Outcomes of pregnancies with more than one positive prenatal screening result in the first or second trimester

OBJECTIVE

To describe adverse outcomes and fetal abnormalities in women with a positive prenatal screening result for more than one disorder.

STUDY DESIGN

Study participants were drawn from a population of 452 901 women pregnant with singletons entering the California Prenatal Screening Program in their first-trimester. Risk assessment was provided for trisomy 21 and trisomy 18 in the first-trimester and trisomy 21, trisomy 18, neural tube defects, and Smith-Lemli-Opitz syndrome in the second-trimester. Inclusion in this study required positive screening for more than one of the screened conditions and a completed outcome of pregnancy survey.

RESULTS

A total of 874 women met our study inclusion criteria. Over 25% of these pregnancies had a fetus with a chromosomal abnormality. Of the euploid pregnancies, 6.9% had a fetus with a major birth defect. Of the pregnancies with a fetus with neither a chromosomal abnormality nor a major birth defect, 9.3% ended in fetal demise. Overall, more than 50% of women with multiple positive screening results had either a fetus with a birth defect or a poor pregnancy outcome.

CONCLUSION

Although it is rare to screen positive for more than one condition, such results indicate a very high risk for chromosomal abnormality, fetal demise, or structural abnormality.

Maternal characteristics and mid-pregnancy serum biomarkers as risk factors for subtypes of preterm birth

OBJECTIVE

To examine the relationship between maternal characteristics, serum biomarkers and preterm birth (PTB) by spontaneous and medically indicated subtypes.

DESIGN

Population-based cohort.

SETTING

California, United States of America.

POPULATION

From a total population of 1 004 039 live singleton births in 2009 and 2010, 841 665 pregnancies with linked birth certificate and hospital discharge records were included.

METHODS

Characteristics were compared for term and preterm deliveries by PTB subtype using logistic regression and odds ratios adjusted for maternal characteristics and obstetric factors present in final stepwise models and 95% confidence intervals. First-trimester and second-trimester serum marker levels were analysed in a subset of 125 202 pregnancies with available first-trimester and second-trimester serum biomarker results.

MAIN OUTCOME MEASURE

PTB by subtype.

RESULTS

In fully adjusted models, ten characteristics and three serum biomarkers were associated with increased risk in each PTB subtype (Black race/ethnicity, pre-existing hypertension with and without pre-eclampsia, gestational hypertension with pre-eclampsia, pre-existing diabetes, anaemia, previous PTB, one or two or more previous caesarean section(s), interpregnancy interval ≥ 60 months, low first-trimester pregnancy-associated plasma protein A, high second-trimester α-fetoprotein, and high second-trimester dimeric inhibin A). These risks occurred in 51.6-86.2% of all pregnancies ending in PTB depending on subtype. The highest risk observed was for medically indicated PTB <32 weeks in women with pre-existing hypertension and pre-eclampsia (adjusted odds ratio 89.7, 95% CI 27.3-111.2).

CONCLUSIONS

Our findings suggest a shared aetiology across PTB subtypes. These commonalities point to targets for further study and exploration of risk reduction strategies.

TWEETABLE ABSTRACT

Findings suggest a shared aetiology across preterm birth subtypes. Patterns may inform risk reduction efforts.

Hormonal evidence supports the theory of selection in utero

OBJECTIVES

Antagonists in the debate over whether the maternal stress response during pregnancy damages or culls fetuses have invoked the theory of selection in utero to support opposing positions. We describe how these opposing arguments arise from the same theory and offer a novel test to discriminate between them. Our test, rooted in reports from population endocrinology that human chorionic gonadotropin (hCG) signals fetal fitness, contributes not only to the debate over the fetal origins of illness, but also to the more basic literature concerned with whether and how natural selection in utero affects contemporary human populations.

METHODS

We linked maternal serum hCG measurements from prenatal screening tests with data from the California Department of Public Health birth registry for the years 2001-2007. We used time series analysis to test the association between the number of live-born male singletons and median hCG concentration among males in monthly gestational cohorts.

RESULTS

Among the 1.56 million gestations in our analysis, we find that median hCG levels among male survivors of monthly conception cohorts rise as the number of male survivors falls.

RESULTS

Elevated median hCG among relatively small male birth cohorts supports the theory of selection in utero and suggests that the maternal stress response culls cohorts in gestation by raising the fitness criterion for survival to birth.

Use of the phenylalanine:tyrosine ratio to test newborns for phenylketonuria in a large public health screening programme

OBJECTIVE

To assess the benefits of using the phenylalanine:tyrosine ratio to screen newborns for phenylketonuria (PKU).

SETTING

Data were collected from all newborns in California during a ten month period (n = 404,381).

METHODS

Dried blood spot specimens were analysed at nine laboratories. To assure that the results reported from multiple sites were matched accurately, an automated methodology was chosen that included sample processing, analysis, telecommunications, reporting, and information technology. Phenylalanine and tyrosine concentrations were measured independently by continuous flow fluorometry, for which precision, recovery, detection limits, carryover, chemical specificity, reportable range, and number of repeats are reported.

RESULTS

In this study, 37% of the newborns were tested at less than 24 hours of age. For this population, using a phenylalanine only cut off of 200 mumol/l, there were 48 recalled infants per case of classic PKU. Using the phenylalanine:tyrosine ratio with a cut off of 1.50, screen positives could be reported with phenylalanine as low as 150 mumol/l and with only 12 recalls per case.

CONCLUSIONS

The phenylalanine:tyrosine ratio can be measured accurately at multiple laboratories using two channel chemical analyses. Having applied the methods to the routine clinical screening of a large population, it was confirmed that the clinical sensitivity and specificity of the PKU screening test are higher when the phenylalanine:tyrosine ratio is incorporated into the cut off than when the cut off is based on the phenylalanine concentration alone.

Prenatal ultrasound findings in affected and unaffected pregnancies that are screen-positive for trisomy 18: the California experience

This study investigated whether significant differences in ultrasound findings exist between trisomy 18 affected and unaffected pregnancies positive by serum screening. Ultrasound reports were reviewed for 335 screen-positive women. This represented 65% of all trisomy 18 screen-positive patients who had follow-up services at any of 117 Californian state-approved Prenatal Diagnosis Centers during a six-month period from November 1, 1995 to April 30, 1996. Ultrasound reports were available for 100% of trisomy 18 fetuses diagnosed during the six month period (n=23). Ultrasound findings were reported as normal in 35% of the fetuses affected with trisomy 18. The number and type of abnormalities observed in the affected and unaffected groups are described. When compared to unaffected cases, the trisomy 18 affected fetuses had a greater re-dating discrepancy on follow-up ultrasound evaluation and significantly lower femur length to biparietal diameter (FL/BPD) ratio measurements. We recommend that all women who are screen positive for trisomy 18 be encouraged to have amniocentesis, regardless of ultrasound findings, since affected fetuses may not be detected otherwise.

Neural tube defect prevalence in California (1990-1994): eliciting patterns by type of defect and maternal race/ethnicity

This study presents race/ethnicity-specific prevalence estimates of neural tube defects (NTDs) in California using 5 years of population-based data. NTD prevalence estimates include prenatally diagnosed cases, as well as cases diagnosed at birth. The California NTD Registry contains NTD case reports identified through the California Maternal Serum Alpha-Feto Protein (AFP) Screening Program, the California Birth Defects Monitoring Program, and additional reports from clinicians and clinics throughout the state. These data were used to estimate NTD prevalence in a large population-based study (n = 1,618,279). The overall NTD prevalence among White, Black, Hispanic, and Asian women are reported, as well as race/ethnic prevalence, for anencephaly, spina bifida, and encephalocele. Rates are expressed as the number of cases per 1,000 women screened between 1990 and 1994. Among 1,457 women with an NTD-affected pregnancy, the overall rate for anencephaly, spina bifida, and encephalocele was 0.49 (95% CI 0.46-0.53), 0.42 (95% CI 0.38-0.45), and 0.08 (95% CI 0.07-0.09), respectively. When these types of NTDs are combined, Hispanic women had the highest overall rate (1.12, 95% CI 1.04-1.21), followed by Whites (0.96, 95% CI 0.89-1.04), Blacks (0.75, 95% CI 0.59-0.91), and Asians (0.75, 95% CI 0.60-0.90). Hispanic women were 45% more likely than White women to have a pregnancy affected with anencephaly (odds ratio = 1.45, 95% CI 1.24-1.70), while Asian women were over two times less likely to have a pregnancy affected with spina bifida (odds ratio = 0.44, 95% CI 0.29-0.65). Considerable variation exists in the prevalence of NTDs by race/ethnicity and by type of NTD, with Hispanic women exhibiting the highest overall NTD rate.

Replacing time since human immunodeficiency virus infection by marker values in predicting residual time to acquired immunodeficiency syndrome diagnosis. Multicenter AIDS Cohort Study

It is widely assumed that the time since human immunodeficiency virus (HIV) infection is an important indicator of HIV disease stage, yet for most infected individuals the date of infection is unknown. We consider whether marker values, such as CD4 lymphocyte number or percent and levels of serum beta2 microglobulin or serum neopterin, render time since infection unimportant for predicting the residual time to acquired immunodeficiency syndrome (AIDS) diagnosis. The Multicenter AIDS Cohort Study (MACS) contains a subsample of homosexual men whose date of HIV seroconversion is known within +/-6 months and who provide data for this analysis. From this subsample, we extract two overlapping data subsets. The first subset consists of 370 persons whose 3,723 study visits include complete data on the cellular markers CD4 lymphocyte number and percent for a period of 9 years. The second consists of 272 persons whose 1,593 visits include complete information on cellular markers and on the serological markers beta2-microglobulin and neopterin for a period of 5 1/2 years. We model the residual time to AIDS diagnosis with a regression model, in which cellular and serologic markers are the explanatory covariates (independent variables) and the residual time to AIDS is the responses variable (dependent variable). A robust estimate of the variance-covariance matrix corrects for the dependence of repeated measurements in the same individual. In the case of CD4 number and percent, the results indicate that time since infection is of none or at most little importance if the marker value is known, suggesting that time since infection can be adequately replaced by the combination of marker values. However, the serological markers alone do not eliminate the importance of the time since infection.

Neuropsychological test performance in patients with dominantly inherited spinocerebellar ataxia: relationship to ataxia severity

To determine whether the cognitive status of patients with dominantly inherited spinocerebellar ataxia (DSCA) might be related to neurologic severity, we administered a comprehensive neuropsychological test battery to 43 patients with DSCA, ranging in ataxia severity from mild to end-stage. As compared with the controls, the mildly ataxic patients scored normally or close to normal as a group on all of the neuropsychological tests. In contrast, approximately one-half of the moderately and all of the severely ataxic patients showed poor performance, independent of age, Hamilton Rating Scale for Depression score, or education, on the Wisconsin Card Sorting Test, suggesting impaired executive system function. In addition, a subgroup of these patients had a neuropsychological profile suggestive of mild generalized cognitive impairment. We conclude that DSCA is not a homogeneous group of disorders with respect to cognitive status and that the neurologic severity of the disorder is a major factor. Impaired executive system function could be explained by damage to olivopontocerebellar system control over cerebral cortical function or to damage to other neuronal systems (especially cholinergic) that degenerate in parallel with the olivopontocerebellar system.

Striatal monoamine neurotransmitters and metabolites in dominantly inherited olivopontocerebellar atrophy

We measured the levels of the monoamine neurotransmitters and metabolites in striatum of 14 patients with end-stage dominantly inherited olivopontocerebellar atrophy (OPCA). On average, dopamine levels were reduced in putamen (-53%), caudate (-35%), and nucleus accumbens (-31%). However, individual patient values showed a wide variation, indicating that mild to moderate striatal dopamine loss is a common but not constant feature of OPCA. Seven patients had marked putamen dopamine loss (-62% to -81%) but without evidence of correspondingly severe substantia nigra cell damage; this suggests the possibility of a "dying-back" phenomenon in which nerve terminal loss precedes cell body degeneration. Severe substantia nigra cell loss with almost total (-95% to -99%) putamen and caudate dopamine depletion was present in two patients; however, none of the 14 patients had had a clinical diagnosis of parkinsonism or was receiving antiparkinsonian medication. Mean striatal serotonin levels were normal, whereas concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid were elevated by 47% to 63%; this suggests increased activity of raphe dorsalis serotonin neurons innervating the striatum, which might aggravate the functional consequences of the dopamine deficit.

Lyme disease: the picture in Iowa

Lyme disease in Iowa increased sharply in 1989 and 1990, creating concern in Iowans who spend considerable time out-of-doors. The authors review the history of Lyme disease and its symptoms and present an update on the status of Lyme disease and its tick vector in Iowa.

Cerebellar [3H]inositol 1,4,5-trisphosphate binding is markedly decreased in human olivopontocerebellar atrophy

We examined the behaviour of [3H]inositol-1,4,5-trisphosphate (IP3) binding in autopsied cerebellar and cerebral cortex of 10 neurologically normal controls and 8 patients with end-stage olivopontocerebellar atrophy (OPCA), a cerebellar ataxia disorder characterized histologically by severe degeneration of Purkinje cells. [3H]IP3 binding to normal human cerebellar cortex was 6-15 times higher than in cerebral cortex. As compared with the controls, mean [3H]IP3 binding to cerebellar cortex was markedly reduced by 61% in the OPCA patients whereas levels were normal in frontal and occipital cortices. Since the Purkinje cell dendrite receives neuronal input from granule cells and climbing fibers utilizing glutamate and aspartate, respectively, as neurotransmitters, the reduced IP3 binding in OPCA cerebellar cortex may reflect a loss of Purkinje cells containing these excitatory amino acid receptors linked to the phosphatidylinositide second messenger system. Our data suggest that in humans, IP3 receptors may be highly localized to the Purkinje cell dendrite.

Is early and periodic screening, diagnosis, and treatment (EPSDT) worthwhile?

The State and Federal governments invest many tax dollars to provide health screening for millions of Medicaid families. Justification for such investment is based on the experience of Sweden's screening of 4-year-old children, a University of Texas Health Service Center study on cost benefit of EPSDT, and the Michigan experience. In Sweden's health screening program, health problems of functional importance were found in 21.6% of the screenees, and 71.8% of these were newly discovered by the screening. The results of Texas study indicated that an effective EPSDT program would result in a savings of $43 billion in 1976 currency over a 20-year period. In Michigan, a drop of 13% occurred in the referral rate for health problems during a 6-month period among those who were screened a second time or more.