Conception delay after oral contraceptive use: the effect of estrogen dose.

A significant delay was observed in conception among 248 former oral contraceptive (OC) users compared with women discontinuing other methods of contraception (n = 1,365). The mean time to conception was 5.88 cycles (95% confidence interval [CI] 5.38, 6.38) for former OC users and 3.64 cycles (95% CI 3.49, 3.79) after other contraceptives. Women discontinuing OCs with higher doses of estrogen (greater than or equal to 50 micrograms) had greater conception delays than those on lower estrogen doses who, in turn, had longer delays than other method users. Oral contraceptive use was associated with significant reductions in conception for each of the first six cycles after discontinuation. This study provides further evidence for a direct effect of oral contraception on delayed conception, suggests that the delay lasts longer than previously thought, and finds that the probability of conception after OC discontinuation depends on the estrogen dose of the OC.

Effect of maternal work activity on preterm birth and low birth weight.

The association of the prolonged standing required by certain jobs with the rate of preterm births and low birth weight deliveries was examined in New Haven, Connecticut, between 1980 and 1982. In a sample of 1,206 women, the rate of preterm births (births occurring less than 37 weeks from the last menstrual period) was higher among women with jobs requiring prolonged standing (7.7%) compared with those with sedentary (4.2%) or active jobs (2.8%). The odds of preterm delivery in the standing group was 2.72 (95% confidence interval of 1.24-5.95). A significant association between standing on the job and preterm birth was demonstrated when adjustment was made for the following variables in a logistic regression model: parity, smoking, education, caffeine use, marijuana use, race, gestational age at interview, and marital status. The low birth weight (less than 2,500 g) rate was higher among those in the standing group (5.5%) compared with those in the sedentary (4.0%) and active groups (4.0%), but this association was not significant when confounding factors were controlled.

Proportional weight gain and complications of pregnancy, labor, and delivery in healthy women of normal prepregnant stature.

Detailed reproductive information was obtained through interview at early prenatal visits to hospital clinics, private medical groups, or health maintenance organizations for 4186 women delivered at Yale-New Haven Hospital. From these women, 1,396 were selected who had no preexisting chronic disease, were within their normal prepregnant weight for height as determined by Quetelet's Index (weight2/height2), and were delivered of single infants with no major congenital malformations between 37 and 42 weeks. These women were divided into four quartiles according to their proportional weight gain (weight gain/prepregnant weight): quartile 1 = gains less than or equal to 15%; quartile 2 = gains 16% to 25%; quartile 3 = gains 26% to 35%; quartile 4 = gains greater than 35%. Complications of pregnancy, labor, and delivery were recorded within 2 days of delivery. Compared with the women in quartile 2 those in quartile 4 were 3.8 times more likely to develop gestational hypertension and had a fourfold risk of becoming preeclamptic. They were also significantly more likely to require cesarean section. The size of the infant was a significant risk factor for prolonged second stage of labor in primigravid women (greater than 2 hours) but not in multigravid women (greater than 1 hour). Weight gains of more than 35% almost doubled the risk of a prolonged second stage of labor for multigravid women. High proportional gains were not associated with adverse neonatal outcomes. Clinicians should consider proportional weight gain when advising healthy women about weight gain during pregnancy.

Low birth weight in pregnancies following induced abortion: no evidence for an association.

Compared with women delivering a first pregnancy, those delivering a second pregnancy after aborting the first have similar rates of low (less than 2,500 g) birth weight newborns (relative risk (RR) G2A1/G1 = 0.86, 95% confidence interval (CI) = 0.49-1.51) and mean birth weight (delta = 16.3 g, p = 0.63). Abortion of the first pregnancy prevents the reduction in low birth weight and increase in mean birth weight in the second pregnancy which delivery of the first pregnancy normally bestows (RR G2P1/G2A1 = 0.48, 95% CI = 0.25-0.90; delta = 135.3 g, p less than 0.0001). Two prior induced abortions do not significantly increase risk for low birth weight (RR G3A2/G1 = 1.14, 95% CI = 0.37-3.56) or decrease mean birth weight (delta = 29.0 g), compared with women delivering their first pregnancy. The second of two deliveries has a reduced risk of low birth weight irrespective of whether both deliveries follow an aborted first pregnancy. Adjustment for confounding factors did not materially change these results. Low birth weight rates were higher after abortions performed in hospital compared with elsewhere (p = 0.03), but mean birth weight was not affected. Gestation at abortion, vacuum aspiration or dilatation and curettage, and abortion complications were unrelated to birth weight of subsequent pregnancies. Pregnancies conceived within six months of a prior abortion or delivery had lower birth weight than if the antecedent pregnancy ended more than six months previously.

Methylprednisolone and neurological function 1 year after spinal cord injury. Results of the National Acute Spinal Cord Injury Study.

A multi-center double-blind randomized clinical trial was conducted by the National Acute Spinal Cord Injury Study Group to examine the efficacy of high-dose methylprednisolone (1000-mg bolus and 1000 mg daily thereafter for 10 days) compared with that of a standard dose (100-mg bolus and 100 mg daily for 10 days). No significant difference was observed in neurological recovery of motor function, pinprick response, or touch sensation 1 year after injury between the two treatment groups, after adjustment for other potentially confounding factors. Analyses that specifically took into account the patients' total steroid dose and relative weight confirmed the lack of a steroid treatment effect. The case fatality rate was 10.7% during the 1st year after injury, and this was not associated with the steroid treatment protocol or the patient's gender. Deaths did occur significantly more frequently among patients who were completely (15.3%) and partially (8.6%) plegic than among those who were paretic (2.5%, p = 0.0005), and among patients aged 50 years or older (38.6%, p = 0.0001).

Efficacy of methylprednisolone in acute spinal cord injury.

A multicenter double-blind randomized trial was conducted to examine the efficacy of a high dose of methylprednisolone (1,000-mg bolus and daily thereafter for ten days) compared with a standard dose (100-mg bolus and daily thereafter for ten days) in 330 patients with acute spinal cord injury. No difference in neurological recovery of motor function or pinprick and light touch sensation was observed between the two treatment groups six weeks and six months after injury. The lack of a treatment effect was independent of the severity of the initial lesion or the time from injury to starting treatment. Although not statistically significant, early case fatality was greater in the high-dose protocol (relative risk of 3.1 and 1.9, less than or equal to 14 and 15 to 28 days after injury, respectively) but not from 29 to 210 days after injury. Wound infections of both trauma and operative sites were more prevalent in the high-dose regimen (relative risk of 3.6).

Dietary salt intake and blood pressure.

With an index for dietary salt use designed to provide a semiquantitative estimate of salt intake, we have found that in a sample representative of the 2.1 million adults in Connecticut, the mean BP of those at the 90th percentile or higher of salt intake differs by a quantitatively insignificant amount from the mean BP of those at the tenth percentile or lower of salt intake. When we examined the obese (body mass index, 90th percentile or higher) separately, similar results were obtained. These findings indicate that it is unlikely dietary salt intake has a clinically significant effect on BP in the majority of individuals in a large defined population, but do not exclude the possibility of a clinically significant effect in a small subgroup of salt-sensitive individuals.