Case control study identifying the maternal risk factors for congenital syphilis in Texas: 1998--2001

Background. Congenital syphilis (CS) is the oldest recognized congenital infection in the world. CS infection can affect multiple organs and can even cause neonatal death. CS is largely preventable when maternal syphilis is treated in an adequate and timely manner. During the decade of the nineties, rates of CS in Texas have often exceeded the overall US rate. Few studies, with adequate sample sizes, have been conducted to determine the risk factors associated with CS while controlling for factors associated with adult (maternal) syphilis infection. Objective. To determine the current maternal risk factors for CS infection in Texas from 1998–2001. Methods. A total of 1083 women with positive serological tests for syphilis during pregnancy or at delivery were reported to, and assessed by, health department surveillance staff. Mothers delivering infants in Texas between January 1, 1998 and June 30, 2001 comprised the study population. Mothers of infants diagnosed with confirmed or presumptive CS (N = 291) were compared to mothers of infants diagnosed as non-cases (N = 792) to determine the risk factors for vertical transmission (while controlling for risk factors of horizontal transmission). Logistic regression analyses were conducted to determine the associated odds between selected maternal variables and the outcome of CS. Results. Among 291 case infants, 5 (1.7%), 12 (4.1%), 274 (94.2%) were classified as confirmed cases, syphilitic stillbirths, and presumptive cases, respectively. Lack of maternal syphilis treatment was the strongest predictor of CS: odds ratio (OR) = 199.57 (95% CI 83.45–477.25) compared to those receiving treatment before pregnancy, while women treated during their pregnancies were also at increased risk (OR = 6.67, 95% CI 4.01–11.08). Women receiving no prenatal care were more likely (OR = 2.77, 95% CI 1.60–4.79) to have CS infants than those receiving prenatal care. Single women had higher odds (OR = 1.90, 95% CI 1.10–3.26) than ever-married women. African-Americans (OR 0.91, 95% CI 0.37–2.23) and Hispanics (OR = 1.66, 95% CI 0.68–4.05) may be more likely to have a CS infant than non-Hispanic Whites. Conclusions. The burden of CS in Texas can be alleviated through the provision of quality health care services, particularly prenatal care and treatment for sexually transmitted diseases. ^

The association between maternal use of spermicides, condoms, intra-uterine devices or progesterone and major structural birth defects

Birth defects occur in 1 of every 33 babies born in the United States, and are the leading cause of infant death. Mothers using contraceptives that become pregnant may continue to use their contraceptives after their first missed menstrual period, thus exposing their baby in utero to the contraceptive product. Progesterone is also sometimes prescribed during the first trimester of pregnancy to mothers with a history of miscarriages or infertility problems. To ensure the safety of these products, it is important to investigate whether there is an increased occurrence of babies born with birth defects to mothers using various contraceptive methods or progesterone in early pregnancy. Using data from the National Birth Defects Prevention Study (NBDPS), an ongoing multi-state, population based case-control study, this study assessed maternal exposures to IUDs, spermicides, condoms and progesterone in early pregnancy. ^ Progesterone used for threatened miscarriage during the first three months of pregnancy was associated with an increased occurrence of hypoplastic left heart (adjusted odds ratios (OR) 2.24, 95% CI 1.13-4.21), perimembranous ventricular septal defects (OR 1.64, 95% CI 1.10-2.41), septal associations (OR 2.52, 95% CI 1.45-4.24), esophageal atresia (OR 1.82, 95% CI 1.04-3.08), and hypospadias (OR 2.12, 95% CI 1.41-3.18). Mothers using progesterone for injectable contraception had increased (OR > 2.5), but insignificant odds ratios for anencephaly, septal associations, small intestinal atresias and omphalocel. Progesterone used for fertility was not associated with an increased occurrence of any birth defects examined. ^ Mothers using progesterone for fertility assistance and threatened miscarriage were very similar with respect to their demographics and pregnancy history. They also both reported similar types of progesterone. Thus, if progesterone was a causal risk factor for birth defects we would have expected to observe similar increases in risk among mothers using progesterone for both indications. Because we predominantly observed increased associations among mothers using progesterone for threatened miscarriage but not fertility assistance, it is possible the increased associations we observed were confounded by indication (i.e. progesterone was administered for vaginal bleeding which occurred as a sequelae to the formation of a congenital anomaly. ^ No significant increased associations were observed between maternal spermicide use during pregnancy and 26 of 27 types of structural malformations. While multiple statistical tests were performed we observed first trimester maternal spermicide use to be associated with a significant increased occurrence of perimembranous ventricular septal defects (OR 2.21, 95% CI 1.16-4.21). A decreased occurrence (OR < 1.0) was observed for several categories of birth defects among mothers who conceived in the first cycle after discontinuing the use of spermicides (22 of 28) or male condoms (23 of 33). ^ Overall the percent of IUD use was similar between mothers of controls and mothers of all cases in aggregate (crude OR 1.05, 95% CI 0.61-1.84). Power was limited to detect significant associations between IUD use and birth defects, however mothers using an IUD in the month immediately prior to conception or during pregnancy were not associated with an increase of birth defects. Limb defects and amniotic band sequence previously reported to be associated with IUD use during pregnancy were not found to occur among any mothers reporting the use of an IUD during pregnancy.^