Scientists have long debated what causes morning sickness, and with up to 80 per cent of pregnant women suffering some symptoms it’s worth knowing what you can do about it.
For most pregnant women morning sickness is like a brief gaunt on The Good Ship Lollipop, queasy, unsettling, but transient in nature. As for myself, I was assigned to HMS Sirius, for a long and arduous journey on the high seas. My saving grace? Sausage rolls, at least three of them, consumed one after the other with orange juice every morning.
This became somewhat of a ritual for me and as long as I kept eating (mostly sausage rolls, unfortunately) it kept the nausea monster at bay. Eventually the winds died down, the seas turned calm and I was given permission to go ashore.
The sausage rolls worked for me, but everyone is different. While many pregnant women suffer from the same debilitating symptoms, there is no pattern, no template, and the jury is still out on how it all works.
Morning sickness – causes and treatments …
The classic misnomer
Morning sickness, or NVP (nausea and vomiting of pregnancy) as the medical community prefers to call it, is the classic misnomer: while it is predominantly worse in the morning, it can strike at any time and last all day long. Besides, it is not exactly a “sickness” in the pathological sense of the word, as it usually happens to healthy women who bear healthy babies.
There are some women who are predisposed to morning sickness: those who have a family history of it or who have had it with previous pregnancies, women who are sensitive to oestrogen found in birth control pills, or those who suffer from migraines or motion sickness. Multiple births and girl babies are also high on the list of culprits.
For the 50 to 80 per cent of pregnant women who experience morning sickness, the queasiness usually starts at around the six-week mark but can easily begin at four weeks. It settles down in about half of pregnant women at around 14 weeks, but for the rest, morning sickness takes another month or so to subside and, for an unfortunate few, it can be an ongoing battle until their baby is born.
Hormones and superhuman smells
Scientists have long debated the physiological mechanism that triggers morning sickness. Many believe it is related to the increased level of hormones, such as human chorionic gonadotropin (HCG), which is produced in large amounts very soon after conception in order to support the developing foetus.
Although it is not yet known how HCG causes nausea, the timing is appropriate as nausea tends to peak at around the same time as HCG levels. However, pregnancy hormones cannot by themselves trigger symptoms of morning sickness, but are usually triggered by certain sensory sensitivities.
In fact, pregnant woman will often attest to their almost superhuman sense of smell. This heightened sense of smell and taste is usually accompanied by food aversions, most commonly meats, fish, poultry and eggs. These are the kinds of foods that consistently trigger morning sickness and historically were most likely to carry harmful micro-organisms and parasites. Pregnant women are more susceptible to food-borne illnesses and diseases because their immune systems have been depressed to facilitate the developing foetus.
Some strong-tasting vegetables are also notably off the menu for a lot of women during early pregnancy. Certain food plants like broccoli and cabbage contain teratogenic phytochemicals – natural toxins that have evolved to protect plants from being eaten. While they pose no threat to most people, some phytochemicals can interfere with normal embryonic development, especially in the early stages of pregnancy.
Nowadays, refrigeration and safer food processes reduce the risk of food-borne diseases and vegetables have minimal phytochemicals because of artificial selection. These products contain important nutrients and vitamins so pregnant women should not omit them entirely from their diets.
Are there any benefits to having morning sickness?
Aversions to meats and certain vegetables make sense in evolutionary terms. In fact, in 2000, Dr Samuel Flaxman and Professor Paul Sherman, from Cornell University, New York, proposed that morning sickness was beneficial to both expectant mother and foetus. After analysing hundreds of studies covering tens of thousands of pregnancies, they suggested that by vomiting, and learning to avoid certain foods altogether, pregnant women not only keep themselves healthy, they also protect the developing foetus from potentially harmful components in food.
Further support for this theory is provided by the fact that morning sickness symptoms generally peak between weeks six and 18 of gestation. While the foetus is vulnerable to toxins throughout pregnancy, the first three months are most crucial. This is a time of rapid growth and development when the foetus is more susceptible to chemicals that can damage their organs. While it may make the mother feel dreadful, morning sickness, it seems, serves a useful function. Could it be that trying to alleviate the symptoms of “normal” (not severe) morning sickness will probably not help the outcome of a pregnancy and may interfere with this natural phenomenon?
Morning sickness and dietary considerations
Three years ago, Dr Gillian Pepper and Dr Craig Roberts at the University of Liverpool, UK, carried out 56 studies across 21 countries, which compared the rates of nausea and vomiting in pregnancy with diet. The research showed that morning sickness was more prevalent in those countries with a high consumption of macronutrients (kilocalories, protein and fat) than those with a high intake of cereals and pulses. In seven traditional communities with virtually no morning sickness, animal products were not part of the dietary stable.
It would appear that cultures that consume more meat, strong-tasting vegetables and alcohol have higher rates of morning sickness than those communities who eat mostly bland plant products. Which adds to the growing body of evidence suggesting a link between morning sickness and diet.
Does morning sickness harm the foetus?
Morning sickness is considered a normal part of early pregnancy and the medical fraternity seems to agree that uncomplicated morning sickness does not harm the foetus and is not a major drain on a pregnant woman’s resources.
During the first trimester there is not a great demand for nutrients by the foetus. In addition, any reduced nutrition of the mother that may be caused by vomiting does not have sufficient impact for concern.
A more severe form of morning sickness called hyperemesis gravidarum (HG) results in persistent vomiting and is associated with weight loss, dehydration and electrolyte imbalance. It affects one to three percent of women, who may require hospitalisation to avoid potential complications for mother and foetus. Research has shown HG increases the risk of miscarriage, premature delivery and low birth weight.
Is there a link between morning sickness and miscarriage?
Doctors have long advocated morning sickness as a positive sign of a healthy pregnancy and generations of pregnant women have accepted it as par for the course.
In 2006, the International Journal of Obstetrics and Gynecology reported that in a study of 7,000 pregnant women, those who had morning sickness in the first four months of pregnancy were less likely to miscarry. The National Institute of Health in the UK conducted a similar study and found that women who had morning sickness in early pregnancy were 30 per cent less likely to have a miscarriage.
Statistics for pregnant women who do not encounter morning sickness and sadly suffer miscarriages are somewhat elusive. Which also makes one wonder: if morning sickness is a by-product that indicates a healthy pregnancy then why does it not accompany all successful births? Why is it that some pregnant women get it and others don’t?
Still so much to learn about morning sickness
Medical research into the physiological workings of morning sickness has been extensive and insightful, the cause, however, is still unknown.
As a result, the management of morning sickness remains focused on alleviating the symptoms.
Since the thalidomide disaster of the 1960s, use of pharmacological treatments has been viewed with much trepidation. Morning sickness is therefore most commonly treated with dietary or lifestyle changes, as well as alternative therapies such as vitamins, herbal products, homeopathic preparations, and acupressure and/or acupuncture. Unfortunately, diet modification and avoiding certain foods does not work for everyone and there is still a lack of research to support or refute the benefits or risks of alternative approaches.
Morning sickness can dramatically affect a woman’s social, family and professional life. Further research into its cause and treatment may advance the use of natural, alternative and drug therapies with significant implications for the way pregnancy itself is handled. In the meantime, morning sickness will be, no doubt, the bane for many pregnant women for years to come.
How to ease your morning sickness
Almost 80 per cent of pregnant women suffer symptoms of morning sickness to varying degrees of severity. Every woman is unique and every pregnancy is different so what works to alleviate the symptoms of morning sickness for some will not work for others. However, if you are suffering from morning sickness, some of the following suggestions may help to ease the discomfort.
- Eat frequent, small meals. The emphasis traditionally has been on bland and dry foods, high protein snacks, and crackers at the bedside in the morning before getting up.
- Avoid aggravating smells, foods or beverages that can trigger nausea.
- Avoid fatty or spicy foods.
- Take sips of fluids throughout the day to prevent dehydration. Sports drinks that contain salt, glucose and potassium, or high-protein liquid drinks, are usually recommended.
- Put your feet up whenever you can, especially when you are feeling tired or nauseous.
- Avoid hot places (feeling hot adds to nausea).
- Get plenty of cool, fresh air.
- Exercise – within your comfort zone.
- Vitamins – the most extensively studied vitamin-based therapy is vitamin B6 (pyridoxine).
- Herbal products – ginger, chamomile, peppermint. Among these remedies, only ginger has been studied in well-controlled trials for the treatment of morning sickness.
- Acupuncture and acupressure – acupressure is one of the best-studied alternative remedies for morning sickness. The acupoint is located on the inside of the wrist and is thought to relieve nausea and vomiting.
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