SingaporeMotherhood | Pregnancy

February 2022

Misconceptions about Miscarriages Cleared Up

The birth of a new baby is a joyous occasion. However, for every mother who carries a precious pregnancy to term, there may be a friend or relative who miscarries. Such a loss triggers myriad emotions — anger, guilt, sadness, fear — and questions that often go unasked, and unanswered. This has led to a general lack of understanding about miscarriages. Dr Zeng Shanyong of DTAP Clinic helps address some common misconceptions about miscarriages, while shedding light on the causes and risk factors involved.

First of All, What is a Miscarriage? 

Simply put, a miscarriage, otherwise known as spontaneous abortion, is the unexpected ending of a pregnancy.

Common Misconceptions about Miscarriages

There are many misconceptions regarding certain lifestyle choices during pregnancy that can result in miscarriages. There is no truth to them. However, certain harmful practices should be avoided to reduce the risk of miscarriages. Let’s break down what’s true and what’s not.

miscarriages is not a failure
Image: Unsplash

Miscarriages are rare — FALSE

Miscarriages in early pregnancy are extremely common. Studies have shown that approximately 8 to 20 per cent of women who know that they are pregnant have a miscarriage some time before they reach 20 weeks of pregnancy. In fact, 80 per cent of those miscarriages occur in the first 12 weeks.

However, actual rates of miscarriages are likely higher, as they can occur even before the pregnancy is known. Some studies estimate that rates could be as high as 30 per cent.

However, miscarriages after a 20-week gestation period are relatively rare, accounting for only 1 per cent of total miscarriages.

Miscarriages are preventable — FALSE

The truth is that most miscarriages are unpreventable due to factors out of one’s control. During early pregnancy, more than 50 per cent of miscarriages are due to chromosomal abnormalities in the embryo.

Extra chromosomes, such as in Down Syndrome, can lead to developmental abnormalities resulting in a spontaneous abortion. These abnormalities are not within anyone’s control. Unfortunately, the lack of recognition for this fact often leads to immense guilt for the mother.

(See also: Prenatal Scans and Tests for your Peace of Mind when Pregnant)

Having one miscarriage means you are likely to have another miscarriage — FALSE

Miscarriages are one of the most common complications of pregnancy. However, a single miscarriage does not mean that subsequent pregnancies carry an increased risk of miscarriages. Prospective studies show that overall risk of miscarriage remains at 15 per cent, a baseline risk after one miscarriage.

However, recurring miscarriages do increase the risk of subsequent miscarriages. The same studies show that the risk increases by 17 to 31 per cent after two consecutive miscarriages. This increases further to 25 to 46 per cent after three or more miscarriages.

does exercise cause miscarriages

Exercise can induce a miscarriage — FALSE

For majority of mums-to-be who are healthy and are having uneventful pregnancies, most exercises are safe and do not increase the risk of spontaneous miscarriages. If you are already an experienced sportswoman to start with, it should be safe to continue with your normal activities after consulting your doctor.

There are certain sports that should be avoided. Contact sports like boxing, basketball, and football can lead to abdominal trauma. Sports like off-road cycling, skiing, and surfing can increase the risk of falls and should be avoided as well. The safest exercises during pregnancy, according to the American College of Obstetricians and Gynecologists, are walking, swimming, and water-workouts, stationary bike cycling, and modified yoga/Pilates.

However, women with certain medical conditions or complications during pregnancy should not exercise during pregnancy. For example, certain heart and lung conditions, severe anaemia, pregnancy with twins or triplets, pre-eclampsia, and placenta previa. Always consult your healthcare providers before embarking on exercises during pregnancy if you have any existing medical conditions or experience pregnancy complications.

(See also: Exercise during Pregnancy: What you need to know)

Sex can induce a miscarriage — FALSE

When the pregnancy is uneventful, having sex is safe and will not lead to spontaneous miscarriages. The developing foetus is well cushioned by the strong walls of the uterus as well as the amniotic fluid. The mucus plug in the cervix also prevents infection from ascending into the uterus.

There are, however, a few conditions when sex should be avoided. When the placenta is lying directly over the cervix, a condition known as placenta previa, penetrative sex can cause bleeding. Sex should also be avoided during preterm labour, as well as when the amniotic sac has ruptured, as it could lead to an ascending infection into the uterus.

Stress and injuries can induce a miscarriage — PARTIALLY TRUE

Up to 75 per cent of women believe that maternal stress can induce an abortion, though everyday stressors such as arguments and disagreements with spouses are unlikely to harm the foetus. However, prolonged exposure to stress, such as living in poor conditions or staying in abusive relationships, can impair one’s mental health and increase the risk of spontaneous abortion.

Similarly, the foetus is unlikely to be affected from falls and minor bumps to the belly as the uterus cushions it with strong muscular walls and amniotic fluids. However, significant trauma such as car accidents, or even medical procedures like chorionic villi sampling or amniocentesis can potentially cause pregnancy loss.

does caffeine cause miscarriages
Image: Unsplash

Caffeine increases the risk of miscarriages — UNCERTAIN

The effect of caffeine on miscarriages is uncertain, with multiple studies providing mixed reports.

A review of the medical literature in 2011 noted that intake of caffeinated beverages did not increase the risk of spontaneous pregnancy loss, even at the amount of around 10 cups of coffee per day. Many studies did not observe an association with miscarriages with any degree of caffeine exposure.

For the studies that do, there seems to be a relationship between the dose of caffeine and the risks of spontaneous miscarriage. However, the ‘safe’ threshold differs from study to study. Some report increasing risks at more than 300 mg of caffeine per day, about three cups of coffee. Others say the risk increases from above 100 mg of caffeine per day.

As the results are inconsistent, we are uncertain of the risk of caffeine on miscarriages. However, a very low dose of caffeine, i.e. a small cup of coffee or tea daily, appears to be safe.

(See also: Super 7: Popular Tonics and Supplements for Pregnancy and Beyond)

Smoking increases the risk of miscarriages — TRUE

Smoking has been associated with numerous adverse pregnancy outcomes, such as placental abruption, preterm labour, and low birth weight. It may also have a modest effect on miscarriages.

Mums-to-be who smoke increase the relative risk of miscarriage by around 1 per cent per cigarette smoked per day. Passive smoke exposure through partner smoking also increases the risk of miscarriages by around 17 per cent.

Alcohol consumption increases the risk of miscarriages — TRUE

Alcohol is a teratogen, which can cause physical, mental, behavioural, and cognitive problems to the developing foetus with in-utero exposure. The most severe consequences of prenatal alcohol exposure are stillbirths and a condition known as Foetal Alcohol Spectrum Disorder (FASD).

A study in the United States also noted that alcohol exposure during weeks 5 to 10 of pregnancy was associated with increased risk of early pregnancy loss. Each successive week of alcohol exposure causes an 8 per cent increase in risk of early pregnancy loss compared to non-drinkers, with the risk being cumulative. There is no confirmed ‘safe’ threshold for alcohol exposure during pregnancy. Hence the safest approach is to avoid it altogether.

Risk Factors and Causes of Miscarriages

children with Down syndrome - dna

Congenital chromosomal abnormalities make up the most common causes of miscarriages by far. However, there are also other maternal factors that can lead to spontaneous pregnancy losses: 

  • Uterine abnormalities: Abnormalities within the uterus such as fibroids, adhesions, or an incompetent cervix, can lead to second-trimester pregnancy losses.

  • Infections: Various infections have been associated with increased risk of miscarriages. For instance, untreated syphilis leads to a 21 per cent increased risk of foetal loss and stillbirth. Parvovirus B19, Zika, and Cytomegalovirus infections are also associated with increased risk of pregnancy loss at 8, 6, and 2.5 per cent respectively.

  • Maternal age: Increasing maternal age increases the risk of pregnancy loss. Starting from the age of 35 years and up being the most significant risk factor. This is due to the higher likelihood of foetal chromosomal abnormalities.

  • Diabetes: Uncontrolled diabetes can result in lethal foetal anomalies and foetal loss. Fortunately, good sugar control preconception can bring the risk back to the baseline.

  • Obesity: Having a Body Mass Index of more than 25 increases the risk of pregnancy loss within the first 20 weeks of gestation by nearly 70 per cent.

  • Thyroid disease: Both uncontrolled hyperthyroidism and hypothyroidism have been associated with increased risk of pregnancy loss. Some studies suggest that it can double the baseline risk.

(See also: Dealing With Miscarriage)

Recurrent Pregnancy Loss

Some unfortunate couples experience recurrent miscarriages. For women with two or more failures of clinically recognised pregnancies before 20 to 24 weeks of gestation, this is termed Recurrent Pregnancy Loss (RPL).

Unfortunately, there is no singular treatment available for RPL. The main goals are to identify and treat any reversible maternal and foetal risk factors for miscarriages. This involves a complete medical, surgical, genetic, and family history check-up with a physical examination.

It may also involve medical imaging of the uterus, a genetic analysis of both parents, as well as a full medical workup to identify any underlying medical conditions that the mother may have. 

Thankfully, even with RPL, most women have a good prognosis for eventually having a successful pregnancy. This is true even without a definitive diagnosis and treatment. One study estimated that the overall live birth rates after a diagnosis of RPL range from 71 to 77 per cent.

(See also: True Story: Baby after Cancer, Business after Miscarriages)

How to Ensure a Safe Pregnancy Journey

Even though miscarriages are fairly common and sometimes unpreventable, there are still many things we can do to help give Baby the best chance at life. Getting regular health check-ups, a healthy lifestyle and diet, and sufficient prenatal vitamins are just some of the many things that can help increase the chances of a safe pregnancy.

Pregnancy is just the start of a wonderful journey that does not end with birth and will last for a lifetime. Many mothers look back fondly on the times when they were pregnant as this is the time when they were closest in body and spirit with their children.

So for all the expecting mummies out there, enjoy the ride! Despite morning sickness, the constant need to urinate, backaches, leg swelling, and breathlessness, when you finally hold your wailing newborn in your arms, you will look back and remember the most magical nine months of your life.

(See also: Pregnancy Self-Care, Trimester-by-trimester)

Dr Zeng Shanyong is the resident doctor at DTAP Clinic. He graduated from the Yong Loo Lin School of Medicine, National University of Singapore in 2010 with a Bachelor of Medicine and Bachelor of Surgery. He subsequently attained his postgraduate qualifications for Membership to the Royal College of Physicians (UK) in 2017 and his Masters of Medicine in Internal Medicine in 2018. Dr Zeng firmly believes that holistic patient care is at the very heart and soul of his medical practice.

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Misconceptions about Miscarriages Cleared Up