Problems in Pregnancy and Causes Of Miscarriage
More Common Causes: Stress, Abnormal Gene Formations, Premature Membrane
This factsheet is for people who have had a miscarriage or for those who want to know more
Each year in the UK, hundreds of thousands of women are affected by miscarriage. A
miscarriage is when a pregnancy ends before 24 weeks. In the vast majority of cases, there is no way of
preventing a miscarriage.
Having a miscarriage does not mean that you won't be able to get pregnant again, and most
women go on to have a successful pregnancy.
Causes of Miscarriage
The most common reasons include the following:
a. An abnormal fetus causes almost all miscarriages
during the first three months of pregnancy (first trimester). Problems in the genes are responsible for an
abnormal fetus and are found in more than half of miscarried fetuses.
The risk of defective genes increases with the woman's age, especially over if she is older
than 35 years.
b. Stress - Researchers have long known that during
times of stress, the brain releases several hormones -- including one called corticotropin-releasing hormone
(CRH). In past research, women who deliver prematurely or have low-birth-weight babies were often found to
have high levels of CRH in their bloodstream, and other studies show a greater risk of miscarriage in women
CRH is a hormone the brain secretes in reaction to physical or emotional stress, and it is
also produced in the placenta and the uterus of a pregnant woman to trigger uterine contractions during
c. Fetal chromosomal abnormalities are the commonest
cause of sporadic miscarriage affecting more than half of all early miscarriages. This may be due to
abnormalities in the egg, sperm or both.
The usual chromosomal pattern is 46 chromosomes which are arranged in 23 pairs, one of
these pairs is called sex chromosomes, females will have two X chromosomes and males will have one X
chromosome and a Y chromosome.
The genes we all have are lined up along the chromosomes.
Trisomy: It is a type of chromosomal abnormality where there will be three
chromosomes of one type rather than a normal pair. This results in an embryo with 47 chromosomes instead of
46 and will either abort, or develop into a baby with congenital abnormalities. It is more common as
reproductive age increases and the abnormalities are not very likely to recur.
Monosomy: In this type, you will notice missing of one chromosome. This
condition is called Turner's syndrome where pregnancies will carry on with only one X
d. Premature Rupture of Membranes and Early
Many miscarriages begin with cramping and labor-like symptoms, but true PROM and Early
Labor are usually associated with babies that are in the second or third
Early labor can often be treated with drugs that relax the uterus and women are placed on
bed rest either at home or in the hospital.
Sometimes, however, the baby comes anyway. This is one of the most traumatic of losses,
technically a stillbirth and not a miscarriage after 20 weeks, because you will hold and see your baby and
beg him or her to breathe.
For some women, the baby will even be born alive, but only live for a few minutes, hours or
days. There really is nothing harder in life than this.