Inducing Labor from WebMD

Inducing Labor

In many cases if a pregnancy isn't proceeding as it should, or if the health of the mother or baby is threatened, doctors have to speed up the process by inducing labor.

Why Is Labor Induced?

According to the CDC, about one out of every five pregnant women in the U.S. has their labor induced. There are a number of reasons for inducing labor, from a late delivery to a medical complication in the pregnancy.

Your doctor might induce labor if:

*You are one to two weeks past your due date. Past 42 weeks, you and your baby are at greater risk for complications, and the placenta that nourishes your baby in the womb may have diminished so much that it can no longer properly feed your baby. The baby also may breathe in his first bowel movement (called meconium), which can block his airways.

*The membrane that holds the amniotic sac surrounding your baby breaks (your "water breaks") and you don't go into labor on your own (once your water breaks, you and your baby are at greater risk for infection).

*You have a health condition, such as high blood pressure (preeclampsia), gestational diabetes, bleeding, or an infection in your uterus, which puts your health or your baby's health at risk.

*Your placenta is partially or totally covering the opening to the uterus (placenta previa), or has separated from the wall of the uterus (placenta abruption).
*The umbilical cord drops down into the vagina (prolapses).

*The baby is sideways (transverse) in the uterus.

*Tests show that your baby is no longer growing or developing at a normal rate, or the baby's heart rate is abnormal.

Sometimes women (or their doctors) decide to induce labor for nonmedical reasons, for example if they live far away from the hospital and their doctor is worried that they won't get there in time if they do go into labor. Inducing labor for nonmedical reasons is controversial, however, because there are some minor risks involved.

How Is Labor Induced?

Normally during labor, the lower end of the uterus (cervix) softens. This is called ripening. The cervix thins out (effaces) and opens (dilates). In order for the baby to be born, the cervix must be fully effaced and dilated to allow the baby's head to get through.

Before the doctor will induce labor, she will check your cervix and the baby's position to find out whether you are far enough along for induction will work.

Doctors use medications and other methods to efface and dilate the cervix artificially so that the baby can be born. Labor induction techniques include:

*Stripping the membranes. The doctor will insert a gloved finger into your vagina and move it back and forth to separate the membrane that connects the amniotic sac to the wall of the uterus. This is called "stripping the membranes," and it causes the body to release hormones called prostaglandins, which ripen the cervix and may lead to contractions. You may feel some cramping and have some spotting after this procedure. Usually this method of inducing labor is done in your doctor's office, and you'll be sent home to wait until contractions begin.

*Ripening the cervix. Medications called prostaglandins can dilate your cervix enough to prepare it for labor. Prostaglandins are manmade versions of chemicals in the body that both ripen the cervix and stimulate the uterus to contract. You take prostaglandins either by mouth or via a gel or suppository inserted in the vagina. (Your doctor shouldn't give you prostaglandins if you've had a previous c-section because of the increased risk of uterine rupture.) Another way to ripen the cervix is by inserting a thin tube called a catheter with a balloon at the tip. When the catheter is placed in your uterus, the balloon is inflated with water, which causes the cervix to expand.

*"Breaking your water." If your cervix is already at least partially dilated, your doctor can "break your water" by making a hole in your amniotic sac using a small plastic hook. Once your amniotic sac has broken, you should start having contractions. You'll need to deliver within about 24 hours to prevent infection.

*Triggering contractions. The drug Pitocin can bring on contractions to induce or move your labor along. Pitocin is an artificial form of the hormone oxytocin, which triggers and strengthens contractions. It's delivered through an intravenous (IV) tube in your arm. Your doctor will start with a small dose and will gradually increase it until your contractions are strong and frequent enough for the baby to be born.

Aside from stripping the membranes, which is typically performed in the doctor's office, these methods of inducing labor will be done in a hospital where both you and your baby can be carefully monitored.

Some women go into labor and deliver within a few hours after induction of labor begins. Others take one or two days to begin labor. If you don't go into labor with any of these methods, especially once your water is broken, you'll need to have a C-section.

What Are the Risks of Inducing Labor?

Generally, inducing labor is safe. The techniques used to induce labor shouldn't hurt, although they may cause your contractions to come on stronger and more often than they would naturally.


Inducing labor, especially with prostaglandins and Pitocin, may be more risky for women who have had a previous C-section or other surgery to the uterus. There is also a very small risk that the placenta will separate from the wall of the uterus (placental abruption) with these medications if the contractions become too intense. If the contractions are too strong, the doctor will reduce the dose of medication or stop it altogether.

Breaking the amniotic sac can lead to infection if you don't deliver within a day or two after your doctor tries to induce labor. In rare cases, the umbilical cord can slip out before the baby (prolapsed cord).

Can I Induce Labor Myself?

Tales abound of home remedies that supposedly bring on labor. Women past their due date have done everything from downing castor oil to rubbing their nipples to expedite the process. These methods can be uncomfortable, and there really isn't much scientific evidence to back them up.

Here is a rundown of a few popular home labor-induction methods:

*Sexual intercourse. The idea is that sex can trigger contractions, both from the sperm (which contain prostaglandins) and from the woman's orgasm. However, research is lacking on the subject, and one study found that sex didn't have any effect on time to labor.

*Nipple stimulation. Stimulating the nipples releases the hormone oxytocin, which naturally triggers contractions, but the cervix must already be ripe for this to work. Too much nipple stimulation also can produce very strong contractions that can actually be dangerous to the baby.

*Herbal remedies. A number of herbs, including blue cohosh and black cohosh, have been touted for triggering labor, but there isn't enough evidence to prove they work. What's more, herbs can be dangerous if not used properly, so don't take any herb for inducing labor without first talking to your doctor.

*Castor oil. Research shows castor oil probably won't do anything to induce labor, but it probably will irritate your gastrointestinal tract enough to make you feel sick to your stomach.

*Walking . It's always a good idea to stay active throughout your pregnancy, but studies haven't proved that walking can induce labor.

Unless your doctor feels that it's time to induce labor for medical reasons, it's always better to let nature take its course.

Antepartum Testing from Healthline.com

Definition

Antepartum testing involves the use of electronic fetal monitoring (EFM) or ultrasound (US) to assess fetal well-being as determined by the fetal heart rate (FHR) and other characteristics during the antepartal period, which is the period spanning from conception to labor. Antepartum tests include the nonstress test (NST), modified biophysical profile (MBPP), contraction stress test (CST), oxytocin contraction stress test (OCT), biophysical profile (BPP), doppler flow studies, amniocentesis, cordocentesis, and fetal echocardiography.

Purpose

Antepartum testing can start as early as 24 weeks but usually begins after 32 weeks of pregnancy depending on the mother's physical status. It provides a means for the physician and pregnant woman to identify any problems and be alert to any changes that may necessitate additional testing or interventions. The testing results reflect how well the placenta is functioning in its ability to adequately supply blood and, therefore, oxygen to the fetus.

The testing is done for pregnancies at risk for maternal and/or fetal complications. Some of these risks include:

any chronic illness in the mother, such as high blood pressure, diabetes, or autoimmune diseases, including systemic lupus erythematosus (SLE)
problems with previous pregnancies, such as a history of unexplained stillbirth
fetal complications, such as intrauterine growth restriction (IUGR) (growth in the fetus below the tenth percentile), birth defects, twins, or other multiple gestations in which a growth discrepancy occurs, such as twin-to-twin transfusion syndrome
problems in current pregnancy, including pregnancy-induced hypertension frequently referred to as preeclampsia); gestational diabetes (diabetes caused by pregnancy) requiring the use of insulin; premature rupture of the membranes (PROM); too little or too much amniotic fluid (the liquid surrounding the fetus) called oligohydramnios and polyhydramnios, respectively; vaginal bleeding; placental abnormalities, i.e., partial abruption (a portion of the placenta pulls away from the wall of the uterus), or placenta previa (a condition in which the placenta is covering the cervix instead of near the top of the uterus)
Antepartum testing is also used in low-risk pregnancies to evaluate decreased fetal activity, a lag in fundal height (as measured from top of the pubic area to the highest point in the midline at the top of the uterus), and postdates or post-term pregnancy. A normal pregnancy is 40 weeks and testing should begin at 41 weeks to assess the status of the placenta, which may no longer be capable of meeting the baby's needs. This can be indicated by the FHR pattern, amniotic fluid status, and fetal movement patterns.

Description

The spectrum of fetal assessment includes fetal movement (FM) counting, nonstress test (NST), modified biophysical profile (MBPP), contraction stress test (CST), oxytocin contraction stress test (OCT), biophysical profile (BPP), doppler flow studies, amniocentesis, cordocentesis, and fetal echocardiography. Fetal movement should be determined on a daily basis by all pregnant women regardless of risk status. The woman should be instructed to monitor fetal movement by selecting a consistent time of day to document how long it takes to feel 10 fetal movements. She should call her healthcare provider if there are fewer than 10 movements in a 10-hour period or immediately if there are no movements in any 10-hour period. She should also be instructed to report significant decreases in fetal activity from the baby's normal pattern. This daily monitoring of FM by all pregnant women is the least expensive and easiest of all antepartum tests to perform.

Non-stress test (NST)

The NST is performed with an electronic fetal monitor (EFM) that traces the fetal heart rate (FHR) and the presence of any contractions on a monitor strip. The mother reclines with a slight pelvic tilt to prevent compression of the large blood vessels by the pregnant uterus. The EFM is applied to her abdomen by two straps: one is to listen to the FHR by means of a transducer, and the other is to pick up any contractions by pressure on a tocodynameter. The NST indirectly provides information about fetal status by the observation of FHR accelerations that occur with fetal movement. If a fetus is not receiving adequate oxygen from the placenta, the FHR will not accelerate, but if the oxygen supply is sufficient, accelerations will be noted. If it is difficult to obtain fetal movements, a vibroacoustic stimulator (VAS) is sometimes used to provide a loud noise to awaken the fetus and produce the desired results. The minimum amount of time required for an NST is 20 minutes. During those 20 minutes, there must be two accelerations in the FHR that are 15 beats above the baseline FHR and last for 15 seconds, often called the 15 by 15 rule. Depending upon the conditions, however, it may sometimes take up to 60 to 90 minutes to obtain definitive results.

Modified biophysical profile (MBPP)

The MBPP is performed in the same manner as the NST with a limited ultrasound (US) performed to assess the amount of amniotic fluid, which is reported as the amniotic fluid index (AFI). Following the NST, an US is done to observe the amount of amniotic fluid present in four quadrants, which are divided along the umbilicus midline and perpendicular to the midline. There must be no fetal parts or any umbilical cord present in any of these pockets of fluid in order to be counted.

Contraction stress test (CST) and oxytocin contraction stress test (OCT)

The contraction stress test (CST) is similar to the NST except the FHR is evaluated for accelerations, 15 beats higher than baseline lasting 15 seconds, and in response to contractions as well. A CST requires the presence of three uterine contractions (UCs) within a 10-minute period lasting at least 40 seconds and of moderate intensity. During a contraction, the blood flow to the baby is temporarily restricted, which provides a form of "stress" to the baby. The baby's response to this stressor reveals significant information regarding available oxygen stores. If contractions are not spontaneously present, the pregnant woman will be instructed on the use of nipple stimulation to produce contractions through the release of natural oxytocin, or oxytocin can be administered through an intravenous infusion (IV) called pitocin to produce contractions. When oxytocin is administered IV, it is called an oxytocin contraction stress test (OCT). The CST/OCT is generally used after an abnormal NST is obtained in order to verify if there are problems present. Many clinicians require their diabetic patients to have at least one CST/OCT a week to assure fetal well-being. Maternal blood pressure is taken with each test.

Biophysical profile (BPP)

The biophysical profile (BPP) is performed by an ultrasound exam over a 30-minute period. The ultrasonographer/examiner looks for gross fetal movement, i.e., kicking and moving around; fetal tone, i.e., making a fist; breathing movements (which the mother can often perceive as hiccoughs); and amniotic fluid volume. A score of 0 or 2 points is assigned to each observation with the results of the NST also adding 2 points for a total possible score of 10 points.

Doppler flow studies, amniocentesis, cordocentesis, and fetal echocardiography

A physician or specially trained ultrasonographer performs Doppler flow studies, which examines the blood flow in the umbilical artery and the baby's middle cerebral artery. An experienced obstetrician/perinatologist performs the amniocentesis or the cordocentesis. For the amniocentesis, an US is used to determine an appropriate place to insert a needle and withdraw amniotic fluid for testing. In a similar manner, US is used with cordocentesis, but in this procedure a needle is guided into the umbilical cord to withdraw fetal blood for testing. Fetal echocardiography is a specialized ultrasound of a baby's heart. Since it detects most congenital heart defects, it is recommended if a baby is at a higher risk for a defect than the risk in the general population. The majority of health insurance companies do cover a portion, if not all, of the tests' costs.

Precautions

Clinicians should only prescribe these tests if they are ready to intervene when faced with worrying results. A fetus is considered viable at 24 weeks since that is the minimum gestational age for sufficient lung development. There are no significant risks to the mother or the fetus from the nonstress test (NST), modified biophysical profile (MBPP), or the biophysical profile (BPP). Ultrasound waves utilized in detecting the FHR and for the BPP are painless and safe because this method employs no harmful radiation. There is no evidence that sound waves cause any harm to the mother or the baby.

Aftercare

If the test results are acceptable, the pregnant woman is instructed to continue following her current medical regimen and return for additional testing on the dates prescribed. For NSTs/MBPPs/CSTs, the time period between tests should be no longer than three to four days under high-risk conditions with fetal movement counting taking place in between testing dates. Ultrasounds should be rescheduled as the need dictates per the physician. Electronic fetal monitoring occurs after an amniocentesis or cordocentesis to assure fetal well-being.

Risks

There are no complications per se from the tests themselves with the exception of unfavorable test results or supine (lying horizontality on the back) hypotension secondary to a pregnant woman lying on her back for an ultrasound. When a pregnant woman lies on her back, the vena cava (one of two large veins that return blood from peripheral circulation to the heart) can become compressed from the pressure of the pregnant uterus such that blood flow to the heart is significantly reduced. There are potential complications from an amniocentesis, i.e., preterm labor, spontaneous rupture of membranes, fetal or placental injury; and the clinician performing the procedure should explain what these are prior to the procedure. There are similar risks and potential complications from cordocentesis as well which should be explained.

Normal results

Usually, a report of normal results for NSTs provides reassurance that the fetus is healthy and should remain so for three to four days, at which time repeat testing will be necessary. A normal NST is reported as being reactive, which means the fetal heart is "reacting" to movement such that the FHR is accelerating 15 beats per minute above the baseline FHR for 15 seconds twice within a 20-minute period of time. A non-reactive NST is one that fails to meet this criterion within an 80 to 90 minute period of time. For an extremely preterm fetus, a normal NST is reported as being reactive for gestational age, which indicates the FHR demonstrated two accelerations of 10 beats per minute above baseline for 10 seconds over a 20–30 minute period. Typically, the central nervous system is not completely mature until approximately 32 weeks gestational age, and a report of reactive for gestational age takes this into consideration. It is important to remember that a normal result does not guarantee that no problems are present. Although very rare in occurrence, false normal results can be observed.

The CST results are reported as reactive/negative, reactive/suspicious, reactive/positive (a very unlikely result), or non-reactive/negative, non-reactive/suspicious, non-reactive/positive. The reactive/non-reactive part of the test report refers to the presence or absence of accelerations. The negative part refers to no decelerations being present with uterine contractions (UCs). "Suspicious" refers to the presence of some decelerations with UCs, and "positive" refers to the presence of decelerations more than 50 percent of the time with UCs. A suspicious or positive result requires further evaluation, i.e., prolonged EFM monitoring or a BPP. A normal BPP report without an NST is 8 points and 10 points with a reactive NST. Six points is suspicious and requires either a CST or a repeat BPP within 24 hours. A total of 4 points is not reassuring and requires immediate evaluation by prolonged EFM.

All results are given to the primary physician who must then make a decision as to the appropriate course of action. Abnormal CST results generally indicate the baby is not receiving sufficient oxygen and may not be capable of withstanding the stress of labor and subsequent vaginal delivery. If this is the case, a cesarean section may be performed. The final outcome depends on the mother's individual circumstances. Severe pregnancy-induced hypertension may require immediate delivery via cesarean section. In some cases, medications such as betamethasone may be given to the mother to speed up the lung maturity of the baby. If the mother's cervix is favorable for induction, labor may be induced.

KEY TERMS

Amniotic fluid—The liquid in the amniotic sac that cushions the fetus and regulates temperature in the placental environment. Amniotic fluid also contains fetal cells.

Deceleration—A decrease in the fetal heart rate that can indicate inadequate blood flow through the placenta.

Fundal height—Measured by a tape measure from the top of the symphysis pubis, over the arch of the growing uterus, to the top of the fundus.

Oxytocin—A hormone that stimulates the uterus to contract during child birth and the breasts to release milk.

Pitocin—A synthetic hormone that produces uterine contractions.

Vibroacoustic stimulation—In the biophysical profile, use of an artificial larynx to produce a loud noise to "awaken" the fetus.

Parental concerns

The healthcare provider should give a complete explanation to the pregnant woman and her partner regarding the tests, i.e., what to expect, how long the test may take, what it means, and why it is being done. It frequently helps if the pregnant woman has eaten prior to undergoing the test. Pregnant women should know that every test is not compulsory, and that if the results of the test do not matter to the parents, it may not have to be performed.

See also High-risk pregnancy.

BOOKS

Freeman, Roger, et al. Fetal Heart Rate Monitoring, 3rd ed. Philadelphia: Lippincott Williams & Wilkins, 2003.

Gabbe, Steven, et al. Obstetrics, 4th ed. London: Churchill Livingstone, 2001.

Neilson, J. P., and Z. Alfirevic. "Doppler ultrasound for fetal assessment in high risk pregnancies (Cochrane Review)." In The Cochrane Library, vol. 3. Chichester, UK: John Wiley & Sons, Ltd., 2004.

Pattison, N., and L. McCowan. "Cardiotocography for antepartum fetal assessment (Cochrane Review)." In The Cochrane Library. Chichester, UK: John Wiley & Sons, Ltd., 2004.

Tucker, Susan. Pocket Guide to Fetal Monitoring and Assessment, 4th ed. St. Louis, MO: Mosby, 2000.

ORGANIZATIONS

American College of Obstetricians and Gynecologists. 409 12th Street, SW, PO Box 96920, Washington, DC 20090. Web site: .

Association of Women's Health, Obstetric, and Neonatal Nursing. 2000 L Street, NW, Suite 740, Washington, DC 20036. Web site: .

Linda K. Bennington, RNC, MSN, CNS