What Causes Miscarriage in First 6 Weeks of Pregnancy 2024

Miscarriage in the First 6 Weeks: Miscarriage, also known as spontaneous abortion, is the loss of a pregnancy in the first 20 weeks. The first 6 weeks of pregnancy, in particular, is a crucial time when miscarriages frequently occur. Approximately 10-25% of clinically recognized pregnancies end in miscarriage, with the majority happening in the first trimester.

Understanding the potential causes behind early pregnancy loss can help women identify any risks and get proper care. While first-trimester miscarriages are typically due to chromosomal abnormalities, various other factors could contribute.

What causes a Miscarriage in the First 6 Weeks of Pregnancy

Miscarriages, especially in the first 6 weeks of pregnancy, often occur due to reasons outside of the mother’s control. Here are some of the main causes:

Chromosomal abnormalities

The most common cause of early miscarriage is chromosomal abnormalities in the fetus. About 50% of first-trimester miscarriages happen because the fetus did not develop typically.

Issues with the number of chromosomes, such as having missing or extra copies, almost always result in the pregnancy ending. These abnormalities occur by chance when the egg and sperm form the embryo.

As women get older, chromosomal abnormalities become increasingly common. Women over the age of 35 have a higher risk of miscarriage in the first trimester.

Hormonal problems

Hormonal issues and imbalances can interfere with a healthy pregnancy. Low levels of progesterone can lead to miscarriage. Progesterone helps prepare the uterine lining for implantation and supports the embryo.

High levels of testosterone or low levels of hCG may also cause early pregnancy loss. Polycystic ovarian syndrome involves hormone imbalances that make miscarriage more likely.

Uterine or cervix issues

Structural abnormalities in the uterus or weaknesses in the cervix can result in miscarriage. An abnormally shaped uterus, fibroids, or cervical insufficiency tends to be associated with pregnancy loss.

Scarring or adhesions in the fallopian tubes or uterus from past medical procedures, infections, or endometriosis may also play a role. A weak or short cervix may cause miscarriage in the second trimester.

Medical conditions

Various maternal medical conditions increase the risk of miscarriage, especially in the first trimester. These include:

  • Uncontrolled diabetes
  • Thyroid problems
  • Infections such as rubella, listeria, toxoplasmosis, and cytomegalovirus
  • Autoimmune disorders like lupus or antiphospholipid syndrome
  • Kidney disease
  • Celiac disease

Lifestyle factors

A woman’s behaviors and exposures can negatively impact a pregnancy. Smoking, drug use, high caffeine intake, and alcohol consumption tend to increase the chances of miscarriage.

Environmental toxins like pesticides, lead, and formaldehyde are also risk factors. Stress does not cause miscarriage directly but may contribute in some cases.

Maternal age

As a woman gets older, her odds of miscarriage rise steadily. Women under 30 have a 10-15% chance, while women over 45 have an over 50% chance. The increased frequency of chromosomal abnormalities plays a major role.

Egg quality also declines with age, making implantation and development less likely. Preexisting medical conditions which become more common as women age also contribute to higher miscarriage rates.

History of miscarriage

After one miscarriage, a woman has a 15-20% chance of another. After two consecutive miscarriages, the risk jumps to 25-30%. Several miscarriages in a row are defined as recurrent pregnancy loss.

Uterine or hormonal abnormalities often come to light after investigating repeated early pregnancy loss. A health issue may require treatment to have a successful pregnancy.

Miscarriage in Pregnancy: Causes, Symptoms, Risks, Treatment

Miscarriage in the first trimester can be a frustrating and disheartening experience for expectant mothers. Understanding the signs, causes, risk factors, and treatment options helps guide conversations with your doctor.

Signs and Symptoms

The most common symptom of a miscarriage is vaginal bleeding, ranging from light spotting to heavy bleeding with clots. Cramping in the abdomen, lower back pain, and disappearing pregnancy symptoms can also indicate miscarriage.

Miscarriage typically completes on its own within several hours or days. The expelled tissue and clots should be saved and brought to the doctor to test for any retained products of conception. Bacterial infection is a rare but serious complication.

Causes and Risk Factors

  • Genetic or developmental abnormalities in the fetus are the leading cause of early miscarriage. Chromosomal errors frequently lead to pregnancy loss.
  • Hormonal irregularities, uterine abnormalities, weak cervix, and chronic conditions like diabetes or thyroid disorders also increase miscarriage risk.
  • The most significant risk factors are increased maternal age and previous history of miscarriage. Smoking and drug/alcohol abuse also raise risk.
  • While stress and excessive physical work do not directly cause miscarriage, maintaining good health habits may help promote a healthy pregnancy. There are often no clear preventable causes.

Diagnosis and Treatment

Miscarriage is diagnosed through pelvic exams to assess bleeding, cramping, uterine size, and any tissue passing. Blood tests check hormone levels and ultrasound confirms the loss of the pregnancy.

Treatment depends on whether miscarriage is complete versus incomplete. Complete miscarriage involves the passage of all pregnancy tissue and the stopping of bleeding. Incomplete miscarriage requires additional interventions.

  • Expectant management involves waiting 1-2 weeks for a complete miscarriage. Medications like misoprostol can help expel tissue.
  • D&C surgery removes any remaining tissue not passed from the uterus. This avoids infection and bleeding complications.
  • Blood type testing, examinations of conception tissue, and other tests help identify any correctable causes of recurrent miscarriage.

Emotional Support and Next Steps

Experiencing miscarriage can be deeply saddening and traumatic even early in pregnancy. Seeking counseling or joining support groups helps process these emotions. Resting physically and delaying future pregnancy attempts for several menstrual cycles is also recommended. Maintaining a hopeful outlook and recognizing that the majority of women go on to have successful pregnancies after an early pregnancy loss is very important.

Also Read: Negative Health Effects of Portobello Mushrooms

What Causes Miscarriage to Happen?

Miscarriage, defined as pregnancy loss under 20 weeks, is a relatively common experience that affects up to 1 in 4 pregnancies. Understanding what causes miscarriage can bring some closure and guidance on preventing future loss.

Fetal Development Issues

Around half of early miscarriages are caused by fetal chromosomal abnormalities that interfere with proper development. As maternal age rises, abnormal chromosomes become more common. Issues like missing or extra genetic copies almost always lead to miscarriage.

Major developmental defects of fetal organs also often lead to first-trimester loss. Pregnancy hormones or random chance can contribute to these fatal flaws in fetal formation that prevent further development.

Uterine and Cervical Abnormalities

Congenital uterine abnormalities like a septate or bicornuate uterus double the risk of miscarriage. Scarring or weakened uterine tissue from prior surgery, infection, endometriosis, or fibroids may also play a role. A weak cervix that prematurely opens, called cervical insufficiency, is another anatomical risk factor.

Hormonal Imbalances

Too much or too little of key hormones like progesterone, hCG, estrogen, or testosterone disrupts pregnancy. Polycystic ovarian syndrome involves hormonal imbalances that can cause recurring early miscarriages. Certain endocrine disorders also lead to insufficient hormones.

Chronic Maternal Health Conditions

Diabetes, thyroid disorders, autoimmune issues, and kidney disease are examples of conditions that heighten miscarriage risk. Celiac disease, infections, and obesity also contribute. Such conditions can interfere with implantation, placental function, fetal development, and other pregnancy processes. Managing the conditions is important.

Lifestyle Factors

Exposure to environmental toxins, excessive caffeine, smoking, alcohol, illicit drugs, and certain medications raises the risk of miscarriage. While moderate exercise is beneficial, excessive physical exertion and work stress correlate with higher risk. Taking prudent measures improves outcomes.

Types of Miscarriage

Threatened miscarriage involves vaginal bleeding in early pregnancy. Around half of threatened miscarriages ultimately complete as a miscarriage while the other half progress. Inevitable and incomplete miscarriage involves delayed passing of conception tissue. Missed miscarriage occurs when a fetal loss occurs without symptoms. Recurrent loss requires specialized testing.

Understanding the types and causes of miscarriage helps determine any corrective treatment needed. While miscarriage risk declines after the first trimester, loss remains possible later in pregnancy. Working closely with your doctor and adopting healthy pregnancy practices helps foster a successful pregnancy.


The content provided in this article is intended for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. You should always consult your doctor with any questions or concerns you have regarding your health or pregnancy. This article is not meant to provide a definitive explanation for miscarriage or predict individual risk. Medical knowledge about miscarriage is still evolving and not all causes may be fully understood. Always follow your doctor’s personalized recommendations regarding pregnancy management, testing, lifestyle changes, and possible treatments.

FAQs About Miscarriage in the First 6 Weeks

  1. What percentage of pregnancies end in miscarriage in the first 6 weeks?
  • Around 10-25% of pregnancies confirmed by testing and medical care end in miscarriage overall. However, when you include very early pregnancy loss before the first missed period, the rate is estimated to be up to 50%. Most miscarriages occur within the first trimester.
  1. What is considered a missed miscarriage?
  • A missed miscarriage is when the fetus dies but is not physically expelled from the uterus for days or weeks. The mother may not experience bleeding or cramping. It is typically discovered during an ultrasound when no heartbeat is detectable. A D&C procedure is usually required in this situation.
  1. How is a miscarriage confirmed?
  • Miscarriage is confirmed via ultrasound to verify loss of pregnancy, pelvic exam to check any tissue passing, and blood tests to check falling hCG levels. These help differentiate between complete, incomplete, missed, threatened, or inevitable miscarriage.
  1. Does bleeding always mean miscarriage?
  • Light spotting or bleeding in the first trimester does not necessarily indicate miscarriage. Around half of women with early vaginal bleeding go on to have healthy pregnancies. Heavy bleeding with cramping is more likely to signal loss.
  1. Should you go to the ER for a miscarriage?
  • Going to the emergency room is advisable if you are experiencing very heavy bleeding, fever, fainting, or severe pain. Otherwise, contacting your doctor promptly about any suspected miscarriage symptoms is recommended for examination and monitoring.


Miscarriage, especially in the first weeks of pregnancy, is a frustratingly common occurrence. While the causes are not always preventable, being aware of potential risk factors empowers women to adopt prudent habits and work closely with their doctors on management strategies. Getting emotional support, testing to uncover any correctable contributors, and focusing on future positive outcomes are also very important. Early pregnancy loss, while deeply upsetting, does not necessarily preclude a healthy pregnancy or live birth down the road. Staying hopeful and informed aids the journey forward.

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