Selective Fetal reduction
Being pregnant with two or more babies has its own challenges. Twins or higher order pregnancies are more prone for pre term deliveries and fetal growth restriction. A procedure to lower the number of foetuses and increase the chances of healthy pregnancy and survival is called selective fetal reduction.
What is selective fetal reduction?
When a high order multiple pregnancy (three or more fetuses present in the womb at the same time) is ‘selectively reduced’ to twin or singleton pregnancy, the procedure is called ‘selective fetal reduction’. It is a procedure whereby one or more fetuses are reduced so as to improve the outcome of the remaining fetuses.
Why is it advised?
As the number of fetuses in the womb increases, the risks of preterm (early) delivery also increases. In an average singleton pregnancy, the average length of pregnancy is around 40 weeks whereas for twins it is 36 weeks. This reduces dramatically to 32 to 33 weeks for triplets and 28 to 29 weeks for quadruplets.
What are the benefits of selective fetal reduction:
The benefits of embryo reduction far outweigh the risks associated with the procedure. Embryo reduction substantially increases the duration of pregnancy, reduces the incidence of premature delivery which in turn has the benefit of increasing the baby’s birth weight and reducing neonatal mortality along with shortening the neonatal intensive care stay.
Most studies suggest an improved perinatal outcome for triplet pregnancies reduced to twins compared with non-reduced triplet pregnancies. The benefits are even more pronounced with quadruplets and other higher order multiple pregnancies.
When is selective fetal reduction done?
It is usually done between 11 to 13 weeks of pregnancy after the first trimester screening and after ruling out any structural abnormalities in the babies. In addition, about 8 to 20% multiple pregnancies may reduce by themselves by the end of first trimester. The ‘vanishing’ twin does not have any adverse effect on the surviving fetus.
How is it done?
Embryo reduction is done by passing a thin needle through the mother’s abdomen under local anaesthesia and injecting a medicine into the fetus that has to be reduced. It is done under continuous ultrasound guidance.
What are the risks associated with the procedure?
After fetal reduction, there is a 5-10 % chance that the woman might lose the entire pregnancy prior to 20 weeks’ gestation. The original number of fetuses, the route of the needle as well as the number terminated may influence the likelihood and the rate of pregnancy loss.
What should I expect after the procedure?
You will be asked to rest and the baby’s heart beat will be checked after half an hour of the procedure. You may have slight bruising at the site of needle entry. You may also have some spotting or mild cramping for a couple of hours for which you may take oral paracetamol. There is no restriction to your daily activities though the doctor may advice you to stay home for 3 days to minimize chances of infection.
If you have fever, vaginal bleeding or leaking or contractions, you must report to the hospital.