Prior Fetal Loss Research Articles

Aspirin therapy is associated with a lower risk of pregnancy loss in both JAK2- and CALR-mutated essential thrombocythemia-A Mayo Clinic study of 200 pregnancies.

Two-hundred pregnancies involving 100 women with essential thrombocythemia (ET) were accessed from Mayo Clinic databases (1990-2023). Median platelet count displayed a decline during pregnancy, nadiring at 48% of baseline, in the third trimester: 704-369 × 109/L. Live birth rate was 72%. Of 53 (27%) unintentional pregnancy losses, 48 (24%) occurred in the first trimester. Other fetal complications included preterm birth 3%, intrauterine growth retardation 3%, and stillbirth 1%. Maternal complications included major hemorrhage (7%), preeclampsia (6%), thrombosis (1%), and placental abruption (0.5%). Antepartum management included no specific therapy in 52 (26%), aspirin alone in 112 (56%), aspirin combined with cytoreductive drugs or systemic anticoagulants in 23 (12%), and other permutations in the remaining. Postpartum systemic anticoagulation was documented in 29 (15%) pregnancies. Unintentional first-trimester loss was predicted by prior fetal loss (43% vs. 18%; p < .01), diabetes mellitus (DM; 67% vs. 23%; p = .02), and absence of aspirin therapy (45% vs. 14%; p < .01); the salutary effect of aspirin therapy was independent of the other two risk factors and apparent in both high (presence of ≥1 risk factor; 33% vs. 61%; p = .07) and low (absence of both risk factors; 10% vs. 34%; p < .01) risk scenarios. The benefit of aspirin therapy, in preventing first-trimester loss, was significant in both JAK2-mutated (18% vs. 50%; p < .01) and CALR-mutated (8% vs. 43%; p < .01) cases. Aspirin use was also associated with a lower risk of venous thrombosis (0% vs. 3%; p = .03). By contrast, the use of systemic anticoagulation, antepartum or postpartum, did not influence fetal or maternal complication rates. CALR mutation and DM predicted maternal hemorrhage (13% vs. 4%; p = .05) and preeclampsia (33% vs. 5%; p = .03), respectively. The current study demonstrates the protective role of aspirin in preventing first-trimester loss in ET, independent of driver mutation status or other risk factors.

Determinants of congenital syphilis in Fortaleza, Brazil: A retrospective case-control study.

Congenital syphilis (CS) is a significant public health problem in Brazil. Despite efforts to increase syphilis testing and treatment among pregnant women, rates of CS in the country remain high. We conducted a retrospective case-control study to identify potential associations between the mothers' sociodemographic characteristics, clinical factors related to the current and previous pregnancies, and the occurrence of CS among newborns in Fortaleza, a populous city with one of the highest incidences of CS in Brazil. Data from newborns diagnosed with CS between 2017 and 2020 were extracted from SINAN, the national database for notifiable diseases. Data from women who had delivered an infant with CS were extracted from SINASC, the national database for registration of live births, and linked with their infant's data. CS cases and non-CS controls were matched by year of birth at a ratio of 1:3 respectively. Potential associations were estimated using a multivariate regression model accounting for sociodemographic, obstetric, and antenatal care-related factors. Epidemiological data from 8,744 live births were included in the analysis, including 2,186 cases and 6,588 controls. The final multivariate regression model identified increased odds of delivering an infant with CS among pregnant women and girls aged below 20 years (OR 1.29), single women (OR 1.48), women who had less than 8 years of formal education (OR 2.42), women who delivered in a public hospital (OR 6.92), women who had more than 4 previous pregnancies (OR 1.60), and women who had one or more prior fetal loss (OR 1.19). The odds of delivering an infant with CS also increased as the number of antenatal visits decreased. Women who did not attend any antenatal visits had 3.94 times the odds of delivering an infant with CS compared to women who attended 7 or more visits. Our study found that increased odds of delivering an infant with CS were highly associated with factors related to socioeconomic vulnerability. These determinants not only affect the access to essential antenatal care services, but also the continuity and quality of such preventive measures. Future policies aimed at reducing the incidence of CS should not only target those pregnant women and adolescents with identifiable risk factors for testing, but also assure high quality care, treatment and follow-up for this group.

19 Maternal and early childhood exposures in relation to juvenile idiopathic arthritis

Abstract Background Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in children. JIA likely has a complex aetiology, with multiple genetic and environmental factors contributing to its development. Existing data on associations between maternal and early childhood exposures and JIA is rare. Previous studies showed potential role for prematurity, number of siblings and infections. Objectives The aim of our study is to assess maternal and early childhood exposures in patients with JIA. Methods Mothers of children with JIA followed in rheumatology department were asked about maternity related data as well as the course of perinatal period of the child with JIA based on the International League of Associations for Rheumatology (ILAR) criteria. Exposure information from birth included: Maternal factors (age when they had the first child, age when they had the child with JIA, plurality (singleton, twin/multiple gestation), number of prior fetal losses, number of prior births; delivery method (vaginal, cesarean section)) and also information about birth weight (low (&amp;lt;2500 grams), normal (2500– 4000 grams), excessive (4000+ grams)); size for- gestational-age and gestational age (preterm, normal term, post term) and postpartum complications. Results Thirty children (sixteen females and fourteen males) with JIA were included. The most common type of JIA was enthesitis-related in 13 cases, then oligoarthritis in 8 cases, polyarthritis without rheumatoid factor in 4 cases, polyarthritis with positive rheumatoid factor in 2 cases and psoriatic arthritis in 3 cases. The mean age of the mothers was 27.1 years [22–40] when they had their first child and 30.27 years [22–42] when they had their child with JIA. They were nulliparous in 40% of the cases. All of the children were from a singleton pregnancy. Thirty percent of the mothers had at least one prior fetal loss before they had their child with JIA. During their pregnancy with their child with JIA, five mothers had pre-eclampsia and two of them had gestational diabetes. None of them smoked during the pregnancy. Only 2 children had preterm birth. Birth weight was normal (2.500–4.000 grams) in 24 cases, low in 3 cases (&amp;lt;2.500 grams) and above normal (&amp;gt;4000 grams) in 3 cases. Size for gestational age was normal in all cases. Nineteen mothers had vaginal delivery and eleven had cesarean section. Neonatal complications were noted in 7 cases who needed to be admitted to neonatal intensive care unit (1 for hypoglycemia, 1 for jaundice, 2 for infection, 1 for respiratory distress and two because of preterm birth). Maternal complications were noted in four cases: 2 postpartum hemorrhage and 2 postpartum infections. Conclusion Our study assessed maternal and early childhood exposures in patients with JIA. Further studies are required to explore associations between these factors and the occurrence of the disease for a better knowledge of etiologies of JIA and for a possible prevention from this pathology.

Juvenile idiopathic arthritis in relation to perinatal and maternal characteristics: a case control study

BackgroundExisting data on associations between maternal and early childhood exposures and juvenile idiopathic arthritis (JIA) risk is scant and inconsistent with previous studies showing potential role for prematurity, number of siblings and infections. We explored JIA and International League of Associations for Rheumatology (ILAR) JIA categories in relation to selected infant (birthweight, size-for-gestational-age, gestational age), and maternal (parity, delivery type, prior fetal loss) characteristics that may be markers for exposures related to two pathways (hygiene hypothesis, microchimerism) potentially associated with autoimmune disorder occurrence.MethodsA case–control analysis with 1,234 JIA cases and 5,993 birth year-matched controls was conducted. Exposure information was obtained from WA state birth certificates. Multivariable logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) for associations with maternal and early life exposures for JIA and JIA categories.ResultsGreater maternal parity was associated with a decreased OR for JIA (most marked for persistent oligoarticular JIA, OR 0.32, 95% CI 0.15; 0.71, p for trend = 0.0001). Prior fetal loss (except for oligoarticular JIA) was associated with an increased OR for JIA. Prematurity was associated with increased risk of enthesitis related arthritis (OR 1.9, 95% CI: 1.3–2.9) and rheumatoid factor positive polyarticular JIA (OR 2.2, 95% CI: 1.0–4.8).ConclusionsWe observed associations of selected maternal factors with JIA, some of which varied across JIA categories. The findings of decreased ORs for JIA in relation to greater maternal parity may be consistent with the hygiene and microchimerism hypotheses. Future studies with biomarkers relevant to these hypotheses will help elucidate any associations.

Comparative incidence of pregnancy outcomes in treated obstetric antiphospholipid syndrome: the NOH-APS observational study

AbstractThe incidence of pregnancy outcomes for women with the purely obstetric form of antiphospholipid syndrome (APS) treated with prophylactic low-molecular-weight heparin (LMWH) plus low-dose aspirin (LDA) has not been documented. We observed women without a history of thrombosis who had experienced 3 consecutive spontaneous abortions before the 10th week of gestation or 1 fetal loss at or beyond the 10th week. We compared the frequencies of complications during new pregnancies between treated women with APS (n = 513; LMWH + LDA) and women negative for antiphospholipid antibodies as controls (n = 791; no treatment). Among APS women, prior fetal loss was a risk factor for fetal loss, preeclampsia (PE), premature birth, and the occurrence of any placenta-mediated complication. Being positive for anticardiolipin immunoglobulin M antibodies was a risk factor for any placenta-mediated complication. Among women with a history of recurrent abortion, APS women were at a higher risk than other women of PE, placenta-mediated complications, and neonatal mortality. Among women with prior fetal loss, LMWH + LDA–treated APS women had lower pregnancy loss rates but higher PE rates than other women. Improved therapies, in particular better prophylaxis of late pregnancy complications, are urgently needed for obstetric APS and should be evaluated according to the type of pregnancy loss.

Stroke in pregnancy: A rare case of protein C and protein S deficiency

Stroke in pregnancy is a rare occurrence, its reported incidence being 11–26 deliveries per 100,000. Ischemic strokes are slightly more common than hemorrhages. Subarachnoid hemorrhage, embolism and cerebral venous thrombosis can also occur, albeit with a lesser incidence. Peak incidence of stroke is in the peripartum and postpartum period. Mortality rate of pregnancy associated stroke is 10.13%. Therefore, rapid recognition and management of these patients are imperative to ensure successful outcome. We report a rare case of stroke during pregnancy which has the protein C and protein S deficiency as its precipitating cause.We report a case of a 24-year-old female, with previous cesarean section in her third trimester, suddenly developed weakness of left side of the body and deviation of face to the right. There was no history of head trauma, fever, unconsciousness or seizure. She did not have any skin rash, arthritis or signs of deep vein thrombosis. There was no history of prior fetal loss. Protein C and protein S levels were low. We report a rare case of stroke during pregnancy which has the protein C and protein S deficiency as its precipitating cause. Stroke is a recognized complication of pregnancy, is uncommon but feared. Stroke in young adults aged 15–35 years is more common in women with poorer outcome in terms of disability and dependence. Most pregnancy related stroke occurs in peripartum and puerperium.

Perdas fetais espontâneas e voluntárias no Brasil em 1999-2000: um estudo de fatores associados

Despite its illegality in Brazil, about 31% of all pregnancies end in abortion. Most abortions are performed by unskilled personnel and under unsafe conditions, resulting in increased female mortality. This study used data from a cross-sectional representative sample of 3,047 puerperal women, in 1999-2000, part of a national multicenter study on the prevalence of syphilis in Brazil. Of these, 1,838 women with at least one previous pregnancy before the reference pregnancy were included in the analysis. The outcomes studied were voluntary prior fetal loss, spontaneous prior fetal loss, and no prior fetal loss. The analysis was carried out using multinomial logistic regression. The results indicated a high number of fetal losses per woman (up to six); and 31% of the losses were voluntary. The absence of prenatal care, history of STD in the reference pregnancy, and absence of living children were factors that increased the odds of fetal loss. For voluntary fetal loss, being non-white, having more than one partner in the previous year, and an early age at first sexual intercourse also increased the odds of fetal loss. These data confirm the public health relevance of abortion in Brazil. Characteristics related to women´s vulnerability should be considered in family planning programs in order to reduce the number of abortions and their consequences. Counseling must also be provided, targeting women with a previous abortion.

Outcome of pregnancies in women with thrombophilic disorders

Women with thrombophilic disorders may have pregnancy complications including fetal loss (FL); however, the impact of thromboprophylaxis with low molecular weight heparin (LMWH) and previous obstetric history remains to be clarified. Our aim was to compare the effects of LMWH in three groups of women with thrombophilia who had varying numbers of prior fetal losses. We prospectively investigated the live birth rates in 66 women with thrombophilic conditions, treated with a LMWH (enoxaparin, 40 mg daily). Groups 1, 2 and 3 included patients with 0–1, 2–3 and ≥4 pregnancy losses, respectively. Groups 1, 2 and 3 had 90.47%, 83.78% and 50.00% live birth frequencies, respectively. Group 3 had a significantly lower chance of a live birth compared with Group 1, regardless of type of thrombophilic disorder. FL aetiology in thrombophilic patients with multiple miscarriages appears multifactorial, and thromboprophylaxis alone may not be sufficient.

Thrombophilias and Stillbirth

It is often postulated that both inherited and acquired thrombophilias increase the risk of stillbirth. In an attempt to reduce this theoretical risk, pregnant patients with prior fetal losses and thrombophilias are anticoagulated. However, there is no definitive proof that thrombophilias are causally linked to stillbirth. Prospective studies have failed to establish a definitive link between inherited thrombophilias and stillbirth. The extant literature suggests that only high concentrations of antiphospholipid antibodies are associated with stillbirth. Moreover, when pregnant women with prior fetal losses even in these cases are placed on anticoagulation, it is unclear that their recurrence risk of stillbirth decreases.

A High Incidence of Patients with MTHFR (methylenetetrahydrofolate reductase) Gene Mutations Noted in An Appalachian Population Seen for Thrombophilia at the West Virginia University Outpatient Hematology Clinic, 2006–2008

Background: One or more risk factors for deep vein thrombosis (DVT) and pulmonary embolism (PE), either hereditary or acquired, can be identified in up to 80% of patients with venous thromboembolism (VTE). Some patients have more than one form of inherited thrombophilia and appear to be at greater risk for thrombosis. We noted a higher than expected incidence of MTHFR gene mutations C677T or A1298C in Appalachian patients referred to our benign hematology clinic. Studies have suggested an increased risk of venous thromboembolism (VTE) in patients with hyperhomocysteinemia, and the C677T mutation in the MTHFR gene has been thought responsible for hyperhomocysteinemia. However, the association of MTHFR gene mutations C677T and A1298C and VTE remains controversial.Methods: We reviewed the records of 72 patients for risk factors for acquired or inherited thrombophilia. These patients were referred to our benign hematology clinic for thrombophilia evaluation between 2006 and 2008. All available medical history for risk factors and laboratory test results, obtained from first VTE through time of consultation, including genetic testing, were reviewed. Anti-cardiolipin antibody (ACA), MTHFR genotyping and Protein C and Protein S assays were performed at Warde Medical Laboratory, Ann Arbor, MI.Results: 72 patients were seen from 2006–2008. Of these, 45 patients (63%) had established VTE per ATS clinical practice guidelines and are the subject of this report. Excluded patients had stroke only (CVA) without other VTE, or were screened for thrombophilia based of family history or prior fetal loss. Of the 45 patients with established VTE, median age at first clot was 34 years (range 14–65) and median age at consultation was 41 years (range 19–72). There were 21 men and 24 women (47% and: 53%). Recorded sites of VTE were legs (54 events), arms (8 events), pulmonary embolism (22 events) and stroke with VTE (3 events). Review of risk factors showed that 90 % of the patients had good performance status (NCI 0,1); 47% were obese with BMI > 30 (median BMI was 29.6); 47% were smokers; 49 % had a positive family history of VTE; 42 % had dyslipidemia; 9% had cancer (3 prior, 1 active germ cell testis tumor); and 16% used oral contraceptives or hormones. 33 of the 45 VTE patients had homocysteine levels available, and the median homocysteine level was 10 micromol/L (range 5.8 –63); 7 (21%) had an elevated homocysteine level, greater than 14. 32 of the 45 VTE patients had MTHFR gene mutation testing done, and 28 of the 32 (88 %) had one or more positive mutations, with alleles C677TT (10%-high risk), C677T (68%), A1298CC (14%), A1298C (39%). Further, 9 of the 32 patients (32%) and the “high risk” C677T-A1298C mutation. Thus, 42% of all patients tested had a “high risk” MTHFR gene mutation for VTE.Coagulation Profile of 45 Thrombophilia Clinic Patients with established VTE# tests (+)# tests done%Anti-Cardiolipin Antibody53613Anti-Thrombin III2366Factor II 20210 Gene Mutation2406Factor V Leiden Gene Mutation104025Lupus Anti-coagulant2316.4xMTHFR Gene Mutation283288Protein C2307Protein S32910Conclusion: Patients with established VTE in our clinic population inherited risk factors as tabulated above. The Factor II and Factor V mutation incidences of 6% and 25%, as well as the number of abnormalities in Protein C, Protein S, and Anti-Cardiolipin Antibody, appear similar to data reported in the literature for Caucasian populations. However, Rodrigues et al reported a C677TT and C677T prevalence of 14–19% and 36–47% respectively in 1,277 normal persons and a A1298 CC and A1298C prevalence of 7–11 % and 28–35 % respectively (Am J Clin Nutr 2006; 83:701).,. In our Appalachian population, the overall incidence of MTHFR genetic mutations (88 %) and the number of “high risk” MTHFR mutations (42%) appears excessive and deserves further investigation.

Birth Characteristics, Maternal Reproductive History, and the Risk of Infant Leukemia: A Report from the Children's Oncology Group

Leukemias with MLL gene rearrangements predominate in infants (<1 year of age), but not in older children, and may have a distinct etiology. High birth weight, higher birth order, and prior fetal loss have, with varying consistency, been associated with infant leukemia, but no studies have reported results with respect to MLL status. Here, we report for the first time such an analysis. During 1999 to 2003, mothers of 240 incident cases (113 MLL(+), 80 MLL(-), and 47 indeterminate) and 255 random digit dialed controls completed a telephone interview. Odds ratios and 95% confidence intervals for quartile of birth weight, birth order, gestational age, maternal age at delivery, prior fetal loss, pre-pregnancy body mass index, and weight gain during pregnancy were obtained using unconditional logistic regression; P for linear trend was obtained by modeling continuous variables. There was a borderline significant linear trend of increasing birth weight with MLL(+) (P = 0.06), but not MLL(-) (P = 0.93), infant leukemia. Increasing birth order showed a significant inverse linear trend, independent of birth weight, with MLL(+) (P = 0.01), but not MLL(-) (P = 0.18), infant leukemia. Other variables of interest were not notably associated with infant leukemia regardless of MLL status. This investigation further supports the contention that molecularly defined subtypes of infant leukemia have separate etiologies.

A population-based prospective cohort study of personal exposure to magnetic fields during pregnancy and the risk of miscarriage.

To study the effect of magnetic fields on the risk of miscarriage, we conducted a population-based prospective cohort study among pregnant women within a large health maintenance organization. All women with a positive pregnancy test at less than 10 weeks of gestation and residing in the San Francisco area were contacted for participation in the study. We conducted in-person interviews to obtain information on risk factors for miscarriage and other potential confounders. All participants were also asked to wear a magnetic field-measuring meter for 24 hours and to keep a diary of their activities. Pregnancy outcomes were obtained for all participants by searching the health maintenance organization's databases, reviewing medical charts, and telephone follow-up. We used the Cox proportional hazard model for examining the magnetic field-miscarriage association. A total of 969 subjects were included in the final analyses. Although we did not observe an association between miscarriage risk and the average magnetic field level, miscarriage risk increased with an increasing level of maximum magnetic field exposure with a threshold around 16 milligauss (mG). The rate ratio (RR) associated with magnetic field exposure > or = 16 mG (vs <16 mG) was 1.8 [95% confidence interval (CI) = 1.2-2.7]. The risk remained elevated for levels (in tertiles) of maximum magnetic field exposure > or = 16 mG. The association was stronger for early miscarriages (<10 weeks of gestation) (RR = 2.2, 95% CI = 1.2-4.0) and among "susceptible" women with multiple prior fetal losses or subfertility (RR = 3.1, 95% CI = 1.3-7.7). After excluding women who indicated that their daily activity pattern during the measurements did not represent their typical daily activity during pregnancy, the association was strengthened; RR = 2.9 (95% CI = 1.6-5.3) for maximum magnetic field exposure > or = 16 mG, RR = 5.7 (95% CI = 2.1-15.7) for early miscarriage, and RR = 4.0 (95% CI = 1.4-11.5) among the susceptible women. Our findings provide strong prospective evidence that prenatal maximum magnetic field exposure above a certain level (possibly around 16 mG) may be associated with miscarriage risk. This observed association is unlikely to be due to uncontrolled biases or unmeasured confounders.

Tetrachloroethylene in drinking water and birth outcomes at the US Marine Corps Base at Camp Lejeune, North Carolina.

A study of mean birth weight, small-for-gestational-age infants, and preterm birth was conducted at the US Marine Corps Base at Camp Lejeune, North Carolina, where drinking water was contaminated with volatile organic compounds. Tetrachloroethylene (PCE) was the predominant contaminant. The authors used multiple linear and logistic regression to analyze 1968-1985 data from 11,798 birth certificates. Overall, at most weak associations were observed between PCE exposure and study outcomes. However, associations were found between PCE exposure and birth-weight outcomes for infants of older mothers and mothers with histories of fetal loss. Adjusted mean birth-weight differences between PCE-exposed and unexposed infants were -130 g (90% confidence interval (CI): -236, -23) for mothers aged 35 years or older and -104 g (90% CI: -174, -34) for mothers with two or more previous fetal losses. Adjusted odds ratios for PCE exposure and small-for-gestational-age infants were 2.1 (90% CI: 0.9, 4.9) for older mothers and 2.5 (90% CI: 1.5, 4.3) for mothers with two or more prior fetal losses. These results suggest that some fetuses may be more vulnerable than others to chemical insult.

Maternal mortality in different Pakistani sites: ratios, clinical causes and determinants.

Population-based estimates of maternal mortality from Pakistan are inadequate to define the magnitude of the problem or provide information on clinical causes and determinants. Surveys were conducted in selected clusters in Karachi, Balochistan and North West Frontier Province from 1989-1992. Pre-coded questionnaires were administered to 38,563 households to ascertain household characteristics, complete pregnancy histories and deaths of household members in the five years preceding the survey. Verbal autopsy questionnaires were then conducted to establish cause of death to women in the reproductive age group. Descriptive, bivariate and multivariable analyses were carried out to determine the association between the background variables, biological and women's status indicators and maternal mortality using a nested case-control design. Overall, the estimated maternal mortality ratio combining the data from the different sites was 433 per 100,000 livebirths. The estimated maternal mortality ratios per 100,000 livebirths ranged from a low of 281 in Karachi to a high of 673 in Khuzdar [Balochistan]. Hemorrhage (52.9%), puerperal sepsis (16.3%) and eclampsia (14.4%) were the leading causes for direct maternal deaths. Logistic regression identified the important risk factors as poor housing construction material (OR = 2.1; 95% CI = 1.3,3.2), distance of 40 or more miles from nearest hospital (OR = 1.3; 95% CI = 0.9,1.8), grandmultigravidity (OR = 1.6; 95% CI = 1.1,2.4) and prior fetal losses (OR = 5.3; 95% CI = 3.8,7.4). Focusing on special groups of pregnant women with targeted programs such as training, monitoring and supervision of birth attendants for the provision of oxytocics, will go a long way in decreasing the proportion of maternal deaths attributed to direct, avoidable causes.

The antiphospholipid antibody syndrome

Antiphospholipid antibody syndrome is of importance to the primary care physician because of its association with a number of medical complications. More specifically, a variety of obstetric complications, including recurrent fetal loss, preeclampsia, and intrauterine growth restriction, are more common in pregnancies of women with antiphospholipid syndrome. Accepted criteria for the diagnosis of antiphospholipid syndrome include the occurrence of moderate-to-high levels of antiphospholipid antibodies in the presence of fetal loss, arterial or venous thrombosis, or autoimmune thrombocytopenia. Optimal management includes preconceptional counseling to discuss the potential maternal and fetal complications of antiphospholipid syndrome. Treatment with heparin and low-dose aspirin is indicated in women with prior fetal loss. Antiphospholipid syndrome patients with a history of thrombosis should receive heparin thrombo-prophylaxis even if they have no history of fetal loss.

Evaluating the relationships among maternal reproductive history, birth characteristics, and infant leukemia: A report from the children's cancer group

PURPOSE: Specific events in the mother's reproductive history and certain birth characteristics have been associated with childhood leukemia. Few studies have explored these associations specifically in infants. METHODS: The Children's Cancer Group (CCG) conducted three separate case-control studies of childhood leukemia that involved similar methodologies and data collection. Data from interviews of the mothers of a total of 303 children diagnosed with leukemia at 1 year of age or younger and their matched controls ( n = 468) were available from the three studies. These data included maternal reproductive history (stillbirths, abortions, and miscarriages) and certain birth characteristics of the index child. RESULTS: Compared with controls, cases were significantly more likely to be female ( P < 0.01) and were more often heavier at birth (particularly cases diagnosed after 6 months of age (odds ratio, 4.18; 95% confidence interval, 1.75–10.02)). Overall, there were no statistically significant differences between cases and controls in regard to maternal report of any type of previous fetal loss. Finally, being a later-born child was associated with an increased risk of acute myeloid leukemia but not of acute lymphoblastic leukemia. CONCLUSIONS: The relationships among birthweight, prior fetal loss, and risk of infant leukemia appear to be complex. Further studies of infant leukemia that incorporate molecular as well as epidemiologic data may help to elucidate these differences.

Miscarriages among Female Physical Therapists Who Report Using Radio- and Microwave-frequency Electromagnetic Radiation

Physical therapists are exposed to radio- and microwave-frequency electromagnetic radiation by operating shortwave and microwave diathermy units. Recent studies suggest that use of shortwave diathermy is associated with an excess risk of birth defects, perinatal deaths, and late spontaneous abortions among the offspring of exposed female therapists. To assess the impact of occupational use of microwave and shortwave diathermy at the time of conception, the authors mailed questionnaires to 42,403 physical therapists in 1989. Both occupational and reproductive histories were obtained. Exposures to shortwave and microwave diathermy were both assessed in the same fashion and were examined in relation to early recognized fetal loss in a nested case-control design. A total of 1,753 case pregnancies (miscarriages) were matched to 1,753 incidence density control pregnancies (other pregnancies except ectopic pregnancies). A pregnancy was considered "exposed" if the mother reported using microwave or shortwave diathermy anytime during the 6 months prior to the first trimester or during the first trimester. Pregnancies of mothers reporting microwave use 6 months prior to the pregnancy or during the first trimester were more likely to result in miscarriage (odds ratio (OR) = 1.28, 95% confidence interval (CI) 1.02-1.59). The odds ratio increased with increasing level of exposure (chi 2 = 7.25, p < 0.005). The odds ratio in the highest exposure group (20 or more exposures/month) was 1.59. The overall odds ratio was slightly lower after it was controlled for prior fetal loss (OR = 1.26, 95% CI 1.00-1.59), but the exposure-response effect remained (chi 2 = 5.17, p < 0.01). The risk of miscarriage was not associated with reported use of shortwave diathermy equipment (OR = 1.07, 95% CI 0.91-1.24). The odds ratio in the highest exposure group was 0.87.

Concordance of parental race/ethnicity in relation to the risk of sudden infant death syndrome (SIDS).

It has been reported that parental human leukocyte antigen (HLA) compatibility is associated with certain adverse reproductive outcomes such as multiple spontaneous fetal losses and malformations, particularly among women without a prior livebirth. In order to study the relation between parental HLA compatibility and the risk of SIDS, a population-based case-control study was conducted using 1982-1990 Washington State linked birth and death certificate data. Concordance of parental race/ethnicity combined with prior maternal fetal loss was used as surrogate measures of parental HLA compatibility. The relation was evaluated separately among infants with and without a prior live-born sibling. Among first liveborn infants, those of racially discordant parents were at reduced risk of SIDS compared with those of racially concordant parents (relative risk [RR] = 0.57, 95% confidence interval = 0.34-0.96). Infants of white-minority parents were all at lower risk of SIDS than infants of white-white parents. Infants of racially concordant parents with two or more prior fetal losses were at increased risk of SIDS (RR = 2.44, 1.07-5.56), relative to infants of racially discordant parents. No such associations were observed among infants with prior live-born siblings. In fact, in this latter population, infants of racially concordant parents tended to have a lower risk of SIDS than those of discordant parents. This study suggests that a portion of SIDS cases, particularly among first live-born infants, may be due to parental HLA sharing. However, final determination of the existence of this relationship requires actual HLA typing of parents of both cases and controls.

A prospective, controlled multicenter study on the obstetric risks of pregnant women with antiphospholipid antibodies

A prospective, controlled multicenter study was performed to estimate the obstetric risks of antiphospholipid antibodies (the lupus anticoagulant and anticardiolipin antibodies). In addition, the risks of prior thrombosis, obstetric history, systemic lupus erythematosus, and high-dose prednisone treatment were evaluated. After screening for antiphospholipid antibodies in patients with lupus erythematosus or women with prior fetal loss(es), 59 subsequent pregnancies with and 54 without these antibodies were followed. The presence of the lupus anticoagulant and a history of at least three spontaneous abortions could predict fetal loss (p = 0.032 and 0.001, respectively). In live born infants, a low birth weight could be predicted by the presence of anticardiolipin antibodies (p = 0.034), prior intrauterine fetal death (p = 0.025), and treatment with high-dose prednisone (p = 0.002). No relationships were seen between antiphospholipid antibodies and small-for-gestational-age newborns and pregnancy-induced hypertension or preeclampsia. The disappearance of antiphospholipid antibodies during pregnancy was not correlated with live birth. It is concluded that the presence of antiphospholipid antibodies is a risk factor for adverse pregnancy outcome.

Risk factors for spontaneous abortion: a case-control study in France

A case-control study was conducted in seven maternity hospitals in the Paris area in 1988 to evaluate the role of several risk factors in spontaneous abortion. A total of 279 cases and 279 controls were compared for socio-demographic characteristics, reproductive history and for conditions of conception. Prior fetal losses [odds ratio (OR) = 2.30 for n greater than or equal to 2; 95% confidence interval (CI) = 1.17-4.61] and maternal age at pregnancy (greater than 30 years) appeared to be major and independent risk factors of spontaneous abortion. Other factors associated with an increased risk of fetal loss were: geographical or ethnic origin (OR = 2.85 for North African women; 95% CI = 1.58-5.10); psychological problems at the time of conception, either related to the outcome of the pregnancy (OR = 3.08; 95% CI = 0.92-10.25) or unrelated to this outcome (OR = 3.35; 95% CI = 1.41-8.00). The following factors were not associated with spontaneous abortion: gravidity, parity, prior induced abortion, prior sexually transmitted diseases and Chlamydia trachomatis serology, menstrual cycle abnormalities, induced conception cycle and in-vitro fertilization, cigarette smoking, current or past use of combined oestrogen/progestagen pill or intrauterine device. These findings confirm the importance of two risk factors for fetal loss: maternal age and number of prior spontaneous abortions. Two risk factors, ethnic origin and psychological problems at the time of conception are also identified, which require further study.