Preterm labour is defined as one where the labour starts before the 37 completed weeks counting from the first day of the last menstrual period. There are regular uterine contractions with the opening of the cervix between 20 weeks and 37 completed weeks of pregnancy.
Preterm labour can lead to the premature birth of a baby which needs special intensive care in the hospital. If childbirth occurs before 35 completed weeks then there will be a higher health risk to the baby.
Preterm birth is the significant cause of perinatal morbidity and mortality; occurs in 5-10% of pregnancies.
Causes
The cause of preterm labour is not known in about 50% of cases. The following are the factors related to an increased incidence of preterm labour-
- Any previous history of preterm birth or induced abortion or spontaneous miscarriage.
- Recurrent urinary tract infections during pregnancy.
- Smoking habits or using other drugs in pregnancy.
- Anaemic women.
- Complications in present pregnancy like pre-eclampsia, premature rupture of the membranes, placenta praevia, polyhydramnios, cervical incompetence, uterine malformations, genital tract infections, medical and surgical conditions
- Having multiple pregnancies
- Congenital malformations and intrauterine death of the fetus
- Stressful life events
- Shortened cervix
- Elective induction of labour with the wrong estimation of gestational age
- Early engagement of the head
- Premature effacement of the cervix with a hyper irritable uterus.
Symptoms
Signs and symptoms of preterm labour include
- Regular and painful uterine contraction coming at least once in 10 minutes and lasting for 30 seconds or more
- Vaginal bleeding
- Constant back pain
- Feeling of pressure in the lower abdomen
- If the membranes have ruptured then there is continuous leaking of amniotic fluid
- Watery, mucus-like and bloody discharge from the vagina
Diagnosis
If you’re experiencing regular uterine contractions once in 10 minutes and lasting for 30 seconds or more with progressive dilatation and effacement of the cervix before 37 weeks of pregnancy, you’ll likely be diagnosed with preterm labour. Your doctor may perform a vaginal examination to confirm the diagnosis. Other investigations may include
- Complete blood count
- Urine for routine analysis, culture and sensitivity
- Cervicovaginal swab for culture and fibronectin (a protein that binds fetal membranes to the decidua)
- Ultrasonography can be done to monitor the fetal well being, cervical length and placental localisation
- Serum electrolytes and glucose levels are checked when tocolytic agents are to be used
Prevention
Preterm labour cannot be prevented but there is much you can do to promote a healthy and full-term pregnancy.
Regular antenatal visits- If you have a history of preterm labour then you might need to see your health care provider more often during pregnancy. During antenatal visits, your healthcare provider will monitor your and your baby’s health.
Avoid substance use- It is better to quit smoking and use of other substances during pregnancy and thereafter because it has many health hazards on your baby.
Healthy diet- Eating a healthy diet during pregnancy is very helpful to maintain your health and your baby’s development. Some research suggests that a diet high in polyunsaturated fatty acids (PUFAs) is associated with a lower risk of premature birth. PUFAs are found in nuts, seeds, fish and seed oils.
Control medical conditions- It is very important to control medical conditions like diabetes, high blood pressure, fever and obesity during pregnancy, otherwise, it could lead to preterm labour.
Cerclage operation can be done in case of cervical incompetence. Cervical cerclage might be recommended if you’re less than 24 weeks pregnant, you have a history of early premature birth, and an ultrasound shows your cervix is opening or your cervical length is less than 25 mm.
Take adequate rest throughout the pregnancy.
Before induction of labour always check the gestational age.
Hormone therapy – If you have a history of premature birth, your health care provider might suggest weekly shots of a form of the hormone progesterone called hydroxyprogesterone caproate, starting during your second trimester and continuing until week 37 of pregnancy.
Treatment
The scope to arrest preterm labour is limited. Once you’re in labour, there are no medications or surgical procedures to stop labour, other than delaying delivery for at least 48 hours, if required. However, your doctor might recommend the following regime in an attempt to arrest preterm labour-
Bed rest- If you experience any uterine contractions then you need to take bed rest in the left lateral position. If it does not subside then you need to consult your healthcare provider immediately.
Adequate hydration- Maintain adequate hydration by taking plenty of fluids.
Tocolytics – Your doctor may give you tocolytic medication to delay delivery for at least 48 hours to allow glucocorticoid therapy to enhance fetal lung maturation, if necessary, for you to be transported to a hospital that can provide specialized care for your premature baby.
Glucocorticoid therapy- Your doctor may administer glucocorticoids when the pregnancy is less than 34 weeks. This helps in fetal lung maturation and helps to prevent respiratory distress syndrome in the baby. Either betamethasone 12 mg I.M. 24 hours apart (2 doses) or dexamethasone 6 mg every 12 hours (4 doses) is given. Betamethasone is the corticosteroid of choice.
Magnesium Sulphate- It reduces the risk of a specific type of damage to the brain (cerebral palsy) for babies born before 32 weeks of gestation. So it is administered in women who have a high risk of delivering between 24 and 32 weeks of pregnancy.
Management of Preterm Labour
If a woman is in labour then delivery is conducted. The woman is brought to bed to prevent early rupture of the membranes. To ensure adequate fetal oxygenation by giving oxygen to the mother by mask.
Labour should be watched by continuous electronic monitoring. In case of any delay or risk of any traumatic vaginal delivery, it is better to deliver by cesarean section.
After the delivery of the baby, the cord is clamped and the baby is shifted to the Intensive Neonatal Care Unit for specialized care.
When the foetus is in a breech position before 34 weeks of pregnancy are generally delivered by cesarean section.
With an intensive neonatal care unit, the survival rate of the baby weighing between 1000 to 1500 grams is more than 90%.
Conclusion
In the above post, we have discussed preterm labour. Preterm labour occurs when there are regular uterine contractions with the opening of the cervix before 37 completed weeks of pregnancy. To manage this condition, hospitalization is required. Premature birth usually leads to the birth of a premature baby which needs intensive care for survival in the hospital.
