Hugh M. MacDonald

Neonatal asphyxia. II. Neonatal mortality and long-term sequelae

Neonatal asphyxia, defined in this study as delay of greater than 1 minute in onset of spontaneous respiration at birth, occurred in 1% of 13,221 live-born infants of birth weight greater than 500 gm between 1970 and 1971. Seventy-five (56%) of 133 asphyxiated infants survived the neonatal period. Survival was directly related to gestational age. The 65 survivors of asphyxia available for study were seen at a mean age of 4.8 years to determine the incidence and extent of neurologic and developmental abnormalities. Twelve children (18.5%) had severe impairment: nine had both neurologic and intellectual handicaps, two had neurologic impairment alone, and one had intellectual impairment alone. The incidence and severity of impairment were not related to gestational age. Postasphyctic seizures were associated with poor outcome.

Prevention of iatrogenic neonatal respiratory distress syndrome: Elective repeat cesarean section and spontaneous labor

Neonatal respiratory distress syndrome (RDS) is an important complication of elective repeat cesarean section. In a review of 68,880 consecutive deliveries, 1,897 women underwent elective cesarean section at a gestation estimated to be greater than or equal to 38 weeks. Seventy-one (4.3%) of the infants of the 1,649 women who were not in labor at the time of delivery developed neonatal RDS. None of the infants of the 248 women who were in spontaneous labor at the time of delivery developed RDS (P less than 0.005). There were no cases of uterine rupture in either group. Of the 71 infants who developed RDS, 29 (41%) were judged to be at term on the basis of both examination and birth weight. Misapplication of fetal ultrasound data contributed to the premature delivery of more than one third of the infants with RDS. Awaiting the onset of spontaneous labor to determine the timing of repeat cesarean section in women at term is an effective way to preventing iatrogenic neonatal RDS.

Eclampsia at Magee-Womens Hospital, 1970 to 1980☆

Abstract The medical records of 52 eclamptic patients at Magee-Womens Hospital from 1970 through 1980 were reviewed in regard to age, parity, socioeconomic status, race, gestation, prenatal care, management, mode of delivery, and maternal and fetal complications. Unique features of this series included eclampsia among private, white patients early in gestation in spite of prenatal care. There was a high incidence of fetal distress leading to operative delivery.

Effects of electronic fetal heart rate monitoring on perinatal outcome and obstetric practices

Perinatal outcome and obstetric practices during 1970 and 1977 were compared. None of the 6,740 fetuses delivered with birth weights of 1,000 gm or greater in 1970 had electronic fetal monitoring (EFM). In 1977, 5,987 of 8,174 fetuses delivered had EFM (72.7%). High-risk factors were significantly more frequent in the pregnant patient population in 1977. The incidence of intrapartum stillbirths and severe birth asphyxia was significantly lower in 1977. These reductions remained significant when corrected for changes in obstetric practices other than EFM as well as for changes in patient population. The neonatal death rate was not significantly changed. The primary cesarean section rate increased from 4.4% to 10.1%, mostly because of a greater number of cesarean sections done for failure to progress in labor and breech presentation. Only 15% of the overall increase in cesarean section rate was because of a greater frequency of the indication of fetal distress. The incidence of severe birth asphyxia was the same among the unmonitored patients in 1970 and 1977. In 1977, however, the monitored patients had a significantly lower incidence of severe birth asphyxia than the unmonitored patients.

Nonimmunologic Hydrops Fetalis: A Review of 19 Cases

Nineteen cases of nonimmunologic hydrops fetalis occurring during a nine‐year period were reviewed. The pregnancies were complicated by hydramnios (78%) and preterm delivery (84%). Hydramnios appears to be the most useful indicator of the pregnancy at risk; its occurrence should prompt ultrasonographic investigation for evidence of hydrops. Modalities available for antenatal diagnosis of underlying fetal abnormalities include amniocentesis, serologic tests, fetal cardiac monitoring, radiography, hemoglobin electrophoresis and glucose tolerance testing. A specific cause for the hydrops may not be detectable (42% of our cases were idiopathic). Management of affected pregnancies is influenced by the frequent occurrence of fetal asphyxia and premature delivery. Outcome is poor: only 32% of the babies survived beyond the neonatal period. Symptomatic treatment for the neonate includes fluid restriction, maintenance of blood sugar, support of ventilation and attention to the complications of asphyxia.

1255 PRECEDING SPONTANEOUS LABOR (PSL), ELECTIVE REPEAT CESAREAN SECTION(RCS), AND IATROGENIC RESPIRATORY DISTRESS SYNDROME(IaRDS)

All deliveries by RCS at MWH from 1970-79 were reviewed to assess the relationship between PSL at term and IaRDS in infants delivered by elective RCS. Infants of diabetic mothers, of Rh-sen sitized mothers, with congenital anomalies, or with perinatal asphyxia(5 min Apgar <7) were excluded. The results for pregnancies of ≥38 wks gestational age(GA) by obstetrical estimate(OE) were:The 71 infants with IaRDS could be divided into 2 groups by assessment of GA by physical exam(PE) of the infants. Infants in gp A (42/71-59%) with mean BW of 2700 gms had OE of GA >2 wks more than the GA by PE. Infants in gp B (29/71-41%) with mean BW of 3200 gms had OE=GA by PE within 2 wks. Mean hospital stay was 11 days for both gp. Infants in gp A presumably were premature. The rate of IaRDS for this gp might be reduced by improved OE of GA. Infants in gp B were at term by both OE and PE, so for this gp the rate of IaRDS (1.7%) is unlikely to be affected by better OE of GA. Children born at term by elective RCS are at risk for IaRDS. PSL at term in these mothers seems to be a reliable indicator of fetal pulmonary maturity(FPM). Women scheduled to undergo elective RCS should either be allowed to go into labor or should have an L/S ratio to confirm FPM prior to RCS.

1236 CONTRIBUTION OF LEFT-TO-RIGHT (L→R) DUCTUS ARTERIOSUS SHUNTING (DUCT SHUNT) TO PULMONARY BLOOD FLOW (PBF) IN PREMATURE LAMBS WITH AND WITHOUT HYALINE MEMBRANE DISEASE (HMD) DURING THE FIRST HOURS OF LIFE

We tested the hypothesis that net L→R duct shunt contributes to PBF surge in premature lambs during the first hour of life (Pediat. Res., 8:433, 1974) and to high PBF seen later in lambs with severe HMD (Pediat. Res., 9:393, 1975). Total PBF, right ventricular output (RVO) and duct shunt were measured during first hours of life in 1 lamb with and 1 without HMD. At 129-130d gestation, a pre-calibrated electromagnetic flow transducer with non-occlusive zero was implanted on the main pulmonary artery (PA) to measure RVO; a similar transducer was implanted on the postductal portion of the common PA to measure PBF. Duct shunt was calculated as the difference between PBF and RVO. Lambs were returned to the amniotic cavity for 7-8d and then delivered by C-Section at 137d gestation. In each lamb, PBF rose sharply from < 50 to peaks of 487 and 473 ml/kg/min, respectively, at 22 and 29 min of age and then stabilized at lower levels by 1 hr of age. RVO stayed at high levels until after the PBF surge, then fell to stable levels by 1 hr of age. During the first 4 hr, net L→R duct shunt accounted for 28 to 68% of PBF (means 54 and 52%). These data suggest that L→R duct shunt contributes appreciably to PBF during the PBF surge and at age 1-4 hr. L→R duct shunt may be a major source of the high PBF previously reported in lambs with HMD.

ASPHYXIA NEONATORUM: A MAJOR CAUSE OF MORTALITY AND MORBIDITY

Consecutive liveborn deliveries (19,295) during 1970-72 were reviewed to establish the incidence, risk factors, and mortality rate associated with severe asphyxia. 214 infants (1.1%) were severely asphyxiated; mortality was 48%. A strong inverse correlation existed between both incidence of and mortality for asphyxia, and gestational age (GA) and birth weight (BW), Table. Other predisposing factors were low socioeconomic status, history of fetal wastage, and complications of pregnancy or labor. Asphyxia occurred 4 times more commonly with both breech presentation and with non-elective cesarean section, regardless of GA.Neurological and intellectual assessments were performed at a mean age of 4.9 yr on 69/77 survivors of yrs 1970-71. Mean IQ was 106; 49 (71%) of the survivors were completely normal. Severe handicapping defects were present in 13/69 (19%) and were equally frequent in term and preterm survivors. 8 had cerebral palsy (CP) with mental retardation (MR), 2 had CP alone, 2 had MR alone, and 1 was deaf.In this series, asphyxia greatly increased mortality, especially in the mid and high weight groups. The incidence of severe sequelae was high but did not vary with BW or GA.