About Preterm Labor
Preterm labor, which is when a baby is born before 37 weeks of gestation, can have multiple causes and risk factors. Some of these factors are non-modifiable, meaning they cannot be changed, while others are modifiable, meaning they can be influenced or controlled. Let's explore both types of risk factors for preterm labor:
Non-modifiable risk factors for Preterm Labor:
- Urogenital tract infections: Infections in the urinary and reproductive systems can increase the risk of preterm labor.
- Multiple gestation: Carrying more than one baby, such as twins or triplets, increases the likelihood of preterm labor.
- Shortened cervix: A cervix that is shorter than normal may indicate a higher risk of preterm labor.
- History of cervical conization or preterm delivery: Previous procedures on the cervix or a history of preterm delivery can increase the risk.
- Maternal smoking: Smoking during pregnancy is associated with a higher risk of preterm labor.
Modifiable risk factors for Preterm Labor:
- Maternal viral infection: Viral infections during pregnancy can activate inflammatory pathways and increase the risk of preterm labor.
- Preeclampsia: This condition characterized by high blood pressure and organ damage during pregnancy is a modifiable risk factor for preterm labor.
- Premature rupture of membranes: When the amniotic sac breaks before 37 weeks, it can lead to preterm labor.
- Placental abruption: Separation of the placenta from the uterine wall can trigger preterm labor.
- Idiopathic cases: Some cases of preterm labor have no identifiable cause.
It's important to note that these risk factors do not guarantee that preterm labor will occur. They simply indicate an increased likelihood. If you have concerns about preterm labor, it's always best to consult with your healthcare provider for personalized advice and guidance.
Preterm labor is when a person goes into labor before 37 weeks of pregnancy. It can increase the chance of health problems in the baby, as they are not yet fully developed. Here are the most common early symptoms of preterm labor:
- Increase in vaginal discharge
- Pressure in the pelvic area
- Cramping
- Back pain that radiates to the abdomen
- Contractions
As preterm labor progresses or becomes more severe, other symptoms may occur. These can include:
- Diarrhea
- Frequent urination
- Lower back pain
- Tightness in the lower abdomen
- Vaginal pressure
In some cases, the symptoms of preterm labor are more obvious and may include:
- Painful contractions
- Leakage of fluid from the vagina
- Vaginal bleeding
It's important to note that these symptoms can vary from person to person, and some may experience more severe symptoms than others. If you experience any of these symptoms and are worried about being in preterm labor, it's important to call your doctor right away. Depending on your symptoms, your doctor may advise you to go to the hospital for further evaluation and treatment.
It's also worth mentioning that there are risk factors for preterm labor, such as a previous preterm birth, twin or multiple pregnancies, and certain infections. If you have any concerns about preterm labor or if you fall into any of these risk categories, it's important to discuss them with your healthcare provider during your prenatal visits. They can provide guidance and support to help ensure a healthy pregnancy.
To diagnose preterm labor, healthcare providers may perform several examinations, tests, and procedures. These include:
Foetal heart rate monitoring: This procedure involves monitoring the baby's heart rate to assess their well-being and detect any signs of distress.
Vaginal examination: During a vaginal examination, the healthcare provider checks the cervix for any changes that may indicate preterm labor, such as dilation or effacement (thinning).
Ultrasound examination: An ultrasound is used to assess various factors, including the cervical length and shape, fetal gestational age and weight, presence of anomalies, presentation (position of the baby), and amniotic fluid volume. It can also help determine if the cervix is funnel-shaped, which may indicate a higher risk of preterm labor.
Blood tests: Blood samples are taken to measure certain hormone levels that play a role in pregnancy. These include allopregnanolone, progesterone, and oxytocin levels. Abnormal levels of these hormones can sometimes be associated with preterm labor.
Additionally, there are additional examinations, tests, and procedures that can help determine the stage or severity of preterm labor. These include:
Saccadic eye velocity test (SEVT): This test measures the function of GABA A receptors in both groups of pregnant women (with or without threatened preterm labor). The GABA A receptor function is believed to be involved in regulating contractions during labor.
Cervical ultrasound: Instead of manual examinations, cervical ultrasounds are recommended as they provide accurate and objective measurements of the cervical length. This helps determine if the cervix is shortening or funnel-shaped, which are associated with an increased risk of preterm labor.
Fetal fibronectin test (fFN): The fFN test checks for the presence of fetal fibronectin in the vagina near the cervix. It is used for women experiencing symptoms of preterm labor. The amount of fetal fibronectin can help determine if a patient needs closer observation in the hospital or if they can be sent home.
It's important to note that while these examinations, tests, and procedures can provide valuable information about preterm labor, they may not always accurately predict the risk or severity of preterm birth. Further research is needed to develop more effective screening methods for low-risk women to improve outcomes for both mothers and babies.
The goals of treatment for preterm labor are to prolong pregnancy, improve maternal-fetal health, and minimize potential risks to the baby. Here are some recommended treatments and how they work towards these goals:
Medication Types:
- Corticosteroids: These medications, such as betamethasone or dexamethasone, are given to pregnant individuals who are at risk of preterm labor before 34 weeks. Corticosteroids help accelerate the development of the baby's lungs, reducing the severity of lung disease if delivery cannot be delayed.
- Magnesium sulfate: This medication is sometimes used to stop preterm labor and delay delivery. It helps relax the muscles of the uterus, reducing contractions and giving more time for other treatments to take effect.
Therapies and Therapeutic Procedures:
- Antibiotics: All pregnant individuals experiencing preterm labor who haven't been tested for group B streptococcus should receive antibiotics until delivery. Common antibiotics used include penicillin G or ampicillin, or alternatives for those allergic to penicillin. This helps prevent infections that can lead to complications during pregnancy.
- Bed rest: Although bed rest is a commonly recommended approach, its effectiveness in preventing preterm delivery is not supported by scientific studies. However, some doctors may still recommend it to reduce stress on the cervix and hope it prevents contractions.
Health Behavior Changes:
- Lifestyle modifications: Pregnant individuals at risk of preterm labor may be advised to make certain changes in their daily routine. These can include avoiding strenuous physical activity, staying hydrated, reducing stress levels, and getting enough rest.
It's important to note that each treatment option should be discussed with a healthcare provider who can assess individual circumstances and provide personalized recommendations.
The natural progression of preterm labor, or labor that occurs before 37 weeks of pregnancy, can vary from person to person. However, a study found that in both first-time mothers (nulliparous) and mothers who have given birth before (multiparous), the cervix takes more than 1 hour to dilate by 1 centimeter until it reaches at least 5 centimeters. After reaching 6 centimeters, labor tends to progress more rapidly [1].
Complications of preterm labor can occur, although they do not always happen. Some potential complications for the mother include:
- Heavy bleeding or hemorrhaging from the vagina or uterus
- Tearing or lacerations to the cervix or vaginal tissues
- Lacerations to the perineum, which is the area between the vaginal opening and the anus
- Shock after giving birth [2]
For the baby, if a mother goes into preterm labor in an unsterile environment instead of a hospital or birthing center, there is an increased risk of infection during delivery. The baby may also be more likely to breathe in some of the amniotic fluid in this situation [2].
Treatment for preterm labor aims to prevent or reduce complications and delay delivery. A combination of progesterone with cervical cerclage (a surgical stitch to reinforce the cervix) has shown the highest impact in reducing both early and late preterm birth. Other interventions such as progesterone alone or progesterone with a pessary (a device placed in the vagina to support the cervix) have also shown positive effects in reducing early preterm birth. However, it's important to note that for extremely preterm birth, these interventions may not have a significant influence on pregnancy outcomes and may even be associated with increased odds of preterm birth [3].
It's crucial to consult with your healthcare provider about any concerns you have regarding preterm labor. They can provide personalized advice and determine the best course of action for your specific situation.