Sexuality in pregnancy and premature labour

Summary. The relation of sexual behaviour during pregnancy to the initiation of labour was investigated in 358 patients of whom 58 were delivered after premature labour and 300 were delivered spontaneously at term. In all patients the mean weekly coital frequency and the frequency of orgasm were investigated by means of a retrospective questionnaire. There was no significant difference in coital or orgasmic frequency between the women who had a premature labour and those who had a spontaneous delivery at term. This was also true when those having premature labour were divided into those starting labour with ruptured membranes and those starting with contractions.     

Myometrial oxytocin receptor mRNA concentrations at preterm and term delivery – the influence of external oxytocin

The hormonal system for induction of term and preterm labour is not fully understood. Therefore, we investigated myometrial gene expressions for neurohypophyseal hormones and their receptors, prostaglandin F_2α and ovarian steroid receptors in women delivered by Caesarean section. Myometrial tissue for real time PCR was collected from 39 women delivered at term before and after the onset of labour and preterm. Women delivered electively at term had significantly higher oxytocin receptor mRNA expressions (2.52 ± 0.37 oxytocin receptor/actin; median ± SEM) than those delivered with ongoing labour at term (1.01 ± 0.34; p = 0.015) and those at preterm (1.08 ± 0.25; p = 0.004). Sub-analyses revealed that the difference at term pregnancies solely was related to patients receiving oxytocin during labour (p = 0.007). These patients had higher oxytocin peptide mRNA levels than those without labour at term (p = 0.009). PGF_2α receptor mRNA concentrations were 27.80 ± 3.55, 11.46 ± 2.87 and 19.54 ± 5.52 PGF receptor/actin, respectively, for the groups. Women without labour at term had higher concentration than those with labour (p = 0.005). Our results suggest that oxytocin, its receptor and the PGF_2α receptor are involved in the regulation of labour through a paracrine mechanism.     

Relationships of vaginal Lactobacillus species, cervical Chlamydia trachomatis, and bacterial vaginosis to preterm birth

The frequency of genital infection was compared among women in premature labor who delivered preterm (before 37 weeks), women in preterm labor who delivered at term, and control women who delivered at term. Both groups of women in premature labor were younger and had more previous preterm births than did control women. Women in premature labor who delivered preterm were more likely to experience rupture of membranes, intrapartum fever, and postpartum fever than were control women. The presence of bacterial vaginosis (odds ratio 2.3) and Chlamydia trachomatis (odds ratio 3.9) was positively associated, and Lactobacillus sp (odds ratio 0.2) was negatively associated, with birth before 37 weeks, using multivariable analysis to control for confounding variables.     

Predictive Oestradiol Surge of Premature Labour and its Suppression by Glucocorticoids

Summary: Plasma oestradiol-17β and plasma progesterone levels in premature labour have been compared with those measured serially in 33 primigravidae during normal pregnancy and labour. In 31 of the 38 patients in progressive premature labour, the plasma oestradiol level was 2 S.D. or more above the mean for control patients of similar gestational age and was similar to those patients during labour at term. Levels of plasma progesterone in patients in the premature labour group tended to be below the mean for gestation, although still within the normal range. In 12 patients studied serially, oestradiol levels rose dramatically, high values being detected 9.6 ± 5.2 days preceding parturition; progesterone levels gave no consistent trend. Progressive uterine activity in preterm labour and term labour seems to be associated with a progesterone to oestradiol ratio of 6:1. The steroid profiles of 2 patients in premature labour were studied before and after the administration of betamethasone. Both the premature labour and the elevated plasma oestradiol levels were suppressed by the therapy.     

Outcome of the second labour in patients whose first labour was prolonged: the Dublin experience.

This observational study examined the outcome of the second delivery in patients whose first labour was prolonged. The onset of labour was defined as that time when the diagnosis of labour was made on admission to the delivery unit. The first labour was defined as prolonged when delivery occurred more than 12 h later. The study was confined to those patients (n = 66) who had a prolonged first labour with a single, live fetus and cephalic presentation during 1984-1987 and who had a subsequent labour. Sixty-one of the 66 patients (92%) delivered vaginally, and 5 were delivered by emergency caesarean section. Forty-six (70%) delivered within 6 h of admission. Although all 66 had received oxytocin in their first labour, only 8 (12%) required oxytocin in their second labour. Fourteen (82.4%) of the 17 patients with a previous caesarean section had a vaginal delivery. These results indicate that compared to the first labour the duration of the second labour and the oxytocin requirements in the second labour were significantly reduced. These findings are reassuring for patients who have had a long difficult first labour.     

Symptoms and Signs with Scar Rupture - Value of Uterine Activity Measurements

To evaluate the symptoms and signs of scar rupture with special reference to intrauterine pressure measurement a retrospective analysis of labour records of those women who had trial of labour with a previous Caesarean scar in the National University Hospital over a period of 6 years (1985-1990) was carried out. Known symptoms and signs associated with scar rupture, cardiotocographic tracings and fetal and maternal outcome in these patients were studied. Of the 1,018 women with previous Caesarean scar (4.2% of our pregnant population at term) 722 (70.9%) had trial of labour; 70% delivered vaginally. There were 4 (0.55%) incomplete and 5 (0.69%) complete scar ruptures. All 9 women had an oxytocin infusion; 3 were diagnosed postdelivery (all 3 had complete ruptures); 3 of the 6 who had rupture prior to delivery had sudden reduction in uterine activity, 1 had scar pain and prolonged bradycardia and 2 had no symptoms or signs. Continuous cardiotocography with intrauterine pressure measurements may help to identify scar rupture early and may be of value especially in those who have an oxytocin infusion.     

Resistin in amniotic fluid and its association with intra-amniotic infection and inflammation

Objective. Intra-amniotic infection/inflammation (IAI) is one of the most important mechanisms of disease in preterm birth. Resistin is an adipocytokine that has been linked to insulin resistance, diabetes, obesity and inflammation. The objective of this study was to determine if resistin is present in amniotic fluid (AF) and if its concentration changes with gestational age, in the presence of labour, and in IAI in patients with spontaneous preterm labour (PTL) and intact membranes, preterm prelabour rupture of membranes (PPROM) and clinical chorioamnionitis.

Study design. This cross-sectional study included 648 patients in the following groups: (1) women in the mid-trimester of pregnancy (14–18 weeks) who underwent amniocentesis for genetic indications and delivered a normal neonate at term (n = 61); (2) normal pregnant women at term with (n = 49) and without (n = 50) spontaneous labour; (3) patients with an episode of PTL and intact membranes who were classified into: (a) PTL who delivered at term (n = 153); (b) PTL who delivered preterm (<37 weeks gestation) without IAI (n = 108); and (c) PTL with IAI (n = 84); (4) women with PPROM with (n = 47) and without (n = 44) IAI; and (5) patients with clinical chorioamnionitis at term with (n = 22) and without (n = 30) microbial invasion of the amniotic cavity. Resistin concentration in AF was determined by enzyme-linked immunoassay. Non-parametric statistics were used for analyses.

Results. (1) Resistin was detected in all AF samples; (2) the median AF resistin concentration at term was significantly higher than in the mid-trimester (23.6 ng/mL vs. 10 ng/mL; p < 0.001); (3) among patients with PTL, the median AF resistin concentration was significantly higher in patients with IAI than in those without IAI (144.9 ng/mL vs. 18.7 ng/mL; p < 0.001) and those with PTL and intact membranes who delivered at term (144.9 ng/mL vs. 16.3 ng/mL; p < 0.001); (4) patients with PPROM with IAI had a significantly higher median AF resistin concentration than those without IAI (132.6 ng/mL vs. 13 ng/mL; p < 0.001); (5) no significant differences were observed in the median AF resistin concentration between patients with spontaneous labour at term and those at term not in labour (28.7 ng/mL vs. 23.6 ng/mL; p = 0.07); and (6) AF resistin concentration ≥37 ng/mL (derived from a receiver-operating characteristic curve) had a sensitivity of 85.4% and a specificity of 94.3% for the diagnosis of intra-amniotic inflammation.

Conclusions. Resistin is a physiologic constituent of the AF, and its concentrations in AF: (1) are significantly elevated in the presence of IAI; (2) increase with advancing gestation; and (3) do not change in the presence of spontaneous labour at term. We propose that resistin may play a role in the innate immune response against intra-amniotic infection.     

Elevation of total nitrite and nitrate concentration in vaginal secretions as a predictor of premature delivery

We measured the total concentration of nitrite and nitrate, metabolites of nitric oxide, in vaginal secretions from pregnant women at 22 to 32 weeks' gestation. Total nitrite and nitrate concentrations in patients with preterm premature rupture of membranes and in those with preterm labor and subsequent premature delivery were significantly higher than concentrations in patients who were delivered at term. Elevated total nitrite and nitrate concentration may predict premature delivery.     

Expansion of intravascular volume and fetal outcome in patients with chronic hypertension and pregnancy.

Measurements of blood volume were carried out between 24 and 40 weeks of gestation in 20 multiparous patients with chronic hypertension and pregnancy. Hypertensive patients had both reduced blood volume and infants of smaller weight (p less than 0.01) than nonhypertensive control subjects. There was a significant difference (p less than 0.01) in the degree of blood volume expansion in hypertensive mothers who were delivered of infants who were adequate for gestational age (AGA), term, or premature, compared to those who were delivered of infants who were small for gestational age (SGA) or stillborn. Classification of chronic hypertension during pregnancy according to the American Committee on Maternal Welfare classification or according to severity of the hypertension was of no value in identifying the mothers at risk of delivering intrauterine growth-retarded infants. However, failure in achieving a blood volume expansion of at least 60 c.c. per kilogram clearly identified those pregnancies leading to growth retardation and fetal death. The decrease or lack of intravascular volume expansion was reflected in the presence of creatinine clearance values at nonpregnant levels in the mothers who were delivered of SGA infants and in a significant reduction below the nonpregnant levels in those who were delivered of stillborn infants. These data suggest that measurement of blood volume and endogenous creatinine clearance in patients with chronic hypertension and pregnancy is a useful parameter in the identification of those patients who will have a poor fetal outcome.     

Do patients who deliver at term after being hospitalized for preterm contractions have an increased risk for obstetrical complications?

Objectives

To determine the obstetrical complications and perinatal outcomes of patients with recurrent episodes of preterm contractions (PTC) that eventually delivered at term compared to those who delivered preterm.

Methods

A retrospective study evaluating pregnancy complications and adverse perinatal outcomes of patients with recurrent episodes of PTC (three or more) was conducted. A comparison was made between those who delivered preterm to those who eventually delivered at term.

Results

Deliveries occurred between the years 1989 and 2009. During the study period, there were 1,897 singleton deliveries at term and 393 preterm singleton deliveries of patients who were previously hospitalized with PTCs. Patients who delivered at term were significantly more likely to be in their first pregnancy and to be primiparous. Patients in the study group were less likely to have had fertility treatments, a history of miscarriage, a higher incidence of one previous hospitalization but lower rates of multiple hospitalizations for PTC. Patients who delivered at term had a significantly lower rate of severe preeclampsia as well as cesarean delivery and a shorter hospital stay than those who delivered preterm. At term, an increased incidence of small for gestational age (SGA) neonates was noted compared to patients who delivered prematurely (10.07 vs. 5.6 %; P = 0.005).

Conclusion

Patients with symptoms of preterm labor may require further surveillance, not only because of their risk to progress to preterm delivery, but also because they are at an increased risk for delivering an SGA neonate at term.     

Pregnancy outcome in medically complicated and uncomplicated patients aged 40 years or older

Patients (183) who were delivered at age greater than or equal to 40 years were studied to ascertain the nature and frequency of maternal and fetal complications at a single institution in a recent time period. These patients were further grouped into those of low parity, those who began pregnancy without underlying disease, and those who began pregnancy with underlying medical disorders. For the entire group preeclampsia, premature labor, precipitate labor, and malpresentation were significantly more common. The rate of vaginal delivery was substantially decreased, and serious postpartum morbidity was relatively common. The incidence of stillbirth, perinatal mortality, and abnormal birth weight was significantly increased. There were some differences in the nature and frequency of complications encountered among the subgroups, but no subgroup had a complication rate comparable to our general obstetric population.     

Catecholamine abnormalities in transient tachypnoea of the premature newborn.

The aim of the present study was to assess if there was an association between low catecholamine levels at birth in the premature infant and the development of TTN. Blood samples were collected at delivery from the umbilical artery of all preterm infants with a gestational age less than 36 weeks for determination of pH and catecholamine levels (noradrenaline and adrenaline). Amongst non-asphyxiated infants only, cord pH greater than 7.25 and/or Apgar score greater than 7 at five minutes, catecholamine levels were compared between the 10 infants who developed transient tachypnoea of the newborn (TTN) and 13 controls of a similar gestational age range (31-35 weeks) who developed no respiratory distress in the neonatal period. Infants who developed TTN were more often delivered without labour, 8 of 10 compared to 2 of 13 controls (p less than 0.01). There were no significant differences in adrenaline levels between the two groups. Noradrenaline levels, however, were significantly lower in the infants who developed TTN, being a median of 3.1 nmol/l (range 1.07-5.85 nmol/l) compared to a median of 6.4 nmol/l (range 2.38-22.83) in the controls (p less than 0.01). Infants who were delivered following labour had significantly elevated noradrenaline levels compared those delivered without labour (elective delivery) (p less than 0.05). These results suggest that low noradrenaline levels in preterm infants may explain the association in this group of TTN and "elective" delivery.     

Effect of relaxin on prostaglandin E production by human amnion: changes in relation to the onset of labour

The effect of relaxin on prostaglandin E (PGE) production by human amnion in vitro was investigated. When amniotic discs were incubated in the presence of increasing concentrations of relaxin, two distinct effects were observed. Discs prepared from women delivered by caesarean section before the onset of labour showed a significant decrease in PGE output at relaxin concentrations of 0.5-2 micrograms/ml; the effect was abolished at higher relaxin concentrations. Discs obtained from women delivered after labour of spontaneous onset responded to the addition of relaxin (4-8 micrograms/ml) with a significant increase in PGE output, although this increase was only evident in patients in whom labour had started with intact membranes. These results suggest that relaxin, which is present in decidua and chorion laeve at term, may have a paracrine effect on the amnion, inhibiting PGE production during continuing pregnancy but favouring its production during spontaneous labour.     

Effect of relaxin on prostaglandin E production by human amnion: changes in relation to the onset of labour

Summary. The effect of relaxin on prostaglandin E (PGE) production by human amnion in vitro was investigated. When amniotic discs were incubated in the presence of increasing concentrations of relaxin, two distinct effects were observed. Discs prepared from women delivered by caesarean section before the onset of labour showed a significant decrease in PGE output at relaxin concentrations of 0.5–2 μg/ml; the effect was abolished at higher relaxin concentrations. Discs obtained from women delivered after labour of spontaneous onset responded to the addition of relaxin (4–8 μg/ml) with a significant increase in PGE output, although this increase was only evident in patients in whom labour had started with intact membranes. These results suggest that relaxin, which is present in decidua and chorion laeve at term, may have a paracrine effect on the amnion, inhibiting PGE production during continuing pregnancy but favouring its production during spontaneous labour.     

Evidence for the participation of interstitial collagenase (matrix metalloproteinase 1) in preterm premature rupture of membranes

OBJECTIVE: Rupture of membranes is thought to result from the effects of physical forces in localized areas of the membranes weakened by the degradation of structural collagens. Matrix metalloproteinases are enzymes that degrade extracellular matrix components and have been implicated in membrane rupture. The objective of this study was to determine whether spontaneous rupture of membranes is associated with a change in the amniotic fluid concentration of interstitial collagenase (matrix metalloproteinase 1 [MMP-1]), a major collagenase. STUDY DESIGN: A cross-sectional study was conducted to determine MMP-1 concentrations in amniotic fluid from 353 women in the following categories: (1) term with intact membranes not in labor and in labor, (2) preterm labor who delivered at term, (3) preterm labor who delivered preterm without microbial invasion of the amniotic cavity, (4) preterm labor who delivered preterm with microbial invasion of the amniotic cavity, (5) preterm premature rupture of membranes with and without microbial invasion of the amniotic cavity, (6) term premature rupture of membranes not in labor and in labor, and (7) mid trimester of pregnancy. Microbial invasion of the amniotic cavity was determined by an amniotic fluid culture positive for microorganisms. MMP-1 concentrations in amniotic fluid were determined by means of sensitive and specific immunoassays. RESULTS: (1) MMP-1 was detectable in 81.3% of amniotic fluid samples (287/353), and its concentrations increased with advancing gestational age (r = 0.4; P <.001). (2) Preterm premature rupture of membranes was associated with a significant increase in the median amniotic fluid concentration of MMP-1 (P =.02). (3) Women with term premature rupture of membranes had a significantly lower amniotic fluid MMP-1 concentration than those with intact membranes at term not in labor (P <.001). (4) Microbial invasion of the amniotic cavity in patients in preterm labor with intact membranes and in patients with preterm premature rupture of membranes was also associated with significant increases in the median amniotic fluid MMP-1 concentrations (P <.05 and P <.01, respectively). (5) Patients with preterm premature rupture of membranes and microbial invasion of the amniotic cavity had a significantly higher median amniotic fluid MMP-1 concentration than those with intact membranes and microbial invasion of the amniotic cavity (P =.01). (6) Neither term nor preterm parturition was associated with changes in amniotic fluid MMP-1 concentrations (P =.6 and P =.3, respectively). CONCLUSION: (1) Collagenase 1 (MMP-1) is a physiologic constituent of amniotic fluid. (2) Preterm premature rupture of membranes (in both the presence and absence of infection) was associated with an increase in the amniotic fluid MMP-1 concentrations. (3) Neither term nor preterm parturition was associated with a significant increase in the amniotic fluid concentration of MMP-1.     

Midtrimester amniotic fluid matrix metalloproteinase-8 (MMP-8) levels above the 90th percentile are a marker for subsequent preterm premature rupture of membranes

OBJECTIVE: We sought to determine whether midtrimester amniotic fluid levels of matrix metalloproteinase-8 were associated with subsequent preterm premature rupture of membranes. STUDY DESIGN: We conducted a case-control study examining 57 asymptomatic women who underwent genetic amniocentesis from 14 to 21 weeks' gestation and subsequently had preterm premature rupture of membranes (<35 wk) and 58 women with subsequent term delivery. Measurement of total matrix metalloproteinase-8 level in amniotic fluid was conducted using a commercially available enzyme-linked immunosorbent assay and association with preterm birth due to preterm premature rupture of membranes was assessed. RESULTS: The overall distribution of matrix metalloproteinase-8 concentrations was similar in women who had preterm premature rupture of membranes and term controls (median 2.39 ng/mL, 25th to 75th percentile 1.1-10.1 vs 2.37 ng/mL, 25th to 75th percentile 1.5-4.7, P = .94). However, 26% of women who had preterm premature rupture of membranes had a matrix metalloproteinase-8 concentration above the 90th percentile (8.7 ng/mL), compared with only 10% of term controls (odds ratio 3.1, 95% CI 1.1-8.7; P = .03). Elevated matrix metalloproteinase-8 remained associated with preterm premature rupture of membranes after adjustment for maternal age, race, parity, gestational age, and year of amniocentesis (odds ratio 3.4, 95% CI 1.2-9.9; P = .03). CONCLUSIONS: The overall distribution of midtrimester amniotic fluid matrix metalloproteinase-8 levels did not differ between women who had preterm premature rupture of membranes and those delivered at term. However, marked elevations of midtrimester amniotic fluid matrix metalloproteinase-8 were highly associated with subsequent preterm premature rupture of membranes, suggesting that the pathophysiologic processes that contribute to preterm premature rupture of membranes may begin in early pregnancy.     

Exodus-1 (CCL20): evidence for the participation of this chemokine in spontaneous labor at term, preterm labor, and intrauterine infection

AIM: CCL20, also known as MIP-3 alpha, is a chemokine that participates in chemotaxis of immature dendritic cells, effector/memory T-cells, and B-lymphocytes. The objectives of this study were to determine whether CCL20 can be detected in amniotic fluid (AF) and if AF concentration of this chemokine changes with advancing gestational age, parturition (term and preterm), and intra-amniotic infection/inflammation (IAI). METHODS: A cross-sectional study was conducted including the following groups: (1) mid-trimester of pregnancy (n=65); (2) term not in labor (TNL; n=22); (3) term in labor (TIL; n=47); (4) spontaneous preterm labor (PTL) who delivered at term (n=57); (5) spontaneous PTL without IAI who delivered preterm (n=71); and (6) spontaneous PTL with IAI (n=38). AF CCL20 concentrations were determined using ELISA. RESULTS: (1) The median AF CCL20 concentration in TNL was higher than that of mid-trimester patients; (2) Women in spontaneous labor at term had a higher median AF concentration of CCL20 than patients at term not in labor; (3) Patients with spontaneous PTL and IAI had a significantly higher median AF concentration of CCL20 than those without IAI who delivered preterm and those who delivered at term. Moreover, women with spontaneous PTL without IAI who delivered preterm had a significantly higher median AF concentration than those with PTL who subsequently delivered at term. CONCLUSIONS: (1) CCL20 is a physiologic constituent of AF and its concentration increases as term approaches; (2) spontaneous labor (term and preterm) in the absence of IAI is associated with increased bioavailability of AF CCL20 suggesting that an increase in CCL20 is part of the common pathway of human parturition; (3) patients with IAI had dramatic elevations in the AF CCL20 concentrations suggesting that this chemokine participates in the host response to infection or other stimuli associated with intra-amniotic infection.     

Human beta-defensin-2: a natural antimicrobial peptide present in amniotic fluid participates in the host response to microbial invasion of the amniotic cavity.

OBJECTIVE: Human beta-defensin-2 (HBD-2) is a potent antimicrobial peptide that is part of the innate immune response. The purpose of this study was to determine whether HBD-2 is present in amniotic fluid and if its concentration changes with microbial invasion of the amniotic cavity (MIAC) and labor. STUDY DESIGN: Amniotic fluid was retrieved by amniocentesis from 318 patients in the following groups: (1) mid-trimester (n=75); (2) term not in labor (n=28) and in labor (n=51); (3) preterm labor and intact membranes without MIAC who delivered at term (n=36), who delivered preterm without MIAC (n=52), and preterm labor with MIAC who delivered preterm (n=25); and (4) preterm premature rupture of membranes (preterm PROM) with (n=25) and without MIAC (n=26). MIAC was defined as a positive amniotic fluid culture for microorganisms. Amniotic fluid HBD-2 concentrations were determined using a sensitive and specific ELISA. Non-parametric statistics were used for analysis. RESULTS: (1) HBD-2 was detected in all amniotic fluid samples; (2) the concentration of HBD-2 did not change with gestational age from mid-trimester to term (p=0.8); (3) intra-amniotic infection was associated with a significant increase in amniotic fluid concentrations of HBD-2 in both women with preterm labor and intact membranes, and women with preterm PROM (p<0.05 for each comparison); (4) patients with preterm labor and a negative amniotic fluid culture who delivered preterm had a higher median amniotic fluid HBD-2 concentration than those with preterm labor who delivered at term (p=0.001); and (5) among patients with preterm labor without MIAC, those who had intra-amniotic inflammation (amniotic fluid white blood cell count>100 cells per mL) had a higher median amniotic fluid concentration of HBD-2 than those without this condition (p<0.002). CONCLUSION: (1) Amniotic fluid contains HBD-2, a natural antimicrobial peptide, and this may account for some of the antimicrobial activity of amniotic fluid; (2) amniotic fluid HBD-2 concentrations are increased in women with MIAC, regardless of the membrane status (intact membranes or PROM); and (3) we propose that amniotic fluid HBD-2 is part of the innate immune system within the amniotic cavity.     

Why lightning strikes twice: postpartum resumption of sexual activity during adolescence

PURPOSE: To describe the circumstances surrounding the postpartum resumption of sexual activity in a cohort of teenage mothers. The goal was to shed new light on the reasons why teenagers who have just given birth put themselves at risk for conception. METHODS: A racially and ethnically diverse group of 267 poor, predominantly unmarried, primiparous, 13-21 year olds was enrolled consecutively at delivery and followed through the third postpartum month. The primary outcome measure was weeks postpartum at resumption of sexual activity, further categorized as protected or unprotected. The analysis controlled for factors thought to influence the postpartum resumption of sexual activity among adult couples and the use of contraception during adolescence. The Kaplan-Meier method was used to estimate the time to end point and Cox proportional-hazards regression analysis to compute relevant relative risks (RR). RESULTS: By the end of the third postpartum month, 58% of the teenagers had had sexual intercourse and the majority (80%) used contraception when they did so. The median time to first coitus, 10.7 weeks, was unrelated to contraceptive use but was significantly shorter among teenagers who lived with their boyfriends (RR: 2.4; 95%CI: 1.7-3.4) and those who delivered prior to term (RR: 2.1; 95%CI: 1.3-3.6). The analysis revealed that the teenagers who did not use contraception at first postpartum sexual intercourse exhibited more theorized risk factors for conception than those who did and those who remained sexually abstinent. CONCLUSIONS: This new empirical evidence that coital activity resumes soon after delivery should dispel the normative belief that contraception is unnecessary during the puerperium. Early contraceptive vigilence may also decrease the frequency and rapidity with which teen mothers conceive, as the differences in the prevalence of teen pregnancy risk factors we uncovered suggest that decisions about using contraception (not sexual intercourse) determine the risk of rapid repeat conception. Teens with live-in boyfriends and premature babies are especially apt to benefit from the new information in this report as they resume sexual activity sooner than their peers and are less apt to use contraception when they do so.