Metabolic syndrome and time to pregnancy: a retrospective study of nulliparous women

OBJECTIVE

To determine: (1) the association between metabolic syndrome (MetS), time to pregnancy (TTP), and infertility; (2) associations between individual and an increasing number of MetS components, TTP, and infertility; and (3) whether these relationships differ by body mass index (BMI < 30 kg/m² versus BMI ≥ 30 kg/m² ).

DESIGN

Retrospective cohort study.

SETTING

Multiple centres (in Australia, Ireland, New Zealand, and the UK).

POPULATION

Five thousand five hundred and nineteen low-risk nulliparous pregnant women.

METHODS

Data on retrospectively reported TTP (number of months to conceive) and a blood sample to assess metabolic health were collected between 14 and 16 weeks of gestation. MetS was defined according to the International Diabetes Federation criteria. Accelerated failure time models with log-normal distribution were conducted to estimate time ratios (TRs) and 95% CIs. Differences in MetS on infertility (TTP > 12 months) were compared using a generalised linear model (Poisson distribution) with robust variance estimates (relative risks, RRs; 95% CIs). All analyses (entire cohort and split by BMI) were controlled for a range of maternal and paternal confounding factors.

MAIN OUTCOME MEASURES

Time to pregnancy and infertility.

RESULTS

Of the 5519 women included, 12.4% (n = 684) had MetS. Compared with women without MetS, women with MetS had a longer TTP (adjusted TR 1.30; 95% CI 1.15-1.46), which was similar in women who were obese and in women who were not obese. Marginal estimates for median TTP in women with MetS versus without MetS was 3.1 months (3.0-3.3 months) versus 4.1 months (3.6-4.5 months), respectively. Women with MetS were at a 62% greater risk for infertility and were at a greater risk for infertility whether they were obese (adjusted RR 1.62; 95% CI 1.15-2.29) or not (adjusted RR 1.73; 95% CI 1.33-2.23). Reduced high-density lipoprotein cholesterol (HDL-C) and raised triglycerides (TGs) were the main individual components associated with risk for infertility.

CONCLUSION

Metabolic syndrome is associated with longer TTP and infertility, independent of obesity. Additional studies, before pregnancy, are required to support our findings and to determine the applicability of which combinations of metabolic abnormalities pose the greatest risk to delayed fertility, or whether individual components are amenable to modification.

TWEETABLE ABSTRACT

Metabolic syndrome is associated with longer time to pregnancy and infertility, independent of obesity.

A novel embryo culture media supplement that improves pregnancy rates in mice

The preimplantation embryoinvivois exposed to numerous growth factors in the female reproductive tract, which are not recapitulated in embryo culture mediain vitro. The IGF2 and plasminogen activator systems facilitate blastocyst development. We hypothesized that the addition of IGF2 in combination with urokinase plasminogen activator (uPA) and plasminogen could improve rates of blastocyst hatching and implantation in mice. B6BcF1 and CBAB6F2 mouse embryos were divided into one of four supplemented culture media treatment groups: (1) control (media only); (2) 12.5 nM IGF2; (3) 10 µg/mL uPA and 5 µg/mL plasminogen; or (4) a combination of IGF2, uPA and plasminogen treatments. Embryo development to blastocyst stage and hatching were assessed before transfer to pseudopregnant recipient females and implantation, pregnancy rates and postnatal growth were assessed. After 90.5 h of culture, IGF2 + U + P treatment increased the percentage of B6BcF1 embryos that were hatching/hatched and percentage developing to blastocyst stage compared with controls (P < 0.02). Following B6BcF1 embryo transfer, IGF2 + U + P treatment increased implantation sites at day 8 of pregnancy compared with controls (P < 0.05). Replication in the CBAB6F2 mouse strain showed significant improvements in pregnancy rates at days 8 and 18 but not in blastocyst development. No adverse effects were seen on gestational age, litter size or birthweight, or the reproductive capacity of offspring of IGF2 + U + P treated embryos. For embryos susceptible to detrimental effects ofin vitroculture, IGF2, uPA and plasminogen supplementation of culture media can improve pregnancy success, but the effect of treatment is dependent on the mouse strain.

Betamethasone-exposed preterm birth does not impair insulin action in adult sheep

Preterm birth is associated with increased risk of type 2 diabetes (T2D) in adulthood; however, the underlying mechanisms are poorly understood. We therefore investigated the effect of preterm birth at ~0.9 of term after antenatal maternal betamethasone on insulin sensitivity, secretion and key determinants in adulthood, in a clinically relevant animal model. Glucose tolerance and insulin secretion (intravenous glucose tolerance test) and whole-body insulin sensitivity (hyperinsulinaemic euglycaemic clamp) were measured and tissue collected in young adult sheep (14 months old) after epostane-induced preterm (9M, 7F) or term delivery (11M, 6F). Glucose tolerance and disposition, insulin secretion, β-cell mass and insulin sensitivity did not differ between term and preterm sheep. Hepatic PRKAG2 expression was greater in preterm than in term males (P = 0.028), but did not differ between preterm and term females. In skeletal muscle, SLC2A4 (P = 0.019), PRKAA2 (P = 0.021) and PRKAG2 (P = 0.049) expression was greater in preterm than in term overall and in males, while INSR (P = 0.047) and AKT2 (P = 0.043) expression was greater in preterm than in term males only. Hepatic PRKAG2 expression correlated positively with whole-body insulin sensitivity in males only. Thus, preterm birth at 0.9 of term after betamethasone does not impair insulin sensitivity or secretion in adult sheep, and has sex-specific effects on gene expression of the insulin signalling pathway. Hence, the increased risk of T2D in preterm humans may be due to factors that initiate preterm delivery or in early neonatal exposures, rather than preterm birth per se.

IFPA meeting 2015 workshop report I: placental mitochondrial function, transport systems and epigenetics

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2015 there were twelve themed workshops, three of which are summarized in this report. These workshops covered areas of placental regulation and nutrient handling: 1) placental epigenetics; 2) placental mitochondrial function; 3) placental transport systems.

166. MATERNAL OBESITY IS ASSOCIATED WITH AN INCREASED INCIDENCE OF PROSTATE ABNORMALITIES IN ADULT RAT OFFSPRING

The World Health Organization has stated that 75% of adults worldwide are overweight, and in Australia nearly 25% of men are obese. Obesity is associated with an increased risk of cardiovascular disease, type 2 diabetes and cancer, with 30 to 40% of the latter possibly preventable by maintaining a healthy weight (The International Association for the Study of Obesity). Prostate cancer is the most commonly diagnosed cancer in men and there is increasing evidence that obesity increases the risk of prostate cancer mortality. High birth weight, an indication of excess nutrition during foetal development, has been associated with an increased risk of childhood and adult obesity, and for cancer. Using an animal model, we investigated whether obese mothers are more likely to have obese sons who are at an increased risk of developing prostate abnormalities and thus prostate cancer, in adulthood. Female rats were fed with either a control diet (4g fat/kg) or high fat diet (100g fat/kg) from before mating and throughout pregnancy. Prostate tissues were collected from the male offspring at 90 days (post-puberty) and 180 days (young adult). Histological analysis of the day 90 prostates identified hyperplasia in 100% of the ventral lobes (VL) and 64% of the dorsolateral lobes (DLP) in offspring of the maternal high fat group compared to 0% in each respectively, in those of the maternal control diet group. The VL is the most hormone sensitive prostate lobe of the rat, while the DLP is considered the equivalent of the human peripheral zone, the region from which the majority of human prostate cancers arise. These results suggest for the first time that maternal high fat diet may induce prostate abnormalities in male offspring that may in turn, predispose to an increased risk of prostate cancer in later life.