Effects of induced abortion on subsequent reproductive function and pregnancy outcome, Hawaii

158 Pages·2012·26.67 MB·English

by  Chin Sik Chung

Papers
of the
East-West
Population Institute
No. 86
The effects
of induced
abortion
on subsequent
reproductive
function
and pregnancy
outcome:
Hawaii
Chin Sik Chung
and Patricia G. Steinhoff
with Roy G. Smith
and Ming-Pi Mi
East-West Center
Honolulu, Hawaii
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The effects
of induced
abortion
on subsequent
reproductive
function
and pregnancy
outcome:
Hawaii
Chin Sik Chung
and Patricia G. Steinhoff
in collaboration
with Roy G. Smith
and Ming-Pi Mi
Number 86 . June 1983
PAPERS OF THE EAST-WEST POPULATION INSTITUTE
CHIN SIK CHUNG is Professor of Public Health and Genetics,
University of Hawaii. PATRICIA G. STEINHOFF is Professor of
Sociology, University of Hawaii. ROY G. SMITH is Professor
of Public Health, University of Hawaii. MING-PI MI is Pro
fessor of Genetics, University of Hawaii.
Library of Congress Cataloging in Publication Data
Chung, Chin Sik, 1924-
The effects of induced abortion on subsequent
reproductive function and pregnancy outcome, Hawaii.
(Papers of the East-West Population Institute, ISSN
0732-0531 ;no.86)
Includes bibliographical references.
1. Abortion—Complications and sequelae-Hawaii-
Longitudinal studies. 2. Pregnancy, Complications of-
Hawaii. I. Steinhoff, Patricia G., 1941-
II. Title. III. Series. [DNLM: 1. Abortion, induced-
Adverse effects-Hawaii. 2. Pregnancy complications.
3. Fetal viabUity. WQ440C559e]
RG734.C48 1983 618.8*8 83-11536
ISBN 0-86638-046-9
CONTENTS
Acknowledgments xi
Abstract 1
Summary and conclusions 2
Background and aims of study 6
Study plan and materials 13
Ancillary study 25
Methods of analysis 49
Findings 53
Spontaneous fetal loss 53
Ectopic pregnancy 80
Short gestation 89
Low birth weight 98
Pregnancy complications 109
Labor complications 117
Congenital malformations 124
Postnatal death 130
References 137

V
TABLES
1 Number of abortions of cohort women, by month and year of abortion 15
2 Matches of identified induced abortions with records of fetal death and live
birth, by year 17
3 Elective and therapeutic abortions, by source of data 18
4 Distributions of cohort women, cohort women having a tleast one subsequent
live birth or spontaneous fetal death, and general population in 1975, by race
and age at initial induced abortion 19
5 Distribution of cohort women having subsequent pregnancy, by race, age at
first induced abortion, and outcome type, and proportion of cohort women
having reported subsequent pregnancy 21
6 Distribution of cohort women having subsequent pregnancy, by number of
subsequent pregnancies, race, and age a ftirst induced abortion 22
7 Control pregnancy outcomes, by race and age 24
8 Number of paired observations, by race and maternal age 26
9 Case loss from original samples due to loss to follow-up and interview
refusal 30
10 Location statuses in 1980 estimated by staff assignment and depreciation
methods, by sample 31
11 Percentages of abortion and control samples estimated to be in state at end of
1980, by staff assignment and depreciation method, shown for selected
variables 33
12 Estimated percentage of abortion and control samples in state to end of .
record-linkage period (1978), by place of birth, ethnicity, age, marital status,
and year of entry into linkage 34
13 Analysis of variance showing relationship of location in or out of state to
prior fetal loss, prior induced abortion, education, social class, age at menarche
and at first intercourse, and frequency of intercourse (Age and parity as
covariates, ethnicity and sample as other factors). 36
14 Analysis of variance for abortion sample only showing relation of location in
or out of state to selected variables (Age and parity as covariates, ethnicity as
additional factor) 37
15 Pregnancies after sampled event, 1970-78, by sample, reporting status, and
subsequent pregnancy order 40
16 Reporting status of all pregnancies after sampled event, 1970-78, by preg
nancy outcome and subsequent pregnancy order, with adjustment for
women's underreporting of induced abortions 42
VI
17 Completeness of record linkage, by sample and pregnancy outcome for next
pregnancy and all pregnancies except sampled event 44
18 First-trimester spontaneous fetal loss of subsequent pregnancies of abortion
and control groups, by age and marital status 54
19 Estimated coefficients of multivariate logistic function and significance test
for first-trimester fetal loss: all vital data 55
20 Comparisons of spontaneous loss rates from matched hospital data 56
21 Estimated coefficients of multivariate logistic function and significance test
for spontaneous first-trimester fetal loss: hospital data 57
22 Matched-pair comparisons of spontaneous fetal loss (+)and relative risks
(RR) for specific combinations of reproductive history 58
23 Adjusted relative risks for first-trimester spontaneous fetal loss associated
with previous induced abortion (IA) factors 59
24 First-trimester spontaneous fetal loss (SA), by method of previous abortion
procedure 60
25 First- and second-trimester spontaneous fetal loss (SA), by pregnancy order,
number of gestation weeks at previous induced abortion, and abortion
procedure 62
26 First- and second-trimester spontaneous fetal loss (SA), all subsequent preg
nancies during 1971—78, by number of gestation weeks at previous induced
abortion and abortion procedure 63
27 First- and second-trimester spontaneous fetal loss (SA), by pregnancy order,
use of laminaria during previous induced abortion, and abortion
procedure 64
28 First- and second-trimester spontaneous fetal loss (SA), by previous abortion
procedure and number of previous induced abortions 66
29 Second-trimester spontaneous fetal loss among abortion and control groups,
by age and marital status 67
30 Estimated coefficients of multivariate logistic function and significance test
for second-trimester fetal loss: all vital data 68
31 Estimated coefficients of multivariate logistic function and significance test
for spontaneous second-trimester fetal loss: hospital data 69
32 Adjusted relative risks for second-trimester spontaneous fetal loss associated
with factors of previous induced abortion (IA) 70
33 Second-trimester spontaneous fetal loss (SA), by method of abortion
procedure 71
vii
34 Third-trimester spontaneous fetal loss among abortion and control groups,
by age and marita lstatus 72
35 Estimated coefficients of multivariate logistic function and significance test
for third-trimester fetal loss: all vital data 73
36 Third-trimester spontaneous fetal loss of all subsequent pregnancies, including
repeat pregnancies, among abortion and control groups, by age and marital
status 74
37 Estimated coefficients of multivariate logistic function and significance test
for spontaneous third-trimester fetal loss: hospital data 75
38 Adjusted relative risks of third-trimester spontaneous fetal loss associated with
factors of previous induced abortion (IA) 76
39 Ectopic pregnancies among abortion and control groups, by age and marital
status 81
40 Estimated coefficients of multivariate logistic function and significance test
for ectopic pregnancy: all vital data 82
41 Matched pairs, by combination o fectopic versus nonectopic pregnancy
outcomes 82
42 Estimated coefficients of multivariate logistic function and significance test
for ectopic pregnancy: hospital data 83
43 Adjusted relative risks of ectopic pregnancy associated with factors of
previous induced abortion (IA) 84
44 Ectopic pregnancy, by abortion procedure 85
45 Ectopic pregnancy, by use o flaminaria at previous induced abortion 85
46 Ectopic pregnancy, by number of previous induced abortions (lAs) 85
47 Ectopic pregnancy, by number of gestation weeks at previous induced
abortion 86
48 Ectopic pregnancy, by whether complications were associated with previous
abortion procedure 86
49 Ectopic pregnancy, by major type of complications associated with previous
abortion 87
50 Ectopic pregnancy, by infection or retained secundines and other
complications 87
51 Short gestation among abortion and control groups, by age and parity
(Parity classified as 0 or 1+ for both groups) 90
52 Short gestation of subsequent pregnancies among abortion and control groups,
by age and parity (Parity 0 versus 1 and 1+ versus 2+ for abortion and control
groups, respectively) 92
via
53 Estimated coefficients of multivariate logistic function and significance test
for short gestation: all vital data 94
54 Distribution of matched pairs, by combination of short gestation 94
55 Estimated coefficients of multivariate logistic function and significance test
for short gestation 95
56 Regression analysis of gestation-length testing effects of history of induced
abortion (IA) and number of previous abortions 96
57 Matched-pair comparisons of short gestation (SG) and relative risks (RR) for
specific combinations of reproductive history 97
58 Adjusted relative risks for short gestation associated with factors of previous
induced abortion (IA) 98
59 Gestation length, by maternal age, parity, and use of laminaria at last
induced abortion 99
60 Low birth weight (LBW) associated with subsequent pregnancies of abortion
and control groups, by age and parity (Parity classified as 0 or 1+ for both
groups) 100
61 Low birth weight (LBW) associated with subsequent pregnancies of abortion
and control groups, by age and parity (Parity 0 versus 1 and 1+ versus 2+ for
abortion and control, respectively) 102
62 Estimated coefficients of multivariate logistic function and significance test
for low birth weight: all vital data 104
63 Distribution of matched pairs, by combination of low birth weight (LBW)
104
64 Estimated coefficients of multivariate logistic function and significance test
for low birth weight: hospital data 105
65 Matched-pair comparisons of low birth weight (LBW) and relative risks (RR)
for specific combinations of reproductive history 105
66 Regression analysis of birth-weight testing effects of history of induced
abortion (IA) or number of previous induced abortions 106
67 Adjusted relative risks for low birth weight associated with factors of previous
induced abortion (IA) 108
68 Pregnancy complications of subsequent pregnancies of abortion and control
groups, by age and parity (Parity classified as 0 or 1+ for both groups) 110
69 Pregnancy complications of subsequent pregnancies of abortion and control
groups, by age and parity (Parity 0 versus 1 and 1+ versus 2+ for abortion
and control, respectively) 111