Superfetation is a rare and extraordinary phenomenon in which a woman becomes pregnant with a second baby while already carrying another baby. This occurs when a woman ovulates and conceives a second time during an ongoing pregnancy, resulting in two fetuses of different gestational ages in the womb.

One notable example of superfetation is the case of Julia Grovenburg, who made headlines in 2009 when she became pregnant with two babies conceived three weeks apart. This remarkable occurrence fascinated the medical community and the general public, shedding light on the rare nature of superfetation.

While superfetation is extremely uncommon in humans, it is more frequently observed in certain animal species, such as rabbits and rodents. This biological marvel continues to intrigue researchers and healthcare professionals, prompting further investigation into the underlying mechanisms and potential implications of superfetation.