March 24, 2011
All About Labor Induction
Labor Induction is a process of giving an artificial start to birth with medical intervention or other methods. When an induction is not performed for emergency or other medical reasons, the method is considered an elective process. The decision to induce labor has increased in recent years due to its convenience or because it easily accommodates busy schedules.
The American College of Obstetricians and Gynecologists, however, say that labor should only be induced when it is more risky for the baby to remain in the mother's uterus than to be born.
* Pregnancy lasting more than 42 weeks. After 42 weeks the placenta normally stops functioning properly enough for the baby to receive adequate nutrition and oxygen.
* Pregnancy lasting more than 38 weeks when having twins.
* The pregnant woman has high blood pressure caused by pregnancy.
* The pregnant woman has an infection in her womb.
* The woman's water has broken, but contractions have not begun.
* The woman has health problems, such as diabetes.
* There are health risks to the woman if pregnancy is continued.
* A growth problem is causing the baby to be too small or too big.
* Intrauterine fetal growth retardation (IUGR).
* Premature rupture of the membranes (PROM). This occurs when the membranes have ruptured, but labor does not start within a certain amount of time.
* Premature termination or abortion.
* Fetal death.
If an induction causes complications, a Caesarean section is almost always conducted in place of inducing. An induction will most likely be successful when a woman is close to or in the early stages of labor. Signs of impending labor may include softening of the cervix, dilation and increasing frequency or intensity of contractions. The Bishop score may be used to assess how suitable induction would be.
The Bishop score, which is also used to assess the odds of spontaneous preterm delivery, grades patients who would be most likely to achieve a successful induction. The duration of labor is inversely correlated with the Bishop score; a score that exceeds 8 describes the patient most likely to achieve a successful vaginal birth. Bishop scores of less than 6 usually require that a cervical ripening method be used before other methods.
Use of medication is a common method in labor induction.
* Intravaginal, endocervical or extra-amniotic administration of prostaglandin, such as dinoprostone or misoprostol. Extra-amniotic administration has appeared to be more efficient than Intravaginal or endocervical administration in the few controlled studies that have been done.
* Intravenous administration of synthetic oxytocin preparations, such as Pitocin.
* Natural Induction. Natural induction includes the use of herbs, castor oil or other medically unconventional agents to stimulate or advance a stalled labor.
* Mifepristone use has been described.
* Relaxin has been studied, but is not a commonly used medication.
There are also other processes and methods for inducing labor besides the use of medication.
* Stripping the membranes (separating the amniotic sac from the wall of the uterus): The amniotic sac is the lining inside the uterus that contains the baby. The doctor gently puts a gloved finger through the woman's cervix. Using the finger, the doctor separates the sac from the uterine wall. The woman may feel some cramping or spotting with this method.
* Ripening the cervix: The doctor places a small tablet or suppository in the vagina up against the cervix. This helps to soften and thin the cervix. After receiving the suppository, the woman may start to have gentle contractions.
* Nipple Stimulation: This is a natural form of labor induction that can be done manually or with an electric breastfeeding pump. The hormone oxytocin will naturally be produced to cause contractions. The concept works the same as when a baby nurses right after birth, stimulating contractions, which slows the bleeding.
* Artificial rupture of the membrane (AROM): When the amniotic sac breaks or ruptures, production of the hormone prostaglandin increases, speeding up contractions. A doctor may suggest rupturing the amniotic sac artificially. A sterile, plastic hook is brushed against the membrane just inside the cervix. The baby's head will move down against the cervix, which usually causes the contractions to become stronger. This method releases a gush of warm amniotic fluid from the vagina.
AROM has advantages and disadvantages.
Advantages include shortening labor by an hour or so, allowing the amniotic fluid to be examined for the presence of me conium, which can be a sign of fetal distress, and doctors can monitor heart rate with direct access to the baby's scalp.
Disadvantages include the baby possibly turning to a breech position, making birth more difficult if the membranes are ruptured before the baby's head is engaged, and leaving the possibility for the umbilical cord to slip out before the baby. Infection can occur if there is too much time between the rupture and the birth.
When to Induce
Until recently, the most common practice has been to induce labor by the end of the 42nd week of pregnancy. While this practice is still very common, recent studies have shown an increasing risk of infant mortality for births in their 41st and 42nd week of gestation, as well as higher risk of injury to the mother and child. The recommended date for induction of labor has now been moved to the end of the 41st week of gestation in many countries including Canada and Sweden.
Risks of Induction
Like any medical procedure, labor induction has potential side effects and health risks to both the mother and the child. Some common ones include:
* Oxytocin can make contractions quite strong and lower the baby's heart rate. Throughout the induction process, it is important for the baby's heart rate to be monitored. Adjusting the dosage of a drug can increase the strength of the contractions and reduce the effect on the baby's heart.
* Women who have inductions are at an increased risk of having an infection, and so are their babies.
* The umbilical cord may slip out into the vagina before the baby does. This is more likely to occur if the baby is breech. Also, the cord may become compressed, decreasing the baby's oxygen supply.
* Often the treatment may not work properly and the mother has to have an emergency cesarean delivery.
A less common complication with induction is uterine rupture, which can cause severe bleeding. Women who have previously had a C-section are at an increased risk of uterine rupture, as cesarean deliveries leave a scar in the uterus.
There is also a risk of babies being born "late preterm." Inductions may contribute to the growing number of "late preterm" births between 34 and 36 weeks gestation. While babies born at this time are usually considered healthy, they are more likely to have medical problems than babies born a few weeks later at full term (37-42 weeks).
While induction has risks, it is sometimes needed to protect the health of the mother and the baby. The pregnant woman needs to understand both benefits and risks of labor induction.
Expectations with Induction
In most cases, labor induction goes well, and the woman can deliver her baby through the birth canal normally. An induction can take anywhere from two or three hours to as long as two or three days, depending on how the woman's body responds to the treatment she is receiving. An induction may take longer if the woman is pregnant for the first time or if the baby is not full term.
Every pregnancy is different. Having an induction is not a sign of failure and it may be the best thing for both the health of the baby and the mother. Medicines used for inducing labor may upset a woman's stomach so normally it is recommended that she eats lightly before going to the hospital. Foods such as Jell-O and soup are good light foods. Medicines may also cause strong contractions. The woman should know that she can always ask if she needs help for her pain.
Criticism of Induction
As induced labor tends to be more intense and painful for women, it can lead to increased use of analgesics and other pain-relieving medications. These medications have been said to lead to an increased likelihood that the pregnancy might result in cesarean delivery for the baby.
However, studies into the issue indicate that labor induction has no effect on the rates of cesarean deliveries. Two recent studies have shown that induction may increase the risk of C-section if performed before the 40th week of gestation, but it has no effect or actually lowers the risk if performed after the 40th week of gestation.
At least one study has indicated that cesarean delivery rates increase with induction. Research published in the Journal of Perinatal and Neonatal Nursing showed induction increased a woman's likelihood of having a C-section by two to three times.