Contractions

Before birth , certain changes occur in the muscular system of the uterus.

This body at different stages of pregnancy performs various functions. During pregnancy, the uterus is the fetus, when conditions are created for the nidation (introduction) of the fetal egg, its development, the development of the placenta , through which gas exchange and metabolism between the fetus and mother take place. In childbirth - the function of expelling the fetus due to periodic contractions (contractions) of the uterus muscle, and in the early postpartum period - a spastic contraction to prevent bleeding from the gaping uterine arteries after separation of the placenta.

Due to different requirements for the uterine muscle during pregnancy, there is very little actomyosin, a contracting protein, in the cells of the uterus muscle (myocytes). Before childbirth, about a day before them, under the influence of hormones, vigorous synthesis of actomyosin in myocytes begins, moreover with the spatial orientation of myofilaments so that when the myocytes contract, their force moment coincides and develops. In case of violation of the synthesis of actomyosin and its spatial orientation in childbirth, complications arise - weakness of the labor forces and discoordination of the labor forces.

Shortly before the birth, the placenta and the pituitary of the fetus begin to produce specific substances (in particular prostaglandins and the hormone oxytocin ), which cause periodic contractions of the uterus muscles lasting 5-10 seconds.

Initially, the intervals between contractions are about half an hour (sometimes more), gradually their frequency, intensity and duration increase. The last contractions occur at intervals of 5-7 minutes and turn into attempts. On average, the whole process of feeling the contractions lasts 12 hours for women giving birth for the first time, and 8-10 hours for repeated births.

All data are approximate and may vary for each woman in labor.

Initial (latent, latent) phase

Duration - 7-8 hours
Fight duration - 20 s
The interval between contractions - 15 minutes
Disclosure of the neck - 0-3 cm

Active phase

Duration - 3-5 hours
The duration of the bout is 20-60 s
The interval between contractions - 2-4 minutes
Neck opening - 3 — up to 7 cm

Transitional phase (deceleration phase)

Duration - 0.5-1.5 hours
Fight duration - 60 s
The interval between contractions - 2-3 minutes
Disclosure of the neck - 7-10 cm

Beginning at the 20th week of pregnancy, some women may experience false contractions , also known as Braxton-Hicks contractions , and precursor contractions may occur in 2–3 weeks. Unlike real contractions, neither one nor the other leads to the opening of the cervix. There are pulling sensations in the lower abdomen or in the lower back, the uterus is as if stony - if you put your hand to your stomach, you can clearly trace this. The same thing, in fact, happens during labor pains, so Braxton Hicks and harbingers often confuse pregnant women. How to understand whether childbirth really begins and is it time to go to the hospital, or is it just a harbinger?

Braxton-Hicks contractions, unlike real labor pains, are rare and irregular. Reductions last up to a minute, can be repeated after four to five hours.

False contractions are usually painless. Walking most often helps to completely relieve the discomfort and tension of the uterus. The role of false contractions is not yet fully understood. Their appearance is associated with an increase in the excitability of the uterus, it is believed that they shortly before birth contribute to the softening and shortening of her neck.

• Childbirth

• Contractions before childbirth
• The beginning of childbirth. Contractions