Inverse association between severe nausea and vomiting in pregnancy and some congenital abnormalities

Maternal factors in the origin of cleft lip/cleft palate: A population-based case-control study

OBJECTIVES

Orofacial clefts are among the most common birth defects, with an estimated worldwide incidence of around 1.5-1.7 per 1000 live-born babies. The most frequent form of orofacial clefts is cleft lip with or without cleft palate (CL ± CP). The role of environmental factors in the development of clefts is unclear in most patients, thus the aim of this study was to estimate possible maternal risk factors in the origin of CL ± CP.

MATERIALS AND METHODS

1648 CL ± CP cases, 2654 matched controls and 57 231 population controls were evaluated from The Hungarian Case-Control Surveillance of Congenital Abnormalities. Maternal factors during the critical period in cases and controls were compared. Adjusted odds ratios (OR) with 95% confidence intervals (CI) were estimated in a multivariable conditional logistic regression model.

RESULTS

Among socio-demographic data, we have found significant differences between maternal employment. The proportion of unskilled mothers (6.5%) were higher in the CL ± CP group than in controls (3.5%). Medically recorded maternal anaemia, excessive vomiting and threatened abortion were associated with a higher risk of CL ± CP. An elevated risk was also found in various acute illnesses such as influenza (OR: 2.4, 95% CI: 3.0-5.8), acute bronchitis (OR: 4.5, 95% CI: 1.6-12.6) and urinary tract infections (OR: 3.5, 95% CI: 2.0-6.0). Maternal migraine and essential hypertension occurred more frequently in the mothers of cases than in controls.

CONCLUSION

The findings of this study suggest that maternal diseases and lifestyle factors during the first trimester play a significant role in the development of CL ± CP.

The timing, duration, and severity of nausea and vomiting of pregnancy and adverse birth outcomes among controls without birth defects in the National Birth Defects Prevention Study

BACKGROUND

Nausea and vomiting of pregnancy (NVP) occurs in approximately 70% of pregnant people, with varying severity and duration. Treatments include pharmacologic and herbal/natural medications. The associations between NVP and birth outcomes, including preterm birth, small for gestational age (SGA), and low birth weight are inconclusive.

OBJECTIVE

To determine whether NVP and reported medications are associated with adverse birth outcomes.

METHODS

We used data from the population-based, multisite National Birth Defects Prevention Study (1997-2011) to evaluate whether self-reported NVP according to timing, duration, and severity or its specific treatments were associated with preterm birth, SGA, and low birth weight among controls without birth defects. Odds ratios (aOR) and 95% confidence intervals (CI) were adjusted for sociodemographic, reproductive, and medical factors. For any NVP, duration, treatment use, and severity score analyses, the comparison group was participants with no reported NVP. For timing analyses, the comparison group was women with no reported NVP in the same trimester of pregnancy.

RESULTS

Among 6018 participants, 4339 (72.1%) reported any NVP. Among those with NVP, moderate or severe symptoms were more common than mild symptoms. Any versus no NVP was not associated with any of the outcomes of interest. NVP in months 4-6 (aOR 1.21, 95% CI: 1.00, 1.47) and 7-9 (aOR 1.57, 95% CI: 1.22, 2.01) of pregnancy were associated with an increase in the risk of preterm birth. NVP lasting one trimester in duration was associated with decrease in risk of SGA (aOR: 0.74, 95% CI: 0.58, 0.95), and NVP present in every trimester of pregnancy had a 50% increase in risk of preterm birth (aOR: 1.50, 95% CI: 1.11, 2.05). For NVP in months 7-9 and preterm birth, ORs were elevated for moderate (aOR: 1.82, 95% CI: 1.26, 2.63), and severe (aOR: 1.53, 95% CI: 1.06, 2.19) symptoms. NVP was not significantly associated with low birth weight. Our analyses of medications were limited by small numbers, but none suggested increased risk of adverse outcomes associated with use of the medication.

CONCLUSION

Mild NVP and NVP limited to early pregnancy appear to have no effect or a small protective effect on birth outcomes. Long-lasting NVP, severe NVP, and NVP later in pregnancy may increase risk of preterm birth and SGA.

Perinatal outcomes of infants born to mothers with hyperemesis gravidarum: A systematic review and meta-analysis

BACKGROUND

Hyperemesis gravidarum is the severe form of nausea and vomiting during pregnancy and can lead to undernutrition and low maternal weight gain. Previous epidemiologic and animal studies have shown that undernutrition and low maternal weight gain in pregnancy can increase the risk of unfavorable perinatal outcomes, like shorter gestational age, small for gestational age and lower weight at birth.

OBJECTIVE

To evaluate the effect of hyperemesis gravidarum on perinatal outcomes.

SEARCH STRATEGY

OVID Medline and Embase were searched from inception to February 9th, 2022.

STUDY ELIGIBILITY

Studies reporting on perinatal outcomes of infants born to mothers with hyperemesis gravidarum or severe nausea and vomiting in pregnancy were included. Case reports, case series, animal studies, reviews, editorials and conference abstracts were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected and extracted data. Risk of bias was assessed by the Newcastle-Ottawa Quality Assessment Scale. We conducted meta-analyses where possible.

RESULTS

Our search yielded 1387 unique papers, of which 61 studies (n = 20,532,671 participants) were included in our systematic review. Meta-analyses showed that hyperemesis gravidarum was associated with preterm birth < 34 weeks (2 studies n = 2,882: OR 2.81, 95 %CI: 1.69-4.67), birth weight < 1500 g (2 studies, n = 489,141: OR 1.43, 95 %CI: 1.02-1.99), neonatal resuscitation (2 studies, n = 4,289,344: OR 1.07, 95 %CI: 1.05-1.10), neonatal intensive care unit admission (7 studies, n = 6,509,702: OR 1.20, 95 %CI: 1.14-1.26) and placental abruption (6 studies, n = 9,368,360: OR 1.15, 95 %CI: 1.05-1.25). Hyperemesis gravidarum was associated with reductions in birthweight > 4000 g (2 studies, n = 5,503,120: OR 0.74, 95 %CI: 0.72-0.76) and stillbirth (9 studies, n = 3,973,154: OR 0.92, 95 %CI: 0.85-0.99). Meta-analyses revealed no association between hyperemesis gravidarum and Apgar scores < 7 at 1 and 5 min; fetal loss, perinatal deaths and neonatal deaths.

CONCLUSION

Hyperemesis gravidarum is associated with several adverse perinatal outcomes including low birth weight and preterm birth. We also found that pregnancies complicated by hyperemesis gravidarum less frequently were complicated by macrosomia and stillbirth. We were unable to investigate underlying mechanisms.

The association of nausea and vomiting of pregnancy, its treatments, and select birth defects: Findings from the National Birth Defect Prevention Study

BACKGROUND

Nausea and vomiting of pregnancy (NVP) occurs in approximately 70% of pregnant people. Treatments include pharmacologic and herbal/natural products. Research on the associations between NVP and its treatments and birth defects is limited.

METHODS

We used data from the case-control National Birth Defects Prevention Study (1997-2011) to examine whether first-trimester NVP or its specific treatments were associated with 37 major birth defects. Odds ratios (aOR) and 95% confidence intervals (CIs) were adjusted for sociodemographic and reproductive factors.

RESULTS

Mothers of 66.6% of 28,628 cases and 69.9% of 11,083 controls reported first-trimester NVP. Compared to no NVP, mothers with NVP had ≥10% reduction in risk of cardiac and noncardiac defects overall, and of 18 specific defects. Over-the-counter antiemetic use, compared to untreated NVP, was associated with ≥10% increase in risk for nine defect groups (heterotaxy, hypoplastic left heart syndrome [HLHS], aortic stenosis, cataracts, anophthalmos/microphthalmos, biliary atresia, transverse limb deficiency, omphalocele, and gastroschisis), whereas use of prescription antiemetics increased risk ≥10% for seven defect groups (tetralogy of Fallot, HLHS, spina bifida, anopthlamos/microphthalmos, cleft palate, craniosynostosis, and diaphragmatic hernia). We observed increased risks for promethazine and tetralogy of Fallot (aOR: 1.49, 95% CI: 1.05-2.10), promethazine and craniosynostosis (1.44, 1.08-1.92), ondansetron and cleft palate (1.66, 1.18-2.31), pyridoxine and heterotaxy (3.91, 1.49-10.27), and pyridoxine and cataracts (2.57, 1.12-5.88).

CONCLUSIONS

NVP does not increase risks of birth defects. Our findings that some treatments for NVP increase risk of specific birth defects should be investigated further before clinical recommendations are made.

Risk of major congenital malformations associated with first-trimester exposure to propulsives: A health administrative database study in Japan

PURPOSE

To evaluate the risk of major congenital malformations (MCMs) associated with first-trimester exposure to propulsives with a special focus on domperidone using a large administrative database in Japan.

METHODS

A large claims database was used from January 2005 to August 2016. The dates of pregnancy onset and delivery were estimated using the developed algorithms. MCMs were defined according to the International Classification of Diseases, 10th revision codes. We compared the infants' risk of overall MCMs between women with or without first-trimester prescriptions of propulsives and estimated the odds ratios (ORs) with unadjusted and adjusted analyses. We also compared the risk of overall MCMs between women with domperidone prescriptions and those with other propulsive prescriptions during the first trimester.

RESULTS

Among 38 270 women, propulsives were prescribed to 3197 women (8.4%) in the first trimester, including domperidone to 371 women (1.0%). Propulsive prescriptions in the first trimester were not significantly associated with an increased risk of overall MCMs (adjusted OR [aOR] 1.030, 95% confidence interval [CI] 0.843-1.257). Compared to the prescription of other propulsives in the first trimester, the prescription of domperidone in the first trimester was not associated with an increased risk of overall MCMs (aOR 0.724, 95% CI 0.363-1.447).

CONCLUSIONS

The first-trimester prescription of propulsives, including domperidone, was not associated with an increased risk of overall MCMs.

Maternal, paternal, and neonatal risk factors for neural tube defects: A systematic review and meta-analysis

OBJECTIVE

Neural tube defects [NTDs] are severe congenital anomalies. The etiology of NTDs is not fully known, and studies on the potential risk factors of NTDs present inconsistent results. Thus, we conducted a systematic review and meta-analysis to investigate the maternal, paternal, and neonatal risk factors for NTDs.

STUDY DESIGN

We systematically reviewed relative original studies published through October 6, 2018 available in Pubmed, Embase and the Cochrane Library without restrictions for language. The selected studies measured maternal, paternal, and neonatal risk factors and examined their associations with NTDs. A meta-analysis, including subgroup analysis and sensitivity analysis, was conducted to estimate the pooled effect measures. Two reviewers independently extracted data using a predesigned data collection form.

RESULTS

Forty-five studies were eligible for inclusion in the meta-analysis, and twelve potential risk factors were analyzed. The factors that were associated with NTDs risk included stressful life events [odds ratio [OR],1.61; 95% confidence interval [CI], 1.24-2.08; p < 0.001; I2 = 59.2%], low maternal education level [OR, 1.42; 95% CI, 1.19-1.70; p < 0.001; I2 = 47.7%], pregestational diabetes [OR, 2.24; 95% CI, 1.21-4.12; p < 0.010; I2 = 56.3%], low paternal age [OR, 1.41; 95% CI, 1.10-1.81; p = 0.007; I2 = 0.0%], low birth weight [OR, 5.53; 95% CI, 1.95-15.70; p = 0.001; I2 = 98.5%], and neonatal female gender [OR, 1.54; 95% CI, 1.10-2.14; p = 0.012; I2 = 67.8%].

CONCLUSION

Stressful life events, pregestational diabetes, low birth weight, and neonatal female gender are risk factors associated with NTDs. Low maternal education level and low paternal age are factors that are moderately associated with NTDs. Further cohort studies are required to verify the factors associated with NTDs and control the risk of this severe birth defect.

Risk factors for cryptorchidism

Undescended testis - known as cryptorchidism - is one of the most common congenital abnormalities observed in boys, and is one of the few known risk factors for testicular cancer. The key factors that contribute to the occurrence of cryptorchidism remain elusive. Testicular descent is thought to occur during two hormonally-controlled phases in fetal development - between 8-15 weeks (the first phase of decent) and 25-35 weeks gestation (the second phase of descent); the failure of a testis to descend permanently is probably caused by disruptions to one or both of these phases, but the causes and mechanisms of such disruptions are still unclear. A broad range of putative risk factors have been evaluated in relation to the development of cryptorchidism but their plausibility is still in question. Consistent evidence of an association with cryptorchidism exists for only a few factors, and in those cases in which evidence seems unequivocal the factor is likely to be a surrogate for the true causal exposure. The relative importance of each risk factor could vary considerably between mother-son pairs depending on an array of genetic, maternal, placental and fetal factors - all of which could vary between regions. Thus, the role of causative factors in aetiology of cryptorchidism requires further research.

Maternal factors in the origin of isolated anorectal malformations - a population-based case-control study

OBJECTIVE

In most patients affected by isolated anorectal malformation (IARM), the etiology is unknown. Thus, the aim of this study was to analyze the possible role of maternal risk factors in the origin of IARM.

METHODS

The study samples included 231 cases with IARM, 361 matched and 38 151 population controls without any defect in the population-based large dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996. Cases with IARM were evaluated in the function of maternal diseases and related drug use.

RESULTS

The findings of this case-control study suggested that cases with IARM have an obvious male excess. The mothers of cases with IARM had a lower incidence of severe nausea and vomiting in pregnancy and a higher incidence of acute infectious diseases in the urinary tract.

CONCLUSIONS

Lack of nausea and vomiting in pregnancy and the higher incidence of urinary tract infections may have a role in the development of IARM.

Nausea and vomiting in early pregnancy and the risk of neural tube defects: a case-control study

There has been considerable professional debate on the association between nausea and vomiting in early pregnancy (NVP) and neural tube defects (NTDs) risk. This study explored the association between NVP and NTDs risk, and the effect of folic acid supplements on the association. A 1:1 matched case-control study was conducted and conditional logistic regression model was used to analyze the associations. The result showed the odds ratio (OR) of severe NVP for NTDs was 2.403 (95%CI 1.437,4.017; P<0.001) and that of moderate NVP was 1.469 (95%CI 1.063,2.031; P = 0.020) compared with light NVP when adjusted by the potential confounders. Stratified by intake of folic acid supplements, the ORs for severe and moderate NVP turned to 2.147 (95%CI 1.140, 4.043; P = 0.018) and 2.055 (95%CI 1.320, 3.199; P = 0.001) in the stratum of non-intake of folic acid supplements while ORs reduced to 1.851 (95%CI 0.729, 4.699; P = 0.195) and 1.003 (95%CI 0.594, 1.694; P = 0.992) in the stratum of intake of folic acid supplements, respectively. We conclude that severe/moderate NVP has an association with the risk of NTDs, which was not found in the group with intake of folic acid supplements. Folic acid supplements should be recommended to use for the prevention of NTDs.

Nausea and vomiting during pregnancy and neurodevelopmental outcomes in offspring

BACKGROUND

Nausea and vomiting during pregnancy (NVP) is the most common complication of pregnancy. NVP has been associated with improved fetal outcomes, but its association with childhood neurodevelopmental outcomes has rarely been studied.

METHODS

Subjects were children aged 5-12 years (n = 560) who were controls in a previously conducted case-control study of prenatal risk factors for craniofacial malformations. Information on NVP, including trimester, duration, and treatment, was collected through a maternal interview conducted within 3 years of delivery. Neurocognition was assessed using the Peabody Picture Vocabulary Test (PPVT-III) and the Beery-Buktenica Test of Visual Motor Integration-Fifth Edition (VMI-5). Psychosocial outcomes, including internalising and externalising behaviour problems, were measured by maternal report, using the Child Behavior Checklist (CBCL), and teacher report, using the Teacher Report Form. Linear regression models were used to calculate adjusted mean (adjMD -3.04, 95% confidence interval (CI) -5.02, -1.06) differences (adjMD) and 95% confidence intervals [CI] on test scores for children exposed and unexposed to NVP in utero. Differences based on trimester, duration, and treatment were assessed.

RESULTS

NVP was reported among 63% of women and was most common in early pregnancy. Children exposed to NVP performed worse on the VMI-5 [-3.04, 95% CI: -5.02, -1.06] but exhibited few other differences from unexposed children. Durations of NVP ≥4 months were associated with poorer scores on PPVT-III (adjMD -2.52), VMI-5 (adjMD -5.41), and CBCL [adjMD 3.38 (internalising) and adjMD 4.19 (externalising)].

CONCLUSIONS

Overall, there were few differences between children exposed and unexposed to NVP. NVP was associated with slightly worse visual motor performance, and prolonged NVP and NVP extending late into pregnancy were associated with poorer scores on several neurodevelopmental measures.

Early pregnancy exposure to antihistamines and risk of congenital heart defects: results of two case-control studies

We aimed to study the association between use of antihistamines in early pregnancy and congenital heart defects (CHD) in the offspring.

DESIGN

Two case-control studies.

SETTING

HAVEN study, Erasmus MC, University Medical Centre, Rotterdam, and Eurocat Northern Netherlands (NNL), University Medical Center Groningen, Groningen, the Netherlands. We studied 361 children with CHD and 410 controls without congenital malformations from the HAVEN study and replicated the analyses in 445 children with CHD and 530 controls from the Eurocat NNL registry. Information about antihistamine use in early pregnancy and potential confounders was obtained from questionnaires postpartum. We calculated the association between antihistamines and CHD risk by multivariable logistic regression analysis.

MAIN OUTCOME MEASURES

Odds ratios (OR) with 95% confidence intervals (CI). In the HAVEN study, 25 of 771 mothers used antihistamines that were associated with an increased CHD risk (OR 3.0, 95% CI 1.2-7.3), particularly atrioventricular septal defects (AVSD) (OR 5.1, 95 % CI 1.3-20.5) and perimembranous ventricular septal defects (pVSD) (OR 5.1, 95% CI 1.8-14.4). Mothers with severe nausea who did not use antihistamines had a reduced risk (OR 0.7, 95% CI 0.5-0.98), whereas nauseous mothers using antihistamines showed an almost fivefold increased risk of pVSD (OR 4.8, 95% CI 1.1-21.8). The association between antihistamines and AVSD was confirmed in the Eurocat cohort (OR 3.5, 95% CI 1.4-8.7), but we could not replicate the association with overall CHD risk. We found a positive association between antihistamine use in early pregnancy and CHD risk, particularly AVSD, which seemed to be independent of nausea/vomiting.

The protective effects of nausea and vomiting of pregnancy against adverse fetal outcome--a systematic review

Studies have suggested that nausea and vomiting of pregnancy (NVP) may confer favorable pregnancy outcome, when compared to women not experiencing NVP. However, this was never examined systematically.

METHODS

We systematically reviewed all human studies examining potential effects of NVP on rates of miscarriage, intrauterine growth restriction, congenital malformations, prematurity and developmental achievements.

RESULTS

Our analysis reveals a consistent favorable effect of NVP on rates of miscarriages, congenital malformations, prematurity, and developmental achievements. The effect size was clinically important for miscarriage, malformations and prematurity. In a few studies the protective effects were more prominent in women with moderate-severe NVP than among those with mild or no NVP.

CONCLUSIONS

NVP is associated with favorable fetal outcome, and therefore studies of drug exposure in pregnancy should either match their exposed and control cases for existence and severity of NVP, or adjust for these confounders in their multivariate analysis.

Risk factors in the origin of congenital left-ventricular outflow-tract obstruction defects of the heart: a population-based case-control study

The aim of our project was to study possible etiological factors in the origin of congenital heart defects (CHDs) because in the majority of patients the underlying causes are unclear. Cases with different CHD entities as homogeneously as possible were planned for evaluation in the population-based large data set of the Hungarian Case Control Surveillance of Congenital Abnormalities. Dead or surgically corrected 302 live-born cases with different types of left-ventricular outflow tract obstructive defects (LVOT, i.e., valvular aortic stenosis 76, hypoplastic left heart syndrome 76, coarctation of the aorta 113, and other congenital anomalies of aorta 32) were compared with 469 matched controls, 38,151 controls without any defects, and 20,750 malformed controls with other isolated defects. Medically recorded pregnancy complications and chronic diseases were evaluated based on prenatal maternity logbooks, whereas acute diseases, drug treatments, and folic acid/multivitamin supplementation were analyzed both on the basis of retrospective maternal information and medical records. The results of the study showed the role of maternal diabetes in the origin of LVOT in general, while panic disorder was associated with a higher risk of hypoplastic left heart syndrome and ampicillin treatment with a higher risk of coarctation of the aorta (COA). High doses of folic acid had a protective effect regarding the manifestation of LVOT, particularly COA. In conclusion, only a minor portion of causes was shown in our study; thus, further studies are needed to understand better the underlying causal factors in the origin of LVOT.

Impact and risk factors of craniofacial malformations in a Colombian population

OBJECTIVE

Craniofacial malformations comprise diverse diagnoses, implying a wide range of morbidity and disability among populations. Our aim was to study them as a group and describe their epidemiological factors inside a population as well as finding common risk factors for their presentation in Colombia.

METHODS

We conducted a case-control study in several Colombian hospitals participating in the ECLAMC (Spanish acronym for Latin-American Collaborative Study of Congenital Malformations) program. For the analysis we included 374 cases of isolated malformations and 728 controls, out of 44,701 births.

RESULTS

A rate of 83.67 cases per 10,000 births was found for craniofacial malformations as a group, with an overall sex ratio of 1. We found predominance for their presentation on the right side. As main associations we obtained a positive family history of another craniofacial malformation (OR: 3.10 CI 95% [2.24-4.30]), particularly preauricular tags (OR 52.36 CI 95% [12.62-217.16]), preauricular pits (OR: 36.35 CI 95% [4.82-274.27]) and cleft lip with or without palate (OR: 2.50 CI 95% [1.07-5.84]). Medication use during pregnancy was also linked to malformations (OR: 2.00 CI 95% [1.38-2.89]). Specific agents such as ferrous sulfate (OR: 1.46 CI 95% [1.13-1.89]), folic acid (OR: 1.35 CI 95% [1.02-1.79]) and nifedipine (OR: 2.88 CI 95% [1.22-6.79]) also showed a significant correlation. Maternal alcohol use was also identified as a possible risk factor (OR: 2.45 CI 95% [1.39-4.29]).

CONCLUSIONS

Craniofacial malformations are frequently encountered among the group of congenital defects. When they present in an isolated fashion, familial history is an important risk factor, although some prenatal factors such as alcohol and some medications may have influence over their prevalence.

Possible association between maternal recurrent orofacial herpes in pregnancy and a lower rate of preterm birth

OBJECTIVE

To study the possible association between orofacial herpes during pregnancy and pregnancy complications including preterm birth and low birth weight, since the results of previous studies are inconsistent.

METHOD

The population-based large data set of the Hungarian Case-Control Surveillance System of Congenital Abnormalities was used; pregnancies in mothers with and without recurrent orofacial herpes were compared. RESULTS. Of 38,151 newborn infants, 572 (1.5%) had mothers with recurrent orofacial herpes during pregnancy, while 37 577 had mothers with no orofacial herpes. Pregnant women with recurrent orofacial herpes had a higher prevalence of severe nausea and vomiting, threatened preterm delivery, and placental disorders but a lower prevalence of preeclampsia. Mothers with recurrent orofacial herpes during pregnancy also had a somewhat longer (0.4 weeks) gestation (adjusted t = 2.7; p = 0.006) and an obviously lower proportion of preterm births (3.5% vs. 9.3%; adjusted POR with 95% CI = 0.42, 0.27-0.65). However, there was no significant difference in the mean birth weight and rate of low birth weight infants between the two study groups.

CONCLUSION

Recurrent orofacial herpes during pregnancy is associated with a smaller proportion of preterm births.

Morning sickness: adaptive cause or nonadaptive consequence of embryo viability?

"Morning sickness" is the common term for nausea and vomiting in early human pregnancy (NVP). Recent interest in why NVP occurs-that is, in the evolutionary costs and benefits of NVP-has spurred the development of two alternative hypotheses. The "prophylaxis," or "maternal and embryonic protection," hypothesis suggests that NVP serves a beneficial function by expelling foods that may contain harmful toxins and microorganisms and triggering aversions to such foods throughout pregnancy. The alternative "by-product" hypothesis suggests that NVP is a nonfunctional by-product of conflict--over resource allocation--between the pregnant woman and the embryo. The critical predictions of the prophylaxis hypothesis have been developed and tested, whereas the by-product hypothesis has not been subjected to similar scrutiny. To address this gap, we developed a graphical model and used it to derive predictions from the by-product hypothesis under two different assumptions, namely, that NVP is either (i) a by-product of current conflict between a pregnant woman and an embryo or (ii) a by-product of honest signals of viability produced by the embryo. Neither version of the by-product hypothesis is fully consistent with available data. By contrast, the timing of NVP, its variation among societies, and associated patterns of food cravings and aversions are consistent with the prophylaxis hypothesis.

Birth outcomes of cases with unclassified multiple congenital abnormalities and pregnancy complications in their mothers depending on the number of component defects. Population-based case-control study

Multiple congenital abnormalities (MCA) represent the most severe category of structural birth defects, (i.e. congenital abnormalities [CA]). Unfortunately, most MCA are not recognized and/or identified as MCA syndromes or MCA associations in the clinical practice. The term unclassified MCA (UMCA) is used for this category of MCA. We decided to evaluate the component CA of UMCA cases. The population-based large dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities (1980-1996) was evaluated. 'False' MCA, such as complex CA, polytopic field defects and sequences were excluded from the category of MCA. In addition, MCA syndromes caused by chromosomal aberrations and major mutant genes with preconceptional origin were excluded from the dataset of the Surveillance. MCA syndromes caused by teratogens and MCA associations with well-defined component CA were also excluded in the study. Thus, only UMCA cases (i) without the recognition of previously delineated MCA syndromes (ii) and/or without the identification of new MCA syndromes or (iii) caused by random combination of CA were included in the study. We compared data from 1349 cases with UMCA, 2405 matched population controls without any CA, and 21 494 malformed controls with isolated CA. There was a higher rate of stillbirth and a moderate male excess in UMCA cases, a somewhat shorter gestational age at delivery and an obvious reduction in birthweight. The intrauterine fetal growth retardation and rate of low-birthweight newborns showed an association with the number of component CA in UMCA cases. A similar association was not found with gestational age and the rate of preterm birth. UMCA represent one of the most severe categories of CA. The degree of intrauterine fetal growth retardation depends on number of component CA in UMCA cases.

A population-based case-control teratologic study of promethazine use during pregnancy

Objective of the study was to investigate the teratogenic effect of oral promethazine, a phenothiazine derivate in the population-based data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities during the years 1980-1996. Of 22,843 cases with 25 congenital abnormalities, 3648 (16.0%) were born to mothers treated orally with promethazine during pregnancy. Of 38,151 matched population controls without congenital abnormalities, 6025 (15.8%) had mothers with promethazine treatment during the study pregnancy. Of 834 malformed controls (Down syndrome), 142 (17.0%) had mothers with treatment of promethazine in the study pregnancy. The case-all matched population controls analysis showed a higher rate of cleft lip+/-cleft palate (adjusted OR with 95% CI: 1.5, 1.1-2.0) and poly/syndactyly (OR with 95% CI: 1.3, 1.0-1.8) after promethazine treatment during the 2nd and 3rd months of gestation. However, these risks were explained by recall bias, because these associations were not confirmed after the evaluation of only medically recorded promethazine uses. The comparison of promethazine treatment between 25 congenital abnormality groups and malformed controls did also not show any risk. Thus, the overall evidence from analysis presented did not suggest that clinical doses of promethazine increased the rate of congenital abnormalities in humans.

Drug treatment during pregnancy and isolated orofacial clefts in hungary

OBJECTIVE

To evaluate the possible association between all kinds of drug treatments during pregnancy and isolated cleft lip with or without cleft palate (CL/P) and posterior cleft palate (PCP) in the offspring.

SETTING

The dataset of the large population-based Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996, was evaluated.

PARTICIPANTS

One thousand three hundred seventy-four cases with isolated CL/P and 601 with PCP, plus 38,151 population controls (without birth defects) and 20,868 malformed controls with other defects.

INTERVENTION

In this observation case-control study the data collection was based on prospective medical records particularly prenatal logbook, retrospective maternal data via a self-reported questionnaire, and home visits of nonresponding mothers.

MAIN OUTCOME MEASURES

Isolated CL/P and PCP associated with drug treatments during pregnancy.

RESULTS

An increased risk for isolated CL/P was found in cases born to mothers treated with amoxicillin, phenytoin, oxprenolol, and thiethylperazine during the second and third month of pregnancy, i.e., the critical period of isolated CL/P. Risk of isolated PCP was increased in mothers with oxytetracycline and carbamazepine treatment during the third and fourth month of pregnancy, i.e., the critical period of PCP.

CONCLUSIONS

This study confirmed the orofacial cleft (OFC) inducing effect of phenytoin, carbamazepine, oxytetracycline, and thiethylperazine and suggested a possible association between OFCs and oxprenolol and amoxicillin. However, drugs may have only a limited role in the origin of isolated OFCs.