A pregnancy loss can occur at 17 weeks, falling within the second trimester. This event is medically recognized as a late miscarriage or second-trimester loss. While the risk of loss decreases significantly after the first trimester, it remains a possibility at this stage. Understanding the terminology, causes, and warning signs provides necessary context.
Defining Second Trimester Loss
The second trimester is defined as the period from the 14th through the 24th week of pregnancy. A pregnancy loss occurring between the 13th and 20th week is classified as a late miscarriage or a mid-trimester loss. This is distinct from a stillbirth, which is the loss of a fetus after 20 weeks of gestation.
The likelihood of a loss in the second trimester is much lower, occurring in about 1% to 5% of pregnancies. The causes of second-trimester loss are often different from those in the first trimester, which are predominantly related to chromosomal abnormalities.
Specific Causes at 17 Weeks
Causes of second-trimester loss are typically related to maternal health, uterine structure, or infections, rather than purely genetic issues. The most common cause at this stage is cervical insufficiency, sometimes called an incompetent cervix. This condition involves the painless dilation and effacement of the cervix under the pressure of the growing fetus, leading to early delivery.
Infections are another significant factor that can compromise the pregnancy. Bacteria residing in the vagina can ascend into the uterus and amniotic fluid, causing inflammation and triggering premature labor or rupture of membranes. Infections such as bacterial vaginosis are associated with this increased risk. Specific infections like toxoplasmosis, cytomegalovirus (CMV), or parvovirus can also directly infect the fetus, leading to its demise.
Placental issues can also contribute to loss, such as structural problems or conditions that reduce its ability to nourish the fetus, resulting in fetal distress or death. Poorly managed maternal health conditions also increase risk, including severe high blood pressure, uncontrolled diabetes, or autoimmune disorders like lupus. Structural abnormalities in the baby, such as congenital heart defects or neural tube defects, can sometimes result in loss at this stage.
Recognizing Warning Signs
A second-trimester loss can occur without warning, but there are physical signs that require immediate medical attention. Significant vaginal bleeding, ranging from bright red blood to dark brown spotting, is a primary concern. Heavy, bright-red bleeding or the passing of clot-like material signals a serious problem.
Intense abdominal cramping or persistent lower back pain, often more severe than normal period cramps, can indicate the onset of contractions or labor. These true contractions may occur every 5 to 20 minutes and should not be dismissed. The sudden gush or continuous trickle of fluid from the vagina, known as premature rupture of membranes, is another urgent warning sign. This indicates the amniotic sac has broken, increasing the risk of infection and early delivery.
A feeling of sudden, unusual pelvic pressure or a noticeable, sustained change in fetal movement should also prompt contact with a healthcare provider. While many women do not feel regular movement until closer to 20 weeks, any concerning change warrants an evaluation. Recognizing these signs quickly allows for a prompt medical assessment, which may include an ultrasound to check the fetal heartbeat and a physical examination of the cervix.
Medical Care and Next Steps
Once a loss is confirmed at 17 weeks, medical management is necessary to safely empty the uterus. The two primary options are medical induction of labor or a surgical procedure called dilation and evacuation (D&E). Medical induction involves using medications, such as mifepristone followed by misoprostol, to cause the uterus to contract and expel the tissue.
This process often requires hospital admission, as it is similar to early labor. Alternatively, D&E is a surgical option performed under anesthesia to remove the tissue from the uterus. The choice between these methods depends on the patient’s medical history, the provider’s experience, and the patient’s preference.
Following physical recovery, which involves bleeding and cramping similar to a heavy period, follow-up testing is often recommended. A pathology review or genetic testing of the fetal tissue can determine the cause of the loss, which is important for planning future pregnancies. Rhesus D negative women will require a shot of anti-D immunoglobulin to prevent complications in subsequent pregnancies.