James A. Scardo

Twins: Prevalence, problems, and preterm births

The rate of twin pregnancies in the United States has stabilized at 32 per 1000 births in 2006. Aside from determining chorionicity, first-trimester screening and second-trimester ultrasound scanning should ascertain whether there are structural or chromosomal abnormalities. Compared with singleton births, genetic amniocentesis-related loss at <24 weeks of gestation for twin births is higher (0.9% vs 2.9%, respectively). Selective termination for an anomalous fetus is an option, although the pregnancy loss rate is 7% at experienced centers. For singleton and twin births for African American and white women, approximately 50% of preterm births are indicated; approximately one-third of these births are spontaneous, and 10% of the births occur after preterm premature rupture of membranes. From 1989-2000, the rate of preterm twin births increased, for African American and white women alike, although the perinatal mortality rate has actually decreased. As with singleton births, tocolytics should be used judiciously and only for a limited time (<48 hours) in twin births. Administration of antenatal corticosteroids is an evidence-based recommendation.

The effect of indomethacin tocolysis on fetal ductus arteriosus constriction with advancing gestational age

OBJECTIVEnOur purpose was to determine whether continuing exposure to indomethacin tocolysis is associated with an increased incidence of constriction of the human fetal ductus arteriosus with advancing gestational age.nnnSTUDY DESIGNnFetal echocardiograms were reviewed in 61 cases in which the pregnant women were treated for preterm labor with indomethacin (25 mg orally every 6 hours). Density function analysis and regression analysis were used to assess the effect of indomethacin tocolysis on ductal constriction with advancing gestational age.nnnRESULTSnA total of 193 fetal echocardiograms were obtained for 72 fetuses. Ductal constriction developed in 50% of the fetuses ranging from 24.7 to 35.0 weeks gestation. Fetuses with indomethacin-induced ductal constriction demonstrated a greater increase in systolic flow velocities with advancing gestational age compared with the nonconstricted group (p < 0.05). Constriction was detected at a mean gestational age of 30.9 +/- 2.3 weeks at an average of 5.1 +/- 6.0 days after initiation of therapy. Ductal constriction occurred by 31 weeks gestation in 70% of the affected fetuses. After discontinuation of indomethacin therapy, all follow-up echocardiograms demonstrated a return to nonconstricted ductal flow velocities. No significant adverse neonatal outcomes were attributed to indomethacin use.nnnCONCLUSIONSnA dramatic yet reversible increase in the incidence of indomethacin-induced ductal constriction occurs at 31 weeks gestation. However, ductal constriction can occur at any gestational age. With indomethacin tocolysis, weekly fetal echocardiography is warranted for the duration of therapy.

Antepartum detection of macrosomic fetus : Clinical versus sonographic, including soft-tissue measurements

Objective To compare clinical and sonographic estimates of birth weights with five new estimation techniques that involve measurements of soft tissue, for identifying newborns with birth weights of at least 4000 g. Methods Over 1 year, each woman at or after 36 weeks gestation and suspected of having a macrosomic fetus had clinical and sonographic estimates of fetal weight (EFW) based on femur length (FL) and head and abdominal circumference, followed by five additional ways to identify excessive growth: cheek-to-cheek diameter, thigh soft tissue, ratio of thigh soft tissue to FL, upper arm subcutaneous tissue, and EFW derived from it. Areas (± standard error) of receiver operating characteristic (ROC) curves were calculated and compared with the area under the nondiagnostic line. P < .05 was considered statistically significant. Results Among 100 women recruited, 28 newborns weighed 4000 g or more. The areas under the ROC curves with clinical (0.72 ± 0.06) and sonographic predictions using biometric characteristics (0.73 ± 0.06) had the highest but similar accuracies (P > .05). Three of the five newer methods (upper arm or thigh subcutaneous tissue and ratio of thigh subcutaneous tissue to FL) were poor diagnostic tests (range of areas under ROC 0.52 ± 0.06 to 0.58 ± 0.07). Estimated fetal weight based on upper arm soft tissue thickness and cheek-to-cheek diameter (areas 0.70 ± 0.06 and 0.67 ± 0.06, respectively) were not significantly better than clinical predictions (P > .05) for detecting macrosomic fetuses. About 110 macrosomic and nonmacrosomic infants combined would be needed to have 80% power to detect a difference between ROC curves with areas of 0.58 (thigh subcutaneous tissue) and 0.72 (clinical estimate). Conclusion ROC curves indicated that measurements of soft tissue are not superior to clinical or sonographic predictions in identifying fetuses with weights of at least 4000 g.

Hemodynamic effects of oral nifedipine in preeclamptic hypertensive emergencies

OBJECTIVEnOur purpose was to evaluate the hemodynamic effects of oral nifedipine in preeclamptic hypertensive emergencies.nnnSTUDY DESIGNnA prospective observational study of the hemodynamic effects of oral nifedipine was conducted with severely preeclamptic patients receiving magnesium sulfate infusion during a hypertensive emergency. Patients were eligible for the study if systolic blood pressure was > or = 170 m Hg or the diastolic blood pressure was > or = 105 mm Hg on repeat measurements 15 minutes apart at > or = 24 weeks gestation. Nifedipine was given with an initial dose of 10 mg orally followed by 20 mg orally every 20 minutes until systolic blood pressure was > 160 mm Hg and the diastolic blood pressure was < 100 mm Hg, or for a total of five doses. Patients were hemodynamically monitored in the lateral recumbent position by thoracic electrical bioimpedance before during, and after oral nifedipine dosing. Cardiac index, systemic vascular resistance index, mean arterial pressure, heart rate, and stroke index were all recorded at baseline and during treatment. Data were analyzed by analysis of variance for repeated measures (alpha 0.05) and paired t tests, baseline versus 15 minutes (alpha 0.01).nnnRESULTSnTen severely preeclamptic patients at 33.2 +/- 3.0 (mean +/- SD) weeks gestation were enrolled in the study. Mean arterial pressure measurements taken at baseline, 0.25, 0.5, 1, and 4 hours were 133 +/- 10, 119 +/- 8, 109 +/- 8 89 +/- 12, and 100 +/- 13 mm Hg (mean +/- SD, p < 0.0001, analysis of variance repeated measures). Cardiac index increased over time (p = 0.0011, analysis of variance repeated measures). There was no significant effect on maternal heart rate or stroke index. No periodic fetal heart rate changes were noted. One patient had nausea.nnnCONCLUSIONnOral nifedipine appears to be an effective antihypertensive agent in preeclamptic hypertensive emergencies. A steady decrease in mean arterial pressure, systemic vascular resistance, and a mirrored increase in cardiac index are noted.

A review of sonographic estimate of fetal weight: Vagaries of accuracy

Purpose.u2003To determine the factors that might influence the accuracy of sonographic estimated fetal weight. Study design.u2003A PubMed search (Jan 1975 to Jan 2003) of articles published in the English language was carried out and the inclusion criterion was that estimates were within 10% of birth weight. A Chi-square test for trend was used and odds ratio (OR) with 95% confidence intervals (CI) was calculated. Results.u2003Over 28 years, 175 articles were identified but only 54 (31%) met the inclusion criterion. Overall 62% (8895/14 384) of the predictions were within 10% of the actual weight. The accuracy was significantly different in articles where <7 vs. >7 days were allowed to lapse between examination and delivery (OR 2.17, 95% CI 1.93, 2.45); where examinations were done by registered diagnostic medical sonographers (RDMS; 65%) versus physicians (59%) or residents (57%; p < 0.0001); in term vs. preterm patients (OR 1.97, 95% CI 1.67, 2.13); and in studies with >1000 vs. <1000 cohorts (OR 1.62; 95% CI 1.51, 1.74). Conclusions.u2003If feasible the sonographic examination should be done by RDMS and within a week of delivery.

Serum Carotenoids and Fat-Soluble Vitamins in Women With Type 1 Diabetes and Preeclampsia: A longitudinal study

OBJECTIVE Increased oxidative stress and immune dysfunction are implicated in preeclampsia (PE) and may contribute to the two- to fourfold increase in PE prevalence among women with type 1 diabetes. Prospective measures of fat-soluble vitamins in diabetic pregnancy are therefore of interest. RESEARCH DESIGN AND METHODS Maternal serum carotenoids (α- and β-carotene, lycopene, and lutein) and vitamins A, D, and E (α- and γ-tocopherols) were measured at first (12.2 ± 1.9 weeks [mean ± SD], visit 1), second (21.6 ± 1.5 weeks, visit 2), and third (31.5 ± 1.7 weeks, visit 3) trimesters of pregnancy in 23 women with type 1 diabetes who subsequently developed PE (DM PE+) and 24 women with type 1 diabetes, matched for age, diabetes duration, HbA1c, and parity, who did not develop PE (DM PE−). Data were analyzed without and with adjustment for baseline differences in BMI, HDL cholesterol, and prandial status. RESULTS In unadjusted analysis, in DM PE+ versus DM PE−, α-carotene and β-carotene were 45 and 53% lower, respectively, at visit 3 (P < 0.05), before PE onset. In adjusted analyses, the difference in β-carotene at visit 3 remained significant. Most participants were vitamin D deficient (<20 ng/mL), and vitamin D levels were lower in DM PE+ versus DM PE− throughout the pregnancy, although this did not reach statistical significance. CONCLUSIONS In pregnant women with type 1 diabetes, low serum α- and β-carotene were associated with subsequent development of PE, and vitamin D deficiency may also be implicated.

Suspicion of intrauterine growth restriction: Use of abdominal circumference alone or estimated fetal weight below 10%

Objective. To determine, among patients at risk for intrauterine growth restriction (IUGR), the peripartum outcomes and predictive accuracy for those with normal abdominal circumference (AC) and estimated fetal weight (EFW) for gestational age (GA; group 1) versus those with AC ≤ 10% for GA but EFW>10% (group 2) versus those with AC and EFW ≤ 10% for GA (group 3). Study design. We identified, retrospectively, non-anomalous singleton pregnancies with reliable GA, and delivery within 21 days of the examination who were referred for possible IUGR. Odds ratios (OR) and 95% confidence intervals (CI) were calculated, as were likelihood ratios (LR) for detection of small for gestational age (SGA) (birth weight ≤ 10% for GA; SGA). Results. Among the 169 consecutive patients who met the inclusion criteria, the prevalence of SGA was significantly higher for group 3 (80%) than group 1 (42%; OR 4.26, 95% CI 1.94–9.16) or group 2 (49%; OR 5.49, 95% CI 2.13–13.85). The rate of admission to the neonatal intensive care unit (67%, 34%, and 36% for groups 3, 2, and 1, respectively) and the combined perinatal morbidity (35%, 23%, and 15%) were different for the three groups. The LR for detection of SGA was 1.2 (95% CI 1.0–1.4) for group 2 and 2.8 (95% CI 1.6–4.9) for group 3. Conclusions. Among patients suspected for IUGR, the peripartum outcome is poorest for those with AC and EFW ≤ 10% for GA, than for those with AC ≤ 10% but EFW>10%. The detection of SGA is poor regardless of whether just AC or AC plus EFW are ≤ 10%.

Detection of growth-restricted fetuses in preeclampsia: a case-control study ☆

OBJECTIVEnTo determine the diagnostic accuracy of detecting growth-restricted fetuses in women with and without preeclampsia.nnnMETHODSnOver 2 years, parturients with reliable gestational ages, preeclampsia, and sonographic estimates of birth weights were matched (1:1) for gestational age with women without preeclampsia. Paired and unpaired t tests were used; P < .05 was significant. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.nnnRESULTSnTwo hundred eighty-seven preeclamptic women were identified and matched. In each group, mean (+/- standard deviation [SD]) gestational age was 34.9 +/- 4.2 weeks, and 166 (57.8%) infants were born preterm. Fetal growth restriction (FGR) was significantly more common among women with preeclampsia (14.9%) than among controls (5.6%; OR 2.98, 95% CI 1.64, 5.44). The percentage of sonographic estimates within 10% of actual birth weight (57.5% versus 53.6%) was similar in the two groups (OR 1.16; 95% CI 0.84,1.62). Compared with normal growth, the mean (+/- SD) standardized absolute error was significantly higher among those with FGR regardless of group (preeclampsia 109 +/- 100 versus 158 +/- 152 g/kg; P = .009; control 117 +/- 103 versus 233 +/- 206 g/kg; P < .001). Fetal growth restriction was detected more commonly among preeclamptic women than among controls (11.6% versus 0%; OR 4.74 95% CI 0.25, 90.31). The sensitivity and positive predictive value of FGR detection were 10% and 50%, respectively, among women with preeclampsia and 0% each among controls.nnnCONCLUSIONnAlthough FGR was detected more frequently in fetuses of women with preeclampsia than in those of controls, the ability to predict it with sonography remained poor.

Cesarean delivery for fetal distress: Rate and risk factors

Objective The objective of this article was to review the recent English language literature on cesarean delivery for fetal distress to determine its incidence, diagnostic tests, and the contributing factors to this obstetric complications. A PubMed search (1990–2000) with items of “cesarean, fetal distress,” “cesarean, non-reassuring fetal heart rate,” “cesarean, neonatal acidosis,” and “cesarean, umbilical arterial pH,” was undertaken. Reports, letters to the editor, focus on anomalous fetuses, and papers not specifically focused on this topic were excluded. Of the 392 articles that the search yielded, 169 met the inclusion criteria. Based on 37 reports with more than 1,000 patients each, the overall risk of prompt cesarean delivery for fetal concern was 3.1% (43,340 of 13,989,74). The risk exceeded 20% in patients with moderate/severe asthma, severe hypothyroidism, severe preeclampsia, and postterm or fetal growth restricted fetuses with abnormal Doppler studies. Use of likelihood ratios suggests that Doppler of the umbilical artery is a superior diagnostic test to amniotic fluid index in identifying parturients at risk for cesarean for non-reassuring fetal heart rate tracing. Although several risk factors increase the need for cesarean delivery for fetal distress, in general, most are unpreventable. Target Audience: Obstetricians & Gynecologists, Family Physicians Learning Objectives: After completion of this article, the reader will be able to estimate the incidence of cesarean delivery for non-reassuring fetal heart rate tracing, outline potential diagnostic tests that are useful for the detection of fetal distress, and summarize medical and obstetric conditions that place patients at risk for cesarean delivery for fetal distress.

Diphenhydramine overdose during pregnancy: Lessons from the past

A primigravid woman was seen for the first time in a disoriented and combative state, with regular, painful uterine contractions. Evaluation revealed a negative illicit drug screen, no evidence of preeclampsia, and a nonfocal neurologic examination. Further workup revealed urinary diphenhydramine levels suggesting drug overdose. This case serves as a reminder of the oxytocin-like effects of diphenhydramine.