R. Storeng

Obesity is a risk factor for early pregnancy loss after IVF or ICSI

Background. Experience with polycystic ovary syndrome shows that insulin resistance is related to early pregnancy loss. This association was examined by comparing pregnancy outcome in obese and lean women.

Impact of Insulin Resistance on Pregnancy Complications and Outcome in Women with Polycystic Ovary Syndrome

The aim of the study was to determine the risk of developing gestational diabetes mellitus (GDM) and pregnancy-induced hypertension (PIH)/pre-eclampsia in a cohort of pregnant women with the polycystic ovary syndrome (PCOS) and known insulin sensitivity status. Pregnancies and neonatal outcome were recorded in a prospective cohort study comprising 29 non-insulin-resistant PCOS women, 23 insulin-resistant PCOS women and a control group of 355 women who had conceived after assisted reproduction. Hypertension, pre-eclampsia and GDM were recorded as well as pregnancy duration, method of delivery and birth weight. The frequency of hypertension was significantly elevated in PCOS women (11.5%) compared to controls (0.3%), p < 0.01. However, the frequency of pre-eclampsia was significantly elevated only in the insulin resistant PCOS women (13.5%) compared to controls (7.0%), p < 0.02. GDM was significantly more frequent in PCOS women (7.7%) than controls (0.6%), p < 0.01. Insulin resistance prior to pregnancy, determined by continuous infusion of glucose with model assessment (CIGMA) test, did not further increase the frequency of GDM. Newborns from PCOS pregnancies were significantly more often delivered by Caesarean section than controls (40.3 vs. 27.3%, p < 0.05) and transferred to neonatal intensive care unit more often than controls (19.2 vs. 9.0%, p < 0.01). Thus we show that the frequencies of pre-eclampsia and GDM are increased in PCOS pregnancies.

The effect of metformin on ovarian stimulation and in vitro fertilization in insulin-resistant women with polycystic ovary syndrome: an open-label randomized cross-over trial

Metformin effectively restores insulin sensitivity in insulin-resistant women with polycystic ovary syndrome (PCOS). We examined whether metformin ,given prior to and during ovarian stimulation for in vitro fertilization (IVF) ,altered follicle stimulating hormone (FSH) requirement and increased the number of collected oocytes in these women. Seventeen insulin-resistant women with PCOS were recruited to our IVF unit to receive two consecutive cycles of ovarian stimulation with or without metformin co-treatment ,the order of treatments being randomized using a table of random numbers. Metformin treatment (1500 mg/day) started 3 weeks before downregulation with buserelin acetate and was continued throughout ovarian stimulation with human recombinant FSH. Nine women completed both cycles ,the results of eight women being excluded because of pregnancy after the first cycle (n = 4) or because the protocol of the study was not followed (n = 4). Mean total FSH dose was 2301 IU (range 1500-6563 IU) in metformin cycles and 2174 IU (range 1200-3900 IU) in parallel control cycles ,while the mean number of collected oocytes was 8.6 (range 2-28) and 4.6 (range 1-16) ,respectively. Bayesian analysis showed probabilities of 0.05 that metformin reduces FSH requirement by at least 10% ,and of 0.61 that at least 10% more oocytes are collected after metformin co-treatment. Co-administration of metformin is therefore likely to increase the number of oocytes collected after ovarian stimulation in insulin-resistant women with PCOS but is unlikely to reduce the requirement for FSH.

Impaired insulin action on granulosa-lutein cells in women with polycystic ovary syndrome and insulin resistance

We studied the in vitro response to insulin of granulosalutein cells derived from patients with polycystic ovary syndrome (PCOS) and clinically defined insulin resistance. Insulin sensitivity was assessed by continuous infusion of glucose with model assessment test (CIGMA). Insulin resistant (PCOS-IR; n = 8), non-insulin resistant (PCOS-NIR; n = 9) patients with PCOS, and women with tubal factor infertility (TF; n = 8) underwent controlled ovarian stimulation with long-term gonadotropin-releasing hormone (GnRH) agonist, recombinant follicle stimulating hormone (FSH), and in vitro fertilization. Primary cultures of granulosa-lutein cells were incubated with insulin (10, 100, 500 ng/ml) and/or luteinzing hormone (LH) (10, 100 ng/ml) in the presence of low density lipoprotein (100 μg/ml). The progesterone and lactate accumulation were measured in the culture medium. LH potently stimulated the progesterone secretion in all groups. Insulin alone had no effect on progesterone release in any of the groups, but stimulated lactate formation in the PCOS-NIR and TF groups. Insulin augmented the effect of LH on progesterone secretion selectively in the PCOS-NIR group. The expression of the insulin receptor was determined by Western blotting in separate cultures of granulosa-lutein cells, and showed receptor down-regulation in the PCOS-IR patients. We infer that the in vitro effect of insulin on progesterone and lactate release by granulosa-lutein cells is impaired in insulin resistant PCOS patients.

Effect of nickel chloride and cadmium acetate on the development of preimplantation mouse embryos in vitro

Preimplantation mouse embryos were used to investigate the toxic effect of nickel chloride and cadmium acetate on early embryo development in vitro. Embryos at the 2- and 4-8 cell stage were cultured in approximately 0.05 ml of mouse embryo culture medium (No. 16), overlaid with paraffin oil and incubated in a humidified atmosphere of 5% CO2 in air for 48 h. NiCl2 . 6H2O was added to the culture medium at concentrations of 10-1000 microM, Cd(CH3COO)2 . 2H2O at concentrations of 10-50 microM. Morphological criteria were used to check embryonic development. Ten micromolars of nickel chloride affected adversely the development of Day 2 embryos (2-cell stage), whereas 300 microM was needed to affect Day 3 embryos (8-cell stage). Toxic effect of cadmium acetate on Day 2 embryos was observed at a concentration of 10 microM.

Nickel toxicity in early embryogenesis in mice

The development of mouse embryos was studied after intraperitoneal injection of nickel chloride in the preimplantation period. A single intraperitoneal injection of NiCl2 . 6H2O in 0.154 M NaCl corresponding to 20 mg/kg body wt was given to groups of female mice on days 1, 2, 3, 4, 5 or 6 of gestation. Control groups were injected with 0.154 M NaCl. Caesarean section was performed on day 19 of gestation and the following parameters were recorded: implantation frequency, frequency of early and late resorptions, frequency of liver normal fetuses, abnormal fetuses and stillborns, and the weight of each fetus. The implantation frequency of females treated with nickel chloride on the first day of gestation was significantly lower than that of the controls. The size of the litters in the control groups was larger than that of the nickel treated dams, significant difference being observed on days 1, 3 and 5. NiCl2 . 6H2O injection also resulted in diminished body weights of fetuses on day 19 of gestation. The groups of nickel treated mice had a larger frequency of both early and late resorptions and the frequency of stillborn and abnormal fetuses exceeded that of the control groups. This study shows that, by the procedure used, nickel chloride may influence mouse embryos during the passage through the oviduct with subsequent effect on the development after implantation.U

Risk of Cancer in Children Conceived by Assisted Reproductive Technology.

BACKGROUND AND OBJECTIVE: An increasing number of children are born after assisted reproductive technology (ART), and monitoring their long-term health effects is of interest. This study compares cancer risk in children conceived by ART to that in children conceived without. METHODS: The Medical Birth Registry of Norway contains individual information on all children born in Norway (including information of ART conceptions). All children born between 1984 and 2011 constituted the study cohort, and cancer data were obtained from the Cancer Registry of Norway. Follow-up started at date of birth and ended on the date of the first cancer diagnosis, death, emigration, or December 31, 2011. A Cox proportional hazards model was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) of overall cancer risk between children conceived by ART and those not. Cancer risk was also assessed separately for all childhood cancer types. RESULTS: The study cohort comprised 1 628 658 children, of which 25 782 were conceived by ART. Of the total 4554 cancers, 51 occurred in ART-conceived children. Risk of overall cancer was not significantly elevated (HR 1.21; 95% CI 0.90–1.63). However, increased risk of leukemia was observed for children conceived by ART compared with those who were not (HR 1.67; 95% CI 1.02–2.73). Elevated risk of Hodgkins lymphoma was also found for ART-conceived children (HR 3.63; 95% CI 1.12–11.72), although this was based on small numbers. CONCLUSIONS: This population-based cohort study found elevated risks of leukemia and Hodgkins lymphoma in children conceived by ART.

Risk of breast cancer following fertility treatment – A registry based cohort study of parous women in Norway

Despite increasing numbers of women availing themselves of assisted reproductive technology (ART), effects on cancer risk remain unresolved. Given hormonal exposures, breast cancer risk is of particular concern. The aim of this study is to investigate breast cancer risk amongst women giving birth following ART as compared to that amongst women who gave birth without ART. Data on all women who gave birth in Norway with or without ART, between 1984 and 2010 were obtained from the Medical Birth Registry of Norway (MBRN). 808,834 women eligible for study were linked to the Cancer Registry of Norway. Cox proportional models computed hazard ratios (HR) and 95% confidence intervals (CI) of breast cancer between the two groups, adjusting for age, parity, age at first birth, calendar period and region of residence. In total, 8,037 women were diagnosed with breast cancer during the study period, 138 ART women and 7,899 unexposed. Total follow‐up time was 12,401,121 person‐years (median 16.0); median age at entry was 32.5 years (range18.6–49.9) for ART women and 26.3 (range 10.5–54.6) for unexposed. Women exposed to ART had an elevated risk of breast cancer (adjusted HR 1.20, 95% CI 1.01–1.42). Subgroup analyses gave an HR of 1.30 (95% CI 1.07–1.57) for women treated with IVF and 1.35 (95 % CI 1.07–1.71) for women with follow‐up >10 years, compared with controls. Our findings of increased risk in the study population warrant continued monitoring of women treated with ART as this population advances into more typical cancer age ranges.

Clinical Outcome of Day 2 Versus Day 3 Embryo Transfer Using Serum-Free Culture Media: A Prospective Randomized Study

Purpose:The objective was to evaluate whether extending the embryo culture period from 2 to 3 days would yield a more optimal selection of viable embryos, thereby increasing the implantation and live birth rates.Methods:Patients undergoing in vitro fertilization with at least one oocyte fertilized were prospectively randomized to 2 or 3 days of embryo culture in serum-free media. On the basis of their morphology and cleavage rate, a maximum of three embryos was selected for transfer.Results:Embryos transferred on day 2 or day 3 were similar morphologically, however, a higher proportion of retarded embryos was observed on day 3. The implantation rate was 15.8 and 14.3% for day 2 and day 3 transfers, respectively. The increase in live birth rate from 18.5 to 22.6%, possibly suggesting a better embryo selection on day 3, was not statistically significant.Conclusions:Extending the embryo culture period from 2 to 3 days had no effect on implantation and live birth rates.

Cancer risk among parous women following assisted reproductive technology

STUDY QUESTION Do women who give birth after assisted reproductive technology (ART) have an increased risk of cancer compared with women who give birth without ART? SUMMARY ANSWER Without correction, the results indicate an increase in overall cancer risk, as well as a 50% increase in risk of CNS cancer for women giving birth after ART, however the results were not significant after correcting for multiple analyses. WHAT IS KNOWN ALREADY Studies regarding the effects of hormonal treatments involved with ART on subsequent cancer risk have provided inconsistent results, and it has also been suggested that infertility itself could be a contributory factor. STUDY DESIGN, SIZE, DURATION A population-based cohort consisting of all women registered in the Medical Birth Registry of Norway as having given birth between 1 January 1984 and 31 December 2010 was assembled (n = 812 986). Cancers were identified by linkage to the Cancer Registry of Norway. Study subjects were followed from start of first pregnancy during the observational period until the first cancer, death, emigration, or 31 December 2010. PARTICIPANTS/MATERIALS, SETTING, METHODS Of the total study population (n = 806 248), 16 525 gave birth to a child following ART. Cox regression analysis computed hazard ratios (HR) and 95% confidence intervals (CI) comparing cancer risk between ART women and non-ART women; for overall cancer, and for cervical, ovarian, uterine, central nervous system (CNS), colorectal and thyroid cancers, and for malignant melanoma. MAIN RESULTS AND THE ROLE OF CHANCE A total of 22 282 cohort members were diagnosed with cancer, of which 338 were ART women and 21 944 non-ART women. The results showed an elevated risk in one out of seven sites for ART women. The HR for cancer of the CNS was 1.50 (95% CI 1.03– 2.18), and among those specifically subjected to IVF (without ICSI) the HR was 1.83 (95% CI 1.22–2.73). Analysis of risk of overall cancer gave an HR of 1.16 (95% CI 1.04–1.29). Among those who had delivered only one child by the end of follow-up, the HR for ovarian cancer was 2.00 (95% CI 1.08–3.65), and for those nulliparous at entry the HR was 1.80 (95% CI 1.04–3.11). However, all findings became non-significant after correcting for multiple analyses. LIMITATIONS, REASONS FOR CAUTION The results of elevated risk of overall cancer and CNS cancer lost significance when adjusting for multiple analyses, implying an important limitation of the study. The follow-up time was relatively short, especially for ART women. In addition, as the cohort was relatively young, there were few incident cancers, especially for some rarer cancer forms, such as uterine cancer. Risk assessments according to different causes of infertility could not be done. WIDER IMPLICATIONS OF THE FINDINGS In light of the findings in the present study, further studies should be made on risk of CNS and ovarian cancer, and continued monitoring of all those treated with ART is encouraged. Our findings may only be generalizable to women who give birth after ART, and the risk for women who remain nulliparous after ART remains to be assessed. STUDY FUNDING/COMPETING INTEREST The study was funded by the Norwegian National Advisory Unit on Womens Health. All authors claim no competing interests.