After about 30 weeks of pregnancy, many women notice occasional uterine contractions. Called Braxton Hicks contractions, they're normal and usually painless. They tend to occur when you're tired or are exerting yourself, and they usually stop when you rest. True premature contractions come at regular intervals or progressively become more frequent or more painful; Braxton Hicks contractions don't.
You're probably experiencing a whole range of new sensations throughout your pregnancy—so how can you tell if it's just a stomach muscle cramping and stretching over your growing belly, or if it's preterm contractions? Here are the most common warning signs that it's actually preterm labor:
You are considered to be in preterm labor when you have uterine contractions every ten minutes (or more often) as well as cervical changes (dilation, thinning, softening) prior to 37 weeks gestation.
In some cases it can be difficult for even a doctor to determine if a woman truly is in labor. Your doctor will probably tell you to go to the hospital (if you're not already there), where you can be monitored carefully. Some women at high risk for preterm labor are given a belt with electronic sensors. This is strapped around the abdomen to detect early contractions. Once or twice a day, the monitor is hooked up to a telephone so it can relay graphs of uterine activity to a nurse. The goal of home monitoring is to detect preterm labor early, when it's most treatable.
Two tests, one that measures hormones in the saliva and another that measures vaginal secretions, can also aid in diagnosing preterm labor. Doctors may do a swab of the cervix and vagina to test for a protein called fetal fibronectin. The March of Dimes explains, "Fetal fibronectin (fFN) is a protein produced during pregnancy and functions as a biological glue, attaching the fetal sac to the uterine lining. The presence of fFN during weeks 24-34 of a high-risk pregnancy, along with symptoms of labor, suggests that the "glue" may be disintegrating ahead of schedule and alerts doctors to a possibility of preterm delivery."
A vaginal ultrasound, which can accurately assess cervical dilation and other cervical changes, may help too.
If your doctor determines that you are truly in labor, she will probably attempt to halt it, unless for some medical reason it's not advisable. (For instance, if you have very high blood pressure or uterine bleeding due to a problem with the placenta, or if there's fetal distress, such as a slowed heart rate that could indicate a lack of oxygen.)
In some cases, preterm labor can be treated to give your baby more time to grow. "The most common cause is dehydration or bladder infection, so rest and hydration can help it resolve on its own," Kubesh says.
Pelvic rest—which means no sex, no vaginal exams, and nothing put into your vagina—s often a must if you're experiencing preterm contractions. You may also be put on bed rest, at least temporarily, to avoid having gravity put pressure on your cervix. In some cases, your doctor may suggest sewing your cervix shut to help avoid a premature birth, or even resting with your head below the level of your body to further reduce stress on the cervix. "Bed rest is one of the few things that has been shown to help prevent preterm birth," Dr. Putterman says. "The medicines we have are somewhat effective for preterm contractions, but none of them work well to prevent preterm labor."
In fact, according to Dr. Putterman, most studies suggest that the outcome is the same with or without medications—and the medications themselves aren't completely harmless. "The medications can have dangerous side effects, especially when taken for an extended length of time," Dr. Putterman says. "We don't have a really good means for prolonging pregnancy, short of getting you off of your feet."
To try to halt your contractions, your doctor will ask you to rest on your left side (this position increases blood flow to the uterus), and if you seem dehydrated, she will give you intravenous fluids. These steps help stop contractions in about 50 percent of women. If your contractions stop and your cervix doesn't dilate during several hours of observation, you will probably be able to go home.
If your cervix is dilating, however, your contractions are unlikely to stop on their own. If you are between 34 and 37 weeks and the baby already is at least 5 pounds, 8 ounces, the doctor may decide not to delay labor. These babies are very likely to do well even if they're born early.
Your obstetrician may decide that postponing the birth through medication is the appropriate course of action. While there is no established "right" time to start treatment with medication, many doctors recommend beginning once your cervix becomes two to three centimeters dilated.
While drugs usually don't postpone labor for long (often not more than a couple of days), sometimes even a short delay can make a lifesaving difference to your baby.
For example, your doctor can use this time to begin treatment with corticosteroid drugs aimed at preventing or lessening complications in preterm newborns. Corticosteroids speed maturation of fetal organs, reducing infant deaths by about 30 percent and cutting the incidence of the two most serious complications of preterm birth: respiratory distress syndrome and bleeding in the brain. They are given by injection and are most effective when administered at least 24 hours before delivery.
If you have concerns about preterm contractions, speak with your doctor who can recommend strategies to help you safely get to 40 weeks.