Single Embryo Transfer
More than 1.5% of births in the United States are the result of In Vitro
Fertilization (IVF)/Assisted Reproductive Technology (ART.)
Many patients pursue IVF as a final step in their
fertility treatment and are understandably exhausted, both emotionally and financially. There
is often a temptation to maximize success rates (pregnancy) by transferring
2+ embryos. In the past, this practice was regarded as a way to increase
pregnancy rates with the trade-off being a huge increase in multi-fetal
pregnancies (twins, triplets, quadruplets, etc.)
Multi-fetal pregnancy poses the greatest health risk(s) to both mother
and baby after IVF/ART. The maternal risks include miscarriage, high blood
pressure (pre-eclampsia, HELLP syndrome), and gestational diabetes. Due
to these risks, most multi-fetal pregnancies have to be delivered early
via cesarean section (c-section). C-sections are considered to be a major
surgery and can pose additional complications to the mother and baby.
Babies born prematurely are often underdeveloped and suffer from low birth
weight. A high proportion of these babies also end up with extended stays
in the neonatal intensive care unit (NICU) with neurologic and medical
problems that last their lifetime. These problems include cerebral palsy,
language delay, ADHD and behavioral problems. For these reasons, multi-fetal
gestation is regarded as an adverse event of IVF by the American Society
for Reproductive Medicine (ASRM.)
Recognizing the increased risks to mother and baby, the American College
of Obstetricians and Gynecologists (ACOG) advocates single embryo transfer
to reduce the risks of multi-fetal gestation for women undergoing
IVF. To quote ASRM: “the goal of infertility treatment is for each patient
to have one healthy child at a time.”
What is Single Embryo Transfer (SET)?
SET is when one blastocyst (day 5 or 6 after fertilization) embryo is transferred
back into the uterus. Embryos that survive to the blastocyst stage have
a much higher chance of implanting than Day 2 or Day 3 embryos; thus,
fewer embryos are required to achieve pregnancy.
At ACRM, there is a minimal reduction in pregnancy rates with SET, but
a huge reduction in multi-fetal gestation.
With the support of our Ob/Gyn, Maternal Fetal Medicine and Pediatric/NICU
colleagues, we are happy to offer SET to provide the best care for our
patients and their families. We do feel that
“one baby at a time is best” and we want to maximize the chance of a healthy pregnancy from start to finish.