Labor onset is defined when several conditions occur together, such as uterine contractions, effacement (or shortening of the cervix length), and cervical dilation. The active phase of labor usually begins at 4 cm of cervical dilation.
Prodromal or Prelabor
This is a period excluded from active labor, which has no defined start. It begins with the progressive appearance of a set of symptoms and signs that help the mother realize that labor is approaching, although not always immediately. This period can last up to two weeks and ends with uterine dilation. Not all pregnant women perceive they are in the prelabor stage; therefore, some start directly with the rhythmic contractions characteristic of labor. During this period, the frequency and intensity of contractions progressively increase, sometimes the mucus plug is expelled, and pelvic discomfort rises.
Dilation
The first stage of labor aims to dilate the cervix. It occurs when uterine contractions begin appearing more frequently, approximately every 3 to 15 minutes, lasting 30 seconds or more, with increasing intensity. Contractions become more frequent and intense, up to one every two minutes, causing effacement and dilation of the cervix, hence the name dilation stage. The duration varies, depending on whether the woman has had previous labors (for first-timers, up to 18 hours). This stage ends with full dilation (10 centimeters) and cervical effacement.
Expulsion
Also called the expulsive phase or pushing phase, it ends with the baby’s birth. It is the passage of the newborn through the birth canal, from the uterus to the outside, thanks to involuntary uterine contractions and strong abdominal contractions or maternal pushing. This stage has two phases: an early non-expulsive phase, where dilation is complete but there is no urge to push since the fetal presenting part has not descended; and an advanced expulsive phase, where the fetal part reaches the pelvic floor, and the maternal urge to push begins. It is advisable not to force pushing until the mother feels this sensation, to avoid interfering with the normal progress of labor.
Delivery of the Placenta (Alumbramiento)
This begins with the expulsion of the placenta, umbilical cord, and membranes, which takes between 5 and 30 minutes. The descent of the umbilical cord through the vulva after birth indicates the final detachment of the placenta; the more the cord protrudes, the more the placenta advances out of the uterine cavity. This natural movement of the cord proportional to placental descent is known as Ahlfeld’s sign. Placental detachment occurs by two possible mechanisms. The most common (about 95%) is central detachment at the uteroplacental junction, known as the Baudelocque-Schultze mechanism.
Less common is when the placenta initially detaches from the sides of the uteroplacental junction, called the Baudelocque-Duncan mechanism. Uterine contractions continue during placental descent, helping compress terminal myometrial vessels that cease function after birth, a process known as Pinard’s living ligatures in obstetrics. For many authors, labor ends at delivery of the placenta, but others consider a fourth stage called immediate recovery, ending two hours after delivery. During this "immediate puerperium," mother and baby should stay together to encourage breastfeeding initiation, the baby’s safety, and calmness. The concept of "rooming-in" refers to the baby staying in the same room as the mother while in the hospital or birthing place.
The brands Beybies, Pura+ and NrgyBlast belong to Avimex de Colombia SAS. All products have quality certifications and valid health registrations and are manufactured under the strictest international standards. To purchase our products you can visit our Online Shop. All purchases are backed by a 100% satisfaction or money-back guarantee.
