Recurrent Pregnancy Loss (RPL):
Background: Pregnancy loss is one of the most common obstetric complications affecting over 30% of conceptions. A considerable proportion of losses are because of genetic abnormalities. Recurrent pregnancy loss (RPL), it is defined as two or more spontaneous abortions, affects approximately 5% of women of reproductive age. Although several causes of RPL have been established, more than 50% of cases remain unexplained. Spontaneous pregnancy loss can be physically and emotionally hard for couples, especially when faced with recurrent losses. RPL, also known as recurrent miscarriage or habitual abortion, is historically defined as 3 consecutive pregnancy losses prior to 20 weeks from the last menstrual period. Indeed, over 50% of early pregnancy losses have been associated with chromosomal abnormalities.
The medical term for a miscarriage is an abortion. Most miscarriages start with vaginal bleeding which is initially slight and painless. This is called a threatened abortion, because the pregnancy is threatened by the bleeding. This bleeding is from the mother, and is not fetal blood. About half the time this stops spontaneously and results in no harm to the pregnancy.
If a fetal heartbeat can be seen, this means that there is a 95 % chance that the pregnancy will proceed normally. On the other hand, if the ultrasound scan shows that the fetus has not developed properly “blighted ovum ” or anembryonic pregnancy when no fetus can be seen; or a missed abortion or intrauterine fetal death when the fetus is seen but the heart is not beating), then nothing can be done to save the pregnancy.
Causes of a Miscarriage –
- Chromosomal abnormalities
- Hormone imbalance
- Physical Illness
- Polycystic Ovary Syndrome
- Immune problems
- Antiphospholipid antibodies
- Problems in the uterus
- Lifestyle of the woman
- Infections etc.
- Parental balanced structural chromosome rearrangement
- Commonly balanced reciprocal or Robertsonian translocation
- Chromosomal structural abnormality (inversions, Insertions, deletion, duplication, addition, Loss of heterozygosity (LOH)etc.)
- Chromosomal numerical abnormality (Monosomy, trisomy, polyploidy)
- Single gene defects (cystic fibrosis or sickle cell anemia etc.)
- Copy number variants (CNV’s)
- Molecular screening for thrombophilias (SNP’s of factor II, factor IV and MTHFR)etc.
Advance genetic testing like Fluorescence Insitu Hybridization (FISH), Next generation sequencing (NGS) are available that help us in diagnosing the exact condition of a patient by relating it with pedigree also known as family tree. It can help in planning further management or treatment of the patient.
Management – Genetic counselling is recommended in these conditions, where the genetic counselor suggests the tests to know the exact cause of the problem and guide you for the further management and treatment plan of the condition. People usually don’t go to genetic counselor thinking that it is not running in family, but the truth is that the condition could start from you and there could be other reasons which you might not be familiar with but the experts will look into every little detail. So don’t hesitate to meet a right genetic counselor for seeking help.
After proper diagnosis the genetic counselor then refers to the particular clinician (specialist) for further treatment which can be treated by drugs or surgery etc. Sometimes in this case IVF is also suggested and PGD & PGS is advised.
It is always recommended to do genetic testing for all pregnancies but as it is the new field and people are less aware of it, clinicians should advise for genetic testing at least after the first miscarriage.
Ms. Jeanny Dominic, B.Tech – Genetic Engineering and PG Diploma in Genetic Counseling , Kamineni Hospital, Hyderabad, India.
November 29, 2017