Induction of labour
Most women (92%) will begin labour spontaneously by 42 weeks gestation. With more accurate dating scans available there is less uncertainty about the due date than there was in the past. The due date is calculated as 280 days from the date of the last menstrual period. However, women vary in cycle length so a cycle which is typically longer than 28 days may result in a later delivery date and similarly a shorter cycle will often result in an earlier delivery. No-one really knows what triggers natural labour.
The Cochrane collaboration 2012, looked at 10 studies involving about 6,000 women and whether inducing birth one week after the due date produced significant benefits. They showed that doing so:
Being up to one week “late” is not associated with any particular risks for either mother or baby.
Other risks for inducing labour include concerns over the health of mum or baby due to high blood pressure (pre-eclampsia potentially fatal eclampsia), spontaneous rupture of membranes without labour beginning, diabetes, and growth of the baby slowing (Galal 2012).
Many inductions beyond 40 weeks of pregnancy begin with a sweep of the cervix by the midwife to encourage it to thin and open. Pharmacologically most inductions commence with vaginal application of a prostaglandin gel or tablet or controlled-release pessary (the latter is intended to act over a period of 24 hours). If labour has not begun within six hours then a further dose may be given.
Prostaglandins are drugs that help to induce labour by encouraging the cervix to soften and shorten (ripen). This allows the cervix to open and contractions to start. Before giving prostaglandins your baby’s heartbeat will be checked. After being given prostaglandins you will usually be asked to lie down for approximately one hour to ensure the absorption of the pessary. After this you can move about as normal and if all is satisfactory to return home to wait for contractions to start.
We know that animals who labour in a dark environment in which they feel comfortable will birth more easily. Our own mammalian bodies also prefer our own space and transfer to a hospital or maternity unit may slow contractions as our bodies are flooded with adrenaline which works against oxytocin which is so implicitly involved in birth. Induction of labour goes against all of this natural environment. It may also lead to interventions including epidural and stronger pain relief as a result of the rapid increase in strength and frequency of contractions.
If further help is still needed to speed labour you may be given oxytocin (Syntocinon®) via a drip. The rate at which the drug is given can be adjusted according to your response.
If possible moving around in labour helps to relieve pain and speed delivery. Try not to stay horizontal on the bed as this narrows the pelvis making contractions less effective. You may be able to use a bath for pain relief, massage from your partner, relaxation tapes or hypnosis, TENS machine or heat packs as well as prescribed medication or gas and air
Many women may feel the need for some pain relief – that might be paracetamol or something stronger. Currently, the option may be codeine or dihydrocodeine tablets or an injection of pethidine or more rarely diamorphine.
Pethidine is less frequently used than it was 40 years ago. The timing of the administration of pethidine in relation to birth is important. If it is given within 3 hours of birth the baby may be born still being affected by the amount transferred through the placenta. Hogg estimated that if given late in labour the baby may continue to be affected for 2 to 3 days because the baby’s liver and kidneys are too immature to metabolise it as effectively. Whilst the half-life of pethidine in an adult is less than 4 hours, in a new-born has a median of 11 hours but studies have measured times up to 60 hours. The baby may be very drowsy after delivery and reluctant to feed risking hypoglycaemia as well as the multiple opportunities to stimulate the mother’s milk supply. In a report by The National Birthday Trust back in 1993 36.9% of pregnant women received it during labour. Rajan (1994) noted that the pain relief delivered by pethidine in labour is not as effective as might be hoped and has a tendency to make the mother drowsy so that she wakes to full consciousness as the pain of her contraction is increasing and she tenses rather than riding the pain and breathing through the contraction.
Alternatives used more recently have included injections of diamorphine which has a much shorter half-life than pethidine.
Discussing your wishes in advance with your birth partner and having a birth plan prepared are good. However, these may need to be flexible as no one knows how labour will progress. You may find that induction or augmentation of labour is more painful. The baby may be laying back to your back which can produce a longer and more painful labour (sitting back to front on a chair leaning on the back can help with this type of labour). If your labour slows down or the baby shows signs of distress you and your birthing team may need to consider assisted delivery or an emergency caesarean section.
Caesarian sections are performed in about 24% of births in the UK. Many now take place as epidural deliveries using fentanyl, although in an emergency an operation under general anaesthetic may be necessary. The drugs used in general anaesthetics pass out of the body in a very short space of time and if the health of mother and baby permits, the baby may be put to the mother’s breast whilst she is still in recovery. More and more frequently babies are placed in skin to skin in the operating theatre allowing the breast crawl and first feed to take place just as in a natural birth.
In theatre, most women are given an injection or a suppository of morphine to provide pain relief over a number of hours after the surgery. Others may be given diclofenac as a suppository. Postoperatively the analgesia depends on the mother’s needs but includes Oramorph liquid, patient-controlled morphine, regular paracetamol plus non-steroidal drug (naproxen, diclofenac or ibuprofen), tramadol, codeine or dihydrocodeine. All of these drugs can be taken by a breastfeeding mother although the reaction of the baby to the opiate drugs should be monitored. If the baby becomes excessively sleepy or reluctant to feed, the painkillers should be reconsidered.
It can be very difficult to move around after a c- section including lifting the baby to feed so pain relief cannot be underestimated. If you take opiate painkillers you will also find the fourth stage of labour otherwise known as constipation! Keep your fluid levels up as well as consumption of fruit and vegetables. If you need laxatives to help those which help to bulk and soften may be best sooner rather than later. You can take these and breastfeed as normal.
This involves the injection of an anaesthetic into the epidural space in the spine via a very fine needle. The anaesthetic numbs the spinal nerves, blocking the pain signals from the lower part of the body. Epidurals are widely used in caesarean sections to allow the mother to be aware of the birth of her baby. They normally contain fentanyl or sometimes remifentanil. Epidurals can cause your blood pressure to drop making you feel dizzy and sick. Some studies have found that epidurals cause babies to feed less frequently after delivery but this could be due to the more complex labour. Prolonged skin to skin with the baby lightly covered on the mother’s chest with or without feeding helps to stabilise the baby’s temperature, heart rate and blood glucose levels.
Gas and air (Entonox) are widely used (approximately 80% of mothers) in well-established labour. It provides some detachment from the pain. It is composed of half nitrous oxide (laughing gas) and half oxygen. It does not affect your unborn baby as it is impossible to overuse it. If you breathe in too much you become drowsy and let the mouthpiece go.
Syntocinon (oxytocin) can be given to manage the third stage of labour. The injection is given just after the birth of the baby to stimulate the womb to contract. This helps the placenta to separate from the womb speeds up delivery of the placenta and reduces the risk of heavy bleeding. Syntocinon may pass into breast milk in small amounts, but as it is a normal component of breast milk and is one of the hormones needed to produce breast milk, it will not have any harmful effect on breastfeeding the new-born baby. It is rapidly inactivated in the baby’s gut further reducing any risk to the baby. Breastfeeding is associated with the release of oxytocin too so causes the womb to contract to its pre-pregnancy size faster (involution).
Postpartum bleeding or postpartum haemorrhage (PPH) is often defined as the loss of more than 500 ml or 1,000 ml of blood within the first 24 hours following childbirth. It is sometimes recommended that babies of mothers who have received Syntometrine (ergometrine and oxytocin) do not receive breastmilk for 12 hours and that the mother should pump and dump her colostrum on the grounds that ergometrine is secreted into milk and the inhibitory effect of ergometrine on prolactin can cause a reduction in milk secretion. Pumping at this stage would only exacerbate potential low milk supply. There seems to be no reason why breastfeeding should be interrupted as the actual amount secreted in the small volumes of colostrum is low. It may result in a longer delay until full milk production. However, the baby will receive colostrum as it needs and requires no additional supplementation.
Extreme loss of blood (life-threatening leading to the need for blood transfusion) may lead to Sheehan syndrome which may lead to damage to the pituitary gland. This may lead to very low milk production and low blood pressure as well as fatigue. It is rare but should be investigated if there has been a large blood loss at delivery and the mother is struggling to breastfeed.
Raised blood pressure during pregnancy is often a sign of pre-eclampsia. It reduces the blood flow through the placenta to the baby and can result in intrauterine growth retardation (IUGR) so that the baby may be born small for dates. It is important to be aware of the risk of headaches and visual disturbances which may reflect a worsening of the condition and the need for urgent medical attention which may involve delivery of the baby around 37-38 weeks of pregnancy.
The most commonly used anti-hypertensive drug is labetalol. This is a beta blocker which passes through breastmilk in low levels and can be continued after delivery. Beta blockers are associated with changes in blood sugar levels and it is usual to monitor babies exposed to these drugs carefully after delivery. This may involve measurement of blood sugar levels but should include encouragement of regular breastfeeds (or hand expression of colostrum to encourage the establishment of a good milk supply) and assessment of attachment by someone with expertise in breastfeeding. Such monitoring is not related simply to the drug but also to the fact that the baby may be low weight and delivered early.
Because caesarean sections involve a surgical incision a single injection of antibiotics will normally be given in theatre to minimise the risk of infection. Antibiotics may also be prescribed for wound infections or delay in healing of episiotomy.
Homeopathic arnica is taken by some mothers to reduce bruising and aid healing following delivery. The amount passing through breastmilk is minuscule and will not affect the baby.
The risk of developing a clot persists for 6 weeks after birth which is why in some women with a combination of risk factors e.g. c section and excess weight (BMI over 30), multiple births, or being a smoker, will be routinely given a prescription of injections to thin the blood. These are usually called low molecular weight heparins and include dalteparin (Fragmin ®), enoxaparin (Clexane®), and tinzaparin (Innohep®).
If there are concerns that a clot has formed you may be given a VQ scan (which necessitates dumping milk for a period up to 12 hours) or a CT scan (after which you can breastfeed as normal).
Very sadly we have to remember the births where there is no baby to take home, the babies born sleeping or who die soon after birth. The mother’s body does not register that there is no baby to be nurtured by breastmilk and will continue to produce milk as normal.
In the past medical professionals have often hastened to prescribe drugs like bromocriptine and cabergoline to dry up the milk as quickly as possible. These drugs have very severe side effects such as vomiting, postural hypotension, fatigue, dizziness, dry mouth; also, particularly with high doses, confusion, psychomotor excitation, hallucinations; rarely diarrhoea, gastro-intestinal bleeding, gastric ulcer, abdominal pain, tachycardia, bradycardia, arrhythmia, insomnia, psychosis, visual disturbances, tinnitus. Cabergoline can also cause depression. They should be avoided if the mother has experienced pre-eclampsia. Both drugs can produce sudden onset sleep or excessive daytime drowsiness and driving should be avoided.
Although bromocriptine and cabergoline are licensed to suppress lactation, they are not recommended for routine suppression (or for the relief of symptoms of postpartum pain and engorgement) that can be adequately treated with simple analgesics and breast support. If a drug is required, cabergoline is preferred but it causes difficulties if the mother later changes her mind and wishes to continue breastfeeding.
Extracts taken from “Why Mothers Medication Matters” Jones W Pinter and Martin 2017
