Abdominoposterior is an adjective used in pregnancy and childbirth to describe a particular position of the fetus (baby) in the uterus — specifically, one where the fetus’s abdomen (belly) is facing the mother’s back.

The word breaks down neatly: abdomino- (“abdomen,” meaning the baby’s belly) + posterior (“toward the back”). So it literally means “belly-toward-the-back.”

What it describes

During pregnancy and labour, doctors and midwives describe how the baby is lying using reference terms. “Abdominoposterior” tells them which way the baby is facing:

• The baby’s belly (abdomen) is turned toward the mother’s spine/back
• This generally means the baby’s back is turned toward the front of the mother’s body

This is the kind of detail clinicians note when assessing a baby’s lie and position before and during delivery, often by feeling the mother’s abdomen (palpation) or using ultrasound.

Why position matters

The way a baby is positioned can influence how labour and delivery unfold. Knowing whether the baby’s abdomen faces the mother’s front or back helps the care team anticipate how the baby will move through the birth canal and whether any extra support or repositioning might help. It is one of several positional terms — used alongside others describing whether the baby is head-down, breech, and which side it is turned toward.

A note on related terms

“Abdominoposterior” belongs to a family of positional descriptors used in obstetrics. Its natural counterpart is abdominoanterior, where the baby’s abdomen faces the mother’s front instead. These terms, often combined with “left” or “right,” give the care team a precise shorthand for exactly how the baby is oriented.

Disclaimer

This content is for general educational purposes only and is not a substitute for professional medical advice, diagnosis, or care. Assessing a baby’s position during pregnancy and labour is done by trained healthcare professionals such as doctors and midwives. If you are pregnant and have questions about your baby’s position or your delivery, consult your maternity care team, who can assess and advise on your individual situation.