Maternal low birth weight and gestational hyperglycemia

We aimed to investigate whether birth weight could predict the subsequent risk of gestational diabetes and impaired glucose tolerance. Consecutive women with a singleton pregnancy and gestational diabetes (n = 50) ,impaired glucose tolerance (n = 50) and normoglycemia (n = 200) were included in the study. Birth data were collected from original hospital records of the women. Women with gestational hyperglycemia were significantly older and heavier than those with normoglycemia. Maternal birth weights significantly declined for each class of glucose tolerance (3389 ± 644; 3184 ± 583 and 3077 ± 661 ,respectively for women with normoglycemia ,impaired glucose tolerance and gestational diabetes). After adjustment for age ,gestational age and weight gain ,maternal diabetes ,and pre-pregnancy body mass index ,maternal birth weight was negatively related to impaired glucose tolerance (OR 0.88 ,95% CI 0.81-0.97) and to gestational diabetes (OR 0.82 ,95% CI 0.74-0.91) in a multiple logistic regression model. These findings suggest that women with low birth weight constitute a group at increased risk for both gestational impaired glucose tolerance and diabetes.     

Maternal serum alpha-fetoprotein and low birth weight in relation to gestational age

To determine when in the first and second trimester a raised serum alpha-fetoprotein (AFP) level best predicts low birth weight a case-control study was performed on 157 singleton low birth-weight (less than or equal to 2.5 kg) and 314 singleton control pregnancies (birth weight greater than 2.5 kg). The association between raised maternal serum AFP and low birth weight was confirmed, but there was no special time in pregnancy before 29 weeks gestation when a raised AFP level predicted low birth weight materially better than at any other time.     

Maternal serum α-fetoprotein and low birth weight in relation to gestational age

Summary. To determine when in the first and second trimester a raised serum α-fetoprotein (AFP) level best predicts low birth weight a case-control study was performed on 157 singleton low birth-weight (2.5 kg) and 314 singleton control pregnancies (birth weight >2.5 kg). The association between raised maternal serum AFP and low birth weight was confirmed, but there was no special time in pregnancy before 29 weeks gestation when a raised AFP level predicted low birth weight materially better than at any other time.     

Low first-trimester hemoglobin and low birth weight, preterm birth and small for gestational age newborns.

OBJECTIVE: To examine the relationship between first-trimester hemoglobin (Hb) concentration and risk of low birth weight (LBW), preterm birth and small for gestational age (SGA). METHODS: Data were obtained from a population-based prenatal care program in China. A total of 88,149 women who delivered during 1995-2000 and had their Hb measured in the first trimester were selected as study subjects. RESULTS: The prevalence of anemia (Hb<110 g/L) was 22.1% in the first trimester. The risk of LBW, preterm birth and SGA was increased steadily with the decrease of first-trimester Hb concentration. After controlling for confounding factors, women with Hb 80-99 g/L had significantly higher risk for LBW (OR=1.44, 95% CI 1.17-1.78), preterm birth (OR=1.34, 95% CI 1.16-1.55) and SGA (OR=1.13, 95% CI 0.98-1.31) than women with Hb 100-119 g/L. No elevated risk was noted for women with Hb> or =120 g/L. CONCLUSION: Low first-trimester Hb concentration increases the risk of LBW, preterm birth and SGA.     

Inaccuracy of Dubowitz gestational age in low birth weight infants

The Dubowitz gestational age was compared to the obstetric clinical age of 119 predominantly black mother-infant pairs for whom certain clinical criteria were met. Forty-five hypertensive and 74 nonhypertensive gestations with infant birth weight less than 2500 g were evaluated. Overall the clinical age was 33.6 +/- 4.5 weeks versus 34.7 +/- 4.3 weeks by Dubowitz age (P = NS). The Dubowitz age differed from clinical age by more than 2 weeks in 33.6% (40/119). Of gestations under 33 weeks (clinical age) (N = 45) the clinical age was 30.1 +/- 2.4 weeks as compared to the Dubowitz age of 32.2 +/- 2.7 weeks (P less than .01). Fifty-one percent (23/45) of Dubowitz ages were more than two weeks discordant with the clinical age. The Dubowitz assessment of gestational age may be unacceptably inaccurate in the determination of gestational age in low birth weight infants, particularly in those whose gestational age is less than 33 weeks. The findings suggest that studies in which conclusions were based on the Dubowitz age assessment may need reevaluation.     

Rapid biometric assessment of gestational age in very low birth weight infants.

Foot length and intermamillary distance were compared to gestational age assessment using obstetrical dates, physical criteria of Ballard score and the evaluation of the anterior vascular capsule of the lens (IPM). Thirty-eight healthy and appropriate for gestational age preterm infants (30 +/- 2.4 weeks) with a birth weight of 1280 +/- 410 g were studied. Internipple distance (IM) and foot length (FL) were measured with a sliding caliper graduated in millimeters. Results were analyzed using the linear regression analysis. Obstetrical dates, physical Ballard score and IMP correlated significantly with both biometric measurements. Mean IM was 58.5 +/- 8.5 mm (range: 45 mm-89 mm) and mean FL was 60.6 +/- 7.9 mm (range: 45 mm-75 mm). The data indicate that the appropriate use of biometric parameters in the early postnatal period can be used to improve assessment of gestational age in VLBW infants.     

Maternal serum alpha-fetoprotein levels in low birth weight singleton pregnancies

Maternal serum alpha fetoprotein (MSAFP) measurement between 16 and 21 weeks gestation is used to define a group of women with an increased risk of fetal abnormality, particularly open neural tube defect. The test is strongly gestation dependent and women with high MSAFP levels require sonar scan examination to define gestation, exclude twins and examine the fetus for obvious malformation or death. It has been reported that women with no primary cause for raised MSAFP have an increased incidence of low birth weight babies. Conflicting reports have separately ascribed these to premature delivery and to intra-uterine growth retardation. We have studied the relationship between MSAFP and low birth weight infants with respect to both prematurity and retarded fetal growth. MSAFP values were expressed as multiples of the appropriate weekly median (MOM) values relating to normal pregnancies with normal outcomes at term. For our normal population an MSAFP value of 2 MOM is the 95% centile, i.e. 5% of normal outcome pregnancies of sure gestation will have MSAFP values in the second trimester which are at or above 2 MOM. Information was available on 389 women whose infants were liveborn singletons weighing 2.5 kg or less. 33 (8.5%) of these women had MSAFP greater than 2 MOM (p less than 0.005) and of the 145 women whose babies weighed less than 2 kg, 17 (11.7%) had MSAFP at this level (p less than 0.001) Tab. I).(ABSTRACT TRUNCATED AT 250 WORDS)     

Maternal preconceptional weight and gestational length

Recent animal studies suggest that preconceptional undernutrition shortens gestation. We retested this idea among rural Gambian women who experience annual fluctuations in energy balance caused by the rains (with lowest weights in September to November) using records from 1918 infants. Pregnancies conceived in September to November were significantly shorter than those from better-fed months (38.6 vs 39.0 weeks; log-rank chi 2 = 17.4, P < .0001).     

The very low birth weight and very low gestational age neonates--survival, prognosis and perspectives

The advances in perinatal medicine during the last decades lead to a reduction in neonatal mortality rates in risk newborns and a gradual lowering of the gestational age when survival is possible to 22 weeks of gestation. In the present survey we are making a review of the studies about the survival and the prognosis in neonates with very low birth weight and gestational age (VLBW, VLGA). Infants weighting more than 1000 g and with gestational age above 28 g.w. are with a good prognosis: low neonatal mortality and morbidity rates. In newborns with gestational age between 26 and 28 g.w. the neonatal mortality rates are relatively low, however the trend of further lowering has not changed during the last 15 years; morbidity rates varies between different centers and are relatively high. The greatest medical, social and ethical dilemmas represent the newborns with gestational age less than 25 g.w. In this group with an overall high neonatal mortality (with big variations between different centers), there is a significant high morbidity rate among survived babies. These are the infants at the border of perinatal viability, the "grey zone" of the neonatology, where further discussions are going on about the activity of the obstetric management, the intensity and the amount of neonatal resuscitation.     

The influence of previous low birth weight on birth weight, gestational age, and anthropometric measurements in the current pregnancy.

The effect of a previous low birth weight birth (less than 2750 g) was examined using a series of regression analyses. Effects on birth weight were partitioned into those associated with preterm delivery (128 g) and term delivery (178 g). Among term births, a mean difference of 107 g was associated with a previous birth of less than 2750 g, even after controlling for other risk factors including smoking, drug and alcohol use, maternal race, size, and hypertension. The pattern of measurements seen after a previous birth of less than 2750 g included significantly smaller head, chest, abdomen, arm, and thigh circumferences, but an insignificant impact on skinfold thicknesses and no significant effect on length measurements.     

High gestational weight gain and the risk of preterm birth and low birth weight: a systematic review and meta-analysis

ObjectiveMany women have high gestational weight gain (GWG), but potential neonatal consequences are not yet well quantified. We sought to determine the relationship between high GWG and preterm birth (PTB) and low birth weight (LBW) in singleton births.Data SourcesWe searched Medline and Embase and reference lists.Study SelectionTwo assessors independently performed all steps. We selected studies assessing high total or weekly GWG on PTB (< 37 weeks) and LBW (< 2500 grams).Data extraction and synthesisThirty-eight studies, 24 cohort and 14 case-control, were included involving 2 124 907 women. Most contained unadjusted data. Women with high total GWG had a decreased risk overall of PTB < 37 weeks (relative risk [RR] 0.75; 95% CI 0.60 to 0.96), PTB 32 to 36 weeks (RR 0.70; 95% CI 0.70 to 0.71), and < 32 weeks (RR 0.87; 95% CI 0.85 to 0.90). High GWG was associated with lower risk of LBW (RR 0.64; 95% CI 0.53 to 0.78). Women with the highest GWG had lower risks of LBW (RR 0.55; 95% CI 0.32 to 0.94) than women with moderately high GWG (RR 0.73; 95% CI 0.60 to 0.89). Women with the highest weekly GWG had greater risks of PTB (RR 1.51; 95% CI 1.47 to 1.55) than women with moderately high weekly GWG (RR 1.09; 95% CI 1.05 to 1.13). Women with high weekly GWG were at increased risk of PTB 32 to 36 weeks (RR 1.14; 95% CI 1.10 to 1.17 and < 32 weeks (RR 1.81; 95% CI 1.73 to 1.90).ConclusionAlthough women with high total GWG have lower unadjusted risks of PTB and LBW, high weekly GWG is associated with increased PTB, and more adjusted studies are needed, as are more studies in obese women. Potential benefits of high GWG for the infant must be balanced against maternal risks and other known infant risks such as high birth weight.     

Maternal body weight and relation to birth weight

In The Stockholm Pregnancy and Weight Development Study the relationships between birth weight and maternal initial body weight as well as weight increase during pregnancy were analysed in 2,295 subjects. As expected, the most important predictor of birth weight was total maternal weight increase, followed by initial maternal body weight. However, in women with an initial BMI value above 24 kg/m2, birth weight did not increase significantly in tact with maternal weight. The frequency of cesarean sections, 12% overall, was not significantly increased with maternal body weight. These data show that birth weight increases with maternal weight only up to the upper normal body weight.     

Maternal serum alpha-fetoprotein and birth weight

Maternal serum alpha-fetoprotein (AFP) levels between 16 and 18 weeks of pregnancy were studied in relation to birth weight among 4198 singleton pregnancies resulting in a liveborn or stillborn infant without a neural tube defect. The highest mean birth weight (3365 g) was found among infants born to women with AFP values in the range 0.50 to 0.74 times the normal median for the relevant week of gestation. As the AFP decreased from this level to less than 0.25 times the median, the birth weight decreased by 193 g and the proportion of infants weighing 2500 g or less increased from 4 per cent to 11 per cent. As the AFP level increased from 0.50 to 0.74 times the median to 3.0 times the median or greater, the birth weight decreased by 371 g and the proportion of infants weighing 2500 g or less increased from 4 to 22 per cent. The negative association was the more important of the two since the magnitude was greater and it affected 92 per cent of pregnancies. The positive association among women with low ARP levels was substantially reduced when the analysis was restricted to women who had spontaneous labours. It seems that this minor positive association arises mainly because women in whom gestation is over-estimated tend to have both a low AFP and, later, an apparently prolonged pregnancy leading to the elective delivery of an infant who is, in fact, born early.     

Analysis of birth weight and gestational age in Taiwan.

Appropriate interpretation of monitored fetal growth throughout pregnancy in individual patients and populations is dependent upon the availability of adequate standards. Previously published standards either were based on small samples, data decades old or were characteristic of foreign subpopulations. We have reviewed the data on a series of 46,575 singleton live births at Chang Gung Memorial Hospital from 1979 to 1989. The ratio of males to females was 1.08. The fetal growth pattern in the third trimester of pregnancy approximates a sigmoid curve. Fetal growth was most rapid from the 32nd to the 37th week of gestation with an average increase of 240 g per week. The birth weight declined beyond 42 weeks' gestation. There were significantly greater weight gains amongst male fetuses as compared to female fetuses from the 34th to the 42nd week of gestation. The mean birth weight recorded at 40 weeks' gestation in male and female newborns was 3,381 g and 3,262 g, respectively. Comparing the birth weight of term pregnancies using our data, with those of a previous, two-decade old report (1945-1967) by Chen, we found that birth weight were slightly higher in this study. The derived fetal growth curves are useful for clinical, public health, and investigational purposes.