Introduction

Pregnancy is a joy for many women around the world, but it is just more than that. It is also a complex biological process, with many factors influencing the health of both the mother and the baby. 

One of these factors is maternal age, which plays a significant role in the likelihood of chromosomal abnormalities. 

While conditions like Down syndrome are commonly associated with maternal age, a lesser-known but equally significant condition is triploidy.  

Triploidy is a rare chromosomal disorder where the baby inherits an extra set of chromosomes, resulting in a total of 69 chromosomes instead of the normal 46. This condition is almost always fatal, leading to miscarriage or stillbirth, but in what way, if any, does maternal age influence the risk of triploidy?

In this article, we’ll explore what triploidy is, how it happens, and whether maternal age increases the chances of this condition occurring.  

What is triploidy?  

To understand triploid, we need to understand that chromosomes come in pairs of twenty-three.  During conception, when the egg and sperm meet, each of the biological parents gives you 23 chromosomes, which equals one set. Each set contains 22 numbered chromosomes (autosomes) and one sex chromosome (X or Y) that determines the baby's sex. So, biological chromosomes pair up to equate 46 total chromosomes.¹

Think of it this way, chromosomes come in as a set of twenty-three married couples, each of them coming from the mother and father.

Triploidy is a type of chromosomal abnormality where an embryo receives an extra full set of chromosomes, meaning three sets instead of two in each of the twenty-three pairs. This extra genetic material disrupts normal development, leading to severe abnormalities. 

Triploidy is rare and affects 1% to 3% of all pregnancies in the United States, which accounts for an estimated 30,000 to 200,000 pregnancies. Over 66% of all triploidy cases affect male fetuses.¹

The condition causes several congenital growth abnormalities, and usually, most pregnancies end in miscarriage. If the child survives to term, they could be cases of stillbirth or early infant death.¹

Maternal age and its link to triploidy 

While maternal age is a well-known risk factor for trisomy conditions, which should not be confused with triploidy. There are no studies that have found a definite relationship between maternal age and triploidy.³

So while maternal age may strongly influence trisomy conditions, its role in triploidy is minimal or nonexistent.  

Triploidy can occur by abnormal fertilisation:  

• Digynic: which is when the mother provides the extra set of chromosomes before it is fertilised by a sperm with its own single chromosome, and older eggs are more prone to meiotic errors. At this moment, studies have not found a significant increase in triploidy cases among older mothers⁴ 
• Diandric: occurs when the father provides the extra set of chromosomes. So his sperm has two chromosomes that fertilise a single ovum

These abnormal fertilisations help us to classify triploidy into

• Type I occurs in diandric fertilisation, with the fetus showing moderate growth delay, normal or small head and an enlarged placenta
• Type II is seen with digynic fertilisations where the fetus has severe growth delay in their hands and feet, and trunk²

Risk factors beyond maternal age  

Triploidy is rare and affects 1% to 3% of all pregnancies in the United States. Over 66% of all triploidy cases affect male fetuses.

And while maternal age may not be a sound factor to consider, there are many other contributing factors to the occurrence of triploidy:

• Paternal Factors – as mentioned earlier, certain sperm abnormalities may increase the risk of diandric triploidy⁵
• Assisted Reproductive Technologies (ARTs): Some studies suggest a slightly increased risk of triploidy in pregnancies conceived through IVF, but the data remains inconclusive⁶
• Environmental and Genetic Factors: are rare, and certain genetic predispositions or environmental exposures may increase the likelihood of meiotic errors²

Signs and symptoms 

The signs and symptoms can be divided into maternal and infant symptoms.

Maternal symptoms

Pregnant women carrying fetuses with triploid syndrome may have preeclampsia. certain symptoms of this condition include:

• Albuminuria
• Edema
• Hypertension

Fetal symptoms 

Chromosomes inherited from the father  can cause 

• Small heads 
•  An enlarged
• Cyst-filled placenta 

While the chromosomes inherited from the mother can cause severe growth problems, 

• An enlarged head
• A small placenta without cysts 

Most unborn babies affected with triploidy are spontaneously miscarried early in the pregnancy, and if the pregnancy continues to term, the baby dies within the first days of life.²

Infancy symptoms 

Infants with triploidy who have reached the full-term stage often have one or more birth defects after delivery, including:

• Cleft lip and cleft palate
• Heart defects
• Kidney defects, like cystic kidney
• Twisted intestines.
• Liver defects
• Gallbladder defects
• Short neck
• Facial differences including;
• Wide-spaced eyes, low nasal bridge,
•  Low-set malformed ears, small jaw
• Absent/small eye 
• Deformities of the fingers and toes
• Neural tube defects, like spina bifida
• Growth restriction
• Multiple birth defects, including:
  • Skull defect
  • Adrenal gland defects

Diagnosis and management of triploidy  

Many pregnancies end early due to miscarriage, and this can aid a triploidy diagnosis  even before any tests occur, but the following tests would be run;

A chromosome analysis test can confirm a triploidy diagnosis. This test would involve counting the number of chromosomes in a fetus’s genes to determine if extra chromosomes are present. The doctor would need a tissue sample from the fetus. 

Typically, your provider would want to diagnose triploidy very early in your pregnancy and will look for symptoms of the condition that affect both the pregnant parent and the developing fetus.¹

Other tests to confirm a diagnosis would be :

• An ultrasound: An imaging test that allows your provider to look at the fetus in your uterus to find any congenital growth abnormalities and symptoms of the condition
• Amniocentesis: Done at 15 to 18 weeks gestation. A small sample of your amniotic fluid will be taken to examine it for chromosome abnormalities
• Chorionic villus sampling: A small sample of your placenta will be removed with a needle to examine it for chromosome abnormalities. It is often done at 10 to 13 weeks of gestation

It is important to seek your provider's care for any problems you may have during a pregnancy, as this will allow them to detect problems earlier and deal with them faster.

While Triploidy is a fatal condition, it is not a death sentence to the dream of having a child with proper intervention.

How is triploidy treated?

Triploidy is not compatible with life. If triploidy is detected in the early trimesters, the mother may choose to terminate the pregnancy, so treatment would involve pre or postnatal counselling and support for the family.

They will be mental health professionals as well as counsellors who will help guide the family through the loss. If she does decide to keep the baby, palliative care measures for the newborn would also be provided if the do survive the pregnancy. 

• Hydration with intravenous fluids and respiratory support (e.g., oxygen)
• Genetic counselling and support should be provided to the parents and family members

Conclusion

Triploidy is a chromosomal abnormality involving the presence of three sets of chromosomes instead of two. It is often fatal, leading to miscarriages as well as stillbirths. There is no evidence to support these conditions as a result of maternal age. While this may be the case, it is important to visit your health care provider if you have any worries, as early detection can help. 

Triploidy is not a death sentence; it is not the mother's fault or the father's fault, and one can go on to have perfectly healthy children later on. Stay aware and stay safe.