Pregnancy and Childbirth

Parturition is the process of giving birth or delivery. The signals for parturition originate from the placenta as well as fully developed foetus. Both these induces uterine contractions. These uterine contractions are called as foetal ejection reflex. This then stimulates the release of oxytocin hormone from the maternal pituitary gland. 

Foetal ejection reflex in human female is induced by fully developed foetus and placeta which causes mild contraction. This induces the release of oxytocin from maternal posterior pituitary ultimately leading to parturation due to strong contractions.

Birth occurs when foetal development is complete, typically around 38-40 weeks of gestation. The zygote is the initial single-cell stage formed at fertilization, not the developed stage ready for birth. The uterus is the organ, not the developing organism. At birth, the foetus has developed all major organ systems and is ready to survive outside the womb. Thus, completion of foetal development is the prerequisite for birth.

The process of delivery of foetus is called as parturition. Parturition is the act of expelling the full-term foetus from the mother's uterus at the end of gestation. In this process fully developed foetus produces foetal ejection reflex which stimulates pituitary to release oxytocin hormone. This hormone causes vigorous uterine contraction that leads to the delivery of feotus. This process is also known as the delivery of the foetus when the pregnancy period gets over. The importance of parturition is that the event results in the foetus to come out of the womb. The process is accompanied with the onset of lactation.

Parturition or childbirth is the event of bringing a child into the world from the uterus of the mother. It involves forceful muscle contractions of the uterine wall which push the child out of the womb through the vaginal canal. Several events take place after the birth of the child, including expulsion of the placenta, umbilical cord, and fetal membrane.

The amniotic fluid is the protective liquid contained by the amniotic sac of a gravid amniote. This fluid serves as a cushion for the growing fetus but also serves to facilitate the exchange of nutrients, water, and biochemical products between mother and fetus. Amniotic fluid is present from the formation of the gestational sac. The forewaters are released when the amnion ruptures prior to childbirth.

During pregnancy in the human, hormones such as relaxin allows the pelvic bones to be more flexible for delivery. The gap of the symphysis pubis, normally is 4–5 mm but during pregnancy there is an increase by at least 2–3 mm. The symphysis pubis separates to some degree during childbirth hence pubic symphysis is an amphiarthrodial joint.

In medical terms, the third stage of labor is known as the afterbirth. This stage involves the expulsion of the placenta, umbilical cord, and fetal membranes after the baby has been delivered.

Some drugs cause foetal abnormalities, when given to a pregnant women. These are called teratogens. The most well-known synthetic teratogen is thalidomide.

Colostrum (also called as first milk) is the thin yellowish fluid secreted by the mammary glands at the time of parturition and which precedes the production of true milk. It provides a nursing infant with essential nutrients and infection-fighting antibodies (called as immunoglobulin) to protect the newborn against disease. IgA is the major immunoglobulin in colostrum. It protects from inhaled and ingested pathogens.

Domestic rabbits are typically weaned and become independent of their mothers between 6 and 8 weeks of age.

An obstetrician is a physician who specializes in pregnancy, childbirth, and the postpartum period. The other options refer to different medical specialties or academic degrees.