Pregnancy, like any other event in life also has an end. The process of delivering the baby is called labor. More correctly, labor is defined as a series of involuntary, continuous, progressive contractions of the uterus that help the cervix dilate (open) and efface (thin). This allows the fetus to move through the birth canal and be delivered. The exact time of labor is not exactly known, however, the due date can be safely estimated from the first day of the woman’s last menstrual period. This is anticipated to be about 40 weeks from that date. It can also be estimated from an ultrasound done during the pregnancy. Early ultrasounds within the first 12 weeks are more accurate to predict the date of delivery. Even though there are exceptions, normally, Labor which signals the start of delivery occurs within 2 weeks before or after the due date. This period is filled with anticipation and expectations of the precious moment when a mother meets her baby for the first time. It is also filled with fear of the unknown, pain, and dread of what might happen and what might go wrong. In a first pregnancy, labor usually lasts 12 to 18 hours on average; subsequent labors are often shorter, averaging 6 to 8 hours.
What is normal labor?
According to the World Health Organization (WHO) a normal birth is said to have occurred when:
The birth is spontaneous in onset and low risk at the start of labor and remains so throughout labor and delivery. This means the labor starts on its own, and progresses smoothly without any complications.
The infant is born spontaneously in the vertex (head down) position between 37 and 42 weeks of pregnancy.
After birth, the mother and baby are in good condition.
Nobody really can predict that a labor will be normal. This is because the process and the body’s response can be very unpredictable. Even though some pregnancies may seem perfectly normal and labor seems good at the start, complications may arise in the course of the labor, while some other pregnancies where complications are expected in labor may just end smoothly. Normal labor is therefore a retrospective diagnosis made after the birth of the child.
What happens during the stages of labor?
Labor is a continuous process but for ease of management, it is divided into 3 stages. This makes it easy to know what to anticipate and detect issues in the early stages.
The 1st stage of labor is from onset of labor to when the cervix is fully dilated (about 10 cm). It is heralded by the beginning of persistent contractions. These contractions become stronger, more regular and more frequent over time. They cause the cervix to open (dilate) and soften as well as shorten and thin (efface) to allow the baby to move into the birth canal. This first stage is the longest of the three stages. It’s actually divided into two phases, early or latent labor and active labor.
Early labor is unpredictable. For first-time moms, the average length varies from hours to days. It’s often shorter for subsequent deliveries.
In active labor, the cervix will further dilate from 6 centimeters (cm) to 10 cm. The contractions will also become stronger, closer together and regular. Most women would have been in the hospital at this stage. This stage can last between 4 to 8 hours as the cervix dilates approximately 1cm per hour, although it can last longer if a woman is given epidural. If this stage is not progressing well or an issue is noticed, the doctors may opt for a caesarean section and terminate the process of labor.
The second stage of labor lasts from when the cervix is fully dilated to when the baby actually comes out. This stage can last at most 2 hours (median 50 minutes) in first time mothers and 1 hour (median 20 minutes) in subsequent deliveries.
The third stage, which is the shortest stage is called the after birth which lasts from the delivery of the child to delivery of the placenta. Even though this stage is short, most cases of excessive bleeding in pregnancy (hemorrhage) occurs at this stage if not managed properly.
How does labor start?
Normal labor usually begins within 2 weeks (before or after) the estimated delivery date. The exact stimulus for labor is unknown, but digitally manipulating or mechanically stretching the cervix during vaginal examination by the doctor enhances uterine contractile activity and contractions, most likely by stimulating release of a labor inducing hormone, oxytocin by the posterior pituitary gland.
Researchers however claim that when a baby is ready for life outside his mother’s uterus, his body releases a tiny amount of a substance that signals the mother’s hormones to begin labor.
What are the signs that labor is close?
The signs of labor vary with different individuals, however, there are some well documented signs that show that labor is imminent, even as close as 24 to 48 hours away. These signs are:
- Lightening. The baby drops and takes a comfortable position further down the pelvis in preparation for the big day. The bump will appear to have ‘dropped’ lower and the woman will notice more waddling as she walks. This occurs about 2 to 4 weeks before labor in first time mothers and during labor in subsequent births.
- Braxton Hicks contractions. These are false contractions that occur as a form of ‘test running’ of the real contractions. They are mild, can occur at varying intervals and gradually ease off after a while. In some cases, they may persist and culminate into true labor.
- Nesting instincts. This is the burst of energy women often get in the last few weeks of pregnancy that inspires them to clean and organize the house in preparation for baby’s arrival. This is a sign for a lot of women that labor is very close.
- Increased lower backache. This is a gradual worsening of the dull back ache which may have been noticed in the third trimester.
- Weight gain stops.
- Stomach cramps
- Loose-feeling joints
- Dilation and other cervical changes. The cervix would begin to get softer and shorter, and also gradually begin to dilate or open up. This is usually noticed by a doctor during a vaginal exam. It is a sign that labor may be days or hours away.
- Bloody show. This is when the plug of mucus from the cervix comes away. It is usually noticed as a plug of mucus which is usually bloody in the underwear. It is advisable to contact the doctor if unsure if it is bloody show or bleeding. Bloody show usually signals that labor is not more than 48 hours away.
- Water breaking. This occurs when the amniotic membrane which is the protective cushion for the baby breaks. The fluid is let out as a gush of water. It is usually noticed as a sudden, involuntary wetting of the underwear with clear, fluid which is mostly too much to be urine. This is usually the harbinger of labor. Because the protective layer for the baby has been compromised, if labor does not start within 24 hours after this, a cesarean section is performed to reduce the risk of infection.
- Contractions or tightening. This is the commonest sign that labor is imminent and the most common signal to go to the hospital for women. The contractions are painful uterine contractions that feel like a tight squeeze of the abdomen and lower back. These will continue and increase in frequency and intensity until the woman delivers her baby.
If you are in your third trimester and notice any of the above symptoms, especially the last 3 symptoms, do contact your midwife to know when to come in to deliver your baby.