Preterm labor is one that occurs before 37 completed weeks of pregnancy. Delivering your baby before term puts him at risk which is greater the earlier he is born. It is important the know the risk factors and symptoms and signs for preterm labor so your OB provider can intervene and try to improve your baby's chances.
Symptom Checker for Preterm Labor
According to the American Congress of Obstetricians and Gynecologists (ACOG), preterm labor can lead to early dilation of the cervix and premature birth. Call your doctor or midwife if you have the following symptoms and signs that could suggest preterm labor:
- Tightening of your abdomen or contractions that suggest latent or active labor. Sometimes this feels like menstrual cramps, suggesting early labor. Regular contractions every 10 minutes or more often suggest active labor.
- Onset of a watery discharge that has a slightly fishy smell might suggest leaking amniotic fluid. An increased discharge can also be caused by a cervical or vaginal infection.
- A cloudy or bloody vaginal mucous might mean preterm labor or have another cause such as infection
- Increased pelvic pressure or a feeling that your baby is moving down the birth canal
- A low, dull backache that doesn't go away
- Nausea or vomiting with or without abdominal cramps or diarrhea
- Vaginal bleeding might be from preterm labor or have another cause
What Should I Do if I Think I'm Having Preterm Labor?
If you think you are in preterm labor, call your doctor or midwife or proceed to the hospital for an evaluation. You don't want to run the risk of delivering a premature baby unattended at home.
Until you can get to your doctor or hospital, stay hydrated and reduce your activities. Pay attention to all your signs and symptoms and the pattern of your abdominal or back pain or cramps so you can report them to your healthcare providers.
Risk Factors for Preterm Labor
According to the Mayo Clinic, if you have the following underlying factors, you at risk for preterm labor:
- Previous history of preterm labor
- Being underweight or overweight before pregnancy
- Maternal conditions such as preeclampsia and diabetes
- Twins or other multiple pregnancies
- Placenta previa, where the placenta sits near or covers the uterus placenta
- A baby that is larger-than-dates (macrosomia)
- Polyhydramnious - a larger than normal amount of amniotic fluid
- Uterine fibroids, which make the uterus larger than it should be for that stage of pregnancy
- Previous surgery on the uterus, such as fibroid surgery
- A fetus with congenital abnormalities
- Misuse of unhealthy substances, including tobacco, alcohol, and drugs such as cocaine
- Short interval between pregnancies
- Late enrollment in prenatal care
Note you can go into preterm labor even if you have none of these risk factors. Unknown genetic factors might also be involved.
Causes of Preterm Labor
After years of research, according to the March of Dimes, many of the causes of preterm birth are uncertain, but about half are due to preterm labor. In many cases, the cause of preterm labor is not apparent but in addition to the above risk factors, the following known conditions can trigger it. Identifying the cause(s) can help guide treatment.
Premature Rupture of Membranes
Whereas labor can trigger rupture of membranes, early rupture of membranes can trigger preterm labor. Preterm rupture of membranes can be caused by some of the same factors that lead to preterm labor, such as infection in the vagina, cervix, or uterus.
Infections and the Body's Immune Response
Maternal infection of any kind can trigger preterm labor. This might be through direct proximity of the infection to the uterus and fetal membranes or through the body's immune response to a systemic bacterial or viral infection.
Sites of infection that can directly trigger preterm labor include the urinary tract, uterus, cervix, vagina. Infection in the gums or a maternal systemic febrile illness can also cause early labor.
Placenta abruption - an abrupt a separation of the placenta from the uterus - can trigger preterm labor. The abruption is usually accompanied by vaginal bleeding and uterine contractions. A moderate or large separation or profuse bleeding can cause death of mother and baby.
Structural Defects of the Uterus or Cervix
Structural defects inside the uterus that can initiate preterm labor include intrauterine fibroids and congenital tissue that divides the uterus (intrauterine septum). A short cervix or an incompetent cervix that opens without contractions might result in preterm labor and delivery.
Deficiencies in nutrition leading to poor weight gain in pregnancy can lead to preterm labor. A bigger than normal weight gain from unhealthy eating during pregnancy can also cause women to go into labor preterm.
It is important to follow the guidelines for a healthy pregnancy diet and weight gain. An abnormal placenta or premature aging of the placenta might also cause nutritional deficiences in the baby and trigger preterm labor.
Dehydration might trigger preterm labor. It is important to drink enough fluids to keep up with the increased demands from the mother and fetus.
Chronic Psychosocial Stress
Chronic maternal psychosocial or physical stress at home, on the job, or from other sources might cause increase in stress hormones. This might cause an increase in fetal pituitary corticotropin-releasing hormone (CRH) and lead to the cascade of other hormones that trigger onset of uterine contractions and cause labor.
Preventing Early Labor
OB specialists do not have all the tools to intervene and prevent many of the causes of preterm labor. However, you can control some of the factors that are known to put you at greater risk.
- Eliminate unhealthy habits such as smoking, drinking, and illicit drugs and stay away from herbal medicine.
- Keep your gums and teeth clean to prevent gum disease from being a source of infection.
- Be aware of signs of urinary tract, cervical, and vaginal infections that can ascend into the uterus and trigger contractions. Get evaluated and treated immediately.
- See your doctor early if you develop a systemic illness, especially if you have a fever.
- Ask for help and support from your partner, family, and friends.
- Do your best to decrease or eliminate your sources of stress.
- If you are feeling over-worked or over-stressed, take the time to rest and relax and get enough sleep.
- Relaxation techniques, such as deep breathing and meditation, can help you decrease and manage your stress.
Early attention and management might help to prevent preterm birth and reduce the chance of your baby being born before 37 weeks.
Treating Preterm Labor
Once active labor has started, it will be difficult to stop. For this reason, it is important to call your doctor or midwife immediately if you think you might be in too early labor. In some situations your OB provider might be able stop your labor to buy more time for your baby to develop in your uterus. The decision to hold off labor depends on:
- How far along you are in your pregnancy
- The cause of your preterm labor
- Whether fetal membranes are ruptured
- The condition of you and your baby
Drug Treatment and Hospitalization
Drug treatments your doctor can give you include a medicine (a tocolytic) to stop your preterm contractions in the hospital. If early delivery is inevitable, you might also get a steroid medicine such as betamethasone and dexamethasone. This will mature your baby's lungs to reduce problems with breathing at birth. Hydration and treatment for infections might also be indicated.
You might have to stay in the hospital until delivery, which could be day to months away. Some women might find this prolonged hospitalization and restriction in activities difficult to handle.
Restricted Activity at Home
If labor stops and it is appropriate, your doctor might send you home with a medicine to take by mouth to stave off recurrent contractions. Most OB health care providers recommend women restrict their activities and be on extended bed rest. However, there is little evidence bed rest can effectively hold off preterm labor. Your doctor might also ask you to limit or avoid sexual activity.
Restricted activity or bed rest and the effect on job and other responsibilities might be difficult, depressing, and challenging for some women to deal with. Call on your support system and ask your medical system and social services for help and resources if you are in this situation, especially if you have other young children.
Birth Before 37 Weeks of Pregnancy
Birth before 37 weeks of pregnancy increases the risks for a baby depending on the number of weeks of gestation. According to the Centers for Disease Control and Prevention (CDC), babies born before 32 weeks are especially vulnerable. Fetal complications of premature birth include:
- Increased chance of needing admission to a Neonatal Intensive Care Unit (NICU)
- Low birth weight
- Respiratory distress syndrome
- Cerebral palsy, a nervous system disorder
- Bleeding in the brain (intraventricular hemorrhage) which is more common in babies born before 30-32 weeks
The earlier a baby is born the greater the risk for complications and death.
Follow Medical Advice
If you feel you are at risk for a preterm labor, be sure to discuss this with your doctor or midwife early in your pregnancy and at each prenatal visit. Control the risk factors you can control and follow your provider's advice on what to do if your labor starts too early.