Obstetrics: Stages of Labour

• Obstetrics focuses on pregnancy, childbirth, and the postpartum period.
• Gynaecology deals with the health of the female reproductive system.
• Labour and delivery encompass the physiological process of childbirth.

Stages of Labour

• First stage: begins with the onset of regular contractions and ends with full cervical dilation (10 cm).
  • Latent phase: early part of the first stage, characterized by mild, irregular contractions and slow cervical dilation.
  • Active phase: contractions become stronger, more frequent, and regular, leading to more rapid cervical dilation.
  • Transition phase: the final part of the first stage, with intense contractions and increasing pressure in the rectum.
• Second stage: complete cervical dilation to the birth of the baby.
  • Passive phase: foetus descends further into the pelvis, woman has an urge to push.
  • Active phase: maternal expulsive efforts combined with uterine contractions to deliver the baby.
• Third stage: begins immediately after the birth of the baby and ends with the delivery of the placenta and membranes.
• Fourth stage: the hour immediately following delivery.

Fetal Monitoring

• Electronic fetal monitoring (EFM) is used to assess fetal well-being during labour.
  • External monitoring: uses transducers placed on the mother's abdomen to detect fetal heart rate (FHR) and uterine contractions.
  • Internal monitoring: involves placing an electrode on the fetal scalp to directly measure FHR and an intrauterine pressure catheter (IUPC) to measure contractions.
• Baseline FHR: the average FHR during a 10-minute segment, excluding accelerations, decelerations, and marked variability. Normal baseline FHR is 110-160 bpm.
• FHR variability: fluctuations in the baseline FHR, reflecting the interplay between the sympathetic and parasympathetic nervous systems; indicates fetal reserve.
  • Absent variability: amplitude range undetectable.
  • Minimal variability: amplitude range ≤ 5 bpm.
  • Moderate variability: amplitude range 6-25 bpm.
  • Marked variability: amplitude range > 25 bpm.
• Accelerations: abrupt increases in FHR above the baseline.
  • Visually apparent abrupt increase (onset to peak <30 seconds).
  • At ≥32 weeks of gestation, ≥15 bpm above the baseline and lasting ≥15 seconds but <2 minutes.
  • Before 32 weeks of gestation, ≥10 bpm above the baseline and lasting ≥10 seconds but <2 minutes.
• Decelerations: decreases in FHR below the baseline.
  • Early decelerations: gradual decrease (onset to nadir ≥30 seconds) in FHR with the onset and end coinciding with uterine contractions; caused by fetal head compression.
  • Late decelerations: gradual decrease (onset to nadir ≥30 seconds) in FHR with the onset occurring after the start of a contraction and the nadir occurring after the peak of the contraction; usually caused by uteroplacental insufficiency.
  • Variable decelerations: abrupt decrease (onset to nadir <30 seconds) in FHR, occurring at any time in relation to uterine contractions; usually caused by umbilical cord compression.
  • Prolonged deceleration: FHR decreases ≥15 bpm below the baseline and lasting ≥2 minutes but <10 minutes.

Management of Labour

• Pain management:
  • Non-pharmacological methods: breathing techniques, massage, hydrotherapy.
  • Pharmacological methods: epidural analgesia, systemic opioids.
• Augmentation of labour: stimulation of uterine contractions to accelerate labour.
  • Amniotomy: artificial rupture of membranes (AROM).
  • Oxytocin: synthetic hormone that stimulates uterine contractions.
• Management of the third stage of labour:
  • Active management: administration of a uterotonic drug (e.g., oxytocin), umbilical cord clamping and cutting, and controlled cord traction.
  • Physiological management: allowing the placenta to deliver spontaneously without intervention.

Delivery

• Vaginal delivery: the baby is born through the birth canal.
• Assisted vaginal delivery: use of instruments (e.g., forceps or vacuum extractor) to aid delivery.
• Cesarean delivery: the baby is delivered through an incision in the mother's abdomen and uterus.
  • Indications: fetal distress, breech presentation, placental abnormalities, failure to progress in labour.

Postpartum Care

• Monitoring for postpartum hemorrhage: excessive bleeding after delivery; major cause of maternal mortality.
  • Uterine atony: failure of the uterus to contract adequately after delivery.
• Assessment of perineal healing: the perineum is the area between the vagina and anus, which may be lacerated during delivery.
• Lactation support: assisting the mother with breastfeeding.
• Psychological support: addressing postpartum blues or depression.

Common Obstetric Complications

• Preterm labour: labour that begins before 37 weeks of gestation.
• Post-term pregnancy: pregnancy that lasts longer than 42 weeks of gestation.
• Preeclampsia: a pregnancy-specific condition characterized by high blood pressure and proteinuria.
• Gestational diabetes: diabetes that develops during pregnancy.
• Ectopic pregnancy: implantation of the fertilized ovum outside the uterus.
• Miscarriage: spontaneous loss of a pregnancy before 20 weeks of gestation.
• Stillbirth: the death of a fetus at or after 20 weeks of gestation.

Common Gynaecological Conditions

• Menstrual disorders:
  • Amenorrhea: absence of menstruation.
  • Dysmenorrhea: painful menstruation.
  • Menorrhagia: heavy or prolonged menstrual bleeding.
• Pelvic inflammatory disease (PID): infection of the female reproductive organs.
• Endometriosis: the presence of endometrial tissue outside the uterus.
• Uterine fibroids: non-cancerous growths in the uterus.
• Ovarian cysts: fluid-filled sacs on the ovary.
• Polycystic ovary syndrome (PCOS): hormonal disorder causing enlarged ovaries with small cysts on the outer edges.
• Cervical dysplasia: abnormal changes in the cells of the cervix.
• Gynaecological cancers: cancers of the female reproductive organs (e.g., cervical, ovarian, uterine).

Gynaecological Procedures

• Pap smear: screening test for cervical cancer.
• Colposcopy: examination of the cervix using a magnifying instrument.
• Hysterectomy: surgical removal of the uterus.
• Oophorectomy: surgical removal of one or both ovaries.
• Salpingectomy: surgical removal of one or both fallopian tubes.
• Dilation and curettage (D&C): surgical procedure in which the cervix is dilated and the uterine lining is scraped.
• Laparoscopy: minimally invasive surgical procedure using a small incision and a camera to visualize the pelvic organs.