Common Complications for Babies
Just as with mothers, babies also have a greater chance of experiencing problems during their nine months in the womb. Preterm birth occurs in over 50% of twin pregnancies, 90% of triplet pregnancies and almost all quadruplet pregnancies. Preterm refers to birth prior to 37 weeks gestation.
Average weight for a twin
Multiple birth babies are more likely to be born small for gestational age. The average twin weighs around 5 ¼ pounds at birth and the average triplet will weigh around 3 ¼ pounds. The average singleton weighs about 7 ½ pounds.
Twins and disabilities
Premature births are associated with increased risks of respiratory distress syndrome (RDS), intracranial hemorrhage, blindness, cerebral palsy and neonatal morbidity and mortality. RDS accounts for 50% of all neonatal deaths associated with premature birth.
The odds of retaining life-long disability is over 25% for babies born weighing less than 2lbs, 3oz. Intrauterine growth restriction, miscarriage, congenital anomalies and intrauterine death are all more common in multiple pregnancies.
How Many Multiple Births are Caused by Fertility Treatments?
In general, the chances of having a multiple birth are increased if you undergo fertility treatment. However, not all infertility treatments are the same. For instance, undergoing IUI without ovulation stimulation is not nearly as likely to result in a multiple birth as IUI with Clomid.
IVF is especially known for resulting in twin and multiple pregnancies because multiple embryos are transferred. However, as ART techniques have improved, the number of transferred embryos necessary for pregnancy have decreased with many couples only having one or two embryos transferred instead of the four or five of yesteryear.
That being said, in 2000, the number of twins conceived in the United States using ART was 444.6 per every 1000 live birth. The number of triplets was significantly lower, only 98.7 out of every 1000 live births. The percent of multiple births resulting from all ART treatments was 13.6%.
Selective ReductionBecause of the increased risk of complications to both mother and baby, women having multiple pregnancies may be offered a selective abortion to reduce the number of fetus’ they are carrying. Many women do not feel comfortable with this, though, and choose not to have the procedure.