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Previous research suggests that normal term birth depends on programmed development of the uterus in early pregnancy. A short cervix in mid-pregnancy is associated with an increased risk of spontaneous preterm birth. The present study tested the hypothesis that a long cervix in mid-pregnancy is associated with a higher risk of cesarean delivery during term labor. The study population included 27,472 primiparous women whose cervical length was 16 mm or more at a median gestational age of 23 weeks, and who delivered a live infant in labor at term. Cervical length was estimated by transvaginal ultrasonography. The rate of cesarean delivery at term was lowest (16%) in women whose mid-pregnancy cervical length was in the lowest quartile (16-30 mm). The rate was progressively greater in the second quartile (18%, 31-35 mm), third quartile (22%, 36-39 mm), and fourth quartile (26%, 40-67 mm). Compared with women in the first quartile, the odds ratio (OR) for cesarean delivery in women in the fourth quartile was 1.8 (95% confidence interval [CI], 1.66-1.97). The OR was 1.68 (95% CI, 1.53-1.84) after adjusting for numerous variables including maternal age, body mass index, smoking status, race or ethnic group, gestational age at birth, spontaneous or induced labor, and birth weight percentile. The association with cervical length was slightly stronger when the outcome was limited to operative delivery mandated by the failure of labor to progress. An increased cervical length during mid-pregnancy appears to independently predict the risk of cesarean delivery during labor at term in primiparous women. This finding suggests that poor progress during labor in women who deliver at term may reflect dysfunctional development of the uterus at earlier stages of pregnancy.

Nutrient intake during pregnancy affects foetal development and placental function in a range of species, often with long-term effects on offspring viability. Maternal nutrient supply is believed to affect the ability of the placenta to deliver nutrients to the foetus (Fowden et al., 2006). In ruminant species, the majority of placental nutrient transport occurs in specialised structures called placentomes, which are categorised into 4 types (A-D) based on their morphological appearance. In type A placentomes, maternal tissue surrounds foetal tissues, whereas type D placentomes are typically everted and have a higher ratio of foetal:maternal tissue. It has been suggested that the distribution of placentome types may reflect the ability of the placenta to deliver nutrients (Vonnahme et al., 2006). This study tested the hypothesis that levels of under-nutrition typically encountered by hill ewes during pregnancy would alter the distribution of placentome types and that the relationship between ewe nutrition and placentome type would differ between breeds selected for lean tissue growth (such as the Suffolk) compared to less selected breeds (such as the Scottish Blackface).

The purpose of this study was to investigate maternal plasma concentrations of asymmetric dimethylarginine (ADMA) in mid pregnancy and at the time of disease in women who experience preeclampsia, compared with women with uncomplicated pregnancies and women with small-for-gestational-age infants.Plasma samples were collected at mid-pregnancy and at the time of delivery from 31 women with uncomplicated pregnancies, from 12 women with small-for-gestational-age infants, and from 15 women with preeclampsia. ADMA and L-arginine concentrations were measured using high-pressure liquid chromatography.Maternal ADMA concentrations were elevated at mid pregnancy and remained elevated at delivery in women who later experienced preeclampsia (0.45 +/- 0.09 micromol/L) compared with women with uncomplicated pregnancies (0.34 +/- 0.08 micromol/L; P.01) and with women with small-for-gestational-age infants (0.33 +/- 0.06 micromol/L; P.01).Maternal ADMA concentrations are higher in mid pregnancy in women who experience preeclampsia, compared with women with uncomplicated pregnancies and small-for-gestational-age infants. Elevated ADMA concentration before clinical onset of preeclampsia suggests a role of this nitric oxide synthase inhibitor in the pathophysiologic condition of preeclampsia.

This experiment was conducted to determine the effect of two different feeding levels on ewes during mid and late pregnancy on lamb birthweight and growth to weaning. Twin- and triplet-bearing Romney ewes (n = 80 and 56, respectively) were allocated to one of two feeding regimes and provided pastures with an average sward height of less than 2 cm (~700 kg dry matter/ha) or greater than 4 cm (~1300 kg dry matter/ha). Ewes were allocated to these feeding regimes during mid pregnancy (day 70–107 of pregnancy; P70–P107) and were reallocated in late pregnancy (P108–P147). This resulted in four sward height treatments: 2–2, 2–4, 4–2 and 4–4. During mid pregnancy, ewes provided with >4-cm-high swards had liveweight gains of 262–290 g/day compared with 12–31 g/day for ewes provided with 4-cm-high swards (2–4 and 4–4). On P139, however, ewes provided with 4–4 swards had higher plasma non-esterified fatty acid and β-hydroxybutyrate concentrations than ewes in all other treatments. Lambs born to ewes in the 4–4 treatment had the greatest birthweights (P < 0.05), whereas lambs born to 2–2 ewes had the lowest birthweights. The birthweight of lambs born to 2–4 ewes was similar to that of lambs born to ewes provided with 4–2 and 4–4 swards. At weaning, ewe weights were similar between ewe nutritional treatments and ewes bearing twin or triplet fetuses. These findings suggest that when pasture growth is inadequate to provide pasture sward heights of 4 cm throughout pregnancy, restricted intake in mid-pregnancy may be partially compensated by providing additional pasture in late pregnancy.

In several field studies, mid-pregnancy shearing has increased lamb birthweight, which may be associated with an increase in lamb survival. However, animal numbers have been too low in these studies to accurately examine any effects on survival rates to weaning. This study was designed to investigate the effect of mid-pregnancy shearing on the birthweight of multiple-born lambs and their survival rates to weaning under commercial farming conditions at 2 different sites. At Riverside, 657 twin- and 47 triplet-bearing ewes were either shorn at mid-pregnancy (n = 347) or left unshorn (n = 357). Similarly, at Tuapaka, 532 twin-, and 60 triplet-bearing ewes were either shorn at mid-pregnancy (n = 291) or left unshorn (n = 301). Mid-pregnancy shearing significantly (P

Icon (R) is a water miscible type II synthetic pyrethroid insecticide based on active ingredient lambda cyhalothrin (10% w/v). It was recently introduced to Sri Lanka as an indoor spray against malaria vector mosquitoes. The aim of this study was to ascertain the potential effects of Icon (R) on pregnancy outcome of rats when exposed during mid pregnancy (days 8 -14). Icon (R) was orally administered daily during this period in three different doses: 63, 83, 125 mg/kg body wt./day of Icon (R) (active ingredient; lambda cyhalothrin ; 6.3, 8.3, 12.5 mg/kg/day) respectively. Several parameters of reproduction, pre- and post-natal development were monitored. The results demonstrated that Icon (R) is detrimental to pregnancy outcome (in terms of number of uterine implants, number of viable implants, post implantation loss, number of pups born, litter index, and foetal survival ratio) but induced no changes in gestational length, gross morphological birth abnormalities or detectable pre- and post- natal developmental impairments. The anti-reproductive effects of Icon (R) were mediated by multiple mechanisms (hypophagia, maternal toxicity, stress, uterine myotropic activity, embryofoetoxicity, anti-progestrogenic activity, inhibition of decidualizaton process, abortifacient activity and vaginal bleeding) leading to enhancement of postimplantation losses. It is concluded that exposure to Icon (R) during mid gestation poses a considerable threat to pregnancy of rats.

Pregnancy shearing has been shown to increase lamb birthweights. However, results have been variable between studies. It has been suggested that the birthweight response to pregnancy shearing is greatest in conditions in which the unshorn dam gives birth to lambs of low birthweight. This study was designed to examine the birthweight response under 2 differing maternal treatments (one designed to restrict fetal growth and the other designed not to limit fetal growth), with the aim of explaining the variation observed in pregnancy shearing studies. Mixed aged Romney cross ewes were either shorn during mid pregnancy (n = 55) or left unshorn (n = 50). At shearing, ewes were split into either a ‘maintenance’ group (64 kg at shearing and fed to permit total ewe liveweight gain equivalent to expected conceptus growth during mid- to late-pregnancy) (n = 52) or a ‘low’ group (54 kg at shearing and fed to permit total ewe liveweight to increase at half the expected conceptus growth during mid- to late-pregnancy) (n = 53), respectively. Mid-pregnancy shearing was found to increase the birthweights of singletons (5.6 v. 4.9 kg, P < 0.05) but not twins, and of lambs born to maintenance group ewes (by 0.6 kg, P < 0.05), but not low group ewes. Additionally, mid-pregnancy shearing had no effect on the thermoregulatory capacity of twin-born lambs. When the results of this study are considered with those of previous New Zealand pregnancy shearing studies, they suggest that there are 2 criteria (and not one, as previously suggested) that must be met to achieve a response to pregnancy shearing. Firstly, the dam must have the potential to respond [i.e. have been destined to give birth to an otherwise lightweight lamb(s)], and secondly, the ewe must have the means to respond (i.e. an adequate level of maternal reserves and/or level of nutrition to partition towards additional fetal growth).

The impact of maternal feed restriction during pregnancy on components of the maternal body and feto-placental growth was investigated to assess its influence on lamb birth weight. Single-bearing ewes were well-fed for the duration of pregnancy or feed restricted between the 30th and 96th, 50th and 96th or 75th and 96th day of pregnancy. Well-fed ewes increased in liveweight between the 30th and 96th day of pregnancy (48 g/day), while ewes feed restricted between the 30th and 96th, 50th and 96th and 75th and 96th day of pregnancy lost 55, 87 and 203 g/day respectively. Maternal fat deposits and muscle tissue of feed restricted ewes at the 96th day of pregnancy were less than for well-fed ewes. Placental weight was lower (P < 0.05) in ewes feed restricted between the 30th and 96th day of pregnancy, but not in ewes feed restricted between the 50th and 96th or the 75th and 96th day of pregnancy. Re-feeding ewes at the 96th day of pregnancy following feed restriction between the 30th and 96th day of pregnancy was associated with muscle tissue deposition during late pregnancy, while well-fed ewes depleted both fat deposits and muscle tissue during lat pregnancy. Lamb birthweight was not significantly affected by feed restriction during mid-pregnancy, despite various rates of depletion and repletion of maternal body reserves, and different patterns of placental growth.

Lamb birth weight and ewe gestation length data were collected from a flock of 300-600 parous Border Leicester x Merino ewes over 4 years, as part of a study on nutritional restriction of pregnant ewes. One half of these ewes were nutritionally restricted for a 4-week period commencing 75-95 days post coitus, in order to achieve loss of maternal liveweight and reduction in body fat score to a minimum of 3. The remaining ewes with no nutritional restriction were >6 kg heavier and had a body fat score >0.8 higher at the end of the restriction period. Nutritional restriction affected (P

In two experiments, restriction of feed to levels below maintenance for periods of up to 4 weeks was imposed on groups of ewes bearing single foetuses at 79, 87 or 95 days post coitus. In the first experiment, carried out at pasture, measurements were made of concentration of ovine placental lactogen (oPL) and progesterone in ewe plasma. Effects on lamb birth weight and gestation length were also examined. The second experiment investigated the effect of maternal feed restriction of (i) feed intake, (ii) maternal oPL, (iii) maternal plasma glucose concentration, (iv) lamb birth weight and (v) gestation length. In the first experiment, there were no significant effects of feed restriction on lamb birth weight or gestation length, although foetal growth rate had been reduced in some treatment groups. There were significant interactions between time of sampling and treatment for oPL and progesterone concentration. Control group ewes had lower oPL (P< 0.001) and progesterone (P < 0.05) concentrations than restricted ewes at the end of feed restriction, but higher oPL (P < 0.001) and progesterone (P

The effect of conspecific sex on maternal aggression in hamsters was determined by comparing the frequency of aggressive responses by dams continuously housed with either a virgin male or female cagemate during pregnancy and lactation. Dams easily established aggressive dominance over male cagemates soon after pairing, and their aggression was low thereafter for the duration of pregnancy and lactation. The aggression of dams with females, on the other hand, tended to fluctuate with highs during mid pregnancy and mid lactation and lows around birth. When dam aggression was low around birth, female cagemates frequently became aggressively dominant, and several dams lost their litters. The higher aggression of dams toward females than males is probably a reflection of greater intrasexual competition for environmental resources that includes pups.

Summary A group of 497 women whose pregnancies did not exceed 22 weeks and who were booked at the antenatal clinic between 1st August, 1971 and 31st January, 1972 have been included in a survey of arterial pressures in early pregnancy. The arterial pressures showed a low range and confirmed similar previous observations. The blood pressures among the primigravidae in the group were found to be lower than those of their Aberdeen counterparts. It was also found that the arterial pressures were lower than those of comparable non-pregnant women within the same community. The low arterial pressures in early pregnancy did not offer any special advantage in relation to the incidence of pre-eclampsia and eclampsia, diseases known to be prevalent within the community.

The relationship between fetal weight (FW) at mid-pregnancy, and uterine weight of the area of placental attachment (UW), fetal membrane weight (FMW), allantoic fluid volume (ALFV), amniotic fluid volume (AMFV), fetal sex (FS), left vs. right uterine horn (UH), number of fetuses per uterine horn (NF), fetal location within the uterine horn (FL), fetal age (FA), dietary intake (DI) and year group of gilts (YG) was determined on 935 fetuses from 93 Lacombe gilts, bred to Yorkshire boars, that were slaughtered at 58–62 d of gestation. A stepwise regression analysis was utilized with 9 of the 11 variables found to have a significant effect and accounted for 66.5% of the variation in fetal weight. Uterine weight of the area of placental attachment (UW) accounted for 47.5% of the variation in fetal weight. The next five variables (FA, AMFV, FS, FMW and ALFV) accounted for a further 17.9% of the variation in fetal weight. The remaining 1.1% reduction in variation in fetal weight occurred with the inclusion of FL, DI and NF. The effects of the UH and YG were not significant. Thus, the parameters associated with the individual fetus are the most important variables influencing fetal weight with the uterine weight of the area of placental attachment being of greatest importance. Key words: Gilts, mid-pregnancy, fetal weight

The removal of 100 uterine caruncles before mating reduced by about 17 per cent the mean (± s.e. ) birthweights of 18 single lambs to 3·45 ± 0·10 kg, and decreased the period of pregnancy by about 3 days to 144·5 ± 0·3 days. Ablation of about 20 per cent of the placentomes present at 80 days of gestation reduced by 11 per cent the weight of 12 twin foetuses at 140 days, and showed that the placental reserve capacity of these foetuses in late pregnancy was less than 20 per cent.

Degrees of anxiety concerning fetal malformations were assessed by self-rating on Visual Analogue Scales in early, mid, and late pregnancy in 263 women who agreed to take part in a serum alpha-fetoprotein (AFP) screening program. Women who refused to undergo the test were found to have similar distributions of degrees of anxiety throughout pregnancy. Women with normal AFP-test results showed a significant decrease of anxiety between the assessments in early and mid pregnancy. The distributions in mid and late pregnancy were similar. In early pregnancy the women who refused the test displayed less anxiety than women who accepted the test. In mid-pregnancy the refusing women and the women with normal test results showed similar degrees of anxiety, but on this occasion women with initially abnormal test results displayed even less anxiety than other women. Increased attention to the women with abnormal test results during the period of the investigation together with an altered frame of reference with respec...

The herbage intake and liveweight changes of older gummy ewes and younger sound-mouthed ewes were compared under grazing conditions during early and mid pregnancy. Five herbage allowances were offered, ranging from 1.05 to 2.00 kg dry matter (DM) per ewe per day with the two classes managed separately and with fresh feed breaks offered at 2-day intervals. The gummy ewes consumed herbage more slowly and left a higher residual herbage mass than the sound-mouthed ewes. This resulted in lower apparent intakes and gave correspondingly lower liveweights. At the same level of apparent intake, liveweight changes in gummy and sound-mouthed ewes were similar. Liveweight maintenance was achieved with an intake of 1.0 kg DM per ewe per day. This intake required herbage allowances of 1.6 and 1.3 kg DM per ewe per day for the gummy and sound-mouthed groups respectively.

At mid pregnancy (12th day) fed rats exhibit a drop of blood alanine level when the weight of the fetoplacental unit is still negligible. A primed infusion A-V method was used to measure alanine kinetics in fed midpregnant rats and virgin controls, using L-[2,3–3H]alanine as a tracer. Alanine turnover and metabolic clearance rates were higher on day 12 than in virgin controls. The increase in alanine turnover rate was accounted for by an increase in alanine degradation. Since the liver is the main site of alanine degradation, alanine uptake was studied in isolated hepatocytes. Hepatocytes isolated from midpregnant rats utilized 50% more alanine than those from virgin controls. This increase was mainly due to metabolism rather than incorporation into proteins. In conclusion, the alanine turnover rate and its hepatic metabolism are increased in fed midpregnant rats, resulting in the decrease in blood alanine.

Early-cut, precision-chopped (EP) and late-cut, flail-harvested (LF) silages were offered ad libitum to breeding ewes during mid and late pregnancy in two experiments. Silages offered in late pregnancy were factorially arranged with silages offered in mid pregnancy giving four silage treatments. Voluntary drymatter intake, ewe weight change, lamb birth weight and blood levels of 3-hydroxybutyrate (3-OHB) and non-esterifiable free fatty acids (NEFA) were measured. The intake of LF silage was proportionately 0·61 and 0·72 of that of EP silage in mid and late pregnancy respectively. While type of silage given in mid pregnancy did not affect the mean silage intake in weeks 15 to 20 of pregnancy, the rate of decline in intake was higher and the intake during week 20 of pregnancy was lower following the feeding of EP silage in mid pregnancy. Despite a considerably lower level of body reserves associated with LF silage given in mid pregnancy, there was little effect on levels of 3-OHB or NEFA in late pregnancy or on lamb birth weight.

SummaryTwo experiments, involving a total of 112 sheep, are described, in which ewes at different reproductive states were given complete diets with a varying grain: straw ratio. In Expt 1 ewes at three reproductive states (dry, pregnant and lactating) were given diets with four levels of coarsely ground oat straw (10, 25, 40 and 55% straw). In Expt 2 ewes in five reproductive states (early pregnancy, mid pregnancy, late pregnancy, lactation and dry) were given a basal diet similar to that given in Expt 1 but with five levels of straw (15, 25, 36, 45 and 55% straw).The results showed that the intake of ewes varied with reproductive state, the highest intakes occurring during lactation. No significant diet × reproductive state interaction was observed which suggests that in ewes the physiological state can override some of the physical limitations to intake imposed by increased dietary roughage concentration.

The effect of two stocking rates (16 and 32 ewes/ha) and three initial levels of pasture reserves (1730, 2240 and 2720 kg DM/ha) on animal and pasture production was studied from June to December 1977. Total amount of pasture grown was unaffected by either stocking rate or pasture reserve. At 32 ewes/ha, 96.9% of net pasture production was eaten and no surplus conserved. At 16 ewes/ ha, 50.4% was eaten and 1120 kg DM/ha conserved. Increasing initial pasture reserves gave increased ewe liveweight at weaning at 32 ewes/ha, but no response at 16 ewes/ha. There were no treatment effects on single lamb birthweights or weaning weights. The relationship between ewe intake and pasture allowance at different physiological states is discussed.

SUMMARYForty-eight approximately 18-month-old Scottish Blackface ewes were used to study the effects of two levels of nutrition during mid-pregnancy (30–98 days of gestation) on the birth weight of lambs from ewes varying in weight, size and condition at first mating. The mean live weight (42–4 kg), size index (31–9) and condition score (2–4) at mating of the 26 ewes from flock A were all less than those of the 22 ewes from flock B (54–5, 39–4 and 2–9 respectively). Mean intakes of the low and high nutritional treatment ewes during mid-pregnancy were 10–6 and 22–0 g/kg/day respectively of a pelleted diet supplying 8–81 MJ metabolizable energy and 125–5 g crude protein/kg. These intakes produced estimated changes in net maternal weight of approximately – 5 and 0 kg respectively.Mean lamb birth weights from ewes on the low and high nutritional treatments were:flock A, 3–32 and 3–83 kg; flock B, 4–96 and 4–23 kg respectively. Analyses showed intake during mid-pregnancy to have a positive effect on lamb birth weight in the flock A ewes, and a negative effect in flock B ewes. Mating weight accounted for 78% of the variance in birth weight in the low nutritional treatment ewes but had little effect in those on the higher level of feeding.The practical implications of the results are discussed in relation to levels of juvenile nutrition.

The effect of ovarian steroids on the maintenance of pregnancy in rats on an isoleucine-free diet was investigated. A combination of 0.5 μg of estrone and 4 mg of progesterone or one of these steroids only was injected into the rats for various periods until mid pregnancy. Administration of estrone with progesterone from day 3 to 13 prevented fetal loss completely, and even when injected only from day 9 to 13 about 80 % of the rats maintained pregnancy. Pregnant rats fed an inadequate diet without steroids failed to maintain pregnancy. Pregnant rats receiving deficient diets with or without steroids were sacrificed at intervals during early and mid pregnancy and the nucleic acid and protein contents of the uterus and incorporation of 14C-leucine into uterine proteins were examined. On day 7 of pregnancy, growth of conception products, total RNA, DNA, and protein in the uterus were significantly less in rats that did not receive steroids than in those that did. Incorporation of 14C-leucine into uterine proteins was the same in both groups until day 11, but on day 14 the incorporation rate rose in the group in which pregnancy was maintained and fell in the group in which it failed. These results suggest that ovarian steroids, particularly progesterone, may act on the uterus to inhibit protein degradation, at least during mid pregnancy. The total amount of estrogen receptor proteins in the uterus was maintained until quite a late stage of pregnancy in rats on an inadequate diet.

1. The pool size, space and rate of irreversible loss of glucose were estimated with primed infusions of [U-14C]glucose in reindeer cows within 6 h of being taken from outdoor pens or from free grazing in the field.2. In conjunction with primed infusions of [U-14C]glucose, single injections of [3-3H]glucose were also used to estimate pool size, space, transfer rate, and turnover time of glucose.3. Except in a period of severe undernutrition, the concentration of glucose in plasma was higher (range 0·76–1·40 mg/ml) than that recorded for other ruminants.4. The size of the glucose pool (range 8–35 g) varied in parallel with plasma glucose concentration and was generally distributed in a space in excess of the extracellular fluid volume.5. The lowest rates of irreversible loss of glucose (approximately 1·7 mg/min per kg0·75) were measured when cows were in mid pregnancy and when available food was scarce; the highest rate (5·5 mg/min per kg0·75) was found in cows during mid summer.6. Changes in irreversible loss and transfer rate of glucose are interpreted in relation to changes in body composition (estimated in a parallel study), subjective assessment of available food and factors known to control glucose metabolism in other ruminants.7. The difference between glucose transfer rate and rate of irreversible loss of glucose was used as an index of the rate of resynthesis of glucose from products of glucose catabolism. The rates of glucose resynthesis were highest during a period of rapid growth (4·52 mg/min per kg0·75or 45% of the glucose transfer rate) and in mid and late pregnancy (respectively 4·14 and 4·28 mg/min per kg0·75or 71 and 59% of the transfer rate).

Die Wand der Kapillaren in der menschlichen Placenta aus der Schwangerschaftsmitte wird elektronenmikroskopisch untersucht und zu der Wand des Sinusoides der reifen Placenta in Beziehung gesetzt. Bereits zur Zeit der Schwangerschaftsmitte sind vereinzelt Sinusoide nachweisbar, doch treten sie gegenuber den Kapillaren zahlenmasig in den Hintergrund. Die Kapillaren des Zottenbinnenraumes besitzen keine Basalmembran; sie sitzen meist, nur durch einen Spalt getrennt, einer Pericytenschicht auf. Die Pericyten haben haufig fusformige Auslaufer, die die Basalmembran des Cytotrophoblasten erreichen. Die Kapillarendothelien sind zwar einreihig angeordnet, uberlappen aber einander in ausgedehnter Weise. Im Cytoplasma der Kapillarendothelien findet man haufig eine feinfilamentare Zeichnung, jedoch nur nach Kaliumpermanganat-Kontrastierung. Die Kapillaren der unreifen Placenta sind durch das Fehlen der Basalmembran, durch die ungewohnliche Dicke und durch die starke Uberlappung ihres Endothels fur eine Gefugedilatation besonders geeignet.

To elucidate further the effect of maternal glucose concentration in the regulation of human chorionic somatomammotropin (HCS) secretion, normal women in mid-pregnancy and in the third trimester were subjected to sustained hyperglycemia (via glucose infusion) and transient hyperglycemia (via a rapid intravenous glucose tolerance test), respectively. In all studies, significant changes in serum HCS concentrations were not observed, although the mean serum HCS concentration showed a slight decline during the infusion and slight rise following the infusion.

Summary The pathways of water exchange between liquor amnii and the fetoplacental unit were examined in vivo in pregnancies of 14 to 22 weeks’gestation. Fetal skin permeability appears to decrease with increasing fetal size while the umbilical cord becomes an increasingly important site from 18 weeks. The fetal surface of the placenta appears to be important as a site of water exchange.

Mid-Pregnancy nutrition has been shown to have both positive and negative effects on lamb birth weight in primiparous Scottish Blackface ewes. The direction of the effect depends on the level of body condition at mating, being negative in ewes in high body condition (Russel, Foot, White and Davies, 1981). In the same study, it was argued that the effect in younger ewes could be due to their greater sensitivity to both under- and over-nutrition during the earlier to mid stages of their first pregnancy than is evident in older ewes. Russel et al. (1981) also suggested that the level of mid-pregnancy nutrition is likely to have effects on other aspects of production such as embryonic loss, foetal mortality and even ewe mortality.

SummaryThe embryolethal and teratogenic effects of actinomycin D were studied in Long-Evans rats. Subcutaneous administration extended the teratogenic time range of the drug beyond that previously identified by intraperitoneal injections; a single dose (200 μg/kg body weight) given on day 12 of pregnancy caused club foot, generalized edema, exomphalos, and growth retardation in 14% of surviving young. When equal amounts of L-thyroxine were injected concurrently with actinomycin D on day 12 of development, the effects of actinomycin on the mothers were ameliorated and abnormalities in the young were strikingly reduced. When injected one day previous to treatment with actinomycin D, thyroxine prevented fetal malformations. These results may be interpreted on the hypothesis that the hormone forms a harmless complex with actinomycin D.

Summary Three sows were fed 8.5 mg. dichlorvos (in a slow release preparation) per kg. body weight per day from day 41 to day 70 of pregnancy. Blood cholinesterase levels in the sows were markedly depressed by treatment, and had still not returned to normal at term (115 days). Piglets, removed by hysterectomy at term, appeared clinically and morphologically normal, but the weights of some of their organs (brain, thymus, thyroid, liver and sternocephalic muscle) were heavier, whilst weights of other organs (pituitary, spleen and eyes) were lighter than those of piglets from untreated sows. The effects of dichlorvos appear to be quite different from those of the chemically related organophosphorus compound trichlorphon which, if fed to sows in mid-pregnancy, is teratogenic, causing severe cerebellar hypoplasia with congenital ataxia in the progeny. Zusammenfassung Perorale Wirkung von Dichlorvos bei Schweinen wahrend der mittleren Graviditatsphase Drei Schweinen wurden taglich vom 41. bis 70. Tag der Graviditat 8.5 mg/kg Korpergewicht Dichlorvos (2,2-Dichlorvinyldimethylphosphat, DDVP) in einer langsam absorbierbaren Form im Futter verabreicht. Das Praparat bewirkte eine deutliche Aktivitatsabnahme der Blutcholinesterase, welche zur Zeit der Geburt (115. Graviditatstag) noch immer nachzuweisen war. Die durch Hysterektomie am Ende der Graviditat gewonnenen Ferkel waren zwar klinisch und morphologisch normal, hingegen waren einige Organe (Gehirn, Thymus, Schilddruse, Leber, M. sternocephalicus) schwerer, wahrend andere Organe (Hypophyse, Milz, Augen) im Vergleich zu Ferkeln unbehandelter Muttertiere leichter waren. Die Effekte von DDVP unterscheiden sich erheblich von denjenigen des Trichlorphon, eines chemisch verwandten Organophosphats, welches bei Verabreichung wahrend der mittleren Trachtigkeitsphase bei den Ferkeln eine zerebellare Hypoplasie mit kongenitaler Ataxie hervorrufen. Resume Action perorale de Dichlorvos chez des porcs au milieu de la periode de gestation On a donne a 3 porcs sous forme lentement absorbable dans un aliment quotidiennement du 41e au 70e jour de gestation 8,5 mg/kg de poids de Dichlorvos (2,2-dichlorvinyldimethylphosphate). La preparation a provoque une nette diminution de l'activite de la cholinesterase sanguine qui fut encore plus marquee au moment de la mise bas (115e jour de gestation). Les porcelets nes par hysterectomie en fin de gestation furent cliniquement et morphologiquement normaux; quelques organes (cerveau, thymus, glande thyroide, foie, M. sternocephalicus) furent plus lourds et d'autres organes (hypophyse, rate, yeux) plus legers que ceux de porcelets provenant de truies non traitees. Les effets du DDVP se differencierent nettement de ceux du Trichlorphon, un organophosphate chimiquement apparente, dont l'absorption au milieu de la gestation a provoque une hypoplasie du cervelet avec ataxie congenitale chez les porcelets. Resumen Efecto peroral de Diclorovos en cerdas durante la fase media de gravidez Se administro diariamente a tres cerdas desde el dia 41° hasta el 70° de gravidez 8,5 mg./kg. peso en vivo de Diclorovos (dimetilfosfato de 2,2 diclorovinilo, DDVP) en una forma absorbible lentamente, con el pienso. La especialidad causo la disminucion manifiesta en la actividad de la colinesterasa en sangre, la cual aun se podia poner en evidencia en el momento del parto (dia 115° de gestacion). Los lechones logrados mediante histerectomia al final de la gestacion eran normales clinica y morfologicamente, mientras que algunos organos (cerebro, timo, tiroides, higado, m. esternocefalico) pesaban algo mas, a la vez que otros organos (hipofisis, bazo, ojos) eran mas livianos en comparacion con los lechones procedentes de parideras no tratadas. Los efectos del DDVP son bien diferentes de los producidos por Triclorofon, un compuesto organofosforoso allegado quimicamente, el cual ocasiona en los lechones, si se administra durante la fase media de gestacion, una hipoplasia cerebelar con ataxia congenita.

Summary An analysis of the 156 pregnancies which terminated spontaneously between 16 and 27 weeks gestation, inclusive, indicated that in 41 patients where fetal death was the primary event, maternal arterial pressure was raised in early pregnancy when compared with matched groups of women whose pregnancies had a successful outcome. Blood pressure in the 14th week of pregnancy in women with fetal death was significantly higher than in women with other types of mid-trimester abortion. It is suggested that maternal hypertension predisposes to intrauterine fetal death in the mid-trimester of pregnancy as it does in the third trimester.

1. A serial study of renal clearance of urate and inulin was made in thirteen normal women in early, mid and late pregnancy and 6–15 weeks after delivery. 2. The mean serum urate concentration was low in early and mid pregnancy but rose in late pregnancy towards the control value. 3. Clearances of urate and inulin were consistently elevated throughout pregnancy to about 150% of the post-partum values. The ratio of clearance of urate to clearance of inulin was the same in pregnancy as it was after the puerperium. 4. The urinary excretion of urate was increased only in late pregnancy.

The concentration of proinsulin-like components (PLC) in serum has been determined by gel filtration on samples obtained from eight normal pregnant women and eight nonobese gestational diabetics. The normal women were investigated early in pregnancy and all subjects were investigated in mid pregnancy, late pregnancy, and postpartum. At each occasion, samples were obtained after an overnight fast and after glucose ingestion. In both groups, the concentration of PLC in serum after overnight fast rose with gestation as well as after glucose ingestion, but there were no significant differences between mean levels of PLC of the normals and the gestational diabetics. With gestation, serum insulin rose in parallel with PLC in either group. The proportion of total insulin immunoreactivity composed by PLC thus remained constant and, furthermore, the proportions of PLC in gestation were equal to those observed postpartum. Four to six weeks after delivery, the basal concentration of PLC in serum was higher in the gestational diabetics than in the normals, whereas the concentrations of insulin were equal. Since the biological potency of proinsulin is much less than that of insulin, the results exclude the possibility that the decrease of glucose tolerance in normal pregnant women and gestational diabetics is due to an increased concentration of proinsulin in serum.

Fetal head width and thoracic depth were observed via real-time ultrasound imaging in 12 single-, 12 twin- and 4 triplet-bearing BooroolaxSouth Australian Merino ewes at weekly intervals during mid pregnancy. Fetal age varied by a maximum of 24 h. Relationships between fetal age and the linear measures (head width, thoracic depth) were determined within litter size categories, using both linear and quadratic terms. All relationships tested for linearity were statistically significant (P0.05). A curvilinear relationship (P0.05) was observed for fetal age and thoracic depth of twin fetuses. Significant (P0.05) curvilinear relationships were also observed for fetal age and head width, and fetal age and thoracic depth when litter size data were pooled. We conclude that head width and thoracic depth are acceptable linear measurements for estimating fetal age in the ovine species. Implications of these results for research and for the commercial field are discussed.

In a serial study of insulin receptor binding to monocytes from normal pregnant women, a significant increase in insulin binding in mid pregnancy followed by a significant decrease in late pregnancy at tracer insulin concentration was found. No changes in the insulin concentration necessary to reduce tracer binding by 50% (ID50) were observed. At delivery, binding to isolated adipocytes was significantly lower in normal pregnant women than in non-pregnant normal controls while no difference in ID50 was observed. No differences in insulin binding at tracer insulin concentration to monocytes and adipocytes between normal weight women with gestational diabetes and healthy non-diabetic pregnant controls were found, but the ID50 was significantly lower in women with gestational diabetes diagnosed in late pregnancy than in pregnant controls at the same weeks of gestation.