Birth weight before and after a spontaneous abortion

Recurrent miscarriage is a useful and valid clinical concept

Although epidemiological, clinical and biochemical risk factors are known for recurrent miscarriage (RM), the etiology is mainly unknown. Two main hypotheses dominate: that RM is mainly caused by aneuploid conceptions and other conception errors and that the recurrence rate is explained by the combination of chance and increased risk, or that maternal endocrinological, thrombophilic or immunological abnormalities play a main role in causing loss of euploid conceptions. Believers of the former hypothesis advocate that management of RM should be conservative and that the spontaneous prognosis is very favorable. Believers of the latter hypothesis think that treatments aimed at the woman may improve pregnancy outcome, but that testing of such treatments in randomized controlled trials is needed. In this article in favor of RM being a specific and useful clinical concept, arguments are advanced that a significant subset of RM patients exhibit a poor spontaneous prognosis and should be offered relevant investigations, close surveillance during pregnancy, and treatment, preferably as part of randomized controlled trials.

Families with a perinatal death: is there an association between the loss and the birthweight of surviving siblings?

Our objective was to study birthweight among surviving siblings in families with and without a perinatal loss, and to evaluate whether different causes of death were associated with the results. Data were for 1967-98 from the Norwegian Medical Birth Registry. Births were organised with the mother as the observation unit through the personal identification number, providing sibship files. We analysed 550 930 sibships with at least two singletons, 208 586 sibships with at least three singletons and 45 675 sibships with at least four singleton births. We compared mean birthweight and gestational age between infants in sibships with and without a perinatal loss, total losses and the different causes of death. Surviving siblings in families with a perinatal loss had significantly lower mean birthweights than their counterparts in unaffected families, after adjusting for gestational age, interpregnancy interval, time period and marital status. An exception was found when cause of death was a birth defect, when growth retardation among surviving siblings was not found on average. We conclude that families who have lost an infant because of a birth defect do not appear to have an increased risk of adverse birth outcome associated with growth restriction.

Obstetric and neonatal outcome in women with a history of recurrent miscarriage: a cohort study

Obstetric and neonatal outcomes of women who had a history of recurrent miscarriage were compared with a control population from 1 January 1992 to 30 June 1998. Amongst a total of 162 pregnancies which progressed beyond 24 weeks gestation in women with a history of recurrent miscarriage, there were four perinatal deaths and 16 babies were admitted to the special care baby unit. The rates of preterm delivery (13%), small-for-gestational-age (13%), perinatal loss (2.5%) and Caesarean section (36%) were significantly (P < 0.05) higher than those of the control group (3.9, 2.1, 1 and 16.7% respectively). The ratio of male to female babies was equal. There was no significant difference in the incidence of hypertension or diabetes between the two groups. Patients with recurrent miscarriage represent a population at high risk of obstetric problems and close surveillance in the antenatal period is therefore required.

Study of the birthweight of parents experiencing unexplained recurrent miscarriages

OBJECTIVE

To examine birthweight and preterm birth rates in couples with unexplained recurrent miscarriages.

DESIGN

A case control study. Birth data of couples with recurrent miscarriages were obtained from midwife records. Time and sex-matched births from the same records served as controls.

SETTING

A Regional Hospital in Denmark.

SUBJECTS

79 singleborn women with recurrent miscarriages and 60 of their male partners comprised the main study groups. Two control groups comprised 474 female and 360 male singleborn infants who survived day 7 postpartum.

MAIN OUTCOME MEASURES

Mean birthweight in the two main study groups and in subgroups with histories of 3, 4 and greater than or equal to 5 miscarriages.

RESULTS

The mean birthweight of the women with recurrent miscarriages was 3265 g (SE 70) and in female controls 3414 g (SE 23) (P less than 0.025). The 17 women with five or more miscarriages had a mean birthweight of 2991 g (SD 140) (P less than 0.001 compared with controls). Of the women in the study group 10.8% were born preterm compared with 2.9% of the controls (P = 0.01). The mean birthweight of the male partners in the study group, 3470 g (SE 68), did not differ significantly from that of 3504 g (SE 31) in the male controls (P less than 0.5).

CONCLUSIONS

Women suffering unexplained recurrent miscarriages have on average had a significantly lower than normal birthweight themselves, whereas this was not observed in their male partners. This points towards the existence of a birthweight-reducing trait associated with recurrent miscarriages, the trait being manifest only in the woman.

The role of immunization treatment in preventing recurrent abortion

Published reports of controlled studies of immunization treatment in recurrent abortion have not shown any ability of either third-party cells or the husband's cells to prevent further abortions, whereas preliminary results of ongoing studies speak in favor of a beneficial effect of third-party cells. However, the lack of significant differences so far does not prove that immunotherapy in habitual abortion is ineffective, because all of these studies include too few patients in each group to give any conclusive results. Only a mega-trial could evaluate the efficacy and side effects of leukocyte immunotherapy. Such controlled studies are needed to clarify the true benefits, risks, and limitations of immunization treatment in recurrent abortion. Factors such as appropriate inclusion criteria, the time relationship between immunization and the next pregnancy, the number of immunizations required, the cell source and cell doses need to be established. Until this additional information is available this treatment should not be considered routinely indicated. This approach should be restricted to a few centers in order to provide maximal possibilities for collection and evaluation of the data.

Birth-weight of newborns to Chinese women subsequent to a previous abortion

The mean birth-weight of firstborns of women was significantly higher when there was a previous abortion. The increase was 73.5 and 119.4 g in newborns of women with an induced and a spontaneous abortion respectively. This trend of significant increased birth-weight among firstborns of women with either a previous induced or spontaneous abortion continued for male infants, in recent migrants, and in subjects aged 20-24 and 30-34 years. Stepwise logistic regression analyses showed that a history of an induced or a spontaneous abortion increased the birth-weight of the firstborns, while short maternal stature and female newborn were associated with decreased birth-weight. For low birth-weight, a previous abortion was not selected into the regression models but short maternal stature and female newborns continue to contribute to low birth-weight. Prematurity and mean gestation were found not to be associated with previous abortion using logistic regression analyses.

Outcome of pregnancies progressing beyond 28 weeks gestation in women with a history of recurrent miscarriage

Ninety-seven women who had had three or more miscarriages had also had at least one pregnancy with a singleton birth that had reached 28 weeks gestation. Information was available on these 118 babies: 30% were small-for-gestational age (birthweight less than or equal to 10th centile using figures from Scotland 1973-79), 28% were born preterm, and the perinatal mortality rate (excluding babies of less than 28 weeks gestation) was 161/1000 births, all of which are significantly increased above the prevalence for a normal obstetric population. These observations may serve to alert the clinician to the increased risk of these complications when dealing with women who have a history of recurrent miscarriage.

Risks of preterm delivery and small-for-gestational age infants following abortion: a population study

We examined hospital discharge records in 1980-81 for singleton third trimester deliveries in Scotland. We compared 3000 women who had previously experienced induced termination of pregnancy, and 4000 who had experienced spontaneous abortion with primigravidae and with women in their second pregnancy, their first having resulted in a livebirth. Two aspects of low birthweight were examined: delivery before the 37th completed week of gestation, and low birthweight for gestational age. Our comparisons were further controlled for maternal height, age, sex of infant, marital status and social class. Women with previous spontaneous abortions experienced significantly increased risk of preterm delivery but not of low birthweight for gestational age. Women with a history of induced abortion also experienced increased risk of preterm delivery, but for women aged 18-24 years, risk of low birthweight for gestational age was significantly reduced compared with primigravidae.