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Byline: Nirav R. Shah, Michael B. Bracken Keywords: Preterm delivery; cigarette smoking; meta-analysis Abstract: We have attempted to quantify the most up-to-date estimate of the association between cigarette smoking by the mother and preterm delivery. Studies were selected for inclusion in this review if they were prospective, reported data stratified across at least two levels of maternal smoking, and defined preterm delivery on the basis of gestational age. In a meta-analysis we combined results from multiple studies that reported on preterm delivery and maternal smoking during pregnancy. Pooled odds ratios were computed for various strata of smoking intensity with the Mantel-Haenszel fixed-effects model. Twenty studies met all inclusion criteria and were included in meta-analysis. The pooled point estimate from 20 prospective studies on any maternal smoking versus no maternal smoking was 1.27 (95% confidence interval, 1.21-1.33). Subgroup analyses stratifying maternal smoking on number of cigarettes per day suggest a dose-response relationship at low to moderate levels of smoking, which was not further increased at high levels of smoking. A nonsignificant level of publication bias appears to exist in the smoking-preterm delivery literature. Cigarette smoking is a preventable risk factor that is associated with preterm delivery. Consistent results across many study populations and research designs and evidence of a dose-response relationship support its causal role in preterm delivery. (Am J Obstet Gynecol 2000;182:465-72.) Author Affiliation: Department of Epidemiology and Public Health, Yale University School of Medicine. New Haven, Connecticut Article Note: (footnote) [star] Reprint requests: Michael B. Bracken, PhD, MPH, Department of Epidemiology and Public Health, Yale University, 60 College St, Suite 415, PO Box 208034, New Haven, CT 06520-8034.

OBJECTIVE: Our objective was to determine the relationship between microbial invasion of the amniotic cavity and the presence and severity of acute inflammatory lesions in the placenta. STUDY DESIGN: Placental histologic and amniotic fluid microbiologic studies were performed in 92 consecutive patients who were admitted with preterm labor and intact membranes and delivered within 48 hours after amniocentesis. RESULTS: The prevalence of a positive amniotic fluid culture was 38% (35 of 92). There was s strong association between the presence and severity of inflammation in the amnion, chorion-decidua, umbilical cord, and chorionic plate and the results of the amniotic fluid culture (p < 0.0001 for each tissue section). Three patterns of inflammation of the chorion-decidua were identified: marginating, nonmarginating, and a mixed pattern. The marginating and the mixed patterns of inflammation were strongly associated with the presence of a positive amniotic fluid culture. Acute inflammation of the chorionic plate was the most sensitive indicator of a microbial invasion of the amniotic cavity (sensivity 96.6%), and funisitis and umbilical vasculitis had the highest specificity (85.7%). CONCLUSION: The presence of acute inflammatory lesions of the chorioamniotic membranes can serve as a marker of microbial invasion of the amniotic cavity. (Am J Obstet Gynecol 1992;166:1382-8.)

It is increasingly becoming apparent that the use of drugs and chemicals during pregnancy can adversely affect the fetus. Little is known about the effects most medications can have on the fetus and thus their use during pregnancy should be as limited as possible. Despite this, most studies have shown that 44 to 92 percent of all women take at least one medication during pregnancy. The few studies that have examined maternal characteristics in conjunction with use of medications have been limited to age, race, and smoking history. This study examined the relationship of medication use during pregnancy and various characteristics of the mother. Women planning to deliver at Yale-New Haven Hospital were invited to join the study. A total of 4,186 interviews were completed. During the first trimester of pregnancy, 34.1 percent of the women reported using no medications, 32.3 percent used one, 27.3 percent used two or three, and 6.4 percent used four or more. Prescription drugs were used by 27.3 percent of the women and over-the-counter drugs were used by 54.9 percent of the women. Women taking medication were more likely to be using both prescription and nonprescription drugs. The most commonly used over-the-counter drugs were analgesics such as Tylenol and the most commonly used prescription drugs were parasympatholytic agents such as Bendectin antihistamine. Maternal characteristics associated with use of both types of drugs included being older, married, white, college-educated, and users of caffeine and marijuana. Alcohol use was associated with taking over-the-counter drugs only. These results suggest that women who are more likely to take medications during pregnancy are also more likely to engage in other high-risk activities that could affect the fetus. (Consumer Summary produced by Reliance Medical Information, Inc.)

Second-trimester abortion is known to be associated with increased morbidity and mortality rates. In this paper, possible reasons for delayed abortion are examined by: (1) reviewing the available literature to seek a synthesis of current findings, (2) discussing the findings within the theoretical context of decision-making under conflict which offers a conceptual framework for further understanding delay in seeking abortion, and (3) pointing to some methodologic problems in studies of delay in seeking abortion.

The maternal use of Bendectin (Debendox) in the first trimester of pregnancy was examined in a case-control (n = 1,427 and 3,001, respectively) study of malformed infants whose mothers were interviewed between 1974 and 1976. Mothers of infants with congenital malformation showed an increased likelihood (odds ratio = 1.40) of having used Bendectin, with a stronger association of Bendectin with birth defects for mothers who also smoked (odds ratio = 2.91). A significant association was observed between the occurrence of pyloric stenosis in the infant and exposure to Bendectin in utero (odds ratio = 4.33). When maternal sociodemographic factors, including smoking, and smoking alone, were controlled, the association between Bendectin and pyloric stenosis was further increased (odds ratio = 4.63 and 5.24, respectively). Except for a possible association of Bendectin with heart valve anomalies (odds ratio = 2.99), we were unable to document other significantly increased risks for congenital malformations.

This study examines the effect of laminaria and oxytocin in 638 saline instillation abortions. Laminaria were inserted into the cervical canal in the physician's office 2 to 3 hours before admission to hospital for instillation. Pitocin was given intravenously at a rate of 417 to 555 mu/min starting 2 hours after instillation. Center for Disease Control (CDC) criteria were used to define complications in the present series. Complication rates compared favorably to those in a national CDC study of traditional saline procedures. Instillation-abortion times averaged 12.5 hours in the present series, about half the time previously reported for saline abortion. If confirmed by other studies, laminaria and oxytocin will be beneficial adjuncts for managing patients aborted by saline instillation.

Since the role of oral contraceptives as a risk factor for hypertension is now quite well established, we investigated the possible relationship between recent use of oral contraception around conception and the development of hypertension and preeclampsia later in the pregnancy. Subjects were randomly selected women being delivered during a 24month period at a major medical center who had used oral contraceptives in the 12months before conception. The overall incidence of preeclampsia was 4.69%. Women who discontinued oral contraceptives as recently as 2months before conception or who inadvertently used them in early pregnancy (n=99) did not differ significantly on incidence of preeclampsia (odds ratio (o)=0.55, 95% CL=0.15, 2.00) or hypertension at delivery (o=1.01, 95% CL=0.46, 2.20) than women last exposed 3 to 12months before conception (n=242). Potentially confounding maternal factors were examined and controlled.

Among 4,428 women studied at five large hospitals in Connecticut, those conceiving within two months of cessation of oral contraceptive use had a twofold increased rate of delivering twins. This increase was found in both black and white women. Analysis of unlike and like sex twins indicates that this effect seems to clearly depend on an increased rate of dizygous twinning.

In 1977 we reported the in utero diagnosis of a skeletal dysplasia, chondroectodermal dysplasia. Since then we have used ultrasound to examine 66 pregnant women who were at risk for fetal skeletal dysplasia. In an effort to establish a normal curve for long bone length, the femurs and, in some cases, humeri, of 57 normal second-trimester fetuses were measured by real-time ultrasound. In addition, femur and humerus measurements were obtained in 50 abortuses by means of ultrasound in a waterbath and were compared with blindly obtained extemal measurements of the same long bones. Mean in vivo ultrasound measurements of fetal femur and humerus were consistently less than mean ultrasound waterbath measurements by 16%. External measurements of the femur and humerus of abortuses were in concordance with water-bath ultrasound measurements in the same abortuses until 18 weeks, after which the means progrssively diverged to a difference of 17% at 25 weeks, with the ultrasound measurements being smaller. Based on the above in vivo normative ultrasound data, a positive diagnosis was made in five of seven second-trimester fetuses at risk for a skeletal dysplasia (camptomelic dysplasia, two fetuses with Roberts syndrome, diastrophic dysplasia, and thrombocytopenia with absent radii syndrome). In two others (chondroectodermal dysplasia and osteogenesis imperfecta) long bone measurements were diminished, but not outside 95% confidence levels, and the diagnosis was based on fetoscopy findings and identification of a femoral fracture. All other fetuses were normal at birth following negative ultrasound evaluation. The study demonstrates the feasibility of diagnosing various skeletal dysplasias with ultrasound. Further study will be required before the accuracy of diagnosis in all dysplasias can be fully assessed.

Data are presented describing contraception among 1,022 women during the 12 months preceding induced abortion. Contraception was practiced by 45.5 per cent of the sample, was technically inadequate, was frequently changed for other ineffective methods, and was often discontinued. At conception, 18.8 per cent of patients were practicing contraception. Several variables indicated higher probabilities of contraception: older age, multiparity, previous stillbirths, spontaneous or induced abortions, being white, and no religious preference. Identical variables characterized women continuing contraception who, in addition, were probably married, had experienced fewer changes in their relationships, had told partners about their contraceptive practices, had frequent coitus, and used technically reliable methods. Implications for future research are discussed.

Late pregnancy abortions, with their attendant risk of more serious medical and psychological sequelae, were not randomly distributed among a population of 443 women who successfully applied for an induced abortion. Women between the eleventh and twentieth weeks of pregnancy were significantly more likely to: be under 21 years old, single, have 0 or 1 living child, be Black, not have completed high school, be Protestant, have been referred through clinic or university services, and to have not used a contraceptive at time of conception. Directions for future research are discussed.

One hundred and seventy-one abortion patients, randomly assigned to three defined counseling procedures (group orientation, group process, and individual) were matched by counselor. Data collected were: circumstances surrounding the pregnancy (before counseling); reaction to counseling session (after counseling—before abortion); response to abortion (post abortum). Over-all responses to counseling and abortion were favorable, particularly those of women over 20 years old. Most women preferred individual counseling. Responses to the abortion procedure were more positive among women over 20 years old who had individual counseling. Younger women responded to the abortion more favorably after experiencing either type of group counseling. Women of all ages, when counseled by group process, would be more likely to terminate future unwanted pregnancies by abortion, this being especially significant in the younger age group.