In most pregnancies, labour starts between 37 and 42 weeks after the last menstrual period. Labour is considered preterm labour when it starts before the beginning of the 37th week.
Signs of preterm labor
- Noticeable Increase or change in Vaginal Discharge (enough to make your underwear wet)
- Ruptured Membranes (your “water breaks”)
- Vaginal Bleeding
- Low, Dull Backache (constant OR comes and goes)
- Pelvic Pressure (feels like the baby is pushing down; feels heavy)
- Abdominal cramping (with or without diarrhea)
- Menstrual-like cramps (constant OR come and go)
- Uterine Contractions
If you are noticing uterine contractions, cramping or backache:
- Drink 16 oz. of a non-caffeinated beverage and empty your bladder, then get in a warm bath or lie down, and count the contractions for an hour. Physical and/or emotional stress can increase the number and strength of Braxton-Hicks contractions, so the idea is to relax and de-stress.
Call your midwife if:
- you have six or more contractions in an hour;
- your contractions/cramps/backache are increasing in frequency, duration or strength
- you have risk factors for preterm labour, such as a personal or family history of preterm delivery
What causes preterm labour?
It is not known exactly what causes labor to start. Hormones produced by both the mother and fetus play a role. Preterm labour may be a normal process that starts early for some reason. Or, it may be started by some other problem, like infection of the uterus or amniotic fluid. In most cases of preterm labour, the exact cause is not known. Half of those who go into preterm labour have no known risk factors.
Why the concern?
Growth and development in the last part of pregnancy is critical to the baby’s health. If preterm labour is identified early enough, delivery can sometimes be prevented or postponed. This will give your baby extra time to grow and mature.
The earlier the baby is born, the greater the risk of problems. Preterm birth, especially very preterm delivery before 30 weeks, accounts for about 75% of newborn deaths that are not related to birth defects. Even “late preterm” babies, i.e. born between 34 – 37 weeks, can have problems such as maintaining a normal body temperature. Thus, if you are planning a home birth but find yourself delivering before 37 weeks, it will be recommended that you birth in the hospital.
Diagnosing Preterm Labor
Braxton-Hicks or practice contractions
It can be hard to tell the difference between true labour and strong Braxton-Hicks contractions. Braxton-Hicks start at around 12 weeks of pregnancy, and increase in strength in the third trimester as the uterus gets stronger in preparation for labour. At this time, pregnant people may begin to notice that their bellies regularly get hard (especially with movement such as during exercise, or caused by fetal movement). These “practice contractions” may even be painful and regular, but usually go away within an hour or with rest. Braxton-Hicks contractions can also last for extended periods of time, even up to an hour – these are generally reassuring, unlike intermittent contractions that increase in frequency, duration or strength.
True Preterm Labour
Preterm labour can only be diagnosed by finding changes in the cervix. This can sometimes be done by your care provider doing an internal exam (inserting two fingers into your vagina to feel the cervix). Other times, in the early stages of preterm labour, ultrasound will need to be used to confirm cervical shortening and/or dilation.