Clomid and Birth Defects

Box of Clomid

Women who conceive using one of the most popular fertility medications may wonder about the relationship between Clomid and birth defects.

What Is Clomid?

Clomid is the brand name for clomiphine citrate, one of the most popular fertility medications in the United States. Clomid is often prescribed for a number of fertility problems:

  • Ovulation issues: Women who don't ovulate regularly or who don't ovulate at all may benefit from using Clomid.
  • Male infertility: Even though Clomid doesn't do anything to increase sperm motility or sperm count, many doctors prescribe it as a first line of defense to increase the likelihood of producing better quality eggs.
  • Unknown infertility problems: When a couple has tried to conceive for several months with success but there is no known reason for infertility, Clomid may be used to increase their likelihood of conceiving.

Clomid works by making a woman's body think it isn't producing enough estrogen. This causes the pituitary gland to increase production of the necessary hormones that cause ovulation. In about 10 percent of cases, the extra stimulation causes more than one egg to mature, which can lead to multiple births.

Like any medication that affects hormones, Clomid does cause certain side effects, most notably mood swings, hot flashes, and breast tenderness. But, because the medication can be taken orally and has less side effects than many other treatment options, it is usually the first treatment method offered by most physicians. Clomid is often paired with IUI, but can also be used when trying to conceive through timed intercourse.

Clomid and Birth Defects

It's hard to say for sure whether there is a definite relationship between Clomid and birth defects. Clomid has been labeled in the Category X by the Food and Drug Administration, which means that there is evidence it can cause birth defects when used during pregnancy. This evidence is usually seen in testing done on animals since it is too dangerous to perform such experiments on humans. It's generally assumed that if a birth defect is present in animals exposed to a certain medication, the same will hold true in humans.

It's very important, however, to remember that this is based on the expectant lab animal being exposed to Clomid while she is already pregnant. Since Clomid is used only as a fertility medication, there isn't any reason for a pregnant woman to be taking it. Generally, the only way a pregnant mother would take Clomid is if she didn't realize she was already pregnant, in which case it would still only be used in the first week or so leading up to what she expects to be an ovulation. There is no reason for an expectant mother to take Clomid throughout a pregnancy.

Some women who take Clomid to help them conceive go on to have children born with birth defects, but it's hard to say if the medication is really the cause. It's important to remember that many women who take Clomid are already in a higher risk group for having children with a birth defect.

Women who are over 35 and have difficulty conceiving make up a large group of patients taking Clomid, but they are also at a greater risk of having a child with a birth defect even without using Clomid. Some studies have found that women on Clomid have a slightly higher rate of having a child with birth defects, but there is conflicting evidence as to whether Clomid is the cause of the birth defects or if it may be other problems related to the mother's infertility.

When a birth defect does occur to children of women using Clomid, the most common problems include Down syndrome, congenital heart defects, club foot, or stillbirth. Remember, though, that birth defects can also occur in offspring of women who were not on Clomid or any other fertility medication.


When a baby is born with a birth defect, it's common for the mother to wonder if she did something to cause it. In many cases, there is never a clear reason found for the defect. Although there may be a possible link between Clomid and birth defects, a baby is at very little risk when Clomid is used only during the period of time before conception.

Clomid and Birth Defects