Induction

Induction is a method of artificially or prematurely stimulating labour in a woman.^[1]

Common causes for induction include:

• The baby is believed to be getting too big.
• Postdate pregnancy, i.e. if the pregnancy has gone past the 42 week mark.
• Intrauterine fetal growth retardation (IUGR).
• There are health risks to the woman in continuing the pregnancy (e.g. she has pre-eclampsia).
• Premature rupture of the membranes (PROM); this is when the membranes ruptured, but labour does not start within a specific amount of time.^[2]
• Premature termination of the pregnancy (abortion).
• Scheduling concerns.
• Fetal death in utero.

Methods of induction

Methods of inducing labour include:

• "Membrane sweep", also known as membrane stripping, or "stretch and sweep" in Australia and the UK - during an internal examination, the midwife moves her finger around the cervix to stimulate and/or separate the membranes around the baby from the cervix. This causes a release of prostaglandins which can help to kick-start labour.
• Artificial rupture of the membranes (AROM or ARM) ("breaking the waters")
• Cervically-applied prostaglandin, such as dinoprostone or misoprostol.
• Intravenous administration of synthetic oxytocin preparations, such as Pitocin.
• Natural Induction - Many midwives or other holistic providers practice "natural" induction, which may include use of herbs, castor oil or other medically unconventional agents to stimulate or advance a stalled labor.

If an induction causes complications during labor, a Caesarean section is almost always conducted. An induction is most likely to result in successful vaginal delivery when a woman is close to or in the early stages of labor. Signs of pending labor may include softening of the cervix, dilation and increasing frequency or intensity of contractions. The Bishop score may be used to assess the advisability of induction, and is based on such factors.

When to induce

Until recently, the most common practice has been to induce labor by the end of the 42nd week of gestation. This practice is still very common. Recent studies have shown an increasing risk of infant mortality for births in 41st and particularly 42nd week of gestation, as well as a higher risk of injury to the mother and child ^[3]. The recomended date for induction of labor has therefore been moved to the end of the 41 week of gestation in many countries including Sweden and Canada.

Criticisms of induction

• Induced labour tends to be more intense and painful for the woman, often leading to the increased use of analgesics and other pain-relieving pharmaceuticals (Vernon, 2005). This cascade of intervention has been said to lead to an increased likelihood of caesarean section delivery for the baby. (Roberts 2000). However, studies into this matter indicate that induction has no effect on the rates of caesarean section^[4]. Two more recent studies have shown that induction may increase the risk of caesarean section if performed before the 40th week of gestation, but has no effect or actually lowers the risk if performed after the 40th week.^[5][6]

• Some feel that doctors show increasing propensity toward induction simply for personal convenience or to relieve load on hospital facilities. "[Induction] enables doctors to practice daylight obstetrics," says Dr. Marsden Wagner, a neonatologist who served for 15 years as a director of women's and children's health in industrialized countries for the World Health Organization. "It means that as a doctor, I can come in at 9 a.m., give you the pill, and by 6 p.m. I've delivered a baby and am home having dinner." ^[7] A growing number of pregnant women are opting to have induced labor, according to a 12-year study of women in Illinois that was published in the September 2008 issue of the journal Medical Care. The researchers say that the consequences are not clear, but some believe that elective inductions will be done for convenience reasons.^[8]

References

• Roberts, Tracy, Peat, 2000 Rates for obstetric intervention among private and public patients in Australia: population based descriptive study Christine L Roberts, Sally Tracy, Brian Peat, "British Medical Journal", v321:140 July 2000
• Vernon, David, Having a Great Birth in Australia, Australian College of Midwives, 2005, ISBN 0-9751674-3-X
• Goodman, David, "Forced Labor", Mother Jones

External links

• Family.doctor.org
• Harman & Kim. "Current Trends in Cervical Ripening and Labor Induction" American Family Physician 1999; 60:477-84.
• Inducing Labor - WebMD.com
• Induction of labour. Clinical guideline, UK National Institute for Health and Clinical Excellence, June 2001.
• Josie L. Tenore: Methods for cervical ripening and induction of labor. American Family Physician, 15 May 2003.