marques I, Paixão J, Almeida M do C. Incidental Finding of Extreme Elevation of Serum Alkaline Phosphatase in Pregnancy. Cureus. 13(8):e17211. doi:10.7759/cureus.17211 https://pubmed.ncbi.nlm.nih.gov/34540438/

2. Alkaline Phosphatase: MedlinePlus Medical Test. Accessed August 5, 2026. https://medlineplus.gov/lab-tests/alkaline-phosphatase/ 

3. Sharma U, Pal D, Prasad R. Alkaline Phosphatase: An Overview. Indian J Clin Biochem. 2014;29(3):269-278. doi:10.1007/s12291-013-0408-y https://pubmed.ncbi.nlm.nih.gov/24966474/

4. Connolly CT, Grubman O, Al-Ibraheemi Z, Kushner T. A Case of Markedly Elevated Isolated Alkaline Phosphatase in the Third Trimester of Pregnancy. Case Rep Obstet Gynecol. 2022;2022:1611304. doi:10.1155/2022/1611304 https://europepmc.org/article/med/35531126

5. Ranganath L, Taylor W, John L, Alfirevic Z. Biochemical diagnosis of placental infarction/damage: acutely rising alkaline phosphatase. Ann Clin Biochem. 2008;45(3):335-338. doi:10.1258/acb.2007.007098 https://pubmed.ncbi.nlm.nih.gov/18482929/

6. Stanley Z, Vignes K, Marcum M. Extreme elevations of alkaline phosphatase in pregnancy: A case report. Case Rep Womens Health. 2020;27:e00214. doi:10.1016/j.crwh.2020.e00214 https://pubmed.ncbi.nlm.nih.gov/32461917/

7. Reference Ranges During Pregnancy. Pathology laboratories NHS. Accessed August 12, 2026. https://pathlabs.rlbuht.nhs.uk/chempregranges.htm 

8. Dajti E, Bruni A, Barbara G, Azzaroli F. Diagnostic Approach to Elevated Liver Function Tests during Pregnancy: A Pragmatic Narrative Review. J Pers Med. 2023;13(9):1388. doi:10.3390/jpm13091388 https://pubmed.ncbi.nlm.nih.gov/37763154/

9. Minz P, Oroan A, Kujur A, Paswan DK, Nag AR. Effects of anticonvulsant drug on liver enzymes among children in a tribal state of India: A longitudinal study. J Family Med Prim Care. 2023;12(7):1394-1398. doi:10.4103/jfmpc.jfmpc_2307_22 https://pubmed.ncbi.nlm.nih.gov/37649745/

10. Crites K, Shanks AL, Maines J. Pregnancy Intrahepatic Cholestasis. In: StatPearls. StatPearls Publishing; 2026. Accessed August 5, 2026. http://www.ncbi.nlm.nih.gov/books/NBK551503/ 

11. Rajab HA. The Effect of Vitamin D Level on Parathyroid Hormone and Alkaline Phosphatase. Diagnostics. 2022;12(11):2828. doi:10.3390/diagnostics12112828 https://pubmed.ncbi.nlm.nih.gov/36428888/ 

12. Cluver C, Novikova N, Koopmans CM, West HM. Planned early delivery versus expectant management for hypertensive disorders from 34 weeks gestation to term. Cochrane Database Syst Rev. 2017;1(1). doi:10.1002/14651858.CD009273.pub2 https://pubmed.ncbi.nlm.nih.gov/28106904/

13. Health Tips for Pregnant Women – NIDDK. National Institute of Diabetes and Digestive and Kidney Diseases. Accessed August 5, 2026. https://www.niddk.nih.gov/health-information/weight-management/healthy-eating-physical-activity-for-life/health-tips-for-pregnant-women 

14. Urgent Maternal Warning Signs and Symptoms. CDC. February 18, 2026. Accessed August 5, 2026. https://www.cdc.gov/hearher/maternal-warning-signs/index.html 

Disclaimer: The information provided here is for educational/awareness purposes only and is not intended to be a substitute for medical treatment by a healthcare professional and should not be relied upon to diagnose or treat any medical condition. The reader should consult a registered medical practitioner to determine the appropriateness of the information and before consuming any medication. PharmEasy does not provide any guarantee or warranty (express or implied) regarding the accuracy, adequacy, completeness, legality, reliability or usefulness of the information; and disclaims any liability arising thereof. 

Links and product recommendations in the information provided here are advertisements of third-party products available on the website. PharmEasy does not make any representation on the accuracy or suitability of such products/services. Advertisements do not influence the editorial decisions or content. The information in this blog is subject to change without notice. The authors and administrators reserve the right to modify, add, or remove content without notification. It is your responsibility to review this disclaimer regularly for any changes.