A case where a 9-month pregnant woman’s belly suddenly started shrinking until it disappeared is extremely rare and raises immediate medical concern. One known explanation is a false pregnancy (pseudocyesis),
where a woman believes she is pregnant, shows many physical signs of pregnancy including abdominal enlargement, but is not actually carrying a baby. Sometimes, after the false pregnancy ends, the belly size rapidly decreases and the "pregnancy" symptoms vanish.
Another possible medical scenario involves complications such as fetal demise with intrauterine contraction or extreme fluid loss (amniotic fluid leaking), which can cause the abdomen to shrink suddenly. In very rare cases, unusual disorders such as "belly dancer dyskinesia," an involuntary abdominal muscle movement condition, can cause abnormal abdominal appearances during pregnancy.
In one documented case, a woman about nine months pregnant came to hospital with a large belly, but doctors found no fetus inside when surgical intervention was initiated, indicating either a case of false pregnancy or a complex medical phenomenon. This resulted in astonishment and required careful medical examination and explanation.
Such situations are medically complex and require thorough ultrasound scans and diagnostics to understand the underlying cause of the sudden abdominal size change near term.
In sum, a 9-month pregnant belly suddenly shrinking until it disappears can sometimes be due to false pregnancy, fluid loss, fetal demise, or rare medical muscle conditions, requiring careful urgent medical evaluation.