What is preterm labor?
Preterm labor occurs when the contractions begin before the 37th week of pregnancy. Along with contractions, changes in the cervix occur which signal labor is beginning. The cervix begins to thin, a process called effacement, and it starts to dilate so that the baby can enter the birth canal. Normal pregnancies last around 40 weeks, so any labor that starts before then is called early labor or preterm labor.
The Centers for Disease Control and Prevention (CDC) reported that preterm birth occurred in about one out of every 10 deliveries in the United States in 2014. The rate peaked in 2006 when the rate was nearly 13%, more than one-third higher than the rate had been in the early 1980s. In most cases, no specific cause is known for early labor. Some risk factors have been identified that make a woman more likely to go into labor early. Besides the premature rupture of the amniotic sac, some of these major risk factors identified by the Mayo Clinic include the following:
Maternal factors for preterm labor:
- Preeclampsia, or high blood pressure during pregnancy
- Chronic medical problems, including diabetes and kidney disease
- Infections, especially strep, urinary tract infections, vaginal infections, and infections of the fetal or placental tissues
- Abnormal structure of the uterus
- Cervical incompetence, or a weak cervix that cannot stay closed as the baby grows larger
- Previous preterm births
Premature labor risk factors involving the pregnancy:
- Abnormal placenta or decreasing placental function
- Placenta previa, in which the placenta lies unusually low in the uterus, sometimes covering the opening to the cervix
- Placental abruption, in which the cervix detaches from the uterus too early in pregnancy
- Premature rupture of the amniotic sac membranes
- Hydramnios, or too much amniotic fluid
Preterm labor risk factors involving the fetus:
- Indications of an unhealthy environment in the uterus, usually detected by fetal behavior
- Pregnant with twins, triplets, or more.
- Erythroblastosis fetalis, or Rh/blood group incompatibility
What are the signs and symptoms of preterm labor?
The warning signs of preterm labor are very similar to labor occurring at term. Every woman experiences them differently. They may be obvious or subtle at first. If you are worried you may be in labor, contact your doctor immediately. Don’t worry about a possible false alarm. Everyone on your birth team will be happy to reassure you if this is the case. If it is early labor, the sooner you and your doctor treat it, the better chance there is for a good outcome for you and your baby.
Warning signs and symptoms of premature labor include:
- Five or more contractions in an hour. These may feel like menstrual cramps, or they may be relatively painless.
- Watery fluid leaking from your vagina, or a gush or trickle of fluid – this may indicate your water has broken
- Dull, low backache felt below the waistline. It may be constant, or it may come and go.
- Intestinal upset, nausea, or diarrhea
- Pelvic or lower abdominal pressure that may feel like your baby is pushing down. The pressure may also feel like you need to have a bowel movement.
- Vaginal spotting or bleeding
- Increase or change in vaginal discharge – it may be watery, bloody, or include mucous
Because preterm labor symptoms can also resemble other medical problems, the best person to make a diagnosis is your doctor. Remember, pregnant women normally have some mild Braxton-Hicks contractions later in pregnancy. However, they do not normally have frequent, regular contractions unless they are in labor!
What are the risk factors for preterm labor?
Having a risk factor, or even several risk factors do not mean you will go into early labor. Women with no risk factors may also experience premature labor for no known cause. However, if you have any of the risk factors below, discuss them with your doctor and know what to do if preterm labor occurs.
- You have a history of bladder or urinary tract infections
- You have a sexually transmitted disease or vaginal infection
- Red blood cell deficiency (anemia), particularly during early pregnancy
- You had an infection with a fever over 101 degrees F during your pregnancy
- You have unexplained vaginal bleeding any time after your 20th week of pregnancy
- You have had multiple abortions in your first trimester, or one or more second trimester abortions
- You were underweight or overweight before you became pregnant
- You have a blood clotting disorder, such as thrombophilia
- You became pregnant through in vitro fertilization (IVF)
- You got pregnant within six months of delivering your prior child
- You have received little or no prenatal care
- You have continued to smoke, drink alcohol, or use illegal drugs while pregnant
- You are in a situation involving domestic violence, physical, sexual, or emotional abuse
- You are in a situation with little social support
- You are undergoing high levels of stress
- You are a person with an income that is uncertain or too low to meet your needs
- Your job involves standing for long periods of time
If you know you are at risk for preterm labor, meet with your obstetrician before getting pregnant so you can start a pregnancy in the best health possible. Once you are pregnant, good prenatal care is essential. Your doctor will discuss managing your pregnancy to prevent preterm labor, based on your situation and risk factors.
In addition to the risk factors above, the CDC has determined some particular risks based on age and ethnicity. For instance, preterm labor and births are 50% more likely among women of African American descent than among Caucasian women. Women under the age of 18 are also more likely to have a preterm delivery, as are women over the age of 35.
If I am at risk for preterm labor, are there things I can do to prevent it?
Even if you are at higher risk for preterm labor, you can do a lot to have a healthy, full-term pregnancy. Get good prenatal care from your obstetrician. Your doctor will monitor your health and that of your baby. Make sure to discuss any symptoms that worry you, even if you think they seem unimportant.
- Eat a well-balanced diet, including extra calcium, iron, and folic acid. Take a prenatal vitamin every day – starting a few months before you get pregnant if possible.
- Stay away from tobacco, alcohol and illegal drugs throughout your pregnancy.
- Check with your doctor regarding any medication you take, including over the counter medicine and herbal supplements.
- Research from the Mayo Clinic suggests a link between preterm labor and pregnancies that occur closer than six months apart. Consider discussing pregnancy spacing with your doctor.
- Research also shows a link between preterm labor and in vitro fertilization (IVF), because IVF often results in multiple pregnancies – a risk factor for preterm labor. This is another topic to discuss with your obstetrician.
- Your doctor might recommend medication to reduce the risk of early labor, including weekly injections or vaginal suppositories of progesterone during your second trimester.
- Your doctor may suggest you limit heavy lifting, strenuous physical activities, or spending too much time on your feet if you are at risk for early labor or show signs of preterm labor.
- Because chronic health conditions like diabetes and high blood pressure increase your risk of early labor, it is important that you work closely with your doctor to manage these during your pregnancy.
Thanks to advances in health care for premature babies, more infants born before 40 weeks survive and do very well. Still, preventing early labor and birth is the best way to ensure a healthy baby.
How do I tell the difference between a real contraction and a Braxton-Hicks contraction?
You may have experienced painless Braxton Hicks contractions throughout your third trimester of pregnancy. These are usually irregular, and they do not cause your cervix to open. As you get closer to your due date, these “practice contractions” may become more frequent, and it is common for women to be concerned they may be in labor. For women in their first pregnancy, it can be difficult to tell a “real” contraction from a Braxton Hicks contraction later in pregnancy.
If you think you are having contractions that are not Braxton Hicks contractions, drink fluids, avoid strenuous activity and rest. This often stops false contractions. If you are truly in pre-term labor, the contractions will continue.
To check for contractions, check your abdomen while you are lying down. Use the tips of your fingers on several places across your belly. During a true contraction, your abdomen will harden all over as the muscles of your uterus contract. As the contraction eases, the uterus becomes soft again, and your belly relaxes. Time the contractions, beginning at the start of one contraction to the start of the next.
Time them for at least one hour, unless you experience another symptom such as your water breaking. If you have more than four or five genuine contractions in the space of an hour, or another symptom listed above, contact your doctor or go to the hospital immediately. You may truly be experiencing early labor, and it is important to act right away.
What do I do if I think I am going into preterm labor?
Anytime you think you may be having signs of premature labor, contact your doctor right away. By becoming aware of the symptoms of preterm labor, you are giving yourself and your baby the best chance possible for good health. Take these steps if you feel like you might be experiencing a symptom of early labor:
- Empty your bladder, but do not strain or bear down to try and have a bowel movement.
- Lie down on your left side. Often this slows or stops symptoms of early labor.
- Do not lie flat on your back, as this can increase contractions.
- Drink several glasses of water. Dehydration can sometimes cause contractions.
- Time your contractions for one hour, from the start of one contraction to the onset of the next.
If the symptoms continue or they get worse, such as contractions becoming more frequent or painful, call your doctor again or go to the hospital. The only way to determine if you are really in pre-term labor is for the doctor to examine your cervix. If it is beginning to open, early labor may be to blame.
Your doctor will talk to you about their findings and the options available, once they have examined you. They will want to know the information you have, such as the timing of the contractions, when they started, and any other signs or symptoms you have experienced.
Will preterm labor always lead to early delivery of my baby?
Preterm labor does not always mean you will have a premature delivery of your baby. In fact, according to the CDC, up to 50% of women who experience preterm labor go on to have their babies at 37 weeks or later. Sometimes, early labor stops on its own, while in other circumstances the doctor must intervene to stop labor. For instance, bed rest is sometimes prescribed for women who start labor and are found to have some dilation of their cervix. The goal is to stop the labor and keep the baby in the womb as long as possible.
The American Congress of Obstetricians and Gynecologists reports only about 10% of women in preterm labor give birth within seven days. In about 30% of preterm labor cases, the labor stops on its own. The doctor will determine if treatment, such as medication to try and delay delivery or speed the development of the baby will help, depending on your circumstances.
What treatments are there for preterm labor?
The doctor will do several tests to decide if you need to stay at the hospital or receive other care if you are experiencing preterm labor. They will examine your cervix to determine if you have begun to dilate. Often, they will examine you several times over a period of time. You may have a transvaginal ultrasound to measure the length of your cervix, as well.
The doctor may take a swab of the fluid in your vaginal canal to determine if a protein called fetal fibronectin is present. This protein, if present, indicates preterm birth may be more likely. This protein acts like glue to keep the amniotic sac connected to the inside of the uterus.
The doctor will probably monitor your contractions with a uterine monitor, a belt that goes around your belly and hooks to a machine that tracks contractions. They may also recommend a procedure called maturity amniocentesis. This test removes some of the amniotic fluid from the uterus to determine the maturity of your baby’s lungs, as well as whether there is an infection in the amniotic fluid.
Some women have a short cervix or a weak cervix, a condition called cervical incompetence. This can lead to preterm labor. In these cases, the doctor may recommend a procedure called cervical cerclage if you are less than 24 weeks pregnant, you have a history of preterm labor or a short cervix, or there is an indication that your cervix has begun to dilate. In this procedure, the doctor uses strong stitches to hold the cervix closed until you are at about 36 weeks in your pregnancy.
If you have not reached your 34th week of pregnancy, the doctor might recommend you stay at the hospital and confine you to bed rest to monitor your condition. Your doctor may also recommend more frequent prenatal visits if you are allowed to return home.
Depending on what the doctor finds, you might receive one or more medications. These may be to stop or slow contractions, speed up the baby’s development, or to help you feel better. Common medications given to women in preterm labor include:
- Magnesium sulfate: This is given through an IV line, sometimes in a large dose at first and then in a smaller, continuous dose over 24 hours or more. You will probably receive magnesium sulfate if you are less than 32 weeks pregnant and at risk for early delivery within the next 24 hours. This medication also helps reduce the risk of complications such as cerebral palsy in babies born early.
- Corticosteroids: These drugs cross the maternal-placental blood barrier, and they are given to help speed the baby’s lung and brain development before birth. You are more likely to receive these if you are between 24 and 34 weeks of pregnancy.
- Tocolytic medications: These drugs are given to delay delivery up to 48 hours, so corticosteroids and magnesium sulfate can be administered and have time to work. They also allow women time to be moved to hospitals with special care for premature babies. If your labor does not stop and delivery appears imminent, your baby will need care from specialists such as a neonatologist and a neonatal intensive care unit.
Regardless of the specific procedures your doctor recommends, your doctor will discuss the pros and cons of each, the expected outcomes of the treatments, and the reasons for the recommendations. If treatments do not stop preterm labor, or the doctor feels that you or your baby are in danger, you will deliver the baby. Sometimes, Cesarean delivery (C-section) may be recommended if the doctor feels there is an emergency situation.
What happens if my baby arrives too soon?
Babies who stay in your womb longer have a better chance of being born healthy. Premature babies have a higher risk for breathing problems, neurological complications, digestive complications. The earlier a baby is born, the more likely problems are to occur, and the more kinds of problems are likely. However, with research, medicine, and technological advances, more premature babies survive and avoid many of the long-term complications than ever before.
Preterm babies born at hospitals with neonatal Intensive Care Units have the best outcomes. Babies who arrive after 32 weeks have a very high survival and success rate. Early babies struggle because their bodies and organs are not yet fully mature. They are small, with birth weights under 5.5 pounds, and they need extra help staying warm, eating, breathing, and fighting infection.
The best prevention for preterm labor is prenatal care, nutrition, and an awareness of the risk factors and signs of early labor. If you have concerns about premature labor, contact us at 913-948-9636 immediately.