Unless you skipped sex ed class, you probably have at least a basic understanding of how babies are made. An egg (ovum) needs to be fertilised by sperm during a precise window in the menstrual cycle for life to happen.

Sexual intercourse provides optimal conditions for reproduction. But that doesn’t mean that every pregnancy happens this way. There are also examples of women conceiving in extremely rare circumstances that you’d expect to be impossible.

While cases of pregnancies resulting from anal sex are incredibly rare, they do happen. But they’ve only ever occurred in people who a reproductive abnormality called a cloacal malformation.

This abnormality occurs in one in every 50,000 girls and will require corrective surgery and even with this there is a high probability of leading to complications such as renal failure, incontinence, difficulty getting pregnant and greater risk of early labour.

A cloaca is a “common hole” for urination, defecation and reproduction. It’s typically seen in reptiles and birds and even platypuses.

In humans, tissue grows down and divides the cloaca into two or three openings – depending on the sex. But in rare cases, this tissue fails to completely split the rectum from the vaginal cavity. When this happens, it may allow sperm to swim through any opening in the dividing tissue wall........

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