Thanks to technology like ultrasound, parents today are able to find out in advance whether they one or more babies on the way. Ten or twenty years ago this was science fiction but times change and go forward. Doctors had problems to diagnose how many babies the mother will give birth to. So they often use former experiences to tell the new parents about their new member or member of the family. Here are some warning signals they used:

■ Fraternal twins tend to run in your family.

■ You have been taking fertility drugs.

■ You experienced excessive nausea and vomiting during the first trimester.

■ Your uterus is growing more quickly or is larger than what would be expected at a particular point in your pregnancy.

■ You notice more fetal movement in this pregnancy than in previous pregnancies (assuming, of course, that this is your second or subsequent pregnancy).

■ More than one fetal heartbeat is heard. If your caregiver suspects that you may be carrying multiples, he will likely send you for an ultrasound. Early ultrasound can detect more than 95 percent of multiple pregnancies.

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