management of preterm labor

2. Preterm Labor

3. Introduction
• A normal pregnancy lasts 37 to 42 weeks, counting from the first day
of the last menstrual period(LMP).
• A pregnancy that continues beyond 37 weeks is called a "term"
pregnancy.

4. Definition
• Definition: Labor that begins before 37 weeks of pregnancy.
• Not all women who have preterm labor will deliver their baby early;
between 30 and 50 percent of women who develop preterm labor
will go on to deliver their infant at term.

5. Newborn complications
If preterm labor leads to an early delivery, the premature newborn is
at risk for problems related to incomplete development of its organ
systems: These problems include:
difficulty with:
1. breathing
2. staying warm
3. feeding
and injury to the:
1. eyes
2. intestines
3. nervous system

6. Risk factors
• most preterm births occur in women who have no known risk
factors.
• The strongest one: a previous preterm birth.
• Black women appear to have double the incidence of preterm labor
and delivery when compared to white women.
• The risk is also higher in women under 18 to 20 years of age.( Older
maternal age alone (over 35 to 40) is not associated with an
increased risk of preterm labor)

7. Risk factors
• Being pregnant with twins, triplets, or
more
• A history of cervical surgery (eg,
conization or cone biopsy) for abnormal
Pap smears, if the amount of the cervix
removed is large
• Abnormalities of the uterus
• Uterine bleeding, especially in the 2nd or
3rd trimester
• illicit drugs, such as cocaine
• Cigarette smoking
• Some infections
• Low prepregnancy weight
• low weight gain during pregnancy
• Excessive amniotic fluid
• Moderate to severe anemia early in the
pregnancy
• A short interval (less than 12 to 18
months) between pregnancies
(deliveries)
• Abdominal surgery during pregnancy

8. Causes
1. Uterine bleeding : Conditions like placenta previa and placental
abruption can cause the fetal membranes to rupture prematurely and
can trigger preterm labor.
2. Stretching of the uterus : Having twins, triplets, or more, or having
polyhydramnios causes stretching of the uterus, which can lead to
uterine contractions and preterm labor.
3. Bacteria or inflammation : Bacteria or inflammation caused by an
infection in the uterus can stimulate the production of substances that
trigger uterine contractions.
4. Physical or psychological stress : Severe stress can lead to the release of
hormones that cause uterine contractions and preterm labor.

9. Signs and symptoms
The signs of preterm labor are similar to the signs of labor at the end of
pregnancy:
• Change in type or amount of vaginal discharge (watery, mucus, spotting)
• Ruptured membranes (broken water):a trickle to a sudden gush of fluid
will drain from the vagina
• Pelvic or lower abdominal pressure or pain
• Constant, low, dull backache
• Mild or menstrual-like abdominal cramps, with or without
diarrhea(irregular in the early stages,but becomes regular & causes more
pain)
• Regular or frequent contractions or uterine tightening that may be painless

10. a woman should contact her hospital if she has :
1. more than 6 contractions in an hour that continue despite lying down
(Braxton Hicks contractions ,also called false labor contractions, are uterine
contractions that occur less than eight times in an hour or four times every 20
minutes; these contractions are not accompanied by bleeding or vaginal discharge
and are relieved by resting. These are normal and do not increase the risk of preterm
birth. However, it is often difficult to tell the difference between preterm labor and
false labor without having a pelvic examination)
2. she has leakage of amniotic fluid.
3. has any vaginal bleeding.

11. Predicting preterm delivery
1. Fetal fibronectin : is released when the fetal membranes begin to change
prior to labor. if this substance is not present in vaginal discharge in high
concentrations, premature delivery is unlikely. If there are high amounts
of fetal fibronectin, it does not always mean that the woman will deliver
prematurely.
2. Cervical length : Ultrasound measurement of the cervix can help to
predict the risk of preterm delivery; the risk increases as cervical length
decreases.

12. Prevention
• stop habits that can be harmful, such as smoking and use of illegal drugs.
• Women with a history of a previous preterm birth at less than 37 weeks of
pregnancy may be offered a progesterone supplement, either as an
injection or a vaginal gel, to prevent recurrent preterm labor. Progesterone
supplementation is begun between 16 and 26 weeks of pregnancy and
continued until 36 weeks
There is no evidence that this drug is effective in women with no
previous history of preterm labor. In addition, it has not been effective in
women with multiple gestations (eg, twins).

13. Treatment
Goals:
1- to delay delivery long enough that steroids can be given;
–Pregnancies with the GA of less than 34 weeks.
–If tests show that the baby's lungs are not developed.
2- to allow the woman to be transferred, if necessary, to a facility that
can provide specialized care to a premature infant.

14. Treatment
Treatment
to stop labor
to help the infant

15. Treatments to stop labor
If the mother and baby are healthy, medications are often used to try to
relax the uterine muscle and stop contractions ( Tocolytics):
1. Terbutaline
2. Magnesium sulfate
3. Nifedipine
4. Indomethacin
Tocolytics are usually given along with a steroid (glucocorticoid) injection. Tocolytic
medications are intended to delay delivery for several hours and optimally for 48
hours.
While tocolytics are used, the mother is monitored for medication side effects. If
labor stops, the woman is usually kept in the hospital for a period of time to
monitor for more uterine contractions. While at home, the woman may be asked
to limit her activities, and she should contact her hospital or healthcare provider
immediately if signs of labor return.

16. Treatments to help the infant
Steroids (glucocorticoids) are often used,because:
1. Speeds the development of a preterm infant's lungs.
2. Decreases the infant's risk for intraventricular hemorrhage (bleeding into the
brain).
3. Decreases complications affecting the bowels and circulatory system.
The most commonly used steroid is betamethasone.
Steroids are usually administered if the mother is between about 23 and 34 weeks
of gestation.
Steroids must be given to the mother as an injection several hours before the
infant is delivered.
The greatest benefit is seen when the steroid is given at least 48 hours before the
infant is delivered.
It is not usually necessary to repeat the steroid treatment later in pregnancy if
preterm labor recurs.

17. It is important that a woman who is at high
risk for premature delivery be treated in a
hospital with a neonatal intensive care unit.