Spontaneous prolonged hypertonic uterine contractions (essential uterine hypertonus) and a possible infective etiology.

The management of a pregnant woman presenting with prolonged hypertonic uterine contractions (essential uterine hypertonus) and mildly elevated temperature at term is described. Histology of the placenta, cord and membranes, following delivery, revealed evidence of chorioamnionitis, funisitis and deciduitis. Our findings raise the possibility that essential uterine hypertonus may have an infective or inflammatory component to its etiology.

Pregnancy-induced hypertension and duration of sexual cohabitation.

OBJECTIVE: To evaluate the possible association between duration of sexual cohabitation and the risk of pregnancy-induced hypertension (PIH). STUDY DESIGN: A matched case-control design in which each case of PIH was compared with three controls. Information was obtained about use of barrier contraception, duration of intercourse prior to pregnancy and paternity. RESULTS: Sixty-eight cases were included in the study. For primiparous women, a shorter duration of sexual cohabitation without contraception was associated with a small and nonsignificant risk of PIH. For multiparous women, a greater length of time since stopping use of barrier contraception was associated with a greater risk of PIH. CONCLUSION: Advising nulliparous women to prolong the duration of sexual cohabitation prior to conception in an effort to decrease the risk of PIH is not justified, based on the findings of this study.

Fetal growth and body composition in infants of women with diabetes mellitus during pregnancy.

The purpose of this study was to evaluate growth velocities of various neonatal tissues in women with diabetes mellitus. We hypothesize that in large for gestational age (LGA) infants, insulin-sensitive tissue will demonstrate the greatest accelerated growth. Thirty-eight singleton pregnancies had prospective longitudinal ultrasound measurements of the fetal biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), transcerebellar diameter (TCD), liver length, renal length, abdominal fat, and thigh fat in late pregnancy. At birth, neonatal body composition was estimated and anthropometric measurements were obtained. Twenty-four neonates were not large for gestational age (non-LGA) and 14 LGA based on birth weight percentile > or = 90 percentile. The fetal AC (P = 0.0006), liver length (P = 0.01), thigh fat (P = 0.02), and abdominal wall fat (P = 0.001) demonstrated accelerated growth velocity in LGA fetuses. At birth LGA infants had a 17% (P = 0.0001) increase in lean body mass, but a 99% (P = 0.0001) increase in fat mass compared with non-LGA infants. Using stepwise regression, abdominal wall fat accounted for 63% (P = 0.0001) of the variance in AC compared with 3% (P = 0.13) for liver length. In conclusion, ultrasound estimates of adiposity may potentially be a sensitive indicator of growth abnormalities in infants of diabetic women in late gestation.

Relation of amniotic fluid C-peptide levels to neonatal body composition.

OBJECTIVE: To compare the correlation between fetal insulin production (as estimated by amniotic fluid [AF] C-peptide concentration) and neonatal body fat (as estimated by both anthropometrics and total body electrical conductivity) with that between fetal insulin production and birth weight or fat-free mass. METHODS: Amniotic fluid C-peptide concentration measured within 1 week of delivery was correlated with birth weight and neonatal body composition, estimated by both anthropometric measures and total body electrical conductivity within 24 hours of birth. Eighteen term neonates were studied: 13 from pregnancies complicated by diabetes and five from mothers with normal glucose tolerance. RESULTS: Six infants were large for gestational age and 12 were appropriate for gestational age. There was a significant correlation between AF C-peptide level and neonatal fat mass, estimated by either anthropometric measures (r = 0.72, P = .0008) or total body electrical conductivity (r = 0.61, P = .008) methodology. The correlation was weaker between AF C-peptide level and either ponderal index (r = 0.44, P = .064) or total weight (r = 0.39, P = .11). The correlation with fat-free mass estimated by either method was not statistically significant. CONCLUSION: Our results suggest that fetal insulin production, as estimated by AF C-peptide concentration, influences fetal growth primarily through increasing fetal fat deposition rather than lean body mass.

Pharmacokinetics of ritodrine administered intravenously: recommendations for changes in the current regimen.

We define the pharmacokinetics of ritodrine in 13 pregnant women who received the drug intravenously. With constant infusion of 50 micrograms/minute, steady state ritodrine concentrations reached 28 +/- 11 ng/ml (SD) with a range of 15 to 45 ng/ml. This wide variation is a result of differences in plasma clearance, which ranged from 1.0 to 3.3 L/min, mean 1.94 +/- 0.71 L/min. The apparent volume of distribution was 6.95 +/- 3.54 L/kg, indicating that ritodrine is extensively bound to extravascular tissue. When an infusion of ritodrine is stopped, plasma concentrations fall rapidly initially with a distribution half-life of 5.9 +/- 6.0 minutes. After the initial rapid fall, plasma concentrations decrease more slowly with a mean disposition half-life of 156 +/- 51 minutes. On the basis of the pharmacokinetic parameters defined, we recommend that the current infusion regimen for ritodrine be changed. The infusion rate of ritodrine should start at 50 micrograms/minute rather than 100 micrograms/minute. The maximal infusion rate of 350 micrograms/minute should be increased and once labor is inhibited, the infusion rate should be reduced.