Elective Cesarean Delivery, Neonatal Intensive Care Unit Admission, and Neonatal Respiratory Distress

1
Elective Cesarean Delivery, Neonatal Intensive
Care Unit Admission, and Neonatal Respiratory
Distress

• ???

2
Introduction

• GA of elective C/S vs risk of neonatal
  respiratory distress ? guidelines recommending
  elective cesarean delivery at term (39 weeks or
  later).
• 45 of neonates will still develop signs of
  respiratory distress ? labor before caesarean
  delivery is associated with a lower rate of
  neonatal respiratory distress.
• The mechanism of this effect is unknown, but it
  is postulated to be secondary to activation of
  epithelial sodium channels in the fetal lung.

3

• Glucocorticoids appear to be a potent
  up-regulator of the expression of epithelial
  sodium channel genes and are secreted in
  increasing amounts by the fetal adrenal gland at
  term.
• Fetal hypothalamic-pituitary-adrenal axis
  maturation and adrenal glucocorticoid production
  are also felt to be possible triggers for the
  onset of labor at term.
• Adrenal production of glucocorticoids may both
  initiate labor and prepare the fetus for
  extra-uterine life.

4

• It has been postulated that the rates of
  respiratory distress could be reduced further if
  elective cesarean delivery is delayed until the
  onset of labor or ruptured membranes.
• Most of the studies that reported a protective
  effect of labor included women who had cesarean
  delivery after prolonged labor and not just women
  having an elective repeat cesarean delivery
  shortly after the onset of labor.
• The lower rates of respiratory distress observed
  following cesarean delivery after the onset of
  labor may simply reflect that these fetuses were
  more likely to be truly at a term gestation.
• It is not clear whether the short duration of
  labor before elective repeat cesarean delivery is
  protective.

5
Intent of the Study

• To estimate whether the risk of neonatal
  intensive care unit (NICU) admission and neonatal
  respiratory distress was lower in women
  undergoing cesarean delivery after spontaneous
  rupture of membranes or the onset of labor
• To confirm the relationship between gestational
  age at cesarean delivery and risk of respiratory
  distress

6
Materials and Methods

• All elective cesarean deliveries done in the
  Calgary Health Region, Calgary, Alberta, Canada
• March 1, 2004, to April 30, 2005
• 13,360 deliveries, C/S rate 26.4 9 (3527)
• GA ? 37 wks, BW ? 2500 g, Elective C/S
• Maternal data age, gravidity, parity, antepartum
  risksIntrapartum factors including rupture of
  membranes, presence of contractions, and duration
  of labor
• Antepartum or intrapartum maternal medications,
  postpartum complications, and length of stay
• Labor before cesarean delivery was defined as
  the presence of symptomatic contractions or
  rupture of membranes before cesarean delivery.

7
Materials and Methods

• Newborn data birth weight, gender, Apgar scores,
  cord pH, resuscitation parameters, treatment
  provided if admitted to NICU, diagnoses, and
  length of stay.
• Twin A was included only (higher risk in twin B).
• Definition of respiratory distress tachypnea,
  with respiratory rate of more than 60 breaths per
  minute, retractions, grunting, nasal flaring, and
  cyanosis in room air, or requiring treatment with
  any of the following supplemental oxygen, nasal
  continuous positive airway pressure, endotracheal
  intubation, or exogenous surfactant.

8
Results

• 1,193 paired maternal-infant charts matched the
  criteria of study ( 36 wks GA, 2500 g).
• The mean (standard deviation) maternal age was
  32.14.8 years.
• Spontaneous onset of labor before cesarean
  delivery occurred in 225 of 1,193 women (18.9),
  of whom, 142 reported symptomatic contractions,
  and 104 had spontaneous rupture of membranes.

9
Help with image viewing Email Jumpstart To
Image
10
Results

• Previous cesarean delivery (89)Breech (6.5),
  twins (1.9), placenta previa (1.1), primary
  elective (0.8), and previous uterine surgery
  (0.4), others (0.3)
• A third of the mothers were more than 35 years
  of age, and 1315.9 were obese, correlating with
  7.18.0 having diet-managed diabetes, with no
  difference between mothers whose infants had
  symptoms of respiratory distress and those who
  did not .

11
(No Transcript)
12
Results

• The mean ( standard deviation) gestational age
  of the infants at time of elective cesarean
  delivery was 271.46.7 days or 385/7 weeks.
• The mean birth weight was 3,397480 g.
• Fifty-two percent were male infants.
• Twenty-three (1.9) infants were from twin sets,
  and the gestational age of these infants ranged
  from 254 to 268 days (362/7 to 382/7 weeks). Five
  of these infants were at a gestational age of
  less than 259 days (370/7 weeks). From the 23
  twin infants, three were admitted to NICU.

13
Results

• Overall, 156 (13.1) infants delivered by
  elective cesarean were admitted to NICU.
• 126 infants were identified to have respiratory
  distress, although only 118 (9.9) of these
  infants were admitted to NICU.

14
(No Transcript)
15

• Two thirds of the infants admitted to the NICU
  with symptoms of respiratory distress had short
  stays, with a mean of 6.4 hours, but the
  remaining third had a mean length of stay of 1.9
  days. Several infants with other diagnoses had
  lengths of stay beyond 7 days (Table 3).

16
(No Transcript)
17
(No Transcript)
18
Fig. 2. Smoothed fit of relationship between
respiratory distress and gestational days. Points
on the Y axis indicate respiratory distress1 and
no respiratory distress0.
19
(No Transcript)
20
Discussion

• In this study, the risk for admission to NICU and
  development of neonatal respiratory distress were
  significantly associated with gestational age at
  time of elective cesarean delivery and male
  gender.
• In this population studied, if elective cesarean
  delivery were planned for beyond 270 days (384/7
  weeks) of gestation, the risk of respiratory
  distress could be reduced by 50, and NICU
  admission could be reduced by approximately 40
  in these neonates.

21

• It was anticipated that not all cases will be
  appropriate for delay of delivery until 384/7
  weeks and that the risk of respiratory distress
  and neonatal admission will be one of the factors
  in considering the optimal time of delivery.

22

• Numerous studies have identified similar
  relationships between respiratory morbidity, need
  for NICU admission, and gestational age. The
  recommendation from these studies is that
  cesarean delivery at 39 weeks or later
  significantly reduces the risk of respiratory
  morbidity. These recommendations are stated in
  the American College of Obstetricians and
  Gynecologists (ACOG) Committee Opinion 98,
  published in 1991.

23
Conclusion

• In the final model, elective cesarean occurring
  beyond 270 days of gestation (384/7 weeks)
  significantly reduced the risk of NICU admission
  and the risk of respiratory distress, but again
  the presence of precesarean delivery
  contractions or rupture of membranes did not
  further reduce this risk.

24
Many Thanks for Your Attention!