planning baby

Causes of False Negative Pregnancy Test

  • 4.8 (11 Votes)
  • 262574 views

False negative tests may occur due to several reasons including test being done too early, pregnancy strip having low sensitivity, sample containing diluted urine, not enough hCG hormone in urine or hook effect.

You have missed your cycles but still no BFP (Big Fat Positive). Confused as you are not feeling like every day and it’s different this time. You might be ‘expecting’ and be pregnant. There must be little spotting, swollen and tender breasts, food craving, backache and other early pregnancy symptoms which signals pregnancy. You are totally perplexed, as these are pregnancy symptoms or period’s symptoms.But you took a pregnancy test and it says negative. Is there a possibility of getting a false negative on the pregnancy test you took?

The answer to such confusion or question is ‘Yes, It can be’. There are several reasons for getting a false negative on your pregnancy test. But first, understand what home pregnancy tests are?

Home Pregnancy Test

Home Pregnancy test or Human Chorionic Gonadotropin (hCG) pregnancy test is the way to determine pregnancy by detecting hCG hormone in woman’s urine. Doctors suggest waiting for a week more,after you miss your menstrual cycle, for taking a home pregnancy test. If you don’t want to wait to find out and you are sure about the day you have conceived, in that case, you can take a test within 14 days from the possible conception. These home tests are 97% accurate when all the instructions are followed properly plus read the result in the stipulated time frame. Some of the kits have two tests for taking another pregnancy test if you have made mistake in the first attempt.

What are the possible causes of getting a false negative pregnancy test?

There are several reasons for getting a false pregnancy test. And the most common cause of the false result is, missed reaction time. It is important for an individual to follow the directions mentioned on the kit, which clearly indicates the reaction time. The reaction time is the time required for the test to provide with the accurate result. Some of the pregnancy tests like EPT, Pregnancy Test takes about three minutes while other tests can take as long as four minutes to ten minutes.So, it is advised to go through the directions before starting the test, as it will help in preventing you from missing the reaction time. Taking the results before the reaction time or too late after the reaction time can result in false negative test result.

false negative pregnancy test

Below is a quick rundown of the reasons behind getting a false negative pregnancy test:

1- Testing it too early

There are high chances of getting big fat negative (BFN) if you take a home pregnancy test too early even if you are already pregnant. This is one of the major reasons for getting the negative results. The tests work by detecting the hCG presence in urine. After conception, the growing placenta secretes hCG once embryo implants into the uterus wall. It takes place after 7 to 10 days of ovulation. Though the hCG level increases rapidly initially as they double up in every 48-72 hours, but the levels of hCG in very low around 6-8 dpo. Hence, testing before missing periods can result in false negative on pregnancy test.

2- Test sensitivity too low

One should know thaturine pregnancy test strips vary with its sensitivity. Home pregnancy test strips come in different shapes and sizes such as; test strips, midstream tests and digital tests. Some of the HPTs are sensitive to hCGand are made to detect even a low amount of hCG hormone-like 20mlU/ml. While other tests have low sensitivity to hCG and detect the higher amount of hCGsay 50 to 100 mlU/ml.

Some women also get faint lines on pregnancy kits. Know the reasons for getting faint lines on pregnancy test.

3- Urine too diluted

If you consume too much water or urinate frequently before taking tests then there are high chances that you lower down the hCG amount in urine. Try to test by using first-morning urine if you have got a negative result on the pregnancy test. First morning urine is highly concentrated in hCG. It helps in finding out whether your earlier pregnancy test was actually false negative or not. Take a test again after a couple of days. Make sure to take a test in the morning by using a highly sensitive pregnancy test for the best result.

4- Overweight and low hCG level

Women who have high BMI have lower hCG hormone levels. It isalso one of the reasons behind the false test results for pregnancy.

Overweight and low hCG level

5- The Hook Effect

Higher concentration of HCG can result in false negative sometimes. This is called hook effect. Hook effect can be confirmed by the positive pregnancy test after diluting the urine sample. The HCG array works by forming a sandwich where 2 different antibodies namely solid phase antibody and labeled soluble antibody form a sandwich along with HCG molecule in between them. But higher concentration of HCG saturates the antibodies; hence no sandwich is being formed. You get a false negative result in the absence of signal thus, resulting in ‘hook effect phenomenon’.

The name has been suggested after observing the paradoxical decrease in curve plotting with increased antigen concentration appearing as a hook. Until and unless hCG concentration reachesupto 1,000,000 mlU/ml, you cannot observe the hook in the urine hCG test. It is also seen in the gestational trophoblastic disease. Plus, hook effect also results in false negative results in normal pregnancies. 

6- Improper Testing Technique:

Another common reason for false negative pregnancy test result is the improper or erratic testing technique. Most of the test sticks need to be saturated in urine for getting the accurate results. So, if you do not leave the test strip in the urine for a long duration as mentioned then there are chances of getting false negative or false positive pregnancy test results. Go through how to use pregnancy test kit to make the most out of the home pregnancy kits.

Improper Testing technique

7- Expired Pregnancy Kit:

Check the expiry date of the pregnancy test strip before purchasing. You cannot trust the results of the expired kit.

What to do when you get False Negative Results?

Depending upon the test result, you can consider the below steps:

  • When your home pregnancy test is sometimes positive or sometimes negative after taking several tests, the best thing one can do is to consult the doctor. As he or she can determine clearly whether you are expecting or not through the blood test. The doctor will test by examining the blood sample. Blood pregnancy tests help in detecting the much lower levels of hCG. Thus, helps in getting the better results and reduces the false negative chances.
  • When your home pregnancy test is negative and your menstrual cycle does not begin: It is advised to repeat the test. You can take another test in either few days or in one week. It is advised to take a test after missing your menstrual period.
  • You keep getting negative test results and your period doesn’t begin but you still think you are expecting: Consult a doctor. There are several reasons for missing the menstrual cycle (amenorrhea) such as thyroid disorders, low body weight, ovaries problems, excessive stress,and heavy exercise.

Hope, this article helped you in understanding about the possible reasons of getting a pregnancy test false negative. For more information you can also read about Causes of False Positive Pregnancy Test

Dr. Sheetal Pandey Tejwani

About The Author

Gynecologic Surgeon, Laparoscopic Surgeon Dr. Sheetal Pandey Tejwani
Mumbai

Dr. Sheetal Pandey Tejwani is an Infertility Specialist, Gynecologic Surgeon and Obstetrician, located in Mumbai and having an experience of almost a decade. Her alma mater is B J MEDICAL COLLEGE in Pune from where she completed her MBBS and MS in Obstetrics and Gynaecology in 2007 and 2009, respectively. In the following year, she pursued her DNB in Obstetrics and Gynecology. She received her Post Doctoral Fellowship in Reproductive Medicine from Krishna IVF Vizag and Nadkarni IVF Centre, Surat in 2013. She is the member of 3 different associations i.e. Indian Society of Assisted Reproduction (ISAR), Indian Medical Association (IMA), and Association of Medical Consultants. Her area of expertise includes Tubectomy/Tubal Ligation, Hysterectomy (Abdominal/Vaginal), Intrauterine Insemination (IUI), Caesarean Section and In-Vitro Fertilization (IVF). She is a consultant in Veda Fertility And Urology Care, Mira Road and is a visiting consultant in Wockhardt Hospital, Mira Road, Mumbai. You can get the contact details of Dr. Sheetal Pandey Tejwani at elawoman.com

11 Comments

user_img

Kanika Patel

I was looking for this information only because I have recently got negative test but I think I am pregnant may be it is because of hook effect. Fingers crossed!

Oct. 12, 2018, 8:12 p.m. 4.5

user_img

Ankita Sahni

If your inner instinct says that you are pregnant and your test result says it is negative then you should book an appointment with the doctor to clarify your doubts.

Oct. 2, 2018, 5:38 p.m. 4.5

user_img

Shakil Joshi

One should take pregnancy tests too soon. They should wait for atleast a week after missing periods to get precise results. otherwise, one may get false negative tests.

Sept. 10, 2018, 2:23 p.m. 4.0

user_img

Nice information

Nice information

Aug. 24, 2018, 12:37 p.m. 5.0

user_img

Very useful article

Very useful article

Aug. 24, 2018, 12:32 p.m. 5.0

user_img

Anuj Bukhani

I think using low sensitive tests can also result in false pregnancy test. Always use a reliable and branded pregnancy test kits to get accurate results.

Aug. 19, 2018, 9:56 a.m. 5.0

user_img

Shipra Jangra

I got many negative tests before getting a positive ones. Might be sometimes your HCG levels take time to shoot up.

Aug. 11, 2018, 10:33 a.m. 5.0

user_img

Christy Walker

Ok great! Will take every care to avoid a false negative pregnancy test!

June 4, 2018, 3:59 p.m. 5.0

user_img

Anandita Rahee

Knowledgeable article.

May 31, 2018, 8:18 p.m. 5.0

user_img

Anjali Prakash

Great article!

May 31, 2018, 8:11 p.m. 5.0

user_img

Subhash Janardan Patil

I thought using expired pregnancy kit is always safe.

May 22, 2018, 3:01 p.m. 4.5

View all comments

Leave a Comment

Rating

Disclaimer

The information displayed on this webpage covers general information on several medical conditions, fertility treatments, IVF ICSI, surrogacy procedure, home remedies, and their respective treatments. The exclusive purpose of the displayed information is for the sake of general understanding and it has been collected from open sources which heavily rely on research and laboratory tests. However, the information shared here should not be considered as a medical advice or an alternative to consultation with a registered medical practitioner or licensed healthcare professional.

It is not advised to self-diagnose or treat any medical condition or disease following the information given in this article. We insist you to consult a registered practitioner and never try to replace their advice or discontinue treatment in between by relying solely on the information obtained. External links to different websites as well as videos given on the website serve the purpose of sharing knowledge only. Ela being an Independent Medical Information platform is neither responsible nor guarantees the authenticity, reliability, and accuracy of these videos and websites in any way. We do not intend the information displayed here to be used for a medical emergency, if you seek medical attention for yourself (or any other person with whom you want to share the information with), we advise you to directly get in touch with the hospital or the doctor.

More From Author

Pregnancy
Zika Virus - An Alarming Threat to Pregnant Women in the 21st century

Zika Virus - An Alarming Threat to Pregnant Women in the 21st century

posted on 21 Apr 2018 4.8/ 5

Zika Virus is one of the threats for pregnant women in the recent times. Zika Virus symptoms need to be noted to take possible Zika Virus treatment to avoid cases of m...

Read More

Pregnancy
7 Week Pregnancy - Best Time for Pregnancy Announcement

7 Week Pregnancy - Best Time for Pregnancy Announcement

posted on 21 Apr 2018 4.8/ 5

Pregnancy announcement is one of the crucial steps for a couple towards a having a baby. 7 week pregnancy is the best time which couples can do pregnancy announcement....

Read More

Fertility Boosters
Know about Donate Sperm Requirements - Donate Sperm Process

Know about Donate Sperm Requirements - Donate Sperm Process

posted on 21 Apr 2018 4.8/ 5

Donor sperm requirements need to be fulfilled for successful donate sperm process. The physical factors which determine sperm donation procedure includes age of the co...

Read More

Related Article view all

Planning Baby
How to get pregnant fast - How often to have sex to get pregnant?

If you thinking that how to get pregnant fast, then you can implement these tips and these can answer your query on how to become pregnant. Make sure that you keep a track of ovulation and have sex during your fertile period. Both the partners need to stay away from stress to manage their fertility.

Read More

Planning Baby
How to find out the Most Fertile Days to Plan Pregnancy?

You can easily find out the most fertile days to plan pregnancy with ovulation tracker, calculating fertility days, checking Basal Body Temperature (BBT), observing vaginal discharge, and noting other physical signs. The fertile period of a woman usually starts after 10-12 days of the 28 day cycle.

Read More

Planning Baby
What are the top 6 risk factors of pregnancy after 30 and success rates?

Risk factors of pregnancy after 30 years of age includes miscarriage, premature birth, birth defects, increased chances of infertility, high blood pressure, gestational diabetes, multiple births. IVF success rates after 30 is below 40% and reduces with the increase in age of the woman.

Read More

Trending Articles

surrogacy
surrogacy

5 Best Surrogacy Doctors in India

posted on 21 Apr 2018 4.5 / 5(1 Votes)

Find the list of best surrogacy doctors in India who offers the best treatment with the highest success rate. The list has been categorized on the basis of doctors fame, experience, reviews, ratings, and cost. Dr. Mohit Saraogi from Saraogi Hospitals and IRIS IVF Centre and Dr. Kaberi Banerjee from Advanced Fertility Centre top the list of the best surrogacy doctors in India.

Read More

IVF
ivf

Best IVF Doctors in India with Highest Success Rates

posted on 21 Apr 2018 4.7 / 5(3 Votes)

Find here the list of best IVF doctors in India on the basis of Ratings, Success Rate, Services offered, IVF cost packages and available Facilities. Dr. Nisha Bhatnagar, Dr. Kaberi Banerjee and Dr. Anjali A Deval top the list of such IVF doctors in India due to their unique pricing system, popularity and high success rate.

Read More

surrogacy
surrogacy

Top Surrogacy Centres in India with Highest Success Rates

posted on 21 Apr 2018 4.8 / 5(2 Votes)

In this article we bring you the best Surrogacy Centres and clinics in India with Review Ratings, Cost Estimates, and Surrogacy Success Rate to help you make the best choice. Aveya IVF and Surrogacy Centre and Advanced Fertility and Surrogacy Centre tops the list of such surrogacy centres in India due to their low treatment costs, popularity and high success rates.

Read More