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Parturition, commonly known as childbirth or labor, is a natural and complex process through which a pregnant mammal gives birth to her offspring. This transformative event marks the culmination of the pregnancy journey, as the developing fetus is ready to transition from the safety of the mother's womb to the outside world. It is a remarkable phenomenon that involves intricate hormonal, physiological, and behavioral changes in both the mother and the fetus.
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PARTURITION “Every woman is special when she becomes a wife but she is a God when she becomes a MOTHER.” BY:RAJKUMAR JAIN, FOUNDER EDUSKILLS BY RK COURSE:B.Sc(H) ZOOLOGY
LEARNING OBJECTIVES • Parturition and Timing of birth • Stages of birth and labor • Aspects of pre-mature, multiple &difficult births
WHAT IS PARTURITION? • The internal relationship between mother and foetus terminates in childbirth, or parturition. • Parturition means “giving birth to young one.” • Process of bringing forth a child from the uterus, ending pregnancy. • Parturition is the expelling of the fully formed young one from the mother’s uterus after the gestation period.
TIME OF BIRTH • Avg. length of pregnancy in humans is 9 months. • The due date (or term) can be calculated in 3 easy steps: Step 1: Determine the first day of your last menstrual period. Step 2: Next, count back 3 calendar months from that date. Step 3: Lastly, add 1 year and 7 days to that date. • For example: Your menstrual period began on 9 September 2010. Counting back 3 calendar months would be 9 June 2010. Adding 1 year and 7 days would bring you to 16 June 2011, as your estimated due date. • This method is called Naegele’s Rule (German obstetrician) and is based on a normal 28-day menstrual cycle. Hence, one has to adjust dates as per longer or shorter menstrual cycles.
Other ways of calculating due date: Estimate your delivery date by using the steps 1&2 and the chart: 1) Locate the first day of last menstrual period 2) Next, note the date directly below. This is the estimated date of delivery
PREPARATION FOR LABOR 1) 2-3 weeks before labor, women may have some sensation of decreased abdominal distention produced by the movement of foetus down into the pelvic cavity. This is called “LIGHTENING.” 2) This means that the baby has “dropped.” 3) Lightening occurs about 2 weeks before birth in primiparous woman but may not occur until labor in multiparous woman. 4) Allows the woman to breathe easily because of less pressure in diaphragm. 5) The women may also urinate more frequently as the foetus is pressing on her bladder. 6) A few hours to a week before labor begins the head of the foetus moves down into the pelvic girdle. This is called “Engagement of the presenting part.”
HUMAN PELVIC STRUCTURE MALE AND FEMALE
CONTD….. • Take birthing classes: what will happen during labor. Answers your questions about the process. • Take breastfeeding classes: proper latch training, hold baby during feeding • Take parenting classes: to keep baby safe, dress and how to tell baby has medical emergency • Visit the hospital:comfort, baby delivery space, help plan birth process. • Pack your bag: loose and comfortable clothes, breast pads, nipple cream, water bottle, camera, medications, blankets, healthy food etc.
BIRTH PROCESS • The birth process can be divided into three stages viz., (1) cervical effacement and dilation, (2) expulsion of the foetus, and (3) expulsion of the placenta. • The length of each stage varies among individuals and in same individual between first and subsequent births.. • Time period of labor and birth in primiparous women: 8-14 hrs. • Time period of labor and birth in multiparous women: 4-9 hrs.
STAGE 1: CERVICAL EFFACEMENT AND DILATION Cervix effacement aka “ripening of cervix” is when the cervix softens, thins and shortens. The opening of the cervical canal before labor is small normally obliterated and plugged with mucus. The first stage of labor is marked by the onset of regular uterine contractions open or dilate the cervix from 0.2cm to 7-10cm push the baby’s head against the opening of cervix and progressively dilates it. The result of effacement contractions is cervical effacement, which means a thinning of the normally thick walls of the cervix and retraction of the cervical tissue upward into the uterus, making it easier for the foetus to pass into the birth canal (cervical and vaginal canals).
During pregnancy the cervix is blocked by a mucous plug. At, or immediately before the beginning of effacement contractions, mucus is dislodged along with a small amount of blood, and this bloody show(pinkish in colour) exits through the vagina. Also at this time, or in the first stage, an enzyme weakens the amnion. A small tear then appears in the amniotic sac (actually made up of chorion on the outside and amnion on the inside), and clear amniotic fluid trickles or gushes from the sac and is expelled through the vagina. This bursting of the amniotic sac (breaking of the bag of waters) and the bloody show are sure signs that true labor is commencing. The final phase of stage 1 labor, during which the cervix dilates from about 7 to 10 cm in diameter, is called transition dilation. This phase lasts about 20 min–1 h and tends to be shorter in multiparous women. Transition is characterised by very intense transition contractions that last longer (60–90s) than those in earlier stages of dilation.
FALSE LABOR??? It included Braxton-Hicks contractions i.e “false labor” • Occurs after 20 weeks. • Painless • Irregular&Infrequent • Don’t get stronger • Lessen with change of position • Cervix dosent dilate • Interval b/w contractions doesn’t get shorter
WHAT HAPPENS DURING TRANSITION? • Foetus descends into the pelvic basin, puts pressure on the pelvic floor. This causes an urge in pregnant woman to push during these contractions, but she is advised not to do so. [REASON: It will tire the mother but not the move the foetus and cause edema {puffiness caused by excess fluid trapped in the body’s tissues.}of the cervical tissues.] • Pressure on the pelvic floor creates a pushing urge, which women report feeling like an urge to defecate. • Transition is most difficult part of labor, not only because of severity of contractions but because a woman may experience intense pain, nausea, vomiting, trembling, leg cramps, discouragement and restlessness. • During transition, condition of foetus is monitored for signs of fatal distress. Heart functions are monitored by placing wire leads either on mother’s abdomen or foetus’s scalp through cervical opening.
STAGE 2: EXPULSION OF THE FOETUS Begins when the cervix is dilated maximally and ends with the delivery of the infant. Intensity of transition is less than the stage 1. Each contraction lasts upto 60s, with 1-3 min treat intervals between contractions. During this stage of labor, the physician may perform an “episiotomy”to prevent tearing of the perineal tissues as the baby emerges. To do this, a local anesthetic is injected into the perineum (the region between the anus and the vagina) and a small incision is made in the perineal skin. This incision later will be sutured with absorbable material. At this stage the woman is encouraged to push which causes the top of head to appear (crowning). This signifies the baby is about to be born.
Once the head is out, any mucus or amniotic fluid in the baby’s nose or mouth is removed with a suction device. • The infant then rotates so the shoulders emerge in the up-and-down position (facing the mother’s side) that is the largest dimension of the birth canal. • The infant then slides out takes his or her first breath, and usually emits an exhilarating cry. • The umbilical cord is then clamped in two places about 3in from the baby’s abdomen and is cut between the clamps. • There are no nerve endings in the cord, and neither the mother nor the infant feels the procedure. • Drops of penicillin or silver nitrate are then placed in the infant’s eyes to prevent bacterial infection. • This is required by law in all states because of the risk that the infant could be blinded by bacteria if the mother is infected.
STAGE 3: EXPULSION OF THE PLACENTA • Last stage of delivery • Last about 5-30mins, placenta afterbirth is expelled • After the foetus is delivered, the next few contractions push the placenta which has been detached from the uterine wall, through the birth canal. • Normally 8 oz (~240ml) of blood is lost during delivery. OMG!!!!! • Usually the uterus will be massaged through the abdominal wall to encourage contraction, which inhibits uterine blood flow. If uterine hemorrhage (excessive bleeding) persists, oxytocin or a chemical that constricts blood vessels is administered to contract the uterus and inhibit bleeding.
WHAT HAPPENS TO PLACENTA AFTER EXPULSION? • In some societies, expelled placenta is treated with reverence and is buried ceremoniously. • Hospitals in the U.S typically discard it unless it needs to be examined for medical reasons. • Placenta and umbilical cord have valuable pool of stem cells. HSC (Hematopoietic stem cells) found in the cord blood cells have the potential to proliferate and differentiate into RBCs, WBCs and Platelets. • Cord blood can be transplanted into leukaemia and lymphoma cancer patients, where it can restore bone marrow destroyed by radiation and chemotherapy.
PRETERM BIRTHS • Preterm infant- born before 37 weeks. • Characteristics of such infants: low body weight (less than 2.5kg), disability like mental retardation, blindness, deafness & learning disabilities. Eg., infants born weighing less than 5.5 lbs are four times less likely to graduate from high school by age 19. • The normal weight of a foetus 1 month before the due date is about 2.5kg, compared with the average weight of 3.4kg at birth. Many of the foetus’s organs mature in the last weeks of pregnancy, so an infant born before the ned of the full term pregnancy is also often called premature; if length of the gestation exceeds 39 weeks, the infant is posterm, or post-mature.
Causes of preterm births • Multiple pregnancies also lead to preterm birth. • Chronic health conditions, such as diabetes or infections. • Drug or alcohol abuse. • Preeclampsia (high blood pressure during pregnancy) • Problems with uterus or cervix. • Too less time {less than 18 months} between pregnancies. • Vaginal bleeding or infections during pregnancies. • Preterm separation of placenta.
SOLUTION TO PRETERM BIRTHS • Avoid tobacco, alcohol or drugs when you are pregnant. • Take a healthy balanced diet. • Reduce your stress levels. • Wait for at least 18 months in between two pregnancies. • Treatment with a vaginal progesterone gel has also been shown to reduce the risk of preterm deliveries in women with short cervix. (progesterone inhibits uterine contractility, and the ratio of progesterone to estriol decreases in the moth- er’s blood prior to normal labor.)
MULTIPLE BIRTHS • The odds for having twins are about 1 in 71; for triplets 1 in 6400; quadruplets, 1 in 512,000. Heredity can influence the odds of having fraternal twins. • Fraternal twins occur more commonly in women who have a family history of twins. • Delivery of multiple foetuses occur about 22 days earlier, on average, than single births. • Presence of twins can be detected by ultrasounds or detection of two heartbeats. • INTERESTING FACT: There are records of the second twin being delivered up to 56 days after the first! A few of these cases in which a twin is born many days after its sibling may be due to superfetation, i.e. fertilization of a newly ovulated egg occurs while a previous foetus is developing in the uterus. This would have to occur before the fourth month of pregnancy, because after that time the amniotic sac obliterates the uterine lumen and would not allow sperm passage. There is, however, no direct proof that superfetation occurs in humans. • CAUSES: More than one egg is fertilised. • PREVENTION: IVF with single embryo transfer.
DIFFICULT BIRTHS • In most of the births, the foetus position is normal i.e head-down position. However, in 3-4% of births, the foetus, is in breech presentation, at the beginning of labor, which means that the feet, buttocks or knees rest against the cervix. • Breech deliveries often occur with no difficulties, however unfortunately, the labor phase is longer and the gynaecologist has to perform a cesarean delivery. • In 1 out of 200 births, the foetus is in transverse presentation i.e the shoulders and arms emerging first. Such cases also need caesarean deliveries.
FORCEPS DELIVERY • When foetus doesn’t emerge easily, physician can insert an instrument (forceps) into the birth canal and around the head to effect a forceps delivery. • Medical reasons for using forceps are: (1) acute distress of the foetus, such as irregular or weak heartbeat and lack of oxygen caused by premature separation of the placenta, compression of the umbilical cord, or excessive pressure on the foetal head; (2) illnesses of the mother, such as heart problems, tuberculosis, or toxemia; (3) a previous cesarean section, as the wall of the uterus might tear; (4) presentation of the foetus in a breech position; and (5) an abnormally slow labor.
VACCUM EXTRACTION • It is used if labor is lasting too long without progressing, if the foetus is in danger, or if the mother should not push because of cardiovascular or neurological problems. • In this method, a metal cup is placed on top of the foetus’s head, negative pressure is applied to this cup, and the cup is firmly attached. The foetus is then pulled out. • Vacuum extraction is less likely to cause damage to the mother’s perineal tissue than with the use of forceps, but is more likely to cause foetal scalp injury. About 1 in 20 babies born in the United States are delivered vaginally with the assistance of for- ceps or vacuum extraction.
CESAREAN DELIVERY • Latin caedere, meaning “to cut”; also known as cesarean sections, or C-sections. Apparently, the name of this operation had its origin in an order by Emperor Julius Caesar of such an operation to be done on dying pregnant women in hopes of saving the unborn children. • Lasts upto 20-90 mins. • Cesarean delivery is performed when the foetus is in a transverse presentation or less commonly in a breech presentation, when the pelvis of the woman is too small, the foetus is too large, or when the foetus shows signs of distress, such as abnormalities in heart function. • Cesarean delivery is performed if the umbilical cord gets compressed between the head and the wall of the birth canal, if the placenta is coming out before the foetus (placenta previa), or if the placenta prematurely separates from the uterus. • Some of the reasons given for the increase in cesarean deliveries include: (1) the assumption that once a woman has a cesarean, she can never deliver a future child vaginally (this is not true in many cases); (2) using a cesarean delivery for a breech birth (this often is not necessary); (3) the increased use of foetal monitoring to detect foetal problems during labor; (4) the increasing rate of multiple pregnancies and pregnancies of older women; (5) the rising obesity rate of US women and associated risk of pregnancy complications in women with excess body weight; and (6) doctors’ fear of liability lawsuits and reduced physician time required for a cesarean versus a vaginal birth. • Performed in operation theatre by going general or spinal anaesthesia to the mother.
