Miscarriage
The RCOG defines miscarriage as the spontaneous loss of a pregnancy before the fetus reaches 24 weeks of gestation.
It typically occurs within the first 12 weeks, and it is the most common pregnancy complication.
Miscarriages, also known as spontaneous abortions, can occur for various reasons and at different stages of pregnancy. There are several types of miscarriages, classified based on the symptoms and stages of the pregnancy
Causes for miscarriage
- Chromosomal Abnormalities
- Most common cause: The majority of early miscarriages (up to 60%) are thought to be due to chromosomal abnormalities in the fetus. These abnormalities usually occur randomly during the process of fertilization or early cell division.
- Examples:
- Trisomy (e.g., Down syndrome).
- Monosomy (e.g., Turner syndrome).
- Note: These are typically not inherited and are seen as a random error in the genetic material.
- Maternal Age
- Advanced maternal age increases the risk of miscarriage. The risk increases significantly for women over the age of 35.
- As women age, the quality of their eggs decreases, leading to an increased risk of chromosomal abnormalities.
- Hormonal Factors
- Progesterone deficiency: Low levels of progesterone, which is vital for maintaining pregnancy, can lead to miscarriage, especially in the first trimester.
- Polycystic ovary syndrome (PCOS): Women with PCOS may have hormonal imbalances that increase the risk of miscarriage.
- Thyroid disorders: Both hypothyroidism and hyperthyroidism can increase the risk of miscarriage.
- Structural Abnormalities of the Uterus
- Uterine anomalies such as fibroids, polyps, uterine septum, or adhesions (scarring) can affect implantation or lead to pregnancy loss.
- Congenital uterine abnormalities: These include conditions like a bicornuate uterus or septate uterus that can disrupt normal pregnancy development.
- Infections
- Certain infections during pregnancy can increase the risk of miscarriage. These include:
- Bacterial infections (e.g., listeria, mycoplasma).
- Viral infections (e.g., rubella, cytomegalovirus, herpes simplex virus).
- Sexually transmitted infections (e.g., chlamydia, gonorrhea).
- Urinary tract infections (UTIs), if untreated, can also contribute to miscarriage.
- Immunological Factors
- Autoimmune disorders: Conditions like systemic lupus erythematosus (SLE) or rheumatoid arthritis may increase the risk of miscarriage.
- Antiphospholipid syndrome: This is a condition where the immune system creates antibodies that increase the risk of clotting, leading to reduced blood flow to the placenta and miscarriage.
- Environmental Factors
- Toxins and chemicals: Exposure to environmental toxins, such as pesticides, heavy metals, radiation, or chemicals in the workplace, can increase the risk of miscarriage.
- Cigarette smoking: Smoking increases the risk of miscarriage and also can affect the placenta’s function.
- Alcohol consumption: Excessive alcohol consumption is a known risk factor for miscarriage.
- Drug use: Illicit drugs, such as cocaine or methamphetamine, can lead to miscarriage.
- Lifestyle Factors
- Obesity: Being significantly overweight increases the risk of miscarriage.
- Extreme exercise or stress: High levels of physical or emotional stress, particularly if it leads to hormonal imbalances, can also increase the risk of miscarriage.
- Poor diet: Nutritional deficiencies, including a lack of folic acid, can contribute to miscarriage risk.
- Medical Conditions
- Chronic health conditions: Diseases such as diabetes, hypertension, chronic kidney disease, and heart disease can increase the risk of miscarriage, especially if poorly controlled.
- Blood clotting disorders: Conditions such as Factor V Leiden mutation or antithrombin III deficiency increase the risk of clotting, leading to miscarriage.
- Trauma or Injury
- Physical trauma or injury to the abdomen during pregnancy can lead to miscarriage. However, trauma is a rare cause of miscarriage.
- Unknown Causes
- In many cases, the cause of a miscarriage cannot be identified, and it may be due to a combination of factors.
- RCOG notes that in up to 50% of early miscarriages, no specific cause can be identified.
- Recurrent Miscarriage
- For some women, multiple miscarriages (defined as three or more in a row) may occur. Common causes for recurrent miscarriage include:
- Genetic abnormalities (in either partner).
- Structural problems in the uterus.
- Hormonal imbalances (e.g., progesterone deficiency).
- Immunological factors (e.g., antiphospholipid syndrome).
- Inherited blood clotting disorders.
- Medications
- Certain medications, especially those used for conditions like epilepsy, can increase the risk of miscarriage. Some medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), can also affect pregnancy outcomes.
Types
- Threatened Miscarriage:
- Definition: This occurs when there are signs like bleeding and cramping, but the cervix is closed, and the pregnancy is still viable.
- Outcome: The pregnancy may continue or progress to a miscarriage, but it is not certain.
- Complete Miscarriage:
- Definition: This type occurs when the pregnancy tissue (fetus and placenta) is entirely expelled from the uterus. It usually happens in the early stages of pregnancy.
- Outcome: No additional medical intervention is usually needed after a complete miscarriage.
- Incomplete Miscarriage:
- Definition: Some pregnancy tissue remains in the uterus after the miscarriage has started. This can lead to ongoing bleeding and infection risks.
- Treatment: Often requires medical intervention, such as medication or a surgical procedure (e.g., dilation and curettage or D&C), to clear the remaining tissue.
- Missed Miscarriage:
- Definition: The embryo or fetus has died, but the body does not expel the tissue right away. The pregnancy might appear to be progressing for a while, but there are no signs of a heartbeat or growth.
- Outcome: Medical intervention (e.g., medication or surgery) is required to remove the tissue.
- Blighted Ovum (Anembryonic Pregnancy):
- Definition: This occurs when a fertilized egg implants in the uterus but doesn’t develop into an embryo. A sac forms, but there is no baby inside.
- Outcome: The body may eventually expel the sac, or medical intervention may be needed to clear the pregnancy.
- Habitual Miscarriage /Recurrent Pregnancy Loss:
- Definition: This refers to the occurrence of three or more consecutive miscarriages. It may be related to genetic, anatomical, or hormonal factors.
- Treatment: Often requires medical evaluation to determine underlying causes and may involve treatments such as hormone therapy or surgical procedures.
- Inevitable Miscarriage:
- Definition: This is characterized by symptoms such as heavy bleeding, cramping, and dilation of the cervix, indicating that a miscarriage is imminent and cannot be stopped.
- Outcome: The miscarriage typically occurs soon after these signs appear.
Management of Miscarriage and Investigation (according to RCOG)
The management of miscarriage varies based on the type, gestational age, and clinical presentation of the miscarriage.
Management Principles
- Expectant Management: For cases like incomplete or missed miscarriages, if the patient is stable and prefers non-interventional treatment, a period of waiting can be used to allow the body to expel the pregnancy naturally.
Patient should be reviewed in 7-14 day.
2. Medical Management: Involves the use of medication, usually misoprostol, to facilitate the expulsion of pregnancy tissue.
3. Surgical Management: For incomplete or missed miscarriages, if medical management fails or if there is significant blood loss or infection risk, surgical intervention (D&evacuation or suction curettage) is often required to remove remaining pregnancy tissue.
| Type of Miscarriage | Clinical Features | Investigation | Management |
| 1.Threatened Miscarriage | Vaginal bleeding, cramping, cervix closed | – Serum hCG (human chorionic gonadotropin) levels: to check for declining levels. – Ultrasound: to check fetal heart activity, gestational sac size. – Follow-up ultrasound after 7-14 days if no progression. | – Bed rest may be suggested (no definitive evidence of benefit)
Progesterone for the pts with previous miscarraige |
| 2.Complete Miscarriage | Passage of tissue, no ongoing bleeding, cervix closed | . Ultrasound: to confirm the uterine cavity is empty. – Check for any signs of infection or retained tissue | – Usually no further treatment needed after complete passage of tissue |
| 3.Incomplete Miscarriage | Bleeding, cramping, passage of some tissue, cervix open | – Surgical evacuation (e.g., D&C or suction curettage) or medical management with misoprostol. | Ultrasound: to identify retained tissue and confirm the miscarriage. – Blood tests (e.g., hCG levels) to monitor the progression. |
| 4.Missed Miscarriage | No symptoms of miscarriage, absence of fetal heartbeat, closed cervix | – – Ultrasound: to confirm the absence of fetal heart activity and a non-viable pregnancy. – Serum hCG: to assess pregnancy viability and tissue removal. | Medical management (e.g., misoprostol) or surgical evacuation (e.g., D&C) |
| 5.Blighted Ovum | Empty gestational sac, no fetal development | -Ultrasound: to detect the absence of an embryo/fetus within the sac. – Follow-up ultrasound in 1-2 weeks to assess progression | – Expectant management or surgical intervention (e.g., D&C). |
| 6.Inevitable Miscarriage | Heavy bleeding, cramping, cervix dilated | – Ultrasound: to confirm the pregnancy status. – Blood tests: to monitor hCG levels. | – medical/surgical evacuation |
| 7.Recurrent Miscarriage | Three or more consecutive miscarriages |
– Blood tests (e.g., thyroid function, autoimmune screening). – Ultrasound: to assess for uterine abnormalities (e.g., septum, fibroids). – Genetic testing (both partners). – Antiphospholipid antibody testing. |
-Management according to the problem |
some authors and guidelines consider septic abortion also as one of the type of miscarriages.
Investigations:
- Ultrasound is the primary investigation to confirm the diagnosis of miscarriage, determine if the fetus is still viable, and assess the presence of any retained tissue.
- Serum hCG levels are used to monitor the progression of the pregnancy or confirm if the pregnancy is non-viable.
- After complete miscarriage urine hCG should be checked in 3 weeks to rule out H.mole
- Blood tests
Including FBC , grouping
Further investigation like TSH, HBA1c, serum Prolactin, clotting profile,thrombophilia screening including APLS screening are used to assess for underlying causes in cases of recurrent miscarriage.
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