Childbirth is the expulsion of newborn(s) from a woman's uterus, following a period of pregnancy. Full term is when childbirth usually occurs, about 39-40 weeks after conception. Early term is just before, between 37-38 weeks. Late term is just after, between 41-42 weeks.At either extremity, preterm is <37 weeks, and post dates >42 weeks. Perinatal means during birth.
What is childbirth?
The birth of a child lol. Specifically, it's where it comes out from where it's stored in a woman, which is in her uterus.
What's a uterus?
It's also known as the womb. It's found just above the vagina (through the cervical opening). And is central, to the 2 fallopian tubes dangling on its side.
How does it take before bub pops out?
There's standard timing. It can be due before date, or after date. So standard is 40 weeks. 39-40 is considered normal. 41-42 weeks is considered late term. 37-38 is considered early term. We still consider 37-42 not too bad. But anything outside of that is considered abnormal, and we call <37 weeks preterm, and >42 weeks post dates.
Perinatal. That sounds a bit like Perry the platypus. We know that platypuses don't do much
Well mom pushes during pregnancy .
Labor is said to have "onset" when there is both:
Regular contractions occuring less than 10 minutes apart
Progressive cervical dilation or cervical effacement, between consecutive vaginal examinations
When do we say that the process of "childbirth" has started?
We define it with 2 things. Contractions, which have to be regular, at least once every 10 minutes. Vaginal exams should also show progressive cervical dilation and effacement.
Dilation. Effacement. You're speaking gibberish ?
Dilation is the opening of the cervix, which of course is necessary for bub to pass out of the womb, through the cervical opening, into the vagina, and out. Effacement is the thinning of the cervical opening, which makes sense as bub stretches the cervix as it passes through the cervix. Just think of it like passing your head through a jumper with a tight neck.
Signs of onset of labor may occur at any time and in any order, with some women experiencing only contractions, until well into advanced labor. Thus, these are not required to establish labor:
Bloody show, which is a passage of a small amount of blood or blood-tinged mucus through the vagina, towards the end of pregnancy, just before labor begins. As the cervix changes shape, mucus and bleed that occupies the cervical glands or cervical os is freed. It doesn't signify increased risk tot he mother or baby, and is normal. A large bleed however, should rule out placental abruption or placenta previa
Rupture of membranes (waters breaking)
Onset of tightenings/contractions, that move the infant down the birth canal
It can also present with:
Possible distress (fear, anxiety), depending on prior childbirth experience, cultural perception of childbirth and pain, mobility during labor, and support provided during labor
How do you know childbirth is starting?
You can pass blood, which we call a bloody show. You can pass water, which we call rupture of membranes. Or you might start feeling contractions, which can be painful.
What is rupture of membranes? Why does rupture happen?
Membranes just means the amniotic sac. It's the balloon of water that surrounds the baby, protecting it. Just before giving birth, this balloon pops. Amniotic fluid is made from mom's blood, and bub's kidneys. Bub "drinks" it through their skin and gut.
There are 3 stages of labor:
Latent phase (aka quiescent phase, prodromal labor, pre-labor), which begins when the woman receives uterine contractions [not including Braxton Hicks]. It ends with cervical effacement (i.e. thinning and stretching of the cervix) and cervical dilation. Degree of effacement is felt by vaginal exam, and a long cervix implies effacement hasn't occured yet
Active phase, which is cervical dilation of >3cm, cervical effacement >80%, more than 2 contractions in 10 minutes, or rupture of membranes. The definition by cervical dilation has been increased in some jurisdictions to increase NVD rates. The duration of the active phase ranges from 8 hours in primi's, and shorter to those who are multi's, and is considered prolonged when the cervix dilates <1.2cm/hr over the past 2 hours
2nd stage (aka fetal expulsion, involution stage), which begins when the cervix is fully dilated (>10cm), progresses as the baby descends, and ends when the baby is born. It is stimulated by prostaglandins and oxytocin. As pressure on the cervix increases, women have a sensation of pelvic pressure, and have an urge to push. Crowning causes an intense burning/stinging sensation. Delaying clamping the umbilical cord for >1 minute after birth is recommended as there is ability to Tx jaundice if it occurs, decreases risk of anemia, but may increase risk of jaundice. Clamping is followed by painless cutting of the cord
3rd stage (placenta delivery), which begins after fetal expulsion. It begins as separation of the placenta from the wall of the uterus. It usually lasts 11 minutes. Duration >30 minutes raises concern for retained placenta. Delivery en caul is where membranes are intact, which can occur when the maniotic sac hasn't ruptured during labor/pushing
4th stage (postnatal, postpartum), begins after child birth, extending for a bout 6 weeks. If there is an episiotomy or a perineal tear, it is stitched. The mother's hormone levels and uterus size return to it's non-pregnant state, and the newborn adjusts to life outside their mom's body. Nonetheless, afterpains (similar to menstrual cramps) and lochia (vaginal discharge after giving birth, containing blood mucus and uterine tissue, initially bright red fading to yellow/white; that is sterile in the 1st 2-3 days, but not so by the 3rd-4th day as the uterus begins to be colonized by vaginal bacteria, e.g. non-hemolytic streptococci and E coli) continues. Recommendations include skin to skin contact, and breast feeding
The stages of labor. What are they?
There are 4. The 1st stage begins when there's contractions, which we call the latent phase. The active phase is when a certain dilation or effacement has been achieved. Specifically, when the cervical opening is >3cm wide. Or when it has thinned by 80% of its original thickness. It can also be triggered by regular contractions of >2 in 10 minutes. Or rupture of membranes.
The next stage. The 2nd stage. When does it start?
When the cervix is fully dilated. And that's when it hits 10cm wide in diameter. As there's pressure on the cervix, women get the urge to push.
10cm. Why are we using that particular number?
It's based on the average minimum length required for bub's head to pop out.
What's 3rd stage then?
It happens after bub has popped out. And involves the placenta coming out. It usually takes 10 minutes to happen, but if it takes longer than 30, we worry.
Stage 4, what's that?
Postnatal, which lasts for about 6 weeks. It's that period of time when everything returns to normal for mom, and baby adjusts to the outside world. Because it's important, we do a lot of follow up and community nursing in this period.
Vaginal delivery (aka normal vaginal delivery, NVD) is childbirth (naturally) through the vagina, used to contrast vaginal delivery [whether assisted or induced] to contrast from C-section. It thus includes:
Spontaneous vaginal delivery (SVD), where labor occurs without the use of drugs or other techniques (forceps, vacuum extraction, C-section) to induce labor
Assisted vaginal delivery (AVD), where labor [with or without drugs, or other techniques to induce labor], requires:
Instrumental delivery, where special instruments are used to deliver the baby vaginally, including:
Vacuum extractor (aka ventouse)
Caesarean section (aka C-section, C/s) is where surgical incisions are made through a mother's abdomen and uterus, to deliver newborn(s). It is performed when vaginal delivery would put the baby or mother's life or health at risk. They can be performed upon request (and is requested more frequently than necessary) and is a practice health authorities would like to reduce, as it increases bad outcomes in low risk pregnancies. It should not be performed before 39 weeks [as this is considered full term for child development] without medical indication to perform surgery. It includes:
Lower uterine segment C-section (LSCS), the most commonly used. It involves a transverse cut just above the edge of the bladder, and results in less blood loss, and easier repair
Classical C-section, involving a midline longitudinal incision, allowing a large space to deliver the baby, but is rarely performed as it is more prone to complications
Participation of medical managment can either be:
Active management of labor, which results in slightly reducing C-section, but doesn't affect assisted deliveries. It is recommended in the 3rd stage of all vaginal deliveries to help prevent PPH. It involves:
Frequent assessment of cervical dilation
IOL,where if dilation doesn't occur, oxytocin is offered
Administering syntocinon within 1 minute of fetal delivery, controlled traction of the placenta, and uterine massage every 15 minutes for 2 hours
Augmentation, where oxytocin is given to speed progress of labor