A miscarriage is the unexpected ending of a pregnancy before 20 weeks. A missed miscarriage, also called a silent miscarriage, occurs when the embryo or fetus stops developing, but the body does not naturally expel the tissue. Individuals often do not experience typical symptoms of pregnancy loss, such as bleeding or cramping.
Understanding Missed Miscarriage
A missed miscarriage occurs when a pregnancy is no longer viable, but the body does not recognize the loss or initiate the process of passing the pregnancy tissue. The embryo or fetus ceases to grow, often early in the first trimester, yet the gestational sac and placental tissue remain within the uterus. This absence of outward symptoms is a distinguishing feature, making it “missed” by the individual. People may continue to experience typical pregnancy symptoms like breast tenderness, fatigue, and nausea because hormone levels, particularly human chorionic gonadotropin (hCG), may remain elevated.
Some individuals might notice a subtle decrease in pregnancy symptoms or experience light brownish or reddish discharge, but these signs are not always present or specific to a missed miscarriage. Without the typical indicators of pregnancy loss, such as heavy bleeding or severe cramping, a missed miscarriage can remain undetected for weeks. Medical detection often occurs during routine examinations.
Prevalence and Contributing Factors
The overall likelihood of miscarriage in known pregnancies ranges from 10% to 20%, with most occurring within the first trimester. Estimates suggest missed miscarriages affect between 1% and 5% of all pregnancies. The detection of missed miscarriages may be increasing due to more advanced ultrasound technology.
The most common reason for a missed miscarriage is a genetic or chromosomal abnormality in the developing embryo or fetus. These issues, such as an extra or missing chromosome, are often random events and are not typically linked to anything the pregnant individual did or did not do. Approximately 50% to two-thirds of first-trimester miscarriages, including missed miscarriages, are attributed to these chromosomal irregularities.
Other contributing factors can include structural issues with the uterus or cervix, certain underlying health conditions like infections, blood-clotting disorders, or hormonal imbalances. While advanced maternal age can increase the risk of chromosomal abnormalities, in many instances, the precise reason for a missed miscarriage remains unknown. These occurrences are generally beyond an individual’s control.
Detection and Diagnosis
A missed miscarriage is frequently discovered during routine prenatal appointments, given the absence of typical symptoms. The primary method of detection involves an ultrasound scan. During an ultrasound, medical professionals look for specific indicators. These include the absence of a fetal heartbeat when expected for gestational age, an embryo that appears too small for the stage, or an empty gestational sac.
Specific measurements, such as crown-rump length (CRL) or gestational sac diameter, can indicate a non-viable pregnancy. In cases where there is some uncertainty, a follow-up ultrasound may be scheduled, typically a week or more later, to confirm the diagnosis. Blood tests measuring human chorionic gonadotropin (hCG) levels can also provide additional diagnostic information. While hCG levels normally rise in early pregnancy, slower increases or declining levels can indicate a non-viable pregnancy, though hCG levels alone are not sufficient for a definitive diagnosis.
Management and Support
Once a missed miscarriage is diagnosed, several medical management options are available to help the body pass the pregnancy tissue. One approach is expectant management, which involves waiting for the body to naturally expel the tissue. This can take several days to weeks, and while some women prefer this natural process, it may involve heavy bleeding and cramping.
Medical management uses medication, typically misoprostol, to induce the process. Misoprostol causes uterine contractions and helps the cervix relax, facilitating the expulsion of tissue.
Surgical management, such as a dilation and curettage (D&C) procedure, is a third option, where the tissue is surgically removed from the uterus. The choice of management often depends on individual preference, medical history, and the stage of pregnancy.
The emotional impact of a missed miscarriage can be substantial. Individuals may experience a range of emotions, including shock, sadness, anger, and grief, even if there were no physical symptoms beforehand. Emotional support from healthcare providers, loved ones, and professional counselors can be helpful during this time. Support groups also offer a space for individuals to connect with others who have experienced similar losses, fostering a sense of community and shared understanding.