Pregnancy and Childbirth

Monochorionic-diamniotic twins are almost always monozygotic.

Quickening is the early sign of foetus movement during pregnancy.

A genetic disorder is an illness caused by abnormalities in genes or chromosomes.

Colostrum is a form of milk produced by the mammary glands in late pregnancy and in the few days after delivery.

Immunoglobulin G can cross the placenta.

Synctiotrophoblasts are giant cells which hinder the passage of mother's WBC to reach foetal side of the placenta. If they were to reach the foetal side of the placenta, many foreign proteins will be recognised and it will trigger an immune reaction.

German measles (Rubella) during pregnancy can cause congenital rubella syndrome, leading to severe birth defects including heart problems, deafness, and intellectual disabilities. This risk is highest in the first trimester. Chickenpox, Smallpox, and Measles also pose risks but Rubella is most strongly associated with the recommendation for pregnancy termination.

The placenta is the specialized organ that forms during pregnancy and serves as the interface between maternal and fetal blood supplies, allowing nutrient/waste exchange without direct blood mixing. The uterus houses the fetus, fallopian tubes are for egg transport, and 'blood' is too general.

The cervix is the lower, narrow portion of the uterus that opens into the vagina. The urethra and ureter are part of the urinary system, and placenta is a temporary pregnancy organ.

The myometrium stretches during pregnancy to allow for the harboring of the pregnancy, and contracts in a coordinated fashion, via a positive feedback effect on the Ferguson reflex, during the process of labor. After delivery, the myometrium contracts to expel the placenta and reduce blood loss; where the crisscrossing fibres of middle layer compress the blood vessels.

Chorion frondosum and the decidua basalis make up the placenta. Chorion laeve, or smooth chorion, is covered by decidua capsularis. As the fetus and chorion enlarges, the chorion laeve pushes against the decidua parietalis and the capsularis disappears.

The function of the round ligament is maintenance of the anteversion of the uterus (a position where the fundus of the uterus leans ventrally) during pregnancy. Normally, the cardinal ligament is what supports the uterine angle (angle of anteversion). When the uterus grows during pregnancy, the round ligaments can stretch causing pain.

Permeable values of these IgGs through placenta are given in the table below:  ||| |---|---| |IgG type|Permeable value crossed through placenta| |IgG1|1.47| |IgG2|0.8| |IgG3|1.17| |IgG4|1.15 | Hence, IgG2 does not cross through placenta.   

Erythroblastosis fetalis (hemolytic disease of the newborn) occurs when an Rh-negative mother carries an Rh-positive fetus. During delivery or placental disruption, fetal Rh-positive RBCs enter maternal circulation, triggering antibody production. In subsequent pregnancies, these antibodies attack fetal RBCs.

Colostrum is the first milk produced by mammals, including humans, in the initial days after giving birth. It is thick, yellowish, and rich in antibodies, growth factors, and immune cells that provide crucial passive immunity to the newborn. Colostrum is often called 'liquid gold' due to its concentrated nutritional and immunological value. Normal milk production begins several days after birth, while weaning refers to the transition away from milk.