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Prematurity rather than breech presentation may be the primary cause of severe illness or death among otherwise normal very-low-birth-weight (VLBW) infants. A study of 262 VLBW infants in the breech presentation showed that the method of delivery did not influence outcome. The adverse outcomes among VLBW breech-presenting infants who were delivered vaginally may be attributed to a high rate of fetal deaths and congenital malformations. Delivery by cesarean section may be advisable for infants in the feet-first position or infants with standard obstetric indications. Lower rates of cesarean section deliveries may lower the rate of complications in the mothers and reduce the chance of having repeat cesarean deliveries.

Hypertension in pregnancies is associated with complications such as poor fetal growth, fetal distress, and increased infant death at the time of delivery. The incidence of these complications is thought to increase with severity of hypertension. The effect of hypertension is thought to be mediated through constriction of peripheral blood vessels, which should be reflected in abnormal patterns of fetal heart rate (FHR). The association between severity of hypertension and altered FHR patterns was assessed from the records of 666 pregnant women with hypertension. Half of the women had blood pressure between 125/75 and 135/85 (group one), 38 percent had blood pressure up to 150/100 (group two), and the remainder had pressure readings over that level (group three). Up to 85 percent of premature deliveries (occurring before 36 weeks of gestation) were to the women in groups two and three. As hypertension worsened, the rate of cesarean sections increased because of increasing fetal distress. Rather than oscillating normally, FHR in group three significantly more often had a fixed baseline level. Tachycardia, rapid heart beat, tended to occur more often in this group as well, but not to a significant extent. Significantly more infants in group three also scored lower on indexes of cardiovascular function at birth, indicating neonatal depression. This was particularly related to FHR characterized by fixed baseline and late decelerations. Perinatal (last trimester and first month of birth) mortality increased with the severity of hypertension, but neonatal death was related only to lack of the fetus' reaction to nonstress testing of the mother prior to delivery. FHR was not predictably affected by drugs commonly used to treat maternal high blood pressure. The study suggests that close maternal and fetal monitoring should allow appropriate intervention and reduce illness and death related to maternal hypertension. (Consumer Summary produced by Reliance Medical Information, Inc.)

The normal period of gestation, from conception to delivery, is 40 weeks. Pregnancies continuing beyond 42 weeks (294 days from the last menstrual period) can result in poor outcomes for the infant and mother. To reduce the number of deaths from a prolonged pregnancy, most practitioners will use drugs which induce labor. The effect of a prolonged pregnancy on the mother and fetus was evaluated in 379 pregnancies continuing beyond 42 weeks gestation. The fetal heart rate, the characteristics of the labor and delivery, and the infant outcome were monitored. Labor was drug-induced in 48 percent and augmented in 28 percent of the women. Cesarean delivery was performed in 13 percent of the patients and delivery was assisted by forceps in 15 percent of the deliveries. The birth canal was unable to accommodate the passage of the infant in 60 percent of the cesarean sections and 13 percent of the infants were too large to deliver vaginally. Particularly fast fetal heart rates were detected in 39 percent of the infants. Inducing labor did not increase the need for cesarean section. It was concluded that preventive measures such as labor induction are a justified intervention in the treatment of prolonged pregnancies.

Preeclamptic pregnant women who receive infusions of magnesium sulfate to prevent seizures may experience more loss of blood during delivery. Preeclampsia is a serious complication of pregnancy involving high blood pressure and can lead to seizures. Researchers compared the amount of blood loss at delivery in 12 pregnant women with preeclampsia by infusing nine women with magnesium sulfate and withholding it from three others. Eight women treated with magnesium sulfate had a 164% longer bleeding time 12 to 24 hours after delivery.

From a population of 2,774 high-risk patients monitored during labor, 1,304 single pregnancies in cephalic presentation and with direct monitoring for at least 1 hour before completion or cesarean-section were studied. The maternal and fetal clinical data and the tracings were hand reviewed, coded, and programmed for computer analysis. In the record were studied baseline, its changes (tachycardia, fixed, saltatory), the accelerations, and the decelerations (ealy, variable, late). Fifty-four per cent had some type of FHR deceleration. Accelerations were recorded in over 12 per cent of all cases and were associated with cord problems in 41 per cent. Subgrouping the patients by age of gestation (≤36 weeks, 37 to 41 weeks, and ≥42 weeks) revealed a 10 per cent prolonged gestation rate and only 6.8 per cent premature: these had a lower 5 minute Apgar score. Fetal weight and age were positively correlated with Apgar score. Baseline changes were much more frequent among pre- and postmature infants, particularly tachycardia in the latter (40 per cent). The premature infants had a 25 per cent incidence of fetal distress and the postmature infants had 20 per cent. Neonatal morbidity and mortality rates were very high among premature infants and a mortality rate of 2.3 per cent was found among postmature infants. Saltatory pattern and particularly fixed baseline seem characteristic of prolonged gestation and placental insufficiency. With tachycardia, they constitute subtle symptoms of fetal distress.

In a population of high-risk patients who had continuous “direct” monitoring during labor, 598 (46%) had no decelerations during the first stage, while 247 (19%) had presented early decelerations before completion of dilatation. The clinical characteristics, the fetal heart rate (FHR) baseline alterations, and neonatal outcome were compared between these two groups: there were no differences in any of the aspects evaluated, except that there was transient tachycardia more often among the early-decelerations group. The patients who had no decelerations were subdivided into vaginal deliveries and cesarean deliveries, and the same parameters were compared again: the cesarean section group had longer recordings and more contractions, lower Apgar 1 and 5 minute scores, and higher incidences of Apgar scores ≤ 6 at 1 minute, while all other aspects were similar. A possible explanation was that 82% of cesarean sections were done under general anesthesia and only 3% of vaginal deliveries. The implication of ruptured membranes in the etiology of early decelerations was extensively reviewed and discussed in view of these findings. It is concluded that amniotomy does not seem a maneuver deleterious to the fetal well-being.