How can I get myself into labour?
This is a common question asked by a patient when she approaches her expected date of confinement (EDC), and especially if she goes past her EDC.
EDC and onset of labour
The first point to understand is that an EDC is an artificial date and is not meant to be used as the indicator of the date when labour will start. As well, pregnant women’s biological clocks have different settings. Some will deliver before their EDC and some after their EDC. Only about 5% of women go into labour on the actual EDC date.
In calculating the EDC, we add 38 weeks to a pregnant woman’s ovulation (viz. conception) date. As most women do not know the exact date of conception but do know the date of the last menstrual period (LMP), this calculation is based on the assumption that ovulation (viz. conception) occurs 14 days after the first day of the LMP. This is not necessarily the case. Ovulation can occur before or after day 14. The EDC date may be revised if a woman knows her actual ovulation or conception date or according to an ultrasound scan in early pregnancy that estimates the foetal size.
Even if we know the exact conception date, this does not mean her labour will start exactly 38 weeks later.
One Obstetric Unit I worked in as an obstetric registrar in the United Kingdom had two obstetrician consultants. One obstetrician had a more reasonable approach to how much a woman should go overdue before inducing labour, while the other obstetrician refused to induce labour simply because a woman went overdue. The second obstetrician consultant had women going to 44 and 45 weeks of pregnancy before they went into labour. This indicates for these women their biological clocks are set so their pregnancies lasted considerably later than their EDC date. On the other hand, some women will go into labour well in advance of their EDC date, indicating their biological clocks are set so their pregnancies last for shorter durations.
What is interesting is that there is usually consistency. So if a woman goes overdue with the first pregnancy she is most likely going to go overdue in the subsequent pregnancies. If she goes into labour before her EDC with her first pregnancy she is most likely going to have an early mark with other pregnancies’ labour onset and delivery before her EDC.
There is a popular myth in the community that a woman will go into labour after her EDC in her first ongoing pregnancy.
Signs that labour is likely to start soon include:
- Increasing uterine irritability.
- A show (a mucous vaginal discharge streaked with blood) indicating cervical change.
- The baby’s head engaging in the pelvis. A woman usually is aware of this by having a fullness feeling in her pelvis, wanting to go to the toilet more frequently (as the baby’s head presses more on the bladder) and a ‘lightening’ sensation (or ‘more room’ feeling) in her upper abdomen (which is associated with less indigestion and heartburn).
But on occasions, a show can happen and/or the baby’s head can be engaged weeks before labour starts. As well, a woman can go into labour without having had a show or without her baby’s head being engaged. In the second and any subsequent ongoing pregnancy it is most likely her baby’s head will not be engaged when labour starts.
What can stimulate labour onset?
Over the years, various approaches have been tried with varying success. How successful these approaches are has a lot to do with how ready a woman’s body is for her to go into labour. If it is not ready, then they are unlikely to work.
- Being very active. This includes lots of walking, exercising, housework, gardening and other physical activities. All can help. They make use of gravity where through your activity you are helping to push your baby’s head into your pelvis and against your cervix. My wife went into labour after we went on a long walk was around the streets of our suburb. Sometimes the increased activity is contraindicated so check first.
- Going on a car trip over bumpy roads can help. The bumping and jolting can cause your baby’s head to push more against your cervix.
- Sexual intercourse can help. Sex with deeper penetration so the penis stimulates the cervix can help. This may cause some minor bleeding from the cervix. It also may be uncomfortable and orgasm at this stage can be very intense and not as enjoyable for some women. Sometimes sexual intercourse is contraindicated so check first.
- Hot spicy food. Food with hot curry or chilli that brings out sweat and when you need to drink water while eating can help. But such food can cause heartburn so be careful
- Castor oil. This is an old-fashioned approach. Castor oil has been popular over the years to stimulate bowel activity. It can also stimulate uterine activity. In the past, women were given enemas when admitted to the labour ward to empty their bowels and stimulate the onset of labour.
- Cervical stretch and sweep. This is when I (your obstetrician) do an internal examination where I stretch your cervical canal and sweep the amniotic membranes away from the internal cervical os. It is more likely to help if your cervix is ready. If your cervix has started to dilate and shorten, your cervical os is anterior in position, your cervix is soft in consistency and your baby’s head is engaged and well applied to your cervix. But as well, I have had times when a cervical stretch and sweep has stimulated the onset of labour even though the cervix is not ready. A cervical stretch and sweep is usually a very uncomfortable internal examination. It is more uncomfortable if your cervix is not ready. This examination usually causes minor bleeding. It can cause uterine contractions without going into labour. It can result in rupture of membranes without going into labour. The onset of labour is not immediate after such an examination. It can happen even a couple of days later.