Why is the first trimester at high-risk for loss of pregnancy (miscarriage)?

The first trimester is considered a high-risk period for miscarriage (pregnancy loss).  Approximately 80 per cent of miscarriages happen during this time before the 12 week of pregnancy. Miscarriages in the second trimester happen to 5 per cent pregnancies.

So while the first trimester is associated with the highest risk of miscarriages, you must remember that most people have healthy pregnancies and healthy babies.  But if you experience any alarming symptoms, such as vaginal spotting or bleeding, pain or cramping in your abdomen or lower back or discharge of fluid or tissue from your vagina, it’s important to contact your doctor right away.

Just as the first trimester is the most crucial to your baby’s development, when the baby’s heart begins to beat, unfortunately most miscarriages occur during this phase because the foetus isn’t developing as expected. About 50 per cent of miscarriages are associated with extra or missing chromosomes. Foetal Chromosomal abnormalities are the primary cause for loss of pregnancy at this stage.

There are many reasons why a miscarriage can occur in the first trimester –

• Chromosomal abnormalities: Chromosomal abnormalities in the baby cause about 50 per cent of all miscarriages in the first trimester. Of all the chromosomal disorders, abnormalities in chromosome number are the most easily identifiable. Some of the most common chromosomal abnormalities include: Down’s syndrome.
• Hormonal Imbalance – A hormonal imbalance happens when you have too much or too little of one or more hormones.
• Health Conditions – Pregnant women with uncontrolled hyperthyroidism (overactive thyroid) and hypothyroidism (deficiency of thyroid hormones) do appear to be linked with miscarriages. Or there could be excessive or abnormal clotting in the small blood vessels of the placenta. Blood clotting disorders can also cause poor foetal growth, and foetal loss.
• Lifestyle Choices – During pregnancy, you must maintain or acquire healthy habits to protect both your own health and your baby. Avoid the consumption of toxic products such as tobacco and alcohol. Pregnancy is a crucial stage in which you must adopt healthy lifestyles so that progression of her pregnancy proves to be adequate and successful. Poor lifestyle choices can lead to miscarriages.
• Maternal age – There is no universal definition of advanced reproductive age in women, although it is for certain that fertility clearly declines with advancing age. The risk of miscarriage increases with maternal age. Miscarriage rates increase steadily with age, with more substantial increases after age 35.
• Unknown – a lot of times we do not know the exact cause.

While there’s no guaranteed way to prevent miscarriage, there are some steps that you can take to reduce their risk which includes eating a healthy, balanced diet and exercising regularly. Have a discussion with your doctor to help you to work out which treatment options are best and safest for you.