IVF twin pregnancies riskier than singletons: study

Having twins as a results of in vitro fertilization (IVF) carries higher risks of complications for both mother and babies than having two single babies from separate IVF procedures, according to a Swedish study.

The extra concerns that come with multiple births are nothing new. Btu even as many fertility clinics have stopped regularly transferring more than one embryo, debate has continued over whether having twins through IVF is really a bad thing for couples desperate for children.

"The neonatal and maternal outcomes were dramatically better for women undergoing two IVF singleton pregnancies compared with one IVF twin pregnancy after double-embryo transfer," wrote lead researcher Antonina Sazonova in the journal Fertility and Sterility.

"These results support single-embryo transfer to minimize the risks associated with twin pregnancies," added Sazonova of Sahlgrenska University Hospital in Gothenburg, Sweden.

The researchers analyzed data from fresh and frozen embryo transfers done at Swedish IVF clinics between 2002 and 2006. Those records included 991 women who ultimately gave birth to twins after a double embryo transfer and 921 mothers with two children born through separate rounds of IVF.

Almost 47 percent of twin babies were born prematurely and 39 percent were considered low birth weight, the team reported. That compared to the seven percent of singleton babies that were preemies and less than five percent born small.

Twins were also more likely to have breathing complications, sepsis or jaundice. Their mothers had two to three times more preeclampsia - high blood pressure and protein in the urine - and were four times more likely to need a C-section than women who had two single births.

What is involved with in vitro fertilization?

There are five basic steps in the IVF and embryo transfer process which include the following:

Monitor and stimulate the development of healthy egg(s) in the ovaries.
Collect the eggs.
Secure the sperm.
Combine the eggs and sperm together in the laboratory and provide the appropriate environment for fertilization and early embryo growth.
Transfer embryos into the uterus.

Step 1: Fertility medications are prescribed to control the timing of the egg ripening and to increase the chance of collecting multiple eggs during one of the woman's cycles. This is often referred to as ovulation induction. Multiple eggs are desired because some eggs will not develop or fertilize after retrieval. Egg development is monitored using ultrasound to examine the ovaries, and urine or blood test samples are taken to check hormone levels.