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PubMed2005

The impact of interpregnancy interval and previous preterm birth on the subsequent risk of preterm birth.

OBJECTIVE: To examine the impact of the interpregnancy interval and a previous preterm birth on the subsequent risk of a preterm birth. METHODS: A retrospective analysis was conducted on a group of 4072 women who had at least two consecutive births, excluding multiple gestation, fetal anomalies, cervical incompetence, and stillbirth. Multivariate logistic regression was used to investigate the association between interpregnancy interval, preterm birth of the first child in the pair (index pregnancy), and the risk of a preterm birth of the second child in the pair (outcome pregnancy). RESULTS: Women with interpregnancy intervals of less than 12 months (odds ratio [OR] 1.3; 95% confidence interval [CI] 1.0-1.7) were at increased risks of preterm birth with the outcome pregnancy. Furthermore, there was an increased risk for a subsequent preterm birth in women who had a preterm birth in the index pregnancy (OR 4.2; 95% CI 3.0-6.0). The risk decreased as the interpregnancy interval increased, with a relatively low risk at 18 to 48 months; subsequently, it increased sharply. In contrast, women who had delivered their previous infants at term carried an increased risk of preterm birth with the outcome pregnancy only if the interval was less than 6 months. CONCLUSION: A difference was found in the impact of the interpregnancy interval on the subsequent risk of preterm birth between women with a prior preterm birth and those who previously delivered an infant at term.

Adult↗

PubMed2006

Community influenza activity and risk of acute influenza-like illness episodes among healthy unvaccinated pregnant and postpartum women.

This study investigated the relation between weekly levels of influenza activity and the risk of acute influenza-like illness episodes among 8,323 healthy pregnant and postpartum women enrolled in a Puget Sound region, Washington, health maintenance organization, Group Health Cooperative, between June 1991 and December 1997. The authors classified weeks between October and May for isolate activity level based on surveillance data for influenza, respiratory syncytial virus, parainfluenza, and adenovirus infection. Influenza-like illness episodes were identified from medical encounters assigned a diagnostic code consistent with a symptomatic influenza infection. The authors compared the occurrence of influenza-like illness episodes within each pregnancy stage for periods with varying levels of influenza isolate detection in the community. Repeated-measures logistic regression methods accounted for time-dependent factors. The adjusted strength of association between influenza exposure and influenza-like illness episodes increased as the pregnancy stage progressed (first trimester odds ratio = 1.12, 95% confidence interval: 0.79, 1.59; second trimester odds ratio = 1.30, 95% confidence interval: 0.97, 1.73; third trimester odds ratio = 1.84, 95% confidence interval: 1.31, 2.59; postpartum period odds ratio = 2.28, 95% confidence interval: 1.42, 3.68). Pregnancy stage modified the association between influenza activity and influenza-like illness episodes. Findings estimate that 20-43 pregnant/postpartum women would need to be vaccinated with an 80% effective vaccine to prevent one influenza-like illness episode.

Acute Disease↗

PubMed1998

Effect of injection of beta-carotene or vitamin E and selenium on fertility of lactating dairy cows.

Experiments tested whether supplemental antioxidants improved fertility. To test effects of beta-carotene, cows in a hot environment were injected with prostaglandin F2 alpha (PGF2 alpha) and were given 3 injections, i.m., of 800 mg beta-carotene or saline at Days -6 and -3 before the anticipated date of insemination and at insemination (n = 37-41 inseminated cows/group). There was no effect of beta-carotene on the proportion of cows detected in estrus following PGF2 alpha, timing of estrus after PGF2 alpha injection or pregnancy rate in inseminated cows. In a second trial, cows in a temperate climate received intramuscular injections of vitamin E (500 mg) and selenium (50 mg) at 30 d post partum (n = 97) or were untreated controls (n = 89). Treatment did not affect interval from calving to first insemination or the proportion of cows pregnant at first service, but it increased the pregnancy rate at second service (69.8 vs 52.1%; P = 0.07) and reduced services per conception (1.7 vs 2.0; P < 0.05) and interval from calving to conception (84.6 vs 98.1; P < 0.05). Thus, injection of vitamin E and selenium increased fertility in cattle that did not become pregnant at first service.

Animals↗

PubMed1987

Methyl tertiary butyl ether inhalation in rats: a single generation reproduction study.

Male rats exposed to target concentrations of methyl tertiary butyl ether (MtBE) at 300, 1300 and 3400 ppm for 6 hours/day, 5 days/week for 12 weeks were mated to female rats exposed to the same concentrations for a 3-week period. Exposures continued through the mating period and the females continued exposures during gestation and from days 5-21 lactation of the litters (F1a) (no exposures days 0-4 lactation). A second litter (F1b) was produced under the same mating and post mating exposure regimen. No adverse effect of treatment was observed with the adult animals (Fo) throughout the in-life portion of the study. The only remarkable finding was an increased incidence of dilated renal pelves in the low- and high-dose females (Fo). All gonad weights, male accessory reproductive organ weights, organ-to-body weight ratios and reproductive organ histopathology were unremarkable upon comparison of treated animals with air sham controls. The mating indices and fertility indices in exposed animals for both mating intervals (F1a and F1b) were not significantly different from controls. Pregnancy rates were comparable between treated and control females for the first litter interval (F1a) but were slightly lower (not statistically significant) than control on the second litter interval (F1b). Treated animal mean gestation length and the mean number of pups at birth were not statistically different from controls. The pup viability indices at birth were comparable for control and treated groups for the F1a generation, but the mid- and high-dose groups displayed a slight statistically significant decrease in the F1b generation; the decrease was not considered to be biologically significant and perhaps not treatment-related. Litter survival indices were comparable between control and treated groups for both litter intervals. Pups of mid- and high-dose females had slightly lower (not statistically significant) mean weights at days 14 and 21 of lactation but this was not considered treatment-related. The most frequent post-mortem observation for pups sacrificed at day 21 of lactation was dilated renal pelves. This did not appear to be related to treatment. It is concluded that MtBE inhalation in rats results in little adverse reproductive toxicity as shown in a two litter, one generation reproduction assay in rats.

Administration, Inhalation↗

PubMed1989

Gestational trophoblastic disease: a case-control study from the People's Republic of China.

A case-control study involving 331 patients with complete hydatidiform mole and 662 community controls matched to the cases on age and timing of pregnancy was conducted in Beijing, China. A history of a term birth was associated with reduced risk (odds ratio = 0.6, 95% confidence interval 0.4 to 0.9), with some evidence of further decrease with multiple births. Previous spontaneous abortions were not related to risk, although those with a prior induced abortion were at elevated risk, particularly if two or more abortions were involved (odds ratio = 2.8, 95% confidence interval 1.4 to 5.7). A history of having sought medical advice for infertility was associated with reduced risk (odds ratio = 0.5, 95% confidence interval 0.2 to 0.8), but those who reported use of herbal medicines during a first trimester of a previous pregnancy were at excess risk (odds ratio = 2.2, 95% confidence interval 1.3 to 3.6). In addition, a statistically significant trend in risk was observed with years of oral contraceptive use (odds ratio = 2.6, 95% confidence interval 0.9 to 6.9 for greater than or equal to 4 years of use). Dietary habits and family histories of cancer or trophoblastic disease were not related to risk in this study.

Adult↗

PubMed2003

CYP17 genetic polymorphism, breast cancer, and breast cancer risk factors.

BACKGROUND: Findings from previous studies regarding the association between the CYP17 genotype and breast cancer are inconsistent. We investigated the role of the MspAI genetic polymorphism in the 5' region of CYP17 on risk of breast cancer and as a modifier of reproductive risk factors. METHODS: Questionnaire and genotyping data were obtained from a population-based, case-control study of premenopausal (n = 182) and postmenopausal (n = 214) European-American Caucasian women in western New York. Cases and controls were frequency matched by age and by county of residence. Odds ratios and 95% confidence intervals were used to estimate relative risks. RESULTS: The CYP17 genotype was not associated with breast cancer risk; however, controls with the A2/A2 genotype (associated with higher estrogens) had earlier menarche and earlier first full-term pregnancy. Premenopausal women with A1/A1 genotypes, but not with A2 alleles, were at significantly decreased risk with late age at menarche (odds ratio = 0.37, 95% confidence interval = 0.14-0.99), and at increased risk with late age at first full-term pregnancy (odds ratio = 4.30, 95% confidence interval = 1.46-12.67) and with use of oral contraceptives (odds ratio = 3.24, 95% confidence interval = 1.08-9.73). Associations were weaker among postmenopausal women. CONCLUSION: These results suggest that the effects of factors that may alter breast cancer risk through a hormonal mechanism may be less important among premenopausal women with putative higher lifetime exposures to circulating estrogens related to the CYP17 A2 allele.

Adult↗

PubMed1980

The treatment of anoestrus and suboestrus in dairy cattle using a progesterone releasing intravaginal device (PRID) or gonadotrophins.

Dairy cows and heifers which had not shown any detectable oestrus were divided into three treatment groups. Animals with active ovaries (suboestrus) were treated with PRID, whereas those with inactive ovaries (true anoestrus) were treated with either PRID or gonadotrophin injections. When comparing the results of the treatment, the criterion used was the pregnancy (%) achieved within forty days after the commencement of the treatment. Furthermore, the rate of pregnancy after first insemination, the number of inseminations per pregnancy, and the time of conception after treatment, as well as the return interval of the animals not conceiving at first insemination were surveyed.

Anestrus↗

PubMed2002

Factors influencing fertility of Holstein dairy cows: a multivariate description.

Eighty-two multiparous cows of high and low genetic merit were fed one of two isonitrogenous (19.3% crude protein), isoenergetic (11.3 MJ of metabolizable energy) diets that differed in ratio of rumen-undegradable protein to rumen-degradable protein. Factors that influenced reproductive performance were investigated using logistic regression and survival analysis. Significant associations were identified between reproductive performance and indicators associated with nutrient balance. Cows with higher dry matter intake were more likely to show signs of estrus at first ovulation and to become pregnant by d 150 of lactation. Increased ratio of plasma glucose to 3-hydroxybutyrate was associated with a greater probability of estrous expression at first ovulation. Concentrations of plasma cholesterol were positively associated with expression of estrus at first ovulation, interval from calving to conception, and likelihood of conception and pregnancy. Greater concentrations of nonesterified fatty acids in plasma were associated with a lower probability of conception by d 150 of lactation. Increased yield of fat-corrected milk during early lactation was negatively associated with expression of estrus at first ovulation and probability of pregnancy by d 150 of lactation. Cows of high genetic merit were less likely to show signs of estrus at first ovulation. Cows fed the high rumen-degradable-protein diet that also lost more body weight during early lactation were less likely to conceive at first service and to have a prolonged interval from calving to conception. Continued selection for increased production of milk and a more negative nutrient balance during early lactation may reduce reproductive performance particularly for cows fed high concentrations of rumen-degradable protein.

3-Hydroxybutyric Acid↗

PubMed1988

Postpartum weight change: how much of the weight gained in pregnancy will be lost after delivery?

In a large sample (N = 7116) of women who had two pregnancies within six years, the 50th percentile of weight gain between pregnancies was 2 lb (0.9 kg). Weight gain in pregnancy, week of registration, cigarette smoking, race, percent of ideal body weight, complications of pregnancy, and marital status in the first pregnancy, as well as breast-feeding in the hospital and interval between the two pregnancies, correlated significantly with interpregnancy weight change, and explained 24% of the variance (P less than .0001). Weight gain in the first pregnancy alone explained 21% of the variance in weight change between pregnancies. After adjustment for the effects of other variables on weight change, weight gains in pregnancy of 20 lb (9.1 kg) or more were statistically significant (P less than .05); the more weight a woman gained above 20 lb (9.1 kg), the more she retained by the start of her next pregnancy.

Analysis of Variance↗

PubMed1998

Conservative treatment of multiple pregnancies after delivery and a fetal miscarriage: two case reports.

Due to the increased availability of infertility treatment, multiple pregnancies, with various resulting complications, have become more common. Two cases of triplet pregnancies with delayed delivery--interval ranged from 6 to 56 days--are reported. The first woman in the 23rd week of a triplet pregnancy came to the hospital because of premature rupture of membranes of one amniotic sac and had a miscarriage of one of the fetuses the same day. The second woman in the 26th week of a triplet pregnancy also came to the hospital because of bleeding and contractions and had vaginal delivery of the first triplet a few hours later. After confirming that the remaining two fetuses were in good condition, both patients were kept under observation with only antibiotic therapy for the first one and antibiotic and tocolysis for the second. Fifty-six days following admission to our hospital the first woman gave birth to twins while in her 32nd week. The second woman gave birth six days following admission (in her 27th week). The successful outcome of these cases demonstrates that non-intervening conservative methods could be a feasible alternative to invasive intervention. We hope that our cases will encourage more physicians to try out and report non-intervening methods so that enough information can be gathered to help make correct management decisions in the future.

Abortion, Spontaneous↗

PubMed1998

Does child abuse predict adolescent pregnancy?

OBJECTIVE: To determine whether sexual and nonsexual childhood abuse are risk factors for early adolescent sexual activity and pregnancy. DESIGN; Cross-sectional study. SETTING: Prenatal clinic within an inner-city teaching hospital from June 1990 to August 1991. POPULATION: One thousand twenty-six primiparous, African-American women enrolled in a randomized clinical trial of nurse home visitation. MAIN OUTCOME MEASURES: Four measures of child abuse were used: sexual abuse, incidents of physical abuse, any major physical abuse, and emotional abuse. The outcome measures were age of first consensual coitus and age of first pregnancy. RESULTS: After adjustments for household income, parental separation, urban residence, age of menarche, and teen smoking, sexual abuse during childhood was associated with younger age at first coitus (7.2 months; 95% confidence interval [CI], 2.6 to 11.7 months) and younger age at first pregnancy (9.7 months; 95% CI, 3.0 to 16.3 months). Incidents of physical abuse showed minimal effect on age at first coitus (1.2 days per incident; 95% CI, 0.5 to 1.9 days) and no effect on age of first pregnancy. A history of major physical abuse or emotional abuse showed no effect on age of first coitus or first pregnancy. CONCLUSION: Child sexual abuse, but not child physical or emotional abuse, seems to be a risk factor for earlier pregnancy among African-American adolescents.

Adolescent↗

PubMed2003

Obstetric outcome after threatened miscarriage with and without a hematoma on ultrasound.

OBJECTIVE: To examine the effect of threatened miscarriage on second-trimester maternal serum alpha-fetoprotein (MSAFP) levels and pregnancy outcome; and to study the significance of ultrasound evidence of an intrauterine hematoma on pregnancy outcome in these patients. METHODS: A retrospective, case-control study was performed on 144 women presenting with bleeding in the first trimester and 144 age-matched control subjects who attended for routine dating scans during the same time scale. The presence or absence of an intrauterine hematoma, MSAFP, and pregnancy outcomes were recorded. RESULTS: The incidence of adverse pregnancy outcome was significantly (P=.02) higher in women with a history of first-trimester threatened miscarriage than in the control group. The relative risk (RR) of an adverse pregnancy outcome for the study group was 2.22 (95% confidence interval [CI] 1.12, 4.39) compared with the control group. The RR of delivering a baby of less than 1000 g was 4.43 (95% CI 0.5, 39.2) in women with first-trimester threatened miscarriage. This was independent of the presence of an intrauterine hematoma. The RR of MSAFP being raised to more than 2.5 multiples of the median (MoM) in the study group was 6.25 (95% CI 0.77, 50.6). There was no difference between women with threatened miscarriage who had or did not have ultrasound evidence of an intrauterine hematoma. CONCLUSION: Threatened miscarriage in the first trimester is associated with an increased incidence of adverse pregnancy outcome, independently of the presence of an intrauterine hematoma. Higher MSAFP in threatened miscarriage suggests a direct placental injury even in the absence of a hematoma.

Abortion, Threatened↗

PubMed2000

Continued follow-up of pregnancy outcomes in diethylstilbestrol-exposed offspring.

OBJECTIVE: To evaluate long-term pregnancy experiences of women exposed to diethylstilbestrol (DES) in utero compared with unexposed women. METHODS: This study was based on diethylstilbestrol-exposed daughters, the National Collaborative Diethylstylbistrol Adenosis cohort and the Chicago cohort, and their respective nonexposed comparison groups. Subjects who could be traced were sent a detailed questionnaire in 1994 that contained questions on health history, including information on pregnancies and their outcomes. We reviewed 3373 questionnaires from exposed daughters and 1036 questionnaires from unexposed women. RESULTS: The response rate was 88% among exposed and unexposed women. Diethylstilbestrol-exposed women were less likely than unexposed women to have had full-term live births and more likely to have had premature births, spontaneous pregnancy losses, or ectopic pregnancies. Full-term infants were delivered in the first pregnancies of 84.5% of unexposed women compared with 64. 1% of exposed women identified by record review (relative risk [RR] 0.76, confidence interval [CI] 0.72, 0.80). Preterm delivery of first births occurred in 4.1% of unexposed compared with 11.5% of exposed women, and ectopic pregnancies in 0.77% of unexposed compared with 4.2% of exposed women. Spontaneous abortion was reported in 19.2% of DES-exposed women compared with 10.3% in control women (RR 2.00, CI 1.54, 2.60). According to complete pregnancy histories (many women had more than one pregnancy), preterm births were more common in DES-exposed women (19.4% exposed versus 7.5% unexposed (RR 2.93 CI 2.23, 3.86). Second-trimester spontaneous pregnancy losses were more common in DES-exposed women (6.3% versus 1.6%; RR 4.25, CI 2.36, 7.66). More first-trimester spontaneous abortions occurred in DES-exposed women than in controls (RR 1.31, CI 1.13, 1.53), and DES-exposed women had at least one ectopic pregnancy more often than unexposed women (RR 3.84, CI 2.26, 6.54). CONCLUSION: Pregnancy outcomes in DES-exposed women were worse than those in unexposed women.

Abortion, Spontaneous↗

PubMedDate not supplied

Risk factors for febrile seizures in the People's Republic of China: a case control study.

A case control study was conducted to investigate the association of family history of febrile seizures (FS) and history of maternal, pregnancy and delivery, and postnatal factors with FS. Information was gathered by door-to-door survey in six major cities in the People's Republic of China. Factors present before the date of onset of FS were assessed in 182 subjects and in an equal number of controls matched for age, sex, and geographic area. The odds ratio for risk of FS in children with a family history of FS in a first-degree relative was 10.0 (confidence interval 2.7-58.6), confirming other observations that familial factors are an important predisposing characteristic for FS. Maternal acute respiratory infection during the first trimester of pregnancy was slightly more frequent in children with FS (odds ratio, 1.9 confidence interval 1.0-3.9). None of the other examined pregnancy or delivery factors was associated with an increased risk, suggesting that birth history is not an important factor predisposing to FS.

Adolescent↗

PubMed1992

Sirenomelia accompanying exposure of the embryo to cocaine.

We have reported two cases of sirenomelia sequence associated with a history of cocaine exposure during a major part or the entire extent of the first trimester of pregnancy. The two infants were delivered during a 2 1/2-year interval in a newborn population in which prenatal cocaine exposure rose to an estimated 25%. The incidence of sirenomelia in this population was 18-fold higher than previously reported. The potential relationship between sirenomelia and cocaine exposure during the first month of pregnancy warrants further investigation.

Adult↗

PubMed2005

[Analysis of indications in late pregnancy interruption on a two-year material].

Indications for a late pregnancy interruption on a two-year material (2002-2003) were analyzed. In the stated period, there were 101 interruptions of advanced pregnancy in total, out of which 52 occurred in 2002 and 49 in 2003. Out of the total number of interruptions, social indications were the reason in 54 cases, which amounted to 53.46% of the whole material, wherein they amounted to 53.84% in 2002, and in 2003 to 53.06% of indications for late interruption. Average gestational age of patients was X=15 Weeks in 2002, and X=14 Weeks of pregnancy in 2003. Average age of patients in the first year of research was X=29, and in the second year X=28 years of age. Pregnancy interruption was carried out by prostaglandin induction. Average induction-abortion interval was X=9.2 hours for the first group, and X=8.2 hours for the second one. The increased number of social indications for late interruptions in advanced pregnancies is a result of difficult economic conditions of living, and medical ignorance as well.

Abortion, Eugenic↗

PubMed2000

Changing paternity and the risk of preeclampsia/eclampsia in the subsequent pregnancy.

To determine whether changing paternity affects the risk of preeclampsia or eclampsia in the subsequent pregnancy and whether the effect depends on a woman's history of preeclampsia/eclampsia with her previous partner, a cohort study was conducted based on 140,147 women with two consecutive births during 1989-1991 identified through linking of annual California birth certificate data. Among women without preeclampsia/eclampsia in the first birth, changing partners resulted in a 30% increase in the risk of preeclampsia/eclampsia in the subsequent pregnancy compared with those who did not change partners (95% confidence interval: 1.1, 1.6). On the other hand, among women with preeclampsia/eclampsia in the first birth, changing partners resulted in a 30% reduction in the risk of preeclampsia/eclampsia in the subsequent pregnancy (95% confidence interval: 0.4, 1.2). The difference of the effect of changing paternity on the risk of preeclampsia/eclampsia between women with and those without a history of this condition was significant (p < 0.05 for the interaction term). The above estimates were adjusted for potential confounders. These findings suggest that the effect of changing paternity depends on the history of preeclampsia/eclampsia with the previous partner and support the hypothesis that parental human leukocyte antigen sharing may play a role in the etiology of preeclampsia/eclampsia.

Adult↗

PubMed2001

Natural limits of pregnancy testing in relation to the expected menstrual period.

CONTEXT: Pregnancy test kits routinely recommend testing "as early as the first day of the missed period." However, a pregnancy cannot be detected before the blastocyst implants. Due to natural variability in the timing of ovulation, implantation does not necessarily occur before the expected onset of next menses. OBJECTIVE: To estimate the maximum screening sensitivity of pregnancy tests when used on the first day of the expected period, taking into account the natural variability of ovulation and implantation. DESIGN AND SETTING: Community-based prospective cohort study conducted in North Carolina between 1982 and 1986. PARTICIPANTS: Two hundred twenty-one healthy women 21 to 42 years of age who were planning to conceive. MAIN OUTCOME MEASURES: Day of implantation, defined by the serial assay of first morning urine samples using an extremely sensitive immunoradiometric assay for human chorionic gonadotropin (hCG), relative to the first day of the missed period, defined as the day on which women expected their next menses to begin, based on self-reported usual cycle length. RESULTS: Data were available for 136 clinical pregnancies conceived during the study, 14 (10%) of which had not yet implanted by the first day of the missed period. The highest possible screening sensitivity for an hCG-based pregnancy test therefore is estimated to be 90% (95% confidence interval [CI], 84%-94%) on the first day of the missed period. By 1 week after the first day of the missed period, the highest possible screening sensitivity is estimated to be 97% (95% CI, 94%-99%). CONCLUSIONS: In this study, using an extremely sensitive assay for hCG, 10% of clinical pregnancies were undetectable on the first day of missed menses. In practice, an even larger percentage of clinical pregnancies may be undetected by current test kits on this day, given their reported assay properties and other practical limitations.

Adult↗