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SMFM Abstracts www.AJOG.org

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75 AGE AT MENARCHE AND THE RISK OF OPERATIVE FIRST DELIVERY GORDON SMITH1,1Cambridge University, Obstetrics & Gynecology, Cambridge, United Kingdom

OBJECTIVE: The risk of operative delivery at term increases linearly with the ageof the mother. We have hypothesized that this is due to a deleterious effect of aprolonged interval between menarche and first birth on uterine function. The ob-jective of this study was to test a prediction arising from that hypothesis, namely,that the risk of operative first delivery would decline with later age at menarche.

STUDY DESIGN: We studied the relationship between age at menarche and therisk of operative delivery (a composite of cesarean, forceps or vacuum extraction)using data from ALSPAC, a multi-center prospective cohort study of women at-tending for prenatal care in South West England. The study group consisted of 3739primipara in labor at term with a singleton liveborn infant in a cephalic presenta-tion.

RESULTS: The rate of operative delivery was highest among women with age atmenarche in the bottom quartile (32.4%) and was lower in the second (30.3%),third (29.2%) and top (26.9%) quartiles (test for trend, P�0.01). When adjustedfor height, body mass index, marital status, smoking status, induction of labor,week of gestation of delivery and birth weight percentile; the odds ratio for opera-tive delivery associated with a 5 year increase in age at menarche (0.71, 95% CI �0.54-0.92, P�0.01) was very similar to the odds ratio for a 5 year decrease in age atdelivery (0.72, 95% CI � 0.66-0.79, P�0.001). There was no association betweenage at menarche and the risk of operative delivery following adjustment for theinterval between menarche and the first birth (adjusted odds ratio 0.99, 95% CI �0.78-1.25, P�0.91).

CONCLUSION: (1) Later age at menarche is associated with a decreased risk ofoperative first childbirth, consistent with the hypothesis that a prolonged intervalbetween menarche and first birth has a deleterious effect on uterine function. (2)This property of the uterus may explain a significant proportion of recent rises incesarean section rate, through population trends of earlier menarche and later firstchildbirth.

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2008.09.403

76 DO PERINATAL OUTCOMES DIFFER AMONG THE AFRICAN DIASPORA? AYABAWORJOLOH1, LUCHIN WONG2, ALLISON BRYANT3, YVONNE CHENG4, SHANI DELANEY4,AARON CAUGHEY4, 1University of California San Francisco, South San Francisco,California, 2Santa Clara Valley Medical Center, San Jose, California, 3University ofCalifornia San Francisco, San Francisco, California, 4University of California, SanFrancisco, San Francisco, California

OBJECTIVE: To determine whether perinatal outcomes differ by country oforigin among Black women delivering in the U.S.

STUDY DESIGN: This is a retrospective cohort study of all Black women deliv-ering in the U.S. in 2003. We assessed if maternal place of birth, U.S versus non-U.S,was predictive of selected perinatal outcomes. We examined pregnancy-associatedhypertension (PAH), diabetes in pregnancy (DM/GDM), preterm delivery (PTD),low birthweight (�2500 gms) and term cesarean delivery (CD) as outcomes. Weutilized univariate and multivariable analyses to control for potential confounding.

RESULTS: Among the 574,437 Black women delivering in the U.S. in 2003,103,746 were non-U.S. born (18.1%). All of the perinatal outcomes we examineddiffered between U.S. born and non-U.S. born Black women except for term cesar-ean delivery (Table 1). All findings of the univariate analyses persisted when wecontrolled for maternal age, parity, education, prenatal care, and previous pretermdelivery.

CONCLUSION: There is a higher frequency of many adverse perinatal outcomesamong U.S Born black women compared to non-U.S Born. This suggests decreasedrisk for Black women born outside of the United States which may be hypotheticallyrelated to U.S. socioeconomic differences or behavioral or dietary differences. Theexceptions were term cesarean delivery and diabetes of pregnancy. Further study isneeded to determine what might account for these differences.

Table 1 Comparison of perinatal outcomes in U.S. Born vs. Non-U.S. born Black women

U.S. Born Non-U.S. born p-value

PTD 12.6% 10.8% �0.001PTD�32 2.0% 1.6% �0.001GH/preE 4.3% 2.4% �0.001DM/GDM 3.1% 3.8% �0.001Lbwt 8.2% 6.7% �0.001Term CD 14.8% 14.6% 0.250

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2008.09.404

114 American Journal of Obstetrics & Gynecology Supplement to DECEMBER

77 EFFECT OF A PREVIOUS CESAREAN DELIVERY ON NEONATAL OUTCOMES HAIMABENHAIM1, WILLIAM FRASER2, ALICE BENJAMIN3, 1Jewish General Hospital, McGillUniversity, Montreal, Quebec, Canada, 2Ste-Justine, University of Montreal, Mon-tréal, Quebec, Canada, 3McGill University, Montreal, Quebec, Canada

OBJECTIVE: For various reasons, cesarean delivery have increased considerablyover the last several decades resulting in a greater proportion of new pregnanciesbeing in women with prior cesarean delivery. In our study, we sought to examinethe effect of a previous cesarean delivery on neonatal outcomes.

STUDY DESIGN: We conducted a retrospective cohort study on all women witha prior birth who delivered at the Royal Victroia Hospital between 2001 and 2006.We defined our exposure as as having a positive history for cesarean delivery andused unconditional logistic regression analysis to estimate the adjusted effect of aprevious cesarean delivery on adverse neonatal outcomes.

RESULTS: There were 18,673 births that took place of which 9,708 were inwomen with a previous birth (77.0% with no previous cesarean delivery and 23.0%with a previous cesarean delivery). As compared to newborns delivered by motherswith no previous cesarean delivery, newborns of mothers with a previous cesareandelivery were more likely to be born �37 week, OR 1.21 (1.04-1.40), p�0.01,develop respiratory distress syndrome, OR 1.94 (1.50-2.57), p�0.01, and be admit-ted to the neonatal ICU, OR 1.52 (1.30-1.77), p�0.01.

CONCLUSION: Having a previous cesarean delivery is associated with an in-creased risk of adverse neonatal outcomes. When consenting women for cesareandelivery, consideration should be given to the potential effect it may have on neo-natal outcomes of subsequent pregnancies.

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2008.09.405

78 INTIMATE PARTNER VIOLENCE AND ADVERSE PREGNANCY OUTCOMES MATTHEWGARABEDIAN1, KRISTINE LAIN1, WENDY HANSEN1, LISANDRA GARCIA1, ANN COKER1,LESLIE CROFFORD1, 1University of Kentucky, Department of OB/GYN, Lexington,Kentucky

OBJECTIVE: To evaluate the association between intimate partner violence(IPV) by type experienced (sexual, physical, or stalking) and third trimester bleed-ing, preeclampsia, and preterm labor (PTL).

STUDY DESIGN: This is a cross-sectional study of parous women in the Ken-tucky Women=s Health Registry who indicated a history of IPV (n�3331). Adversepregnancy outcomes were identified from a self-report questionnaire. Multivariateanalysis controlled for age, education, race, and gravidity.

RESULTS: A history of any IPV was associated with increased risk of third tri-mester bleeding (aRR 1.8; 95% CI 1.3 – 2.4), preeclampsia (1.5; 1.2 – 1.8), and PTL(1.5; 1.2 – 1.8). Sexual IPV with or without other types of IPV (stalking or physical)was more strongly associated with third trimester bleeding (2.8; 1.8-4.3), pre-eclampsia (1.4; 1.1-1.9), and PTL (1.7; 1.3-2.2) than were other forms of IPV.Physical IPV yet no sexual IPV was associated with bleeding (1.8; 1.2-2.8) and PTL(1.4; 1.1-1.8) but not preeclampsia (1.2; 0.9-1.6). Stalking by an intimate partnerwithout sexual or physical IPV was associated with preeclampsia (1.4; 1.1-2.0) butnot bleeding (1.3; 0.7-2.5) or PTL (1.2; 0.9-1.8).

CONCLUSION: These data suggest different mechanisms by which varying typesof IPV influence maternal complications. The trauma and psychological stress fromphysical or sexual IPV may differentially affect risk of bleeding and PTL. Partnerstalking may affect preeclampsia risk through psychosocial stress levels. IPV isknown to be associated with adverse pregnancy outcomes such as perinatal deathand low birth weight neonates. This cross-sectional study shows significant associ-ations between a history of intimate partner violence with preeclampsia, PTL, andthird trimester bleeding, yet we cannot comment on whether the abuse was ante-cedent to the pregnancy outcomes. Our data highlight the need to screen for IPVamong pregnant women and, when found, provide surveillance for a spectrum ofadverse outcomes.

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2008.09.406

2008