Obstetrics and Gynecology - A.M. Gromova 2000

Miscarriage and Post-Term Pregnancy
Post-Term Pregnancy
Definition of the Concept

It is generally accepted that a normal Pregnancy lasts 280 days (40 weeks, or 10 lunar months) from the first day of the last menstrual period. However, the individual maturation rates of the fetus and Placenta vary. Consequently, a variation of two weeks shorter or longer than this term is not considered pathological.

A fetus may exhibit signs of post-maturity even when pregnancy lasts less than 294 days. The time required for final fetal maturation varies significantly. Therefore, Post-term Pregnancy (by duration) and fetal immaturity are not synonymous. It is clinically useful to distinguish between true biological post-maturity and chronological, or prolonged, pregnancy.

A truly post-term pregnancy is defined as one that extends 10–14 days beyond the expected date of confinement (290–294 days). The infant is born with signs of post-maturity, and its life may be at risk (fetal distress). In almost all such cases, placental alterations are present (such as calcifications and fatty degeneration).

A prolonged, or physiologically extended, pregnancy is considered to be one lasting beyond 294 days that concludes with the birth of a term, functionally mature infant without signs of post-maturity.

A newborn resulting from a biologically post-term pregnancy is termed a foetus hypemiaturus, whereas one from a chronologically prolonged pregnancy is called a foetus postmaturus. This distinction is crucial as it dictates different approaches to the management of pregnancy and labor. The primary complications of delayed delivery include premature or early rupture of amniotic membranes, uterine inertia, Fetal Hypoxia and Neonatal Asphyxia, fetopelvic disproportion, Hemorrhage in the third and early postpartum stages, Soft Tissue Birth canal injuries, increased birth trauma, as well as high perinatal morbidity and mortality. The risk of operative delivery is also elevated.

Post-term pregnancy should not be regarded merely as a variation of normal gestation. It is a pathological condition driven by factors originating from both the maternal and fetal organisms. A history of childhood infectious diseases (such as scarlet fever, mumps, and rubella), which play a significant role in The Development of the FEMALE Reproductive System, along with extragenital disorders, may serve as a premorbid Background for prolonged gestation. Other contributing factors include genital infantilism, a history of abortions, and Inflammatory Diseases of the internal genitalia that cause alterations in the neuromuscular apparatus of the Uterus and lead to endocrine shifts, as well as Lipid METABOLISM disorders, psychological trauma, and Late gestosis.