In simple words: This code is used for medical reasons related to carrying more than one baby at a time (twins, triplets, etc.). It describes problems that happen only when a woman is pregnant with multiples, not problems that could happen with a single pregnancy.

O31, Complications specific to multiple gestation, is an ICD-10-CM code used to classify conditions that arise specifically due to the presence of more than one fetus during pregnancy.These complications are unique to pregnancies involving twins, triplets, or higher-order multiples and differ from those that may occur in singleton pregnancies.The code encompasses a range of issues related to the unique challenges of carrying multiple fetuses, such as twin-to-twin transfusion syndrome or complications stemming from shared placental structures.This code should only be applied to the maternal record and not the newborn record.Specific subcategories under O31 detail different complications, such as continuing pregnancy after spontaneous abortion of one or more fetuses. The appropriate subcategory must be used based on the specific complication present.

Example 1: A pregnant woman carrying twins experiences twin-to-twin transfusion syndrome, where one twin receives disproportionately more blood than the other., In a triplet pregnancy, one fetus spontaneously aborts, requiring close monitoring of the remaining fetuses for complications., A pregnant woman carrying twins develops selective fetal growth restriction, where one twin is significantly smaller than the other.

Detailed medical records including ultrasound findings, fetal monitoring results, and maternal vital signs.Documentation should also detail any interventions, such as blood transfusions or medications, and the outcomes of the pregnancy.

** Always ensure that the specific subcategory of O31 that best reflects the specific complication is used.Use additional codes as needed to fully capture all diagnoses.