This is a cycle, the duration of which begins on the first day of bleeding and lasts until the first day of the next one. Generally these cycles are of 28 days. During these days some of the eggs (ova) in the ovaries mature under the influence of various sex hormones. One of the mature eggs is then released from an ovary. This egg passes via the fallopian tube into the uterus. The sex hormones have already made the walls of the uterus more spongy and thick to ensure the safe anchoring of the fertilised ovum.

Simultaneously, if the sex act has taken place during the same time period, millions of sperms start swimming upwards in the female genital tract—from vagina to the uterus to the fallopian tubes to find the egg. If any of these is able to locate the egg it fertilises the egg. The fertilised egg attaches itself to the prepared uterus and grows into the embryo. If none of these sperms are able to locate the egg, the egg degenerates. The uterine wall which had grown thick and spongy is no longer required, hence the older and extra walls are shed. This results in bleeding due to the raw area created by shedding of the walls. After about 6 – 8 days (commonly known as ‘period’, ‘chums’ or ‘auntie’) the bleeding stops. This cycle of events is repeated once again similarly.

Marriage between close relatives has increased risk of rare genetically transmitted diseases occurring in the children as the chance for presence of same abnormal genes in both parents would be more among close relatives. Hence medically it is advisable to avoid if possible consanguineous marriage. (Socially it is forbidden among Santal’s, Ho’s, Munda’s, Kharia’s and Oraon’s of the Chotanagpur.)

Dr. Manju Kerketta, Birkera Jhariatoli, PO- Ranto Birkera, via Lathikata, Dist Sundergarh, Orissa - 770037. doctor@tribalzone.com