SEARCH · PubMed Health

Results for “First Pregnancy Intervals”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

PubMed1996

Smoking reduces fecundity: a European multicenter study on infertility and subfecundity. The European Study Group on Infertility and Subfecundity.

Several studies published within the past 10 years indicate that smoking reduces fecundity, but not all studies have found this effect, and smoking cessation is not used routinely in infertility treatment in Europe. The present study was designed to examine male and female smoking at the start of a couple's waiting time to a planned pregnancy. Two types of samples were used: population-based samples of women aged 25-44 years who were randomly selected in different countries from census registers and electoral rolls, in which the unit of analysis was the couple; and pregnancy-based samples of pregnant women (at least 20 weeks' pregnant) who were consecutively recruited during prenatal care visits, in which the unit of analysis was a pregnancy. More than 4,000 couples were included in each sample, and 10 different regions in Europe took part in data collection. The data were collected between August 1991 and February 1993 by personal interview in all population-based samples and in all but three regions of the pregnancy sample, where self-administered questionnaires were used. The results based on the population sample showed a remarkably coherent association between female smoking and subfecundity in each individual country and in all countries together, both with the first pregnancy (odds ratio (OR) = 1.7, 95% confidence interval (CI) 1.3-2.1, at the upper level of exposure) and during the most recent waiting time to pregnancy (OR = 1.6, 95% CI 1.3-2.1). Results based on the pregnancy sample were similar (OR = 1.7, 95% CI 1.3-2.3). No significant association was found with male smoking (in the population sample, OR = 0.9, 95% CI 0.7-1.1 (first pregnancy) and OR = 1.0, 95% CI 0.9-1.3 (most recent waiting time); in the pregnancy sample, OR = 0.9, 95% CI 0.7-1.1). The fecundity distribution among smokers appeared to be shifted toward longer waiting times without a change in the shape of the distribution. Women who have difficulty conceiving should try to stop smoking or to reduce their smoking to less than 10 cigarettes per day.

Adult↗

PubMed1995

[The volumetric changes of uterine myomas in pregnancy].

Thirty-six pregnant women with a single uterine myoma were submitted to US at 2 and 4 weeks' intervals. The first US examination was made in 12 patients before pregnancy and in the other 24 patients between 9 and 12 weeks' gestation. The changes in the volume of myomas were analyzed in different periods of pregnancy. Thirty-four women underwent US in puerperium, four weeks after delivery: the myomas were smaller, possibly back to their initial volume. In 11 patients (31.6%), the myomas grew bigger during pregnancy, particularly during the first trimester. A statistically significant change in volume was observed between the first and the third trimester of pregnancy (p < 0.001). When investigating myoma growth in greater detail in the first trimester, we observed that the greatest increase in myoma volume occurred before the 10th gestational week. Three different categories of myoma volume were considered (p < 100 cc, 100-200 cc, > 200 cc) and related to myoma growth in each period. No relationship was observed between myoma volume and myoma growth.

Female↗

PubMed2002

Nuchal translucency measurements in consecutive normal pregnancies. Is there a predisposition to increased levels?

OBJECTIVE: The current study aims to assess the relative risk of isolated increased nuchal translucency (NT) in consecutive normal pregnancies. METHODS: A retrospective search of the fetal medicine unit database in which NT assessment was conducted. Only singleton fetuses with an unremarkable pregnancy outcome were included in this study. The repeated NT either at a threshold of >2.5 mm or > or =95th centile of the normal range for various CRLs (2 mm at a CRL < or =44 mm to 2.85 mm at CRLs 83-84 mm) was assessed. Pearson's correlation was applied to investigate any correlation between a log(10) NT obtained in two consecutive pregnancies. The chance of an increased NT in the first pregnancy followed by similar results in the subsequent one was assessed using Fisher's exact test. RESULTS: Ninety-two pregnant women with two consecutive normal pregnancies were identified. There was a highly significant correlation between the log(10) NT values measured in the consecutive pregnancies (r = 0.38; p < 0.001). The relative risk of an isolated NT > or =2.5 mm in the first pregnancy to be followed by a similar finding in the subsequent one was 18.21 (95% confidence interval [CI]: 3.62-91.55). The relative risk of an isolated NT > or =95th centile in the first pregnancy to be followed by a similar result in the subsequent one was 21 (95% CI: 4.53-97.44). CONCLUSION: The current results indicate a significant correlation of NT values in consecutive unaffected pregnancies. There also was a predisposition for a repeated isolated increased NT in subsequent pregnancies. Additional series and more information are needed before firm conclusions can be made.

Adult↗

PubMed2004

Effects of abnormal ovarian cycles during pre-service period postpartum on subsequent reproductive performance of high-producing Holstein cows.

The primary objective of this study was to investigate the effects of abnormal ovarian cycles during the pre-service postpartum period on subsequent reproductive performance of high-producing Holstein cows. The study was conducted in a commercial dairy farm with approximately 150 lactating cows, in a subtropical region of Japan. Animals were kept in free-stall barn, and fed a total mixed ration. Cows that calved from June 2001 to July 2002 were included in the study. Milk samples were collected twice weekly from 2 to 11 weeks postpartum, and progesterone concentrations in skim milk were determined by ELISA. After a voluntary waiting period of 40 days, cows detected in estrus were bred by artificial insemination (AI). Pregnancy was confirmed by palpation per rectum 40-70 days after AI. Out of a total of 91 cases, 39 (42.9%) had normal ovarian cycles (ovulation within 45 days after calving, followed by normal ovarian cycles), 32 (35.2%) had prolonged luteal phase (i.e. luteal activity for >20 days), and 12 (13.2%) had anovulation or delayed first ovulation (i.e. first ovulation did not occur until >45 days after calving). The remaining (8.8%) had other types of abnormalities. When compared with cows with a normal ovarian cycle, prolonged luteal phase cows had a lower 100 days AI submission rate, conception rate and pregnancy rate (84.2% versus 56.3%; P<0.05, 50% versus 16.7%; P<0.05 and 42.1% versus 9.4%; P<0.01, respectively), and longer intervals to first AI and to conception ( 67+/-6 days versus 98+/-7 days and 95+/-9 days versus 136+/-11 days; P<0.01 for each). Similarly, when compared with cows with normal ovarian cycles, those with anovulation had lower 100 days conception rate and pregnancy rate (50% versus 0%; P<0.05 and 42.1% versus 0%; P<0.01, respectively), and longer intervals to first AI and to conception ( 67+/-6 days versus 93+/-12 days; P<0.05 and 95+/-9 days versus 155+/-14 days; P<0.01, respectively). Survival analysis of the data for calving to conception interval showed that cows with prolonged luteal phase or anovulation were getting pregnant at a slower rate, and took longer to get pregnant than the cows with normal resumption of ovarian cyclicity postpartum. In conclusion, abnormal ovarian cycles during the pre-service period postpartum adversely affected reproductive performance, including AI submission rate, pregnancy rate, interval to first AI, and calving to conception interval in high-producing Holstein cows.

Animals↗

PubMed2003

The association between lameness, ovarian cysts and fertility in lactating dairy cows.

The objective of this observational study was to evaluate the association between lameness, ovarian cysts, and fertility in lactating dairy cows. Data analysis of historical records from a 3000 Holstein farm was conducted. Sixty-five cows that became lame within 30 days postpartum were used as cases, and 130 nonlame cows served as controls. The outcome variables were incidence of ovarian cysts (OC, %), conception rate at first service (CRFS, %), overall pregnancy rate (PR, %), and calving to first service interval (CFSI, day), Incidence of OC and CRFS were analyzed by logistic regression, PR by survival analysis and CFSI by ANOVA. Lame cows had a lower CRFS (17.5% versus 42.6%) and higher incidence of OC (25.0% versus 11.1%) than controls (P 0.05). There was a multicollinearity relationship between lameness and ovarian cysts. The results show that cows that became lame within the first 30 days postpartum were associated with a higher incidence of ovarian cysts, a lower likelihood of pregnancy, and lower fertility than control cows. Because this is an observational study it is not possible to conclude a cause-effect relationship.

Animals↗

PubMed1999

Outcome of pregnancies occurring within 1 year of hydatidiform mole.

OBJECTIVE: To determine the outcome of subsequent pregnancies in patients with partial or complete molar pregnancy who conceive before completing the recommended hCG follow-up of at least 6 months. METHODS: Retrospective record review of patients with partial or complete mole who conceived before the standard gonadotropin follow-up of 6 months was completed during 1980-1998. RESULTS: Sixty-seven patients with molar pregnancy who conceived before completion of hCG follow-up were identified. Thirty-five (52.2%) patients had a prior partial mole, and 32 (47.8%) had a prior complete mole. The mean interval from first achieving undetectable hCG level to new pregnancy was 3.1 and 3.4 months in patients with partial and complete mole, respectively. Eleven patients underwent elective termination, and 12 were lost to follow-up. Of the remaining 44 patients, 33 (75.0%) had live births, 10 had spontaneous abortions, and one had an ectopic pregnancy. A viable pregnancy outcome was achieved in 20 (83.3%) of 24 patients with partial mole and 13 (65.0%) of 20 patients with complete mole. None of the patients developed any evidence of postmolar persistent gestational trophoblastic tumor. None of the live births had any detectable fetal anomalies. CONCLUSION: The risk of persistent tumor is low and reproductive outcome is favorable once undetectable hCG levels are achieved. Pregnancies occurring before the completion of recommended hCG follow-up may be allowed to continue under careful surveillance.

Adolescent↗

PubMed1995

A prospective study of reproductive factors and risk of epithelial ovarian cancer.

BACKGROUND: Parity and long term use of oral contraceptives have been associated consistently with a decreased risk of ovarian cancer. However, previous reports of the relationship of other reproductive factors (time since first use or last use of oral contraceptives, age at menarche or menopause, age at first birth) with ovarian cancer have been inconsistent. METHODS: The authors studied these relationships in the Nurses' Health Study, a prospective cohort study of 121,700 female registered nurses aged 30-55 years in 1976 when the study began. From 1976 to 1988, 260 cases of confirmed epithelial ovarian cancer occurred among 1.2 million person-years of follow-up. RESULTS: A statistically significant inverse association was observed between parity and ovarian cancer risk (relative risk [RR] = 0.84; 95% confidence interval [CI] = 0.77-0.91 per pregnancy); age at first birth was not associated independently with risk. In age-adjusted analyses, a significant inverse association was noted between long term use of oral contraceptives and ovarian cancer, which was no longer significant after controlling for other ovarian cancer risk factors (RR with > or = 5 years' use: 0.65; 95% CI = 0.40-1.05). After control for duration of use, a weak nonsignificant inverse association was observed with time since first oral contraceptive use and no independent effect of time since last use. Neither age at menarche nor age at menopause was associated significantly with ovarian cancer risk. CONCLUSIONS: In this large prospective study, parity was the only reproductive factor that had a substantial independent association with ovarian cancer. Long term oral contraceptive use also appeared to have an inverse relationship with ovarian cancer, although this association was of borderline significance (P = 0.11) after adjustment for other risk factors.

Age Factors↗

PubMed1990

Metabolic balance and reproductive performance in Finnish dairy cows.

The relationships between energy level and reproductive performance were studied in 24 dairy cows, which were fed grass silage. Serum glucose and blood acetoacetate (AA) and beta-hydroxybutyrate (HB) were measured 10, 15, 30 and 50 days postpartum. The cows were examined clinically by rectal palpation 3 times a week during 8 weeks postpartum. The time required for the complete uterine involution and the onset of ovarian activity were recorded. The pregnancy rate at the first insemination and the interval from calving to conception were obtained for each cow. The correlations between blood glucose and ketone bodies were negative, but they were significant only at days 15 and 30 for AA and at day 30 for HB. A low energy level in early puerperium caused a delay in uterine involution and in the onset of ovarian activity. The low energy balance in puerperium prolonged the interval from calving to the first insemination and the interval from calving to conception. The earlier the ovarian activity started the shorter was the interval from calving to conception. The energy level in early puerperium had a greater influence on the interval from calving to conception, whereas in late puerperium it was more important with regard to the interval from calving to the first insemination. Blood glucose had also a significant effect on the reproductive performance. The adverse influence of ketone bodies on fertility depended on duration and timing of their increased levels; the longer and later in puerperium the cow has elevated ketone bodies, the lower is the fertility.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Nutritional Physiological Phenomena↗

PubMed1995

Time interval from human chorionic gonadotrophin (HCG) injection to follicular rupture.

The aim of this study was to estimate the time interval from human chorionic gonadotrophin (HCG) injection to follicular rupture. Furthermore, it was observed whether there was any effect on the pregnancy rate if the insemination was performed at the time of follicular rupture. In a programme of intrauterine insemination 37 consecutive cycles in 32 patients were monitored after stimulation with clomiphene citrate. HCG was administered by i.m. injection when a leading follicle of at least 18 mm in diameter was observed sonographically. All patients were monitored by sonography with 1 h intervals from 32 h after HCG injection until the first rupture of a follicle. Insemination was performed immediately after the first follicular rupture. The pregnancy rate was 16% (5/32). In 66%, the largest follicle was the first to rupture. The mean time interval from HCG administration to first follicular rupture was 38.3 h (SEM = 0.54; range = 34-46). Our findings support the concept that ovulation occurs about 38 h after HCG administration. The pregnancy rate was within the normal range, although insemination was performed at the time of follicular rupture. The largest follicle was not always the first to rupture.

Adult↗

PubMed1984

Retardation of brain growth of guinea pigs by hyperthermia: effect of varying intervals between successive exposures.

Guinea pigs were exposed to a temperature of 42.5-43.5 degrees C on three occasions between days 20 and 23 of pregnancy. In the first experiment, groups of mothers were exposed at intervals of 18-30 hr. Each exposure ended when the deep rectal temperature had been over 43 degrees C for 6 min and mean temperatures were 43.2-43.4 degrees C. Micrencephaly was found in 78% of heated newborn offspring, the mean brain weights of all groups being significantly less than controls. In the heated groups, the brain weights were reduced significantly as the interval between exposures decreased. Abnormalities other than micrencephaly were found in 10% of heated offspring and included exomphalos, clubfoot, and hypodactyly. In the second experiment, groups of mothers were exposed for 1 hour at intervals of 6-20 hr. The mean temperatures of heated groups were 42.6-42.9 degrees C. The mean brain weights of all groups of heated newborn were significantly reduced and micrencephaly was found in 61% of newborn. Brain weights were reduced significantly as mean maternal temperature increased. There was a significant interaction between the level of temperature elevation and the interval between exposures.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2004

Predicting preschooler obesity at birth: the role of maternal obesity in early pregnancy.

OBJECTIVE: Knowing risk factors at birth for the development of childhood obesity could help to identify children who are in need of early obesity prevention efforts. The objective of this study was to determine whether children whose mothers were obese in early pregnancy were more likely to be obese at 2 to 4 years of age. METHODS: A retrospective cohort study was conducted of 8494 low-income children who were enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in Ohio and were followed from the first trimester of gestation until 24 to 59 months of age. Measured height and weight data from WIC were linked to birth certificate records for children who were born in the years 1992-1996. Obesity among 2- to 4-year-olds was defined as a body mass index (BMI) > or =95th percentile for age and gender. Mothers were classified as obese (BMI > or =30 kg/m2) or nonobese (BMI <30 kg/m2) on the basis of BMI measured in the first trimester of the child's gestation. RESULTS: The prevalence of childhood obesity was 9.5%, 12.5%, and 14.8% at 2, 3, and 4 years of age, respectively, and 30.3% of the children had obese mothers. By 4 years of age, 24.1% of children were obese if their mothers had been obese in the first trimester of pregnancy compared with 9.0% of children whose mothers had been of normal weight (BMI 18.5 and <25 kg/m2). After controlling for the birth weight, birth year, and gender of the children plus the mothers' age, race/ethnicity, education level, marital status, parity, weight gain, and smoking during pregnancy, the relative risk of childhood obesity associated with maternal obesity in the first trimester of pregnancy was 2.0 (95% confidence interval [CI]: 1.7-2.3) at 2 years of age, 2.3 (95% CI: 2.0-2.6) at 3 years of age, and 2.3 (95% CI: 2.0-2.6) at 4 years of age. CONCLUSION: Among low-income children, maternal obesity in early pregnancy more than doubles the risk of obesity at 2 to 4 years of age. In developing strategies to prevent obesity in preschoolers, special attention should be given to newborns with obese mothers.

Body Mass Index↗

PubMed2003

Dieting behaviors and risk of neural tube defects.

The authors examined whether maternal dieting behaviors were associated with increased neural tube defect (NTD) risk among offspring, using population-based, case-control data. The analysis included 538 cases and 539 nonmalformed controls delivered from 1989 to 1991 in selected California counties, and exposures were assessed by in-person maternal interview. Among four reported dieting behaviors involving restricted food intake, diets to lose weight (odds ratio=2.1, 95% confidence interval: 1.1, 4.1), fasting diets (odds ratio=5.8, 95% confidence interval: 1.7, 20.0), and eating disorders (odds ratio=1.7, 95% confidence interval: 0.8, 3.6) were associated with increased NTD risk during the first trimester of pregnancy. Risk estimates for these behaviors during the 3 months before conception tended to be closer to 1. The fourth behavior, "other special diets," was not associated with increased NTD risk during either period. Women also reported whether they took diet pills, laxatives, or diuretics, engaged in binge eating, induced vomiting, or exercised excessively from the first 3 months before conception through the end of pregnancy. Only the intake of diuretics was associated with substantially increased NTD risk (odds ratio=2.7, 95% confidence interval: 0.7, 10.2). This study suggests that maternal dieting behaviors involving restricted food intake during the first trimester may be associated with increased NTD risk.

California↗

PubMed1989

Multivitamin/folic acid supplementation in early pregnancy reduces the prevalence of neural tube defects.

We examined the relation of multivitamin intake in general, and folic acid in particular, to the risk of neural tube defects in a cohort of 23,491 women undergoing maternal serum alpha-fetoprotein screening or amniocentesis around 16 weeks of gestation. Complete questionnaires and subsequent pregnancy outcome information was obtained in 22,776 pregnancies, 49 of which ended in a neural tube defect. The prevalence of neural tube defect was 3.5 per 1000 among women who never used multivitamins before or after conception or who used multivitamins before conception only. The prevalence of neural tube defects for women who used folic acid-containing multivitamins during the first 6 weeks of pregnancy was substantially lower--0.9 per 1000 (prevalence ratio, 0.27; 95% confidence interval, 0.12 to 0.59 compared with never users). For women who used multivitamins without folic acid during the first 6 weeks of pregnancy and women who used multivitamins containing folic acid beginning after 7 or more weeks of pregnancy, the prevalences were similar to that of the nonusers and the prevalence ratios were close to 1.0.

Adult↗

PubMed2001

Reproductive performance of postpartum dairy cows under a highly intervenient breeding program involving timed insemination and combinations of GnRH, prostaglandin F2alpha and human chorionic gonadotropin.

Lactating Holstein cows (n=288) were grouped as pairs at parturition and randomly assigned to two treatments (control, C vs intervenient treatment, T). The reproductive management of the Group C cows (n=130) consisted of the intramuscular administration of 500 microg PGF2alpha analogue (PG) on Days 28 and 63 postpartum and breeding on the basis of estrus signs with the a.m.-p.m. rule after Day 63. Cows that were not bred by 77 d postpartum received another injection of PG and were bred at estrus or 84 h after PG treatment. Pregnancy diagnoses were perfomed by palpation of the uterus per rectum 42 to 48 d after AI. Cows in the T group (n=139) received intramuscular injections of 100 microg GnRH 14 d and PG 28 d after calving. On Day 56 postpartum, cows were given a second dose of GnRH followed by PG on Day 63 postpartum and a third GnRH injection 48 h after PG (OvSynch). Cows were inseminated at a fixed time (22+/-1 h) after GnRH. Five days after the fixed-time insemination cows were given 1500 IU hCG i.m.. Group C and T cows that returned to service or were diagnosed as non-pregnant continued to receive PG at intervals of 14 d with breeding at estrus or 84 h after the second PGF2alpha dose. A sustained increase in milk progesterone concentration was observed in 59.0% of T cows after GnRH administration on Day 14. A similar rise in milk progesterone concentrations was observed in 53.8% of C cows. The PG on Day 28 induced luteolysis more in Group T cows (53.2%) than in Group C cows (36.9%). The PG on Day 63 reduced milk progesterone concentrations to basal levels in 50.7% of T and 49.2% of Group C animals. The first service pregnancy rates (T, 40.3% vs C, 36.2%) and the overall pregnancy rates (all services, T, 83.5% vs C, 86.9%) were not different between the two groups. The two treatments did not differ in the interval from first service to pregnancy, calving to pregnancy or in calving interval, number of services per pregnancy or culling rates.

Animals↗

PubMed1999

Delayed interval delivery in multiple pregnancies. Is optimism justified?

OBJECTIVE: Evaluation of the success of delayed interval delivery in multiple pregnancies. METHOD: Retrospective analyses of all multiple pregnancies with the birth of one child at a gestational age of 16-31 weeks (n=80). Three groups were defined: group I, unsuccessful attempt to temporize delivery, group II, interval between the first child and the other child or children 3 hours or more, with delivery of the remaining children before 28 weeks and group III, prolongation of pregnancy beyond 28 weeks. RESULTS: In 15 multiple pregnancies (ten sets of twins, five sets of triplets), the aim was to postpone the delivery of the second (and third) child. The mean gestational age at admittance was 25 weeks. Delay of the delivery of the second child was achieved in ten cases, five in group II and five in group III. In groups II and III, the mean interval of delivery was 12 days; the gestational age at the delivery of the remaining children in these ten patients was 27 5/7 weeks. No relation could be found between the reason for admittance and the interval in delivery between the first and the other children. The only severe maternal complication was blood loss exceeding 2 liters. In the neonatal outcome of first and second children (with a gestational age of 28 weeks or more) no striking differences were observed. CONCLUSION: Delayed delivery in multiple pregnancies after the birth of the first child is only successful in a minority of patients and should be considered prior to the birth of the first child.

Birth Intervals↗

PubMed2001

Does the increased risk of preterm delivery in teenagers persist in pregnancies after the teenage period?

OBJECTIVE: To study the associations between low maternal age at first birth and the risks of very and moderately preterm birth, in first birth and in second successive birth in adulthood. DESIGN: Population-based cohort study. SETTING: Sweden. POPULATION Women aged less than 25 years at first birth (n = 275,933), having two successive live single births from 1973 through 1993. METHODS: Odds ratios with 95 percent confidence intervals were calculated to estimate the effect of low maternal age at first birth. Analyses of first births were adjusted for year of first birth and maternal education and in second births also for previous pregnancy outcomes and interpregnancy interval. MAIN OUTCOME MEASURES: Very preterm birth (less than 33 completed weeks) and moderately preterm birth (33-36 completed weeks). RESULTS: Compared with women aged 20 to 24 years at first birth, mothers aged 13 to 15 years were at increased risk of very preterm birth (odds ratio = 4.8). The corresponding risks among women aged 16 to 17 years at first birth were doubled (odds ratio = 2.3). The influence of maternal age on risks of moderately preterm birth was similar, although the age-related risks were lower. At second birth, risks of preterm birth were reduced in all age groups. However, mothers who were 17 years or less at first birth, faced, compared with mothers aged 20-24 years, significantly larger reduction in risks of very and moderately preterm birth. CONCLUSIONS: Our results suggest that there may be a biological effect of very young maternal age, affecting foremost very preterm birth.

Adolescent↗

PubMed2002

The interval between pregnancies and the risk of preeclampsia.

BACKGROUND: The risk of preeclampsia is generally lower in second pregnancies than in first pregnancies, but not if the mother has a new partner for the second pregnancy. One explanation is that the risk is reduced with repeated maternal exposure and adaptation to specific antigens from the same partner. However, the difference in risk might instead be explained by the interval between births. A longer interbirth interval may be associated with both a change of partner and a higher risk of preeclampsia. METHODS: We used data from the Medical Birth Registry of Norway, a population-based registry that includes births that occurred between 1967 and 1998. We studied 551,478 women who had two or more singleton deliveries and 209,423 women who had three or more singleton deliveries. RESULTS: Preeclampsia occurred during 3.9 percent of first pregnancies, 1.7 percent of second pregnancies, and 1.8 percent of third pregnancies when the woman had the same partner. The risk in a second or third pregnancy was directly related to the time that had elapsed since the preceding delivery, and when the interbirth interval was 10 years or more, the risk approximated that among nulliparous women. After adjustment for the presence or absence of a change of partner, maternal age, and year of delivery, the odds ratio for preeclampsia for each one-year increase in the interbirth interval was 1.12 (95 percent confidence interval, 1.11 to 1.13). In unadjusted analyses, a pregnancy involving a new partner was associated with higher risk of preeclampsia, but after adjustment for the interbirth interval, the risk of preeclampsia was reduced (odds ratio for preeclampsia with a change of partner, 0.73; 95 percent confidence interval, 0.66 to 0.81). CONCLUSIONS: The protective effect of previous pregnancy against preeclampsia is transient. After adjustment for the interval between births, a change of partner is not associated with an increased risk of preeclampsia.

Female↗

PubMed2000

Relationships between fatty liver and fertility and some periparturient diseases in commercial Dutch dairy herds.

Declining fertility in dairy cows is frequently suggested to arise from the occurrence of a more negative energy balance and/or the concomitant increased accumulation of triacylglycerol in the liver. Therefore, we performed a field study to assess the clinical effects of postpartum fatty liver in dairy cows on fertility and reproductive disease. Data were collected from 360 cows from nine dairy herds on fertility, diseases, and the liver triacylglycerol content on two occasions during lactation: 6 to 17 days and 38 to 50 days postpartum. The mean concentration of triacylglycerol in the liver was 54.6 mg/g from 6 to 17 days and 38.4 mg/g from 38 to 50 days postpartum. The probability of pregnancy was 30% lower for cows with higher contents of triacylglycerol in the liver compared to the probability for cows with low liver triacylglycerol (P = 0.049). The probability of estrus was also 35% lower for the cows with high triacylglycerol in the liver. This resulted in larger intervals between parturition and first heat and parturition and pregnancy for these cows. There was no effect observed on the first insemination conception rate. Given a certain level of triacylglycerol, recorded milk production had a positive effect on time to pregnancy. The incidences of endometritis, lochiometra and cystic ovarian follicles were not higher in cows with higher liver triacylglycerol contents. Endometritis was associated with a lower first insemination conception rate and more days open (chi2 = 4.26, P = 0.03 and T-test = -2.02, P= 0.04 respectively). We concluded that our results support the idea that differences in the negative energy balance or the accumulation of triacylglycerol in the liver of postpartum dairy cows affect fertility performance. The data also indicate that an increase in milk production has no negative impact on fertility as long as the amount of triacylglycerol in the liver remains the same.

Animals↗