Multiple Births

There is a higher rate of multiple births for women treated with fertility drugs than in the general population. The actual rate depends on the type of drugs used and the chosen procedure. There are many strategies to minimize the risk of multiple births, but it is always a risk to some degree.

1. Ovulation Induction with Clomiphene

The most commonly used "fertility drug" is clomiphene (Serophene or Clomid). It is an oral tablet usually taken days 5-9 of the menstrual cycle. The overwhelming majority of births are to a single baby. The multiple birth rate for clomiphene is between 5% and 10%. The vast majority of these multiples are twins. There are periodic reports of triplets or more, but these are rare and limited with proper monitoring.

2. Ovulation Induction with Gonadotropins

The next most common use of fertility drugs is for ovulation induction with gonadotropins. This is sometimes called a stimulated IUI cycle. Again, the majority of the births with the help of these drugs are to a single baby. Multiple births can be limited with proper monitoring. At Center for Reproductive Medicine since January of 1998, 17% of all deliveries are to twins. Only about 5% of deliveries are to triplets or more.

3. In-Vitro Fertilization (IVF) procedures with fertility drugs

The last use of fertility drugs is for assisted reproductive technologies, such as IVF. At CRM the overwhelming number of deliveries is to a single baby. Twins happen with some frequency (12%). Additionally, in 1998, we had 3 sets of triplets and 2 sets of quadruplets. The risk of multiple births is significant. Proper monitoring can minimize your risks, but not eliminate them. In 1999, CRM began using a new technique for IVF called Blastocyst Transfer. This shows some significant promise to reduce multiple births even further.

Birth Defects