The value of early third-trimester maternal serum alpha-fetoprotein determination

Localized Placental Mesenchymal Dysplasia in Monochorionic Diamniotic Twin Placenta with Beckwith-Wiedemann Syndrome

IntroductionPlacental mesenchymal dysplasia (PMD) is often associated with Beckwith-Wiedemann syndrome. Case report: A 27-year-old woman with preeclampsia prematurely delivered twin girls. One side of the placenta was larger with numerous grape-like vesicles, histologically with large, cystic, stem villi with cisterns without syncytiotrophoblastic hyperplasia. This side showed mosaicism for chromosome 11 by FISH and hypomethylation at ICR2 by MLPA. The smaller side of the placenta was normal macroscopically, microscopically, and karyotypically. There was symmetric growth restriction, macroglossia and hypoglycemia of the girl corresponding to the abnormal placental side, and lesser symmetric growth restriction and mild hypoglycemia in the other girl. Conclusion: Localized placental mesenchymal dysplasia can occur in monochorionic diamniotic twin placenta with Beckwith-Wiedemann syndrome. Fetal affects may be asymmetric. PMD can be associated with mosaicism monosomy of chromosome 11.

Maternal serum testing for alpha-fetoprotein and human chorionic gonadotropin in high-risk pregnancies

To evaluate the variations and potential clinical use of serial maternal alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) in pregnancies at risk of pregnancy-induced hypertension (PIH) and/or intrauterine growth retardation (IUGR), we investigated the relationship between placental sonographic findings, uterine artery Doppler measurements, and maternal serum AFP, hCG, and uric acid levels between 20 and 34 weeks of pregnancy. Maternal serum samples were collected from 41 singleton pregnancies with bilateral uterine notches and/or an increased uterine artery pulsatility index at 20-24 weeks. Maternal serum AFP, intact hCG and free alpha and beta subunits, and uric acid circulating levels were measured in all cases at 20-24 weeks and 25-28 weeks. Placental sonographic investigations comprised measurements of thickness and morphology. Twenty pregnancies had a normal outcome and 21 had an adverse outcome, including eight complicated by severe PIH with fetal IUGR, eight by isolated IUGR, three by mild PIH with normal fetal growth, and two by placental abruption. At the time of the first scan, the placental thickness and maternal serum levels of AFP, hCG, and uric acid were significantly increased in pregnancies with adverse outcomes, compared with those with a normal outcome. In subsequent maternal serum examinations, the incidence of elevated hormonal levels fell for AFP, intact hCG, and beta-hCG, whereas it increased for the uric acid level. No difference was found at any stage for the alpha-hCG level. Seven out of 11 pregnancies complicated by PIH presented with elevated MSAFP and MShCG and a large heterogeneous placenta at the first visit, whereas no pregnancy with a normal outcome presented with similar features. This study has shown a significant association between abnormal development of the utero-placental circulation, elevated MSAFP and MShCG at mid-gestation, and subsequent adverse pregnancy outcome. Serial measurements of MSAFP and MShCG do not provide extra information for the follow-up of these pregnancies.

Associations between adverse perinatal outcome and serially obtained second- and third-trimester maternal serum alpha-fetoprotein measurements

OBJECTIVE

Our purpose was to determine whether third-trimester maternal serum alpha-fetoprotein predicts adverse perinatal outcome and whether use of both second- and third-trimester maternal serum alpha-fetoprotein enhances the positive predictive value for various abnormal outcomes.

STUDY DESIGN

A cohort study with obstetric outcome assessed by chart analysis after delivery was performed at Regional Medical Center (Memphis, Tennessee), a hospital staffed by university-based physicians serving a large urban population with many indigent patients. A total of 650 women attending prenatal clinics in the above setting with a singleton pregnancy without a neural tube defect, contributing a maternal blood samples in both the second and third trimesters, and delivered in the above hospital participated. Various pregnancy outcomes were correlated with maternal serum alpha-fetoprotein levels in the second and third trimesters and in both.

RESULTS

In the third trimester no significant associations were found between maternal serum alpha-fetoprotein elevations and pregnancy complications. In the second trimester elevation ( > or = 2.0 multiples of the median) were, by contrast, significantly associated with preterm premature rupture of the membranes, preterm birth, and low birth weight. No association was found with certain other complications. When second-trimester data were grouped according to the types of complications occurring in individual women, only preterm premature rupture of the membrane proved statistically significant.

CONCLUSIONS

Second-trimester but not third-trimester maternal serum alpha-fetoprotein is significantly elevated with preterm premature rupture of the membranes, preterm birth, and low birth weight; in this cohort study no association was found with preeclampsia, oligohydramnios, or polyhydramnios.

Risks associated with an elevated maternal serum alpha-fetoprotein level

Among 58,187 women tested, 1002 had a maternal serum alpha-fetoprotein measuring greater than or equal to 2.5 multiples of the median after correction for race, weight, and insulin-dependent diabetes. They were stratified into three groups: group 1, 2.5 to 2.9; group 2, 3.0 to 5.0; group 3, greater than or equal to 5.0 multiples of the median. The initial risk of a serious abnormality detected by ultrasonography or amniocentesis was 17% (5%, 12% and 65% in groups 1, 2, and 3, respectively). After correction for twins and dates, this risk became 23% (7%, 18%, and 71% in groups, 1, 2, and 3, respectively). Among the women with high maternal serum alpha-fetoprotein levels, 556 (77%) had normal ultrasonographic and amniocentesis studies, and the risk of adverse pregnancy outcome ws 27% (19%, 29%, and 70% in groups 1, 2, and 3, respectively). There was a statistically significant increase in late fetal and perinatal death, prematurity and growth retardation, oligohydramnios, abruptio placentae, preeclampsia, and congenital abnormalities. The overall risk for abnormality or adverse outcome was 24% in group 1, 41% in group 2, and 91% in group 3.