Do you really? We often hear from couples that they wish to have twins. For many parents, their ideal number of children is 2. In a review of 9 recent studies, a majority (range 45-90%) of infertile women had a preference for a twin pregnancy. The factors that influenced their choice included prior infertility treatment, prolonged duration of infertility, advanced maternal age and in women who had never delivered a child. Interestingly, the preference for twins was despite the women’s knowledge of the increased maternal and fetal risks due to a twin pregnancy.
The 2 most common forms of twins are Fraternal and Identical.
Fraternal Twins (commonly known as “non-identical twins”) occur when two 2 separate eggs are fertilized by two different sperm. Two-thirds of all twin births result in same sex fraternal twins and one-third are different sex fraternal twins. About two-thirds of all twin births are fraternal.
Identical Twins occur when a single sperm fertilizes a single egg and then the developing embryo divides into two separate embryos. Identical twins are always of the same sex. Identical twins occur about once in every 250 births around the world.
It is generally accepted that the chance of twins in a patient spontaneously conceiving is 1-2%. The 2009 SART data again shows the incidence of twins with IVF in women under age 40 is 30%. This number may approach 50% in women utilizing donor Eggs. We know that the chance of twins with ovulation medication with or without artificial insemination is ~ 10%. We cannot guarantee a couple twins by placing more Embryos back with IVF or increasing the number of follicles with ovulation medications. In fact, by placing more embryos or increasing the number of follicles, we increase the risk of triplets or greater, which in turn further increases the risks. By transferring a single Embryo, IVF patients may reduce the risk of twinning to ~ 1-2% (identical twins).
Any multiple pregnancy, twins or greater, may present significant health risks to both the mother and children. Identical twins can present special issues that will not be covered in this blog. Let’s look at what the risks may be for fraternal twins:
Maternal
Elevated blood Pressure, Pre-Eclampsia
Increased risk of Gestational Diabetes
Anemia
Increased risk of post- delivery bleeding
Increased incidence of C-Section
Increase in pre-term labor/delivery requiring bed rest, medication and hospitalization. This can lead to significant time off work and lost income
The challenges of the care of twins after delivery and beyond
Costs- increased due to pregnancy care and hospitalization. If a prolonged hospital stay is required for either the mother or infants, insurance benefits may be exhausted
Fetal
60 % of twins delivery early (before 37 weeks)
1 in 10 is born at less than 32 weeks
Growth restriction – 50% of twins are considered low-birth weight with 10% weighing less than 1500 grams
Increased risks of long-term handicaps and Cerebral Palsy
Increased risk of congenital anomalies. Since there are 2 fetuses, there is a 2-fold increase
Increased risk of Neonatal death (When a baby dies in the first 28 days of life)
Most twin pregnancies will result in the delivery of 2 healthy children with few significant complications for the mother. Talk with your physician about the risks of a multiple pregnancy with your treatment. Your Physician can help assess your situation and provide you with the information and guidance you may need.
Share your thoughts and concerns about a multiple pregnancy with your partner. Make sure that you both fully understand the potential risks of a twin pregnancy in your case, as each patient is unique and may have additional risk factors. Carefully consider the risks and potential complications that can occur.
Good resources for more information include:
www.marchofdimes.com
www.aap.org
www.acog.org
So do you really want twins?
Dr. Carmelo Sgarlata is a leading Reproductive Endocrinology and Infertility specialist at the Reproductive Science Center of the San Francisco Bay Area. With over 25 years of experience and well over 1,000 babies born through his guidance, Dr. Sgarlata has become well known in the community where he lives and practices. His areas of special interest include Operative Laproscopy and Hysteroscopy, Ovulation disorders including diminished ovarian reserve and recurrent pregnancy loss.
