As a coffee and chocolate lover, I am the first to appreciate that they are both very difficult to limit, or even cut out of your lifestyle. However during pregnancy there are a variety of risks associated with caffeine intake. Each main risk factor is analysed in order to give you the bigger picture. Additionally we look at women who are at higher risk of each of these main risk factors, associated with caffeine intake.
Caffeine Intake During Pregnancy
Caffeine is both a diuretic and a stimulant. As a stimulant, it raises your heart rate and blood pressure, neither of which are recommended during pregnancy. As a diuretic it causes more frequent urination, which in turn can lead to your body fluid being reduced, which could cause dehydration.
What’s more is that caffeine crosses your placenta to baby, whose system is not sufficiently developed to handle the effects. Baby’s metabolism is still maturing and she is not able to fully metabolise the caffeine. She does not have the necessary enzymes to break it down. This can lead to changes in her normal movement pattern as well as her sleeping pattern.
Apart from coffee, caffeine is also found in some headache tablets that you can buy over the counter, chocolate, tea and soda.
What Are Some Of The Main Associated Risks With Caffeine In Pregnancy?
1. Risk of low birth weight
The definition of low birth weight is when the baby is less than 2.5 kg (5.51 pounds) at the time of birth, regardless of when the birth takes place. Although some low birth weight infants are healthy, there are numerous health risks associated with low birth weight, which could affect your baby. We’ve highlighted some of the main risks below:
Necrotizing enterocolitis (NEC) – this is an issue with the intestines which can lead to feeding problems. It can cause baby’s belly to swell as well as other complications. In more extreme cases surgery may be necessary to remove the damaged parts. If a baby has NEC she needs to be fed intravenously and take antiobiotics.
Patent ductus arteriosus (PDA) – unfortunately this is a rather common heart problem found in premature babies. The ductus arteriosus is a large artery that should let blood bypass baby’s lungs. It normally closes after birth letting the blood travel to her lungs and pick up oxygen. If it doesn’t however heart failure is a risk. PDA can be picked up on ultrasound, in which case the medical team can administer medicine which helps close the artery. In the instance that the medication doesn’t work then surgery may be the only choice.
Retinopathy of prematurity (ROP) – Generally ROP affects babies who are born at 32 weeks or earlier. The condition affects the eyes’ blood vessels. Many cases do heal themselves resulting in either no vision loss, or a little. However some babies do require treatment in order to combat vision loss.
Respiratory distress syndrome (RDS) – If babies are born at 34 weeks or earlier RDS is quite a common breathing problem. It occurs because baby hasn’t got a protein which is called surfactant. This protein is responsible for preventing the lung’s small air sacs from collapse. Babies are treated with surfactant to help them breathe, however in some cases they may also need oxygen.
Intraventricular hemorrhage (IVH) – Bleeding in the baby’s brain which can occur during the first 3 days after birth. Many of these are relatively mild and resolve themselves, leaving few or no lasting problems. However some can cause brain damage. Your baby may need medicine or in more extreme cases a tube may be inserted to drain fluid.
Problems Later In Life – there are also problems that can affect your baby later in life, such as diabetes, heart disease and high blood pressure.
Which Women Are At Higher Risk Of Having A Baby With A Low Birth Weight?
- High blood pressure
- Lung problems
- Heart problems
- Kidney problems
- Not gaining enough weight during pregnancy
- Drinking alcohol
- Taking street drugs
- Women under the age of 17
- Women over the age of 35
- Low income
- Low educational standards (lack of understanding re. Nutrition etc.)
Coffee and Tea During Pregnancy Affect Fetal Growth
A very extensive study which took place at the Sahlgrenska Academy at the University of Gothenburg studied 59,000 women. This found that even drinking two cups of coffee a day could cause lower birth weight in babies.
Maternal caffeine intake during pregnancy and risk of fetal growth restriction: a large prospective observational study
This study is published in the British Medical Journal on 3rd November 2008. It was set in two large UK maternity units. It studied a total of 2635 women who were considered low risk and were from 8 to 12 weeks pregnant.
Which Women Are At Higher Risk Of Having A Miscarriage?
- Smoking during pregnancy
- Use of street drugs in pregnancy
- More than 2 units of alcohol each week
- Very high blood pressure
- Kidney disease
- Coeliac disease
- Polycystic Ovary syndrome (POC)
- Womb structural issues such as fibroids or abnormal shape
- Weakened cervix
- Overactive thyroid gland
- German measles
- Bacterial vaginosis
Some medications can also cause miscarriage, however you should always check this with your doctor. Additionally the age of the woman heightens the risk of miscarriage.
Under 30 – 10% risk
35 – 39 – 20% risk
Over 45 – 50%+ risk
Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study
Published in the American Journal of Obstetrics and Gynecology, in 2008, this study concluded that women who drink more than 200 mg of caffeine each day have double the chance of miscarrying than their counterparts who don’t take any caffeine.
3. Premature Labour & Preterm Delivery/Birth
Premature labour or pre term labour is when labour takes place before the completion of 37 weeks of pregnancy. This can in turn lead to premature birth/preterm birth. When babies are born this early they can have serious health issues. In America there are almost half a million preterm births each year.
Although the issue is still a challenge for the medical community, there are a variety of factors that may put a woman at higher risk to experience preterm labour and birth.
Who May Be More At Risk?
(This is not an exhaustive list)
- Having had a premature baby previously
- Being pregnant with twins, triplets etc.
- Issues with the cervix or uterus – past or present
- Under or overweight before pregnancy
- Not putting on enough weight in pregnancy
- 2nd or 3rd trimester bleeding from vagina
- IVF singleton pregnancy
- Becoming pregnant too soon after last child birth
- Family history of preterm labour and birth
- Being exposed to DES – which is a man made version of estrogen
- High blood pressure
- Sexually transmitted diseases
- Other infections of the vagina, uterus or urinary tract
Below is one of numerous studies which have been carried out about the potential risk of caffeine intake during pregnancy and preterm labour and birth. The majority of studies do not find that there is a serious risk. However studies like these are generally carried out on women who are not considered high risk. This means that if you know you have any of the above risk factors that you need to consider that your caffeine intake will be different to that of women previously studied. This goes for any lifestyle choices that are not considered healthy during pregnancy. Each case is individual and you need to consult your medical team about your own.
Additionally as you will have read studies have proven that caffeine does carry other risks.
Caffeine consumption during pregnancy and risk of preterm birth: a meta-analysis
This study is a meta-analysis which examined the connection between consuming caffeine in pregnancy and the risk of pre term birth. The conclusion was that there no important association to be found.
Is It True That Caffeine Can Reduce Fertility?
Caffeine has also been linked to decreased fertility. The reason for this is that it reduces Fallopian tubes muscle activity. This means that the muscles that control the tubes where the eggs are carried from your ovaries to your womb have reduced activity. You can read more about the study in mice here.
All articles on the blog and website are intended as information only. Please do not consider any of the information provided here as a substitute for medical advice. At all times seek medical advice directly with your own doctor and medical team.