Previous Fertilization Research Articles

Hereditary haemochromatosis in a man of Pakistani descent

A 35-year-old Pakistani man, resident in the UK, was referred to his local hospital because of general malaise, weight loss and mildly deranged liver function tests. His medical history included a recent diagnosis of insulin-dependent diabetes mellitus, and previous investigations for testicular atrophy and azoospermia. He drank no alcohol. Clinical examination was unremarkable. Specifically, there were no cutaneous stigmata of chronic liver disease, and abdominal palpation was unremarkable with no hepatosplenomegaly. Blood tests showed deranged liver enzymes: ALT was 92 U/l (normal range <40 U/l), alkaline phosphatase was 155 U/l (normal range <125 U/l). Serum albumin was normal at 39 g/l, bilirubin normal at 8 μmol/l. Subsequent serological testing for hepatitis B, hepatitis C and autoimmune liver disease was all negative, but his serum ferritin was grossly elevated at 3985 μg/l (normal range 30–365 μg/l) and his iron transferrin saturation was 89% (20–50%). Liver ultrasound scanning was normal but liver biopsy revealed severe (Grade 4) liver cell siderosis with the appearances of haemochromatosis with extensive fibrosis (Figure 1). Figure 1. Liver biopsy: ( A ) hematoxylin and eosin staining showing iron (staining brown) within hepatocytes and fibrosis. ( B ) Perls staining showing severe liver cell siderosis. There is striking blue staining of granular iron deposits within hepatocytes, outlining the bile canaliculi. In view of the new diagnosis of haemochromatosis and his previous fertility problems, his pituitary function was assessed. He had normal …

Effect of previous crop fertilization with nitrogen and seed treatments with Co and Mo on the morphological characteristics of soybean

This three-year study examines the effect of previous crop fertilization with nitrogen and seed treatment with micronutrients cobalt and molybdenum on the morphological characteristics of soybean. Data were processed using analysis of variance by two factorial split-plot experiment with influence of year, where examination factors were: year, different doses of nitrogen fertiliser (main plot) and seed treatment (subplot). Significance of differences between treatments was tested by LSD test. Examined morphological characteristics were significantly dependent upon the year, which had a statistically significant effect. Other examined factors and interactions were not significant, except for the interaction of year x fertilization x seed treatment (AxBxC) that was statistically significant for plant height up to the first fertile node.

The influence of the family network on the realisation of fertility intentions

The gap between fertility intentions and behaviour remains a contentious area of theoretical, methodological and policy debate. Previous fertility studies have focused on individual and institutional characteristics, at the expense of the recognition of meso-level family social capital and networks. This study examines the realisation of time-dependent fertility intentions for the transition to first and higher-order births. Building upon and extending the previous literature we explore two competing theoretical mechanisms of how high levels of family social capital operate to either enable or inhibit the realisation of intentions and the impact of cross-sibling effects. Using two waves of the Netherlands Kinship Panel Survey (NKPS), we also introduce a methodological extension by examining whether the inclusion of only those with positive fertility intentions in previous research has resulted in selection bias. By adopting a probit model with sample selection, we both avoid this selection problem and empirically test whether there is a bias. Results show that there are some, albeit negligible, unobserved characteristics affecting both an individual’s fertility intentions and the realisation of these intentions. High levels of family social capital operate to deter from having a child, particularly when individuals already have at least one child, suggesting that individuals adopt a ‘satisficing’ strategy. Our findings also suggest that children may operate as a means to generate family social capital. Having a sibling with a young child is associated with a higher probability to realise one’s own intention to have a first child.

Celebrating 150 Years of Analyzing Fertility Trends in Germany

Ever since the very beginning of the Journal of Economics and Statistics, population economics has featured prominently in the Journal. Fertility naturally plays an important role in population economics. Its size has decreased significantly from the 1900s. Long time-series regarding fertility and basic trends in Germany are documented and analyzed. We identify three different explanatory approaches for the decline in fertility, according to which the various articles of the Journal related to this area are categorized. The paper also investigates previous fertility studies published by the Journal since the beginning. It points out that several articles anticipated subsequent research directions in the area of population economics at an early stage. In addition, significant contributions were made in terms of further developing existing knowledge. Thus, the Journal has helped to expand the research area of population economics.

The experience of young women diagnosed with breast cancer who undergo fertility preservation (FP) consultation.

249 Background: In recent years FP has been a growing concern for young women diagnosed with breast cancer. ASCO has recommended that such women be referred to a reproductive specialist as early as possible before beginning systemic adjuvant therapy. Aim: To gather information about young breast cancer patients’ experiences with FP referral, consultation, and decision making. Methods: Anonymous questionnaires were mailed to consecutive breast cancer patients referred January 2005 through January 2010 from our center to the CReATe clinic in Toronto. Topics included information about demographics, cancer stage and treatment, previous fertility problems, referral source and timing, options presented and chosen, and satisfaction with the referral, consultation and decision making processes. Results: Of the 50 women identified 26 (52%) participated. Average age of respondents was 31 (range 24-41). 17 (65%) were married or in a long-term relationship, and 9 (35%) already had 1 child. Seven (27%) were referred before surgery, 16 (62%) after surgery but before systemic therapy, 2 (8%) after starting hormone therapy, and 1 after completing chemotherapy. Only 54% opted for FP. Of the 17 (66%) who reported plans to start/add to their family prior to diagnosis of breast cancer, 53% proceeded with FP and of the 9 who did not have plans to start/add to their family 5 (55%) pursued FP. 41% had difficulty with decision making and 50% found cost to be a significant barrier. A common theme among respondents was inadequate time for decision making. Several complained about the lack of written material before and/or after their consultation. 85% felt that access to a psychosocial counselor would have been beneficial to the decision making process. 57% were satisfied or extremely satisfied overall. Conclusions: (1) If appropriate, FP referral should be initiated by the surgeon as soon as a diagnosis of invasive cancer is made. Obtaining receptor and HER2 status on core biopsy samples may identify women who will require systemic therapy and may benefit from early FP referral. (2) Women need written materials before and after FP consultation. (3) There is a major role for a FP counselor who is able to spend additional time helping with decision making.

Pregnancy Outcome in Women Following Splenectomy

To investigate pregnancy outcome of patients following splenectomy. A retrospective study comparing pregnancies of women who have and have not undergone splenectomy was performed. The study investigated a select population representing the south of Israel. Women lacking antenatal care as well as those having multiple gestations were excluded from the analysis. Stratified analysis, using a multiple logistic regression model, was performed to control for confounders. During the study period, there were 219,656 deliveries, of which 150 occurred in women who underwent splenectomy. Postsplenectomy women tended to be older, were more likely to be Jewish, and had a lower number of deliveries and an earlier gestational age at delivery. Higher rates of fertility treatment, previous cesarean delivery, and severe preeclampsia were found among postsplenectomy women. In addition, splenectomy was significantly associated with pregnancy and labor complications, such as cesarean delivery, pneumonia during pregnancy, and complications of anesthesia and sedation during labor. Using a multivariate analysis with backward elimination, the following conditions were independently associated with splenectomy: previous cesarean delivery (odds ratio [OR] 1.5, 95% confidence interval [CI] 1.1-2.3, p=0.039), fertility treatment (OR 2.6, 95% CI 1.3-5.4, p=0.008), preterm delivery (OR 1.9, 95% CI 1.3-3.1, p=0.003), and maternal age (OR 1.04, 95% CI 1.015-1.07, p=0.002). After controlling for possible confounders by using another multivariate analysis with preterm delivery as the outcome variable, splenectomy was found to be an independent risk factor for preterm delivery (OR 2.1, 95% CI 1.4-3.3, p=0.001). Splenectomy is an independent risk factor for preterm delivery.

Measuring the Impacts of Malawi's Farm Input Subsidy Program

We measure the impacts of Malawi’s 2009 Farm Input Subsidy Program (FISP) on fertilizer use and maize yields in central and southern Malawi. Using three rounds of panel data and instrumental variables regression strategies to control for endogenous selection into the subsidy program we find positive and statistically significant correlations between participation in the FISP and fertilizer use intensity. Fertilizer use is found to be higher among households that plant improved maize varieties than among those that plant traditional varieties. Results are broadly robust to the inclusion of previous fertilizer intensity to control for household-specific differences in fertilizer use. We combine these results with those from a maize production function to calculate program-generated changes in average maize availability, accounting for estimated subsidy-induced changes in crop area. Our findings have implications for the way input subsidy programs are designed and implemented.

The experience of young women diagnosed with breast cancer who undergo fertility preservation (FP) consultation.

e19708 Background: In recent years FP has been a growing concern for young women diagnosed with breast cancer. ASCO has recommended that such women be referred to a reproductive specialist as early as possible before beginning systemic adjuvant therapy. Aim: To gather information about young breast cancer patients’ experiences with FP referral, consultation, and decision-making. Methods: Anonymous questionnaires were mailed to consecutive breast cancer patients referred Jan 2005 - Jan 2010 from our centre to the CReATe clinic in Toronto. Topics included information about demographics, cancer stage and treatment, previous fertility problems, referral source and timing, options presented and chosen, and satisfaction with the referral, consultation and decision making processes. Results: Of the 50 women identified 26(52%) participated. Average age of respondents was 31 (range 24-41). 17 (65%) were married or in a long-term relationship, and 9 (35%) already had 1 child. Seven (27%) were referred before surgery, 16 (62%) after surgery but before systemic therapy, 2 (8%) after starting hormone therapy, and 1 after completing chemotherapy. Only 54% opted for FP. Of the 17 (66%) who reported plans to start/add to their family prior to diagnosis of breast cancer, 53% proceeded with FP and of the 9 who did not have plans to start/add to their family 5 (55%) pursued FP. 41% had difficulty with decision-making and 50% found cost to be a significant barrier. A common theme among respondents was inadequate time for decision-making. Several complained about the lack of written material before and/or after their consultation. 85% felt that access to a psychosocial counselor would have been beneficial to the decision making process. 57% were satisfied or extremely satisfied overall. Conclusions: 1) If appropriate, FP referral should be initiated by the surgeon as soon as a diagnosis of invasive cancer is made. Obtaining receptor and HER2 status on core biopsy samples may identify women who will require systemic therapy and may benefit from early FP referral. 2) Women need written materials before and after FP consultation. 3) There is a major role for a FP counselor who is able to spend additional time helping with decision-making.

Recovery of Nitrogen (15N) by Sugarcane from Previous Crop Residues and Urea Fertilisation Under a Minimum Tillage System

Residues of green-harvested sugarcane contribute to nutrient recycling in production systems. Therefore, better understanding of trash decomposition dynamics can help crop fertilisation management. This study was conducted during the 2006–2008 seasons in Jaboticabal, north-eastern Sao Paulo State, Brazil and aimed to evaluate the nitrogen recovery rates from the previous crop residues or from urea applied on sugarcane planting in a minimum tillage system, thus without trash and rhizome incorporation in crop renewal. Previous crop residues consisted of 9 and 3 t/ha of sugarcane trash (dry tops + leaves) and root system (roots + rhizomes) enriched with 1.07 and 0.81% 15N isotope, respectively. These contributed 51 and 33 kg/ha of N. 15N labelled trash laid on the soil surface and buried 15N-root system attempted to simulate the original field residues disposal. The SP81-3250 variety was planted with 80 kg N/ha of a 5.17% 15N-labelled urea. Recovery of sugarcane residues-N (trash-N and root system-N) or urea-N incorporated to the soil at planting were evaluated in distinct plant parts (stem, tops and dry leaves) during three consecutive harvest seasons. Recovery of urea-N was higher in the first harvest season (31% of initial N rate) and its uptake decreased in the second and third to 5 and 4%, respectively. In later harvested seasons, urea-N had probably been turned-over as soil organic matter and/or microbial biomass but remained in the soil N pool and available for plant recovery. Trash-N uptake closely resembled urea-N uptake, and only 13% of its N content was recovered in the first year, followed by 7 and 3% in the second and third seasons. Root system-N recovery was different since the second cut uptake was higher than the first followed by the third, 9, 6 and 2% respectively. Three year cumulative recovery of urea-N, trash-N and root system-N was 39, 23 and 17%, respectively. Most recovered N was found in stems followed by tops and dry leaves.

Investigating the effect of previous treatments on wheat biomass over multiple spatial frequencies

Abstract. In this study we use the maximum overlap discrete packet transform (MODWPT) to investigate residual effects on wheat biomass of fertigation treatments applied to a previous crop. The wheat crop covered nine subplots from a previous experiment on melon response to fertigation. Each subplot had previously received a different level of applied nitrogen. Many factors affect wheat biomass, causing it to vary at different spatial frequencies. We hypothesize that these will include residual effects from fertilizer application (at relatively low spatial frequencies) and the local influence of individual plants from the previous melon crop (at high frequency). To test this hypothesis we use the MODWPT to identify the dominant spatial frequencies of wheat biomass variation, and analyse the relationship to both the previous fertilizer application and the location of individual melon plants in the previous crop. The MODWPT is particularly appropriate for this because it allows us first to identify the key spatial frequencies in the wheat biomass objectively and to analyse them, and their relationship to hypothesized driving factors without any assumptions of uniformity (stationarity) of wheat-biomass variation. The results showed that the applied nitrogen dominated the wheat biomass response, and that there was a noticeable component of wheat-biomass variation at the spatial frequency that corresponds to the melon cropping. We expected wheat biomass to be negatively correlated with the position of melons in the previous crop, due to uptake of the applied nitrogen. The MODWPT, which allows us to detect changes in correlation between variables at different frequencies, showed that such a relationship was found across part of the experiment but not uniformly.

Predisposition to repeat breeding in UK cattle and success of artificial insemination alone or in combination with embryo transfer

To investigate whether there was a subpopulation of repeat breeders (cows or heifers that returned to oestrus after three inseminations) that were less fertile after a fourth artificial insemination (AI)...

Single and twin ongoing pregnancies in two cases of previous ART failure after ICSI performed with sperm sorted using annexin V microbeads

To treat couples with intracytoplasmic sperm injection (ICSI) after annexin V sperm sorting. Two case reports. Department of Reproductive Medicine at a private medical institute. Couples on infertility treatment, donor oocytes. Sperm sorted with annexin V magnetic microbeads before ICSI, day 3 embryo transfer; case 1: ovum donation; case 2: patient oocytes. 1) Sperm DNA fragmentation (terminal deoxynucleotide transferase-mediated dUTP nick-end labeling [TUNEL]) and active caspase-3 (immunocytochemistry); 2) fertilization rate, embryonic quality, blastocyst development of nontransferred embryos, and pregnancy outcome after ICSI of sorted sperm. Case 1: Premature ovarian failure patient with previous fertilization failures: asthenoteratozoospermia, abnormal DNA fragmentation (TUNEL 30%; normal <20%). ICSI with annexin V-treated sperm done on six donated metaphase II (MII) oocytes; four fertilized, and a 5-cell/grade-2 and a 6-cell/grade-2-3 embryo were transfered. A day 5 blastocyst was cryopreserved. The patient was in the last trimester of gestation. Case 2: Couple with >4 years of primary infertility and recent ICSI failure. Semen with teratozoospermia (5% normal forms [Kruger]) and abnormal active caspase-3 (16%; normal <11%). ICSI with annexin V-treated sperm done on 9 MII oocytes. All fertilized; a 7-cell/grade-1 and an 8-cell/grade-1-2 embryo were transferred. A day 5 expanded blastocyst was cryopreserved. The patient was in the second trimester of a twin normal pregnancy. Sperm sorting with annexin V columns was effective in the treatment of two cases of ICSI failure, resulting in a single and a twin pregnancy after transfer of two embryos in each case.

Microsurgical Reversal of Sterilisation – Is This Still Clinically Relevant Today?

Women with previous tubal sterilisation seeking fertility are faced with treatment options of reconstructive tubal surgery or in vitro fertilisation (IVF) techniques. The aim was to assess the current viability of tubal anastomosis in a local clinical practice. A retrospective cohort review of all sterilisation reversal cases from January 1998 to January 2008. The main outcome measures included fi rst pregnancy success and live birth after surgery. Subsequent live births, ectopic pregnancies, miscarriages, duration of surgery and hospitalisation within the study period were also reported. We included cases aged less than 40 years, without any known semen abnormalities, and performed by only one operator. Cases with only unilateral reversal were excluded. Nineteen cases with previous Filshie clip ligation (9 laparoscopic/10 open) were reviewed. Cumulative pregnancy rates with surgery were 47.4% (<6 months), 57.9% (6 to 12 months), 68.4% (12 to 48 months) and 73.7% (>48 months). Pregnancy (77.8% vs 70.0%) and live birth rates (66.7% vs 60.0%) were similar between laparoscopy and open surgery. The mean interval to pregnancy was marginally lower via laparoscopy (11.3 vs 13.6 months). Hospitalisation stay was significantly halved (1.43 vs 3.00 days) but ectopic pregnancies were increased 3-fold (3 vs 1) with laparoscopy. Compared with IVF, the estimated average cost per delivery for laparoscopic reversal was reduced for laparoscopic reversal with no multiple pregnancies. Our results favour surgical reversal after sterilisation for patients younger than 40 years old. It avoids hyperstimulation risks and the economic burdens associated with multiple pregnancies. Where expertise is available, laparoscopic reversal should be performed.

Removing Phosphorus from Ecosystems Through Nitrogen Fertilization and Cutting with Removal of Biomass

High amounts of phosphorus (P) are in soil of former farmland due to previous fertilizer additions. Draining these residues would provide conditions for grassland plant species diversity restoration amongst other ecosystem benefits. Nitrogen (N) fertilization followed by cutting with subsequent removal of biomass has been suggested as a P residue removal method. We present a general model of N and P ecosystem cycling with nutrients coupled in plant biomass. We incorporate major P pools and biological and physico-chemical fluxes around the system together with transfers into and out of the system given several decades of management. We investigate conditions where N addition and cutting accelerate fertilizer P draining. Cutting does not generally accelerate soil P depletion under short-term management because the benefits of biomass removal through decreased P mineralization occur on too long a timescale compared to cutting’s impact on the ability of plants to deplete nutrients. Short-term N fertilization lowers soil fertilizer P residues, provided plant growth remains N limited. In such situations, N fertilization without biomass removal increases soil organic P. Some scenarios show significant reductions in available P following N addition, but many situations record only marginal decreases in problematic soil P pools compared to the unfertilized state. We provide explicit conditions open to experimental testing. Cutting might have minimal adverse impacts, but will take time to be successful. N fertilization either alone or in combination with cutting is more likely to bring about desired reductions in P availability thus allowing grassland restoration, but might have undesired ecosystem consequences.

Baseline acceptance of twins before fertility treatment: what do patients and their husbands think?

OBJECTIVE: To evaluate patient acceptance of the possibility of twinning before beginning ovulation induction therapy.DESIGN: Prospective questionnaire study.MATERIALS AND METHODS: Patient demographic information and data on previous fertility treatment, including number of prior pregnancies and living children, personal or family history of multiple gestation, and interval since last fertility therapy, was collected from couples seeking fertility treatment at a single urban referral centre (n=86). A five point scale measured husband & wife perception about twins where 1=undesirable and 5=favourable.RESULTS: Mean(±SD) female age was 35.5±4.7 and husband age was 37.2±5.3yrs. In this sample, 41.9% (n=36) had achieved pregnancy but only 19.8% had living children. 41.9% (n=36) of patients reported a family history of multiple gestation. Mean duration of infertility was 2.8±3.0yrs; 25.5% had already undergone IVF and 63.6% of these patients had ≥2 prior IVFs. Almost all study patients (96.5%) understood that fertility treatments can increase the risk of multiple gestation. Husbands were more likely than wives to report “indifference” to twins (24 vs. 15%), but this difference was not statistically significant (p=0.09). 55% of husbands reported that they were “very excited” about the possibility of twins following fertility treatment, compared to 64% of female patients (p=0.14). No female regarded twins as “undesirable”, while one husband in the sample did.CONCLUSIONS: Most patients are familiar with the known association between multiple gestation and ovulation induction, but women and men have different perceptions about twinning even before fertility treatment begins. Our pilot data quantifies the variance and underscores the role of pre-treatment counselling. OBJECTIVE: To evaluate patient acceptance of the possibility of twinning before beginning ovulation induction therapy. DESIGN: Prospective questionnaire study. MATERIALS AND METHODS: Patient demographic information and data on previous fertility treatment, including number of prior pregnancies and living children, personal or family history of multiple gestation, and interval since last fertility therapy, was collected from couples seeking fertility treatment at a single urban referral centre (n=86). A five point scale measured husband & wife perception about twins where 1=undesirable and 5=favourable. RESULTS: Mean(±SD) female age was 35.5±4.7 and husband age was 37.2±5.3yrs. In this sample, 41.9% (n=36) had achieved pregnancy but only 19.8% had living children. 41.9% (n=36) of patients reported a family history of multiple gestation. Mean duration of infertility was 2.8±3.0yrs; 25.5% had already undergone IVF and 63.6% of these patients had ≥2 prior IVFs. Almost all study patients (96.5%) understood that fertility treatments can increase the risk of multiple gestation. Husbands were more likely than wives to report “indifference” to twins (24 vs. 15%), but this difference was not statistically significant (p=0.09). 55% of husbands reported that they were “very excited” about the possibility of twins following fertility treatment, compared to 64% of female patients (p=0.14). No female regarded twins as “undesirable”, while one husband in the sample did. CONCLUSIONS: Most patients are familiar with the known association between multiple gestation and ovulation induction, but women and men have different perceptions about twinning even before fertility treatment begins. Our pilot data quantifies the variance and underscores the role of pre-treatment counselling.

Repartnering in the United Kingdom and Australia

As a result of a rise in divorce rates coupled with an increased prevalence of cohabitation, a growing percentage of the population has experienced or will experience the breakdown of a relationship and also the possibility of forming another new relationship. This paper explores the impact of previous relationship and fertility histories on repartnering. Using a longitudinal approach we compare the nature of repartnering behaviour in the United Kingdom and Australia, countries with similar policy and legislative frameworks. Using prospective panels surveys (British Household Panel Survey and the Household, Income and Labour Dynamic in Australia), we find that within five years of becoming single, an estimated 49 per cent of the United Kingdom sample and 43 per cent of the Australian sample had entered a new relationship, most commonly cohabitation. Event history analysis reveals strong repartnering patterns by age, and residency of children. The effect of previous relationship type suggests that people who have previously cohabited are more likely to repartner that those who did not.

Delivery rate using cryopreserved oocytes is comparable to conventional in vitro fertilization using fresh oocytes: potential fertility preservation for female cancer patients

To explore the use of oocyte cryopreservation as a fertility-conserving option. Cancer treatments administered during the reproductive and adolescent years can result in sterility. Previous fertility preservation efforts focused on embryo rather than oocyte storage because the latter was deemed inefficient. Recently, several large reports of healthy births resulting from the transfer of embryos derived from frozen/thawed oocytes have been published. We sought to establish an oocyte cryopreservation program at our center. Twenty-three oocyte cryopreservation cycles were performed. Collected oocytes were cryopreserved by either the slow or the vitrification method. Approximately 1-4 months later, a programmed cycle of thawing/warming, fertilization with intracytoplasmic sperm injection, and ET was performed; cycle and pregnancy outcomes were assessed. University-based fertility center. Twenty-two infertile women. Oocyte cryopreservation. Oocyte survival, embryo development, pregnancy outcomes. Oocyte survival, 2-pronuclei fertilization, and blastocyst formation rates were 92%, 79%, and 43%, respectively. Fourteen women became pregnant; one miscarried; 10 have delivered 13 viable infants, and three pregnancies are ongoing for an ongoing/delivered pregnancy rate of 57%. This result was not statistically different from cycles performed consecutively in age-matched controls using fresh, nonfrozen autologous or donor oocytes during a similar time period. Oocyte cryopreservation appears to be a viable option for fertility preservation in some centers.

Rust severity in bioenergy willow plantations treated with additional nutrients

SummaryA 3‐year field study was carried out to determine the effect of wastewater irrigation and previous differences in mineral fertilization on the occurrence of willow leaf rust (Melampsora epitea). The experiment was conducted in two energy forest plantations: one designed for wastewater purification and the other as a mineral fertilization experiment. The severity of leaf rust on different clones and sites with different treatments was assessed by counting the number of uredinia per leaf unit area. Generally, plants irrigated with wastewater consistently had more leaf rust, irrespective of the study years or willow clones. Previous mineral fertilization had mixed effects on different clones 2 years after the last application. Three years after the last fertilizer application, however, no impact of the treatment on rust disease development was detected. In general, the rust levels differed from year to year probably due to climate. In this study, no correlation was detected between shoot age and rust severity, whereas climate and treatments strongly influenced leaf rust levels on some willow clones.

Residual effect and nitrate leaching in grass‐arable rotations: effect of grassland proportion, sward type and fertilizer history

AbstractA key point in designing grass‐arable rotations is to find the right balance between the number of cultivations and the length of the grass phase. In a field experiment, we investigated the effect of cropping history (grazed unfertilized grass–clover and fertilized [300 kg N per hectare] ryegrass, proportion of grassland and previous fertilizer use) on crop growth and nitrate leaching for 2 years following grassland cultivation. In the final year, the effect of perennial ryegrass as a catch crop was investigated. The nitrogen fertilizer replacement value (NFRV) of grassland cultivation was higher at 132 kg N per hectare in the rotation with 75% grassland compared with on average 111 kg N per hectare in rotations with 25 and 38% grassland and the NFRV of ryegrass in the rotation was higher than that of grass–clover. Nitrate leaching following cultivation was not affected by the proportion of grassland in the crop rotation or sward type. However, there was a considerable effect of having a ryegrass catch crop following the final barley crop as nitrate leaching was reduced from 60 to 9 kg N per hectare. When summarizing results from the crop rotations over a longer period (1997–2005), management strategy adopted in both the grassland and arable phases appeared to be the primary instrument in avoiding nutrient losses from mixed crop rotations, irrespective of grass proportion. In the arable phase, the huge potential of catch crops has been demonstrated, but it is also important to realize that all parts of the grass‐arable crop rotations must be considered potentially leaky.

Effect of infertility, maternal age, and number of previous miscarriages on the outcome of preimplantation genetic diagnosis for idiopathic recurrent pregnancy loss

To determine whether preimplantation genetic diagnosis (PGD) would decrease spontaneous abortion rates in patients with idiopathic recurrent pregnancy loss (RPL). Controlled clinical study. IVF center and PGD reference laboratory. Patients with RPL with no known etiology. Preimplantation genetic diagnosis by fluorescence in situ hybridization analyzing nine chromosomes. The spontaneous abortion rate after PGD was compared to the patients' own expected risk of abortion. Patients were evaluated according to the number of previous losses, fertility, and maternal age. Preimplantation genetic diagnosis significantly reduced spontaneous abortions in patients with RPL, especially for patients with more than two previous losses (12.8% vs. 35.9% expected). The PGD significantly reduced the rate of spontaneous abortion in both fertile (15.2% vs. 33.8% expected) and infertile patients (13.0% vs. 29.5%), which also achieved similar delivery rates (37% and 34%, respectively). The beneficial effect of PGD was less pronounced in patients <35 years than in patients > or =35 years old (13.6% vs. 34.0% expected). Overall, the PGD reduced the miscarriage rate to a similar baseline of 14%-16% across all maternal ages. Preimplantation genetic diagnosis improves pregnancy outcome for women with idiopathic RPL, especially those with more than two previous losses, and >35 years of age, and that improvement is not affected by fertility status.