BACKGROUNDEarly and late-onset preeclampsia is thought to be different disease entities. This study aimed to determine the effects of early-onset preeclampsia-like symptoms on feto-placental outcomes and the adverse impacts of various factors on placental and fetal growth and development at different gestational stages in a mouse model.

METHODSPregnant C57BL/6J mice were divided into control and preeclampsia (PE) groups, and injected subcutaneously with the nitric oxide synthase inhibitor L-arginine methyl ester (L-NAME) 50 mgxkg(-1)d(-1). The PE group was divided into early-, mid- and late-PE groups with L-NAME injections starting on days 7, 11 and 16 of pregnancy, respectively. Corresponding control groups were injected with saline at the same time points. Blood pressure was measured until days 14 and 18, when the fetuses and placentas were removed under anesthesia. Blood pressure, urinary protein, and fetal and placental conditions were analyzed.

RESULTSBlood pressure and urinary protein increased following L-NAME injection. The fetal survival rate and fetal weight were reduced and the fetal absorption rate was increased in the early-PE group on days 14 and 18 of pregnancy, compared with the control group. There were no significant differences in these parameters between the late-PE group and the respective control group. Placental weights in the early- and mid-PE groups were significantly reduced at days 14 and 18 of pregnancy compared with the control groups, but there was no significant difference in placental weight between the late-PE group and the respective control group. Morphologic examination of placentas from the early- and mid-PE groups showed varying degrees of fibrinoid necrosis and villous interstitial edema, but no significant pathologic changes were found in the placentas from the late-PE or control groups.

CONCLUSIONPreeclampsia-like symptoms occurring during the early stage of pregnancy are more likely to affect placental and fetal development, whereas late onset preeclampsia-like symptoms have a direct impact on the mothers.

Animals ; Blood Pressure ; Disease Models, Animal ; Female ; Fetal Development ; Fetal Resorption ; etiology ; Fetal Weight ; Mice ; Mice, Inbred C57BL ; Organ Size ; Placenta ; pathology ; Pre-Eclampsia ; pathology ; physiopathology ; Pregnancy

The objective of this investigation was to evaluate dose-incidence relationships on the prenatal effects of gamma-radiation. Pregnant ICR mice were exposed on day 11.5 after conception, coincident with the most sensitive stage for the induction of major congenital malformations, with 0.5-4.0 Gy of gamma-radiations. The animals were sacrificed on day 18 of gestation and the fetuses were examined for mortality, growth retardation, change in head size and any other morphological abnormalities. With increasing radiation dose, incidence of small head, growth retarded fetuses, cleft palate, dilatation of cerebral ventricle and abnormalities of the extremities in live fetuses rose. The threshold doses of radiation that induced cleft palate and dilatation of cerebral ventricle, and abnormal extremities were between 1.0 and 2.0 Gy, and between 0.5 and 1.0 Gy, respectively.
Animals ; Bone and Bones/*abnormalities/radiation effects ; Congenital Abnormalities/embryology/epidemiology/*radionuclide imaging ; Female ; Fetal Death ; Fetal Resorption/epidemiology/radionuclide imaging ; *Gamma Rays ; Incidence ; Mice ; Mice, Inbred ICR ; Pregnancy ; *Prenatal Exposure Delayed Effects ; *Whole-Body Irradiation

OBJECTIVETo compare the obstetric and neonatal outcomes of singleton pregnancies originating from vanishing twin syndrome with those of singleton pregnancies originating from a single gestation following in vitro fertilization-embryo transfer (IVF-ET).

METHODSThis case-control study involved a total of 409 singleton deliveries after IVF-ET/freeze-thawed embryo transfer, including 44 survivors of vanishing twin syndrome (study group) and 365 singletons (control group). The duration of gestation, rate of preterm delivery, neonatal birth weight and proportion of low birth weight were compared between the two groups.

RESULTSOf all the singletons born, 10.8% originated from a vanishing twin gestation. No differences were found in the duration of gestation between the two groups. The mean gestational age was 38.29 ± 1.76 vs 38.45 ± 1.40 weeks (P=0.495) in the study group and controls group, with the rate of preterm delivery of 15.9% vs 10.13% (P=0.298), respectively. The mean birth weight was significantly higher in the control group (3261.8 ± 437.85 g vs 3086.8 ± 527.01 g, P<0.05), but the proportion of low birth weight (<2500 g) showed no significant difference between the study and control groups (6.82% vs 2.74%, P=0.316).

CONCLUSIONSThe survivors of vanishing twin syndrome are at a higher risk of having lower birth weight than singletons of single gestation following IVF-ET.

Birth Weight ; Case-Control Studies ; Embryo Transfer ; Female ; Fertilization in Vitro ; Fetal Resorption ; Gestational Age ; Humans ; Infant, Low Birth Weight ; Infant, Newborn ; Pregnancy ; Pregnancy Outcome ; Pregnancy, Twin ; Premature Birth ; Risk Factors