Main content
NCLEX-RN
Course: NCLEX-RN > Unit 19
Lesson 2: Pregnancy and pregnancy complications- Physiology of pregnancy
- Diagnosis of pregnancy
- Pregnancy physiology I
- Labor and delivery
- Postpartum physiology
- Preeclampsia
- Placenta previa
- Placental abruption
- Placenta accreta
- UTIs in pregnancy
- Blood conditions in pregnancy
- Sheehan syndrome
- Postpartum hemorrhage
- Uterine inversion
- Diabetes in pregnancy
- Preterm labor
- C-section
© 2023 Khan AcademyTerms of usePrivacy PolicyCookie Notice
Postpartum physiology
Visit us (http://www.khanacademy.org/science/healthcare-and-medicine) for health and medicine content or (http://www.khanacademy.org/test-prep/mcat) for MCAT related content.
These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. Created by Nauroz Syed.
Want to join the conversation?
- When she says cervix remains dilated to about an inch at 1 week post partum, I'm curious, is that the os? When we measure dilation, do we measure the os or the cervic itself?(2 votes)
- Amelia: when you asked, is it the os of the cervix that remains dilated to about an inch at 1 week post partum, the answer is YES. Anna's response is incorrect. The os is part of the cervix. The os is the opening in the cervix that leads up into the body of the uterus and the os is where dilation of the cervix is always measured. I like to think of the cervix as the "neck" of the uterus. Before delivery, the cervix extends about 2 inches below the main body of the uterus and the cervical os is generally about the diameter of a Q-tip. As labor progresses, the cervix undergoes 2 simultaneous physical changes. EFFACEMENT is the thinning and "shortening" of the length of the cervix as it is "pulled up" toward/into the uterus. An examiner will generally describe effacement as a percentage, as in 25%, 50% or fully effaced, when an examiner cannot detect any junction or extension of the cervix below the uterus. DILATION (or DILATATION) is the opening up or enlargement of the diameter of the cervical os. It is measured in centimeters and is estimated by the examiner placing his/her index & middle fingers into the cervical os and spreading them apart like calipers to gauge how wide the os opening is. Over the course of labor the cervical opening (os) goes from about Q-tip size (<1 cm) to 10 cm or more, in order to allow passage of the baby's head. If the head is too big or if the delivery happens before the cervix is completely dilated, the cervical tissues can actually be torn. I am confused why Anna mentioned "female orgasm" and cervical dilation "to let the sperm through" because neither one of them have anything to do with the video or cervical dilation in the context of the post-partum period. Hopefully this can clear up any confusion that may exist. Good Luck.(9 votes)
- If you breastfeed for longer than six months, can you put off menses longer as well?(3 votes)
- During the breastfeeding, prolactin production is stimulated, this hormone suppress the ovarian activity, this protection is effective 98% against a new pregnancy.
So, YES, it can put off menses for almost a year if the baby is breastfeeding lots of time a day/night.
But, restarting the ovulation depends on some factors: breastfeeding pattern, mom's biologic variability, nutrition, culture, socioeconomic, so it's difficult to precise when it will happen.(1 vote)
- Couldn't the shiver just be the mothers reaction to what just happened?
I mean that some people my think the feeling of giving birth is weird or gross.(1 vote) - is os the same as labour stages.(1 vote)
- Hw does the baby get too big? should the bod prevent that?(1 vote)
Video transcript
- [Voiceover] You know,
they say that a woman is never the same after she has a baby, but your body works pretty hard, and it starts working right
after the baby is born, to get the body back into
its pre-pregnancy state. It usually takes somewhere
along six to eight weeks to occur, for most of the
organ systems to go back to working the way they
did before pregnancy. What happens right after delivery occurs? For some women, something like twenty-five to fifty percent of women,
so almost half of all women, start shivering. These postpartum shivers, they usually start within
thirty minutes of delivery, and they last anywhere
from two minutes long, to being an entire hour long. We're not exactly sure why they occur. We think that it might be related to sudden thermal imbalances from the separation of the placenta. Maybe it's related to certain
medications or anesthesia that's used during the delivery, or, perhaps, even, due
to bacteria in the blood. We're not exactly sure why they occur, but, in any case, there's
no real treatment for them, other than to give the
woman a warm blanket. They tend to resolve on their own, so, maybe not as clinically significant, but it's important to
know so that you're not startled when you see them
or you experience them for the very first time. Starting with the uterus,
let's talk about what happens after the baby and the
placenta are delivered. Immediately after delivery,
the uterus starts to contract. I mean, baby's out, placenta's out, the uterus immediately starts to contract. After a few of those
successive contractions, the uterine muscle starts to shorten. Those contractions also help
to constrict the blood vessels that are running through
the uterine muscle. That helps to control any
bleeding that might be going on. When you palpate the uterus,
when you feel for the uterus, the uterus should feel more
firm and feel more globular than it did in the pregnancy. Within about twenty four
hours after delivery, the uterus shrinks down,
so you can feel the fundus, which is the top of the
uterus, kind of, at the level of the umbilicus, so at the
level of the belly button. By one week postpartum,
the fundus can be felt halfway between the umbilicus
and the pubic symphysis, so, pretty rapid reduction. Then, by two weeks, you can't
feel the fundus anymore. Within six to eight weeks, it's
returned to its normal size, so, pretty quick reduction
back down to its normal size. The shrinking of the uterus
back down to its normal size, is affected by a couple
of different things. In women who had multiple
babies in the past, and in women in whom
the delivery of the baby occurred by C-section, rather
than by vaginal delivery, the uterus tends to be larger. Compare that with breast-feeding. Breastfeeding tends to cause a quicker reduction in the size of the uterus. A lot of that has to do with
a hormone called oxytocin. So there's hormone called oxytocin that's released from the brain. The primary function of oxytocin has nothing to do with the uterus. The primary function of
oxytocin is to contract the ducts of the breast,
to help release milk. One of the side effects, I
guess you could say, of it, is that it also causes
the uterus to contract, causing it to shrink at a faster rate. That's why women who breastfeed have a quicker shrinking rate,
essentially, of the uterus than women who do not breastfeed. With regards with what's going on on the inside of the uterus,
remember that the placenta attaches itself to the decidua basalis. The placenta is attached
to the decidua basalis of the uterus. That decidua basalis,
that lining of the uterus, is left behind after
the placenta separates. It's left behind, and what it does is, it splits up into two different layers. There will be the superficial
layer, which is shed, and the deeper layer, which sticks around, and it regenerates a new endometrium. When the bloody desidua
sheds, it does so for the first few days following delivery. The woman observes that, she sees it. It's referred to as lochia rubra. The lochia rubra, rubra
meaning red, right, so it's red lochia. After that, the vaginal
delivery becomes very watery. That's called called lochia serosa. That lochia serosa lasts for
about two to three weeks. Ultimately, that vaginal
discharge turns more yellow, yellow-white color. Then it's referred to as lochia alba, with alba meaning white. You can see that vaginal discharge, a significant amount of vaginal discharge lasts for about a month
following delivery. It's not just the uterus which
contracts to become smaller, the cervix and the vagina
do the exact same thing. After delivery, the cervix,
which is the opening of the uterus through which
the baby passes through, as you can probably imagine,
is pretty soft and floppy. After delivery, the
cervix starts to contract. By one week postpartum, you'll see that it's somewhere less than one inch dilated. The external os, or the
external opening of the cervix, actually, never returns to the same shape that it had before pregnancy. Instead of being this small, smooth, circular opening, it becomes a large, sort of, horizontal
slit, after childbirth. Similarly, the vagina is very smooth and dilated after delivery. It slowly, very slowly, contracts to shrink down, but, usually, it doesn't reach its pre-pregnancy size. As the swelling reduces,
the rugae of the vagina come back, usually
within three weeks or so, so the smooth surface is
replaced by the typical rugated surface of the vagina. Normally, it's safe to resume sex about three to four weeks postpartum. Finally, with regards to
the return of ovulation and the return of menses,
that usually occurs within six to eight weeks after delivery in women who don't breastfeed, so that's an important distinction. In women who do not breastfeed,
menses and ovulation usually return within six to eight weeks. In women who do breastfeed, however, ovulation and menses don't
return for up to six months, during the time the
woman is breastfeeding. That's because in order
to sustain breastfeeding, the hypothalamus, which is in the brain, has to produce a hormone called prolactin. So the hypothalamus produces
this hormone called prolactin, which is really important
for stimulating lactation. However, prolactin also inhibits,
I guess you can say again, this is one of the side
effects of this hormone, prolactin also inhibits
sex hormone production, which prevents ovulation from occurring. In fact, in some
under-developing countries, breastfeeding is used as a
main method of contraception after delivery, after
the woman gives birth. Those are some of the changes that occur after the baby is delivered.