Cryptic Pregnancy – Reasons, Signs & Prevention

Cryptic Pregnancy – Causes, Symptoms, and How to Detect It?

Medically Reviewed By
Dr. Sabiha Anjum (Gynecologist/Obstetrician)
View more Gynecologist/Obstetrician Our Panel of Experts

Did you know that there are cases where women haven’t known that they were pregnant until they started experiencing labour pain? While it may seem unbelievable, this condition is not as uncommon as you think. Women whose pregnancies are cryptic have very mild symptoms of pregnancy such as morning sickness, weight gain, and missed periods.

In this article, we delve into the world of cryptic pregnancy, exploring its potential causes, enigmatic symptoms, and the methods that can be employed to detect it. While rare, these cases shed light on the astonishing diversity of human experiences and challenge our understanding of the human body’s ability to hide such a significant event. Let’s learn about stealth pregnancy.

What Is Cryptic Pregnancy?

A pregnancy is termed ‘cryptic’ or ‘stealth’ when a woman remains unaware of her pregnancy. In most of the cases, these women were told that they couldn’t have children or denied pregnancy. In cryptic pregnancy, as the hCG levels are low, pregnancy goes undetected.

How Common It Is?

Cryptic pregnancies are not a common occurrence, with research indicating that approximately 1 in every 475 pregnancies remains undetected until around the 20-week mark of gestation. Furthermore, an even rarer occurrence is observed, where approximately 1 in every 2,500 pregnancies goes unnoticed until the moment of delivery.

Causes of Cryptic Pregnancy

Here are some reasons why cryptic pregnancy happens:

1. Polycystic Ovarian Syndrome (PCOS)

Small cysts on the ovaries can cause a hormonal imbalance in women. PCOS creates hormonal imbalances and irregular periods.

2. Recent Pregnancy

It’s possible for a woman to get pregnant after a pregnancy. In such a case, skipped periods might be mistaken for postpartum recovery. A woman may fail to realise that she’s pregnant again.

3. Perimenopause

Perimenopause is a condition wherein the female body exhibits symptoms of menopause, such as weight gain and hormonal fluctuations. When women fail to distinguish a pregnancy due to perimenopause symptoms, it becomes cryptic.

4. Low Body Fat

For athletes or women with low body fat, hormonal levels may fluctuate, resulting in missed periods. This also makes it harder to detect a pregnancy.

5. Birth Control Pills

Those who use birth control pills and IUDs are usually confident of pregnancy not being a possibility. However, these contraceptive methods don’t guarantee a 100% success rate and can result in pregnancy.

6. Stress


Nowadays, we face a lot of stress due to work or family problems. Stress is one of the major factors of fluctuating hormone levels, especially in women.

Common Symptoms of Cryptic Pregnancy

Cryptic pregnancy also shows symptoms, but women often fail to notice them.

  • Period-like bleeding that resembles a regular menstrual cycle
  • Nausea and vomiting that is mistaken for other conditions
  • Fetal movement in the uterus mistaken for gas or indigestion
  • Negative results of urine and blood tests due to fluctuating hormone levels, especially when done very early
  • Early labour contractions that feel like period cramping
  • No sign of pregnancy in early ultrasounds

How Long Does It Last?

The majority of individuals typically become aware of their pregnancy around the 20-week mark. Nevertheless, it is possible for someone to remain oblivious to their pregnancy throughout the entire 40-week duration. Instances have arisen where individuals experiencing pelvic discomfort seek medical attention in an emergency setting, only to realize that they are, in fact, in the midst of labour.

Does the Fetal Development Get Affected By a Cryptic Pregnancy?

Since most cryptic pregnancies last longer than regular pregnancies, it’s believed that the development of the foetus gets affected. However, this is untrue. The foetus often develops normally, albeit at a slower pace.

Lack of prenatal care like excessive smoking and drinking may inadvertently affect the foetus’ health.

Bleeding or Continued Periods During Cryptic Pregnancy

Bleeding or Continued Periods During Cryptic Pregnancy

In cryptic pregnancy, women get their period every month. However, the duration of bleeding is short. It occurs at irregular intervals or is random. The flow also ranges from spotting to heavy flow and can be pink, red, black, brown or even purple. This occurs because the uterus is removing the inner lining and is not indicative of a miscarriage.

Weight Loss/Gain in Cryptic Pregnancy

Skinny cryptic pregnancy or weight gain in cryptic pregnancy is gradual. Weight gain is slower as compared to a woman undergoing a normal pregnancy. Weight loss may occur due to the food aversion that happens in early pregnancy. Since a woman doesn’t know that she’s pregnant, she may not eat a healthy diet.

Can Cryptic Pregnancy Go Undetected in an Ultrasound?

Many times, cryptic pregnancy goes undetected even in an ultrasound. Some reasons for this are:

1. Retroversion of the Uterus

Retroversion of the uterus is a condition wherein the uterus tilts either sidewards or backwards. If the uterus is in this position, it’s hard for an ultrasound to detect a foetus during early pregnancy.

2. Bicornuate Uterus

A bicornuate uterus is a congenital condition wherein the uterus grows in a heart shape with two horn-like tissues that are divided partially or fully by a wall of tissue. This makes it harder for a woman to conceive as well as increases the chances of cryptic pregnancy.

3. Scar Tissue

Scar tissue doesn’t allow the ultrasound to get a clear picture of cryptic pregnancy belly, as it blocks the waves of the test. Abnormal scarring may happen due to stomach surgery or incomplete abortion in the past.

Why Do Urine and Blood Tests Show Negative Results?

In a normal pregnancy, the result is determined on the basis of the amount of hCG in the blood. hCG is a hormone produced by the placenta during pregnancy. However, in the case of cryptic pregnancy, the uterine lining is regularly removed from the body, not allowing hCG levels to build up. Hence, urine and blood tests cannot detect a pregnancy.

How Do Labour and Delivery Feel With a Cryptic Pregnancy?

Once the baby is fully developed and ready to enter the world, a woman undergoing a cryptic pregnancy feels severe cramps and her cervix dilates in order to push the baby out through the birth canal. Although labour signs in cryptic pregnancy are similar to that of a normal pregnancy, it can cause psychological distress as well.

What Are the Symptoms of Labour in a Cryptic Pregnancy?

Some labour symptoms associated with cryptic pregnancy are:

  • Nausea
  • Vomiting
  • Chills
  • Dizziness
  • Body ache
  • Mood swings
  • Pain in the hips and pelvic region
  • Swelling of the vaginal walls due to an increase in the blood flow
  • Sharp, shooting pain in the breasts
  • Pressure on the cervix

How Can a Woman Not Suspect Pregnancy If She Misses Her Period?

There are many reasons why women miss their periods and don’t suspect pregnancy. These range from stress to PCOS to menopause. Also, the spotting or light flow in cryptic pregnancy can be mistaken for menstrual periods.

How Is Negative Test Result Possible in Cryptic Pregnancy?

During a typical pregnancy, taking a pregnancy test prematurely or not adhering to the instructions can yield a negative result. However, in the context of a cryptic pregnancy, the negative result is attributed to the minimal presence of hCG (human chorionic gonadotropin). Ordinarily, the placenta releases hCG, which traverses the uterine lining, accumulates, and becomes detectable in both urine and blood tests. In cases of cryptic pregnancy, the uterine lining intermittently sheds, preventing the sufficient buildup of hCG required for detection in tests.

Furthermore, individuals who are not anticipating a pregnancy are unlikely to take a pregnancy test, which adds to the complexity of identifying a cryptic pregnancy. The lack of anticipation contributes to a scenario where the pregnancy remains undetected until more pronounced symptoms or unforeseen circumstances, such as medical emergencies, bring the condition to light.


Some complications of cryptic pregnancy include:

  • No access to prenatal care
  • Complications like hypertension and diabetes
  • Foetal harm due to excessive smoking and drinking

How Is It Treated?

The way cryptic pregnancy is managed depends on when the individual becomes aware of the pregnancy. If there is still a considerable period left until the expected delivery, a pregnancy care provider will strive to compensate for the missed prenatal care. This all-encompassing strategy could involve various elements, including:

  • Blood and urine tests
  • Ultrasound
  • Measuring fundal height
  • A physical exam
  • Nutritional and lifestyle counseling

How Can You Prevent a Cryptic Pregnancy?

If you’re married and sexually active, look out for the symptoms of a cryptic pregnancy. If you experience pain or changes in your abdomen or pelvic region, then consult a doctor. If you don’t get your period regularly, inform your gynaecologist about this condition and get yourself checked.


1. How Does a Baby Move in Cryptic Pregnancy?

Fetal movements within cryptic pregnancies mirror those experienced in regular pregnancies. However, there might be instances where the fetus displays fewer movements due to developmental delays. Often, women might misinterpret these fetal movements as commonplace occurrences like gas or muscle spasms.

2. Is There Any Emotional and Psychological Effects of Cryptic Pregnancy?

Cryptic pregnancy can significantly impact a woman’s emotional and psychological well-being, primarily because it often involves a complete denial of the pregnancy until childbirth. The absence of awareness can result in inadequate neonatal care, potentially contributing to the unfortunate loss of the pregnancy, which in turn intensifies feelings of stress and anxiety.

Cryptic pregnancies are hard to detect and affect women physically and psychologically. Knowing all about cryptic pregnancy and keeping your gynaecologist in the loop about your reproductive health is the key to prevent a cryptic pregnancy.


1. Cryptic Pregnancy;;

2. What is a Cryptic Pregnancy?;;

3. Can You Be Pregnant and Not Know It?;;

4. Polycystic Ovary Syndrome (PCOS);;

5. Retroversion of the uterus;;

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Placental Insufficiency – A Pregnancy Complication

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