Could you be pregnant with twins and not able to see but one baby on the ultrasound?

Yes, it is possible to be pregnant with twins and only see one baby on an ultrasound. This can occur for a few reasons:

- Early gestation: If the ultrasound is performed very early in pregnancy, before the twins are fully developed, only one baby may be visible.

- Poor positioning: If the twins are positioned close together or behind each other, it may be difficult for the ultrasound technician to visualize both babies.

- Vanishing twin syndrome: In some cases, one of the twins may not survive and be reabsorbed into the uterus. This can result in a single viable baby even though there were originally two embryos.

- Heterotopic pregnancy: In rare cases, a woman may have a heterotopic pregnancy, in which one baby is developing in the uterus and the other is developing outside the uterus. This can make it difficult to see both babies on a single ultrasound.

If you are concerned that you may be pregnant with twins but only saw one baby on an ultrasound, it is important to talk to your doctor. They may recommend additional tests, such as a repeat ultrasound or a blood test, to confirm the presence of twins.